6J5/6C5/L63/VT-94/CV1932/CV1933/CV1934/CV1047/6P5/76/56/37/...
Tube | Construction+ photos | Impressions | ~$/pair NOS |
6J5/VT-94/CV1933/CV1934 |
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Ken Rad 6J5 (VT-94) | (photo: chrisdrop) -black metal | These are pretty good/ thumpy tubes. They were cheap as chips. Date code C5, I think/ assume that is March 1945 (maybe 55?).
Of all the metal 6J5 tubes I have, I think these are the "bassiest". They don't have the staging of the GECs, but IMO they are worth having if you are using brighter outputs. (chrisdrop)
| $10 |
RCA 6J5 (VT-94) | -black metal | -Well liked by several on thread | $10 |
Mullard 6J5G | (photo: chrisdrop) (photo: leftside) -brown base (uncommon) -can be labelled Marconi -serrated top mica -thin rectangular bottom mica -double support rods -can be labelled CV1932 Bottom rectangular getter -Tungsram factory | -long-ish (50h) burn-in; some GEC can take up to 80 hours though -They are pretty neutral in their representation, not bassy/trebly, etc. I have other tubes that I'd say are more coloured (posts on them eventually).
At the 50h mark, they still sound a touch congested in the mids to me. They have very good tight representation of the whole spectrum. I like their clarity. They don't have the biggest headstage IMO, but they are presented very nicely nonetheless.
Of note, I can't find a date code on these things. The only markings I can find are these "5"s on the bottom of each tube, visible in the picture below.
They are pretty tubes. (chrisdrop)
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Raytheon 6J5G |
(photo: leftside) (photo: L0rdGwyn) -’cross’ orientation top mica rods -heater shield -double support rods -thin rectangular bottom mica -bottom foil getter -can be relabelled as Tung Sol or Zenith |
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STC/Brimar 6J5G |
(photo: L0rdGwyn) (photo: leftside) -blacked or grey ribbed plates -D getters -earlier has smooth black plates, foil getters -can be relabelled GECs, L63! (photo: leftside) -another Brimar variant -top heater shields -ring or rectangular open getter Rounded plates | They come in a few different plate and getter constructions with later models having black ribbed plates, gray ribbed plates, D getters. These are an earlier construction, perhaps the oldest, smooth black plates and foil getters. Right up there with the best of the 6J5G but can be a bit expensive, spacious, slightly warm perhaps, but very detailed. (L0rdGwyn) |
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Sylvania 6J5G | (photo: RoyGB) | Classic Sylvania sound signature. There is a definite increase in the energy in the treble. It does this without feeling harsh or ‘too much’ on my already bright D9200’s. I also don’t perceive it to suffer from a splashiness like the Ken Rad 6C5.
Midrange and bass just seem a touch lacking. IDK exactly what it is that feels lacking though. Possibly dynamics? Possibly detail? Probably both and something else. Music in these ranges just seems a bit thinner and lacking substance on these tubes. I liked these tubes a lot on my KPH30i’s. But I only really have these headphones for convenience, and I don’t typically turn on my tubes if I want to wear my KPH’s.
Likewise I think these do wonderful things to the veil on the 650’s. The reduction to the midbass paired with a bit of extra treble energy allows them to keep their characteristic FR while also helping combat the veil. It’s like going from artificial store bought thick viscous maple syrup to the authentic stuff which is a lot more liquid and flowing. Still that thick sweet HD650 syrup but a whole lot less syrupy. Also the noisefloor is inaudible on the 650’s.
Not really tubey per se(but characteristically different) Distinguishable from SS Below average noisefloor. (RoyGB) |
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Tung Sol 6J5G | (photo: L0rdGwyn) -ladder plate (same construction as Tung Sol black glass round plate 6SN7GT) -foil getter
| Last year, I did a comparison of the 6J5G tubes to the Tung-Sol 6SN7GT BGRP, and Tung-Sol 6SN7GT ladder plate. As you might expect, the 6J5G took the blue ribbon. This was early on in 6J5 experimentation times.
The Tung-Sols are sounding very nice in the 45 amp, up there with some of the best in this family. (L0rdGwyn)
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Tungsram 6J5G | -similar to typical 6C5G construction (metal shield, top mica), top spacers -printed 6J5G on glass and bottom | Their construction with the mesh shields look more like 6C5G but they are clearly branded 6J5G. First impressions are that they sound good, but nothing tooo special. They are slightly warmer than neutral but lack a bit of bass impact. Mids are very smooth and treble is somewhat tame. Thinking of trying these later with some graphite 6080 to liven them up a bit. (tintinsnowydog) | |
Visseaux 6J5G |
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Zenith 6J5G (rebranded Sylvania?) | (photo: RoyGB) (photo: JKJedi) -Almost identical construction to Sylvania 6J5G (front)
| I can see why people like these tubes. They have great bass dynamics and overall retain much of the microdetail that is lost on other tubes. They are a very good technical performer, that being said, they were not ‘tubey’ more so they were really good at reproducing audio. Elevated bass slam and elevated vocal midrange this is done without necessarily sounding warm. Very neutral. Less than average tube treble. Very close to the detail and cleanliness of solidstate. It appears that these are made by Sylvania, they look nearly identical to my Sylvania 6J5 tubes, but they do not sound the same as my Sylvania 6J5's. Not easily distinguishable from SS Not Tubey Average Noisefloor (RoyGB)
I just rolled in a quad of Zenith brand 6J5Gs, I believe they are Sylvania round plates. They sound great, and I feel good about getting them for 15 USD each. (CAJames) |
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Fivre 6J5GT | (photo: chrisdrop) -metal or black base | -These are interesting tubes. They have some of the "air", pleasant mid and treble representation, and a feeling of "delicate sounds". They are quite spacious sounding. They lack a bit in the heft and lower end, but it is compensated nicely by the rest. They do sort of remind me of C3G tubes, which are very clear and can sometimes (to me) become fatiguing.
I can't tell when exactly they are from. The date on them is a tax date from the ministry of finance (in 1959), not a manufacture date. Also the "MM" faintly visible on them denotes that they are military tubes (I think like JAN in the US).
These tubes make me want to hear more Fivre tubes...
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Ken Rad 6J5GT |
(photos: leftside) -top mica with serrated edges -black plates 2 hole -bottom unique mica -bottom foil getter -can be labelled as Brimars -base is often eroded | -similar qualities to the KenRad 6SN7 |
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National Union 6J5GT | (photo: CAJames) | And even with just a couple hours on them they sound fantastic! Probably better than even the GEC L63s, my previous fav. They are detailed, fast and extended and have just a touch of seductive sweetness that sets them apart from the GECs. Also less than half the price says my Scottish Heritage. (CAJames) | |
Philips 6J5WGT ECG | -1980s | -bad do not buy |
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Philips/Mullard 6J5GT | (photo: tintinsnowydog) (photo:leftside) -Philips Miniwatt / Mullard Tottenham factory (same construction) -double support rod -bottom D getter -Top serrated mica -identical internal construction to Mullard 6J5G -prolific relabelling: Left to right Mullard labelled Tungsram, Brimar (unique bottom mica+rounded plate), Sylvania (3 hole plate) | Philips/Mullard acquired British Tungsram in 1952, Tungsram's factory was in Tottenham, London. The Mullard Branded 6J5GT were made there and have some features of Tungsram made tubes because of it, particularly the top mica with the ridged edges. | |
Pinnacle (Russian) 6J5GT | (photos: bcowen) -similar ladder plate construction to 6J5GT (6C2C/6S2S) -shiny metal base -large top O getter -painted metal base | These are my favorite cheapies. Russian, but not sure what factory they came out of. They have that Russian bass-groove thing going on, making them a quite enjoyable with metal and hard rock: (bcowen) |
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Radiotron Australia 6J5GT | (photo: tintinsnowydog) -double metal support rod -smooth black plates -round micas -VT94D JAN and Australian D^D defence force markings -can have a wire connecting the support rod with plate (?) | Sound is very clean and a little forward without being bright- likely due to a slight emphasis to the upper mids but not necessarily the treble. The overall presentation is quite neutral, definitely on the leaner side, possibly due to a small recess in the upper-bass→ bass frequencies. Treble is never fatiguing, and midrange tonality as well as microdetails are excellent and musical. The presentation however cannot be described as warm. Soundstage is quite intimate but imaging and layering of sound is not sacrificed; complex orchestral passages are never congested. It is very comparable to a Sylvania 1940’s 6SN7 in frequency response, tonality and overall presentation. Update: The tube continues to open up. The soundstage is now convincingly wide and impressively deep. The presentation is still forward and very detailed; the small recess in upper bass/lower mids is still present and contributes to a bit of a dry sound in the midrange. Works very well with a warmer power tube or GEC 6080 which has less treble. | ~$15 |
Raytheon 6J5GT | (photos: leftside) -unique top and bottom micas -top heater shield -bottom foil getter (photo: Marutks) -military version 6J5WGT -extra support rods -small round top mica -top rectangular getter -metal skirt with brown micanol base | ||
RCA 12J5 (VT-135) | (photo: GDuss) | I put them in the amp last night (both functional and quiet) and they have an extremely pleasing tonality. I'm a big fan of the metal RCA J5/C5 tubes from the early to mid-40's and so far, with only 2-3 hours of listening, the 12J5's are very close to what I'm used to. It will take more time and burn in to figure out whether they are different than their metal cousins, but first impressions are very good.
I don't know what it is about these 40's RCA tubes that I like. They don't have the best technicalities, but they are just so enjoyable to listen to. There is something "real" sounding about them. Plus they're inexpensive, these were $10 each and look like they have never been out of their original boxes. (GDuss)
I just rolled these RCA 12J5GTs and I'm blown away. $20 total for the pair, and already better than any other tube variant I've rolled. I also picked up the Sylvania 12J5GTs that were linked earlier in the thread, as well as a pair of Tung-Sol 12J5GTs. The RCA pair beats both hands down. There's a new unexplainable sense of realism with these RCAs that the other tubes don't give me. It's not just clarity, but really does more natural, realistic, life-like, etc (wenbinbin2010)
| ~$20 |
RFT/OSW 6J5 (East German) |
(photo: L0rdGwyn) (photo:tintinsnowydog) | Back when I collected 6SN7 tubes, one of my favorites was the RFT 68HC with welded plates and ceramic spacers, beautiful tubes with a great tone. I got to searching for a pair of the equivalent 6J5, and by luck one of my tube sellers discovered they had a triplet, I bought them eagerly.
These have a metallized coating grounded to pin 1, similar to the American-made metallized 6J5.
These tubes match the color of my amp, this is the first time I've used them in it. Not quite as spacious as the MOV L63 or Fivre 6C5G, but very nice tonally, not overally warm or bright, a neutralish tube to my ears, maybe a little rolled off up top, very easy to listen to. (L0rdGwyn) | ‘Collector price’ |
Sicte 6J5GT | (Photo: L0rdGwyn) | Admittedly, they are not the most resolving of the 6J5 tubes, but they have a nice, slightly warm tonality that is very pleasing, much like Fivre tubes. (L0rdGwyn) |
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Sylvania 6J5GT | (photo: chrisdrop) (photo: JKJedi) -metal base -heavy chrome flashing -double support rods -3 hole plate | -These tubes were, for some period of time (probably during Christmas this past year) my most reliable, oft returned to inputs. It is nice to have them back for listening today. Rolling from the Fivres pictured above, a few things are noticeable. By contrast, the Sylvanias are a bit warmer and fuller in the lower end. They have solid representation across the spectrum. They don't sparkle quite like the Fivres, but that is their key trait. I could happily live with these for some time. I consider them neutral to slightly warm with a good sized stage.
These are not expensive tubes FYI. I think they can be had for $10-$20 each NOS. (chrisdrop) -can be labelled Hytron
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Tung sol 6J5GT | (photo:bcowen) (photo: L0rdGwyn) -Tung Sol round plate -ladder style type plate (right) = likely rebrands of Sylvania | I haven't tried any Tung Sol 6C5's, but the round plate Tung Sol 6J5 is becoming one of my favorites…
Not sure how they compare, as I don't have any flat plates. But as of now, they're my second favorite to the GEC L63's. (bcowen)
Entirely possible. I have a pair of Sylvania branded 6J5GT's (also with round plates) that don't sound near as good. Could be a manufacturing year thing though rather than a manufacturer thing. (L0rdGwyn)
I like those ladder plate Tung Sol's so much I bought both 6 and 12V versions of them for the GOTL. They're the tubes I put in if I really want 3D sound on a level where I'm looking around the room to see where sounds are coming from. The 6V is metal base, but they sound almost identical. (GDuss)
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Mazda/Neotron 6J5MG | (photo: tintinsnowydog) -taller construction than the Visseaux silver metal MG | ||
Visseaux 6J5MGT | Incredible width and depth to soundstage = Extremely well separated, imaging and layering highly detailed Overall very smooth, laid back, soft, elegant, but not overly-warm presentation. Details are well preserved Linear, well extended in both directions, musically faithful representation of sound Tight, accurate, deep extending, resonant but non-exaggerated bass; could be interpreted as lean but I believe it is faithfully reproduced with some bloom for added warmth. Treble never fatiguing, upper treble quite rolled off(?)/subdued but easily retains macro and micro details with a nice sparkle. Perhaps some micro-details are not as obvious, less grit/bite/dig -tube was just opening up; attack on notes is now more present. Certainly not super powerful still, but an adequate amount relative to the weight the body of the note conveys. -’everything feels a bit further back’. I do find myself reaching for volume knob to hear a bit more turning it up when chasing details. It is all there, but just more discrete presentation. -dynamics are excellent. Light articulations are delicate, heavier passages have significant weight Expansive decay of sound; like a concert hall rather than a room All notes seem to be delivered in well measured, elegantly controlled doses Main strengths: soundstage, very linear presentation of all frequencies that allows details at every level to shine through effortlessly, neutral/faithful tonality, very resonant sound quality (gives a bit of extra reverb to everything) -potentially the best tubes I have heard for reproducing grand piano and more broadly symphonic music; linear, good resonance. | $70 but rare | |
MOV L63/6J5 |
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MOV L63/6J5[GT] (early) |
(photos: leftside) -metal skirt variant -straight grey glass (later clear glass metal base?) -cup or D getter equivalent of half B65 | If you look closely at the date codes and the getters on these Osram 6J5 you can see roughly when they switched from inverted saucer getter to D getter [1951/52 =G/H]. I also have the tall MWT black base version with inverted saucer getter and D getter with similar date codes. In my amp, I can't tell the sonic difference between these tubes, but they are some of my favourites. (leftside)
Sound is similar/same to B65 (various)
Very forward sounding… feels recessed in the lower mids, and elevated in the treble. More burn-in required… (tintinsnowydog) | $200+ up to $400+ ‘Rarity factor’ |
MOV L63/6J5G (ZA4138) |
(Photos: chrisdrop)
(photo: Velozity) (photo: whirlwind) (photos: chrisdrop) -coke bottle shaped -grey glass -black base -foil getter -older military versions labelled 6J5G and ZA 4138 (pre 1945 late 30s?) (photo: leftside) (photo: OctavianH) -Marconi labelled MOV L63 grey glass | I think they are similar to the other early 40s GEC 6J5Gs that I have. I tend to think they are my favourite inputs, but I am also fickle! I've had these in the amp for the most part since they arrived. I prefer them with the 6BX7s outputs as they can be too much low end w/ any of the 6080s. I'll need to rotate in the other GECs to compare, I haven't done that. I prefer these to the GEC 6J5GTs (which I really do like a lot too). Also, I put in 2x Mullard 6J5Gs today and the Mullards were a bit brighter and not quite as spacious sounding. I the Mullards are also worth rotating in, I just need to sort which outputs support them best.
I killed those other 6J5Gs last week and managed to get these L63s [Osram CE/CG] to replace 'em. It was an arbitrary criteria, but I wanted those vertical clear bits in the grey glass. They are quite similar in sound to the other ones that I killed. The sound is a little thumpier in the lower end than my "usually compared to" GEC 6J5Gs. They are controlled and solid all around. They are silent and look great. I have no logic for why they sound different than the other ones mentioned…
-These are my favourite drivers. I like others, but I always love coming back to these.
These are pre-1945 tubes according to the knowledgable folks over on the Glenn thread. They were expensive-ish but most excellent.
These too a loooong time to get to peak performance. I wasn't even sure I liked them until > 50h perhaps, then they kept getting better and better.
In short, they have all of the right characteristics; clarity, excellent representation across the frequency spectrum, thump, speed, and so on.
I'd love to get more of the M-OV family of tubes from this era, but I believe they will be similar.
(chrisdrop)
-Liked by all who have tried them in thread! | ~60 (used) up to 170 pounds |
MOV CV1047/6J5GT (later) | (photo: chrisdrop) (photo: bcowen) -grey or black base -straight glass -O getter, D getter (rarer earlier) -black base can have cup getter or D getter.
-Right image: -left D getter (lower flash) -right O getter (bigger getter flash) -Can also have smoked/grey glass (similar to metal skirt version; but plastic base) (photo: leftside) -many different label designs! | - Interesting that these tubes sound pretty good right away. One hour in the amp and they already sound nice. I'm surprised also because my coke-bottle GEC 6J5Gs took FOREVER to change/calm. Will these change or stay? (chrisdrop)
-These sound great right out of the box, and not with my favorite rectifier and power tubes. They have the detail of the Tung-Sol 6C5s and the liquidity of the 6P5Gs and the mind boggles at the possibility of them sounding better after some run in. (CAJames)
they are the real deal. I will still have to make more comparisons with the other 12J5/6J5 tubes I have, but they are certainly very pleasing to listen to. Early impression, but they sound just as "natural" as the RCAs with a slight increase in detail and forwardness. EDIT: Maybe even a little too bass-heavy. Are they worth 5x more than the RCAs? Definitely diminishing returns, but it's nice to have a premium tube option as a comparison for all the cheaper ones. (wenbinbin2010)
Is it just me or do the GEC (straight bottle) L63 sound more SolidState compared to Zenith, RCA, 6C5G tubes? (JKJedi)
| £~70 |
6C5/VT-65/CV82 |
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Brimar 6C5G |
(photos: GDuss)
(photos: L0rdGwyn) -coke bottle shaped -plate just behind internal mesh shield -control grid and screen grid with screen connected to plate | In terms of sound, they are both very nice tubes, definitely worth trying, especially at that price. I think I prefer the 6J5G, a little more spacious and airy than the 6C5G, but also 4-5x the price.
Essentially this is a triode strapped 6J7G without a top cap and no suppressor grid.
NOS Brimar 6C5G do seem to be pretty widely available in the UK. I purchased mine from Billington some time ago, in addition to some GEC branded Mullard 6C5G, I think I paid 15 GBP a tube! Yes, please, Martin. (L0rdGwyn)
Very, very, enjoyable and dead quiet! Nothing is really standing out with them. They just sound damn good. Maybe the high end is rolled off slightly compared to the Sylvania, but it's a very pleasing tone. I will be evaluating all these with Chatham 6AS7G powers and GEC U18/20 rectifier in my GOTL. (Velozity) |
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Fivre 6C5G (common version) | (photo: L0rdGwyn) (photo: maxpudding) -brown (or black?) base -shorter bottle -mesh shields -wire spacers replaced by mica | Very nice smooth Fivre midrange, slightly warm, very nice tubes.
here are easily discernible differences, the early black base are more airy and detailed than the brown, smoother, the brown base are a little more "up front and personal" in the midrange, the black base seem more even across the frequency spectrum, handle greater complexity of music with more ease, larger soundstage, more diffuse whereas the brown base staging is more round with more clearly defined boundaries.
Since I already had them in and I was so impressed, I kept going and compared them to the gray glass GEC L63, can't believe it, maybe tastes are changing, but I prefer the black base Fivre...so they stay. Guess I have a new daily driver, maybe it is tube synergy or just my mood, I am seeking a sort of "easy on the ears" sound lately, which isn't to say the L63 aren't, but the Fivre are very chill and smooth.
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Fivre 6C5G (early version) | (photo: L0rdGwyn) (photo: leftside) -black base -mesh shields (grounded through pin 1) -wire spacers -early foil getter suspended from internal shields -longer, narrower bottle | Very nice smooth Fivre midrange, slightly warm, very nice tubes.
here are easily discernible differences, the early black base are more airy and detailed than the brown, smoother, the brown base are a little more "up front and personal" in the midrange, the black base seem more even across the frequency spectrum, handle greater complexity of music with more ease, larger soundstage, more diffuse whereas the brown base staging is more round with more clearly defined boundaries.
Since I already had them in and I was so impressed, I kept going and compared them to the gray glass GEC L63, can't believe it, maybe tastes are changing, but I prefer the black base Fivre...so they stay. Guess I have a new daily driver, maybe it is tube synergy or just my mood, I am seeking a sort of "easy on the ears" sound lately, which isn't to say the L63 aren't, but the Fivre are very chill and smooth.
I find the 6C5 to be very similar to the 76 in my amp. Lighter/airy/spacious sound. Great to have in your arsenal of tubes. (leftside)
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Fivre 6C5G (solid shield) | (photos: chrisdrop) -solid instead of mesh shields
| Very nice smooth Fivre midrange, slightly warm, very nice tubes.
here are easily discernible differences, the early black base are more airy and detailed than the brown, smoother, the brown base are a little more "up front and personal" in the midrange, the black base seem more even across the frequency spectrum, handle greater complexity of music with more ease, larger soundstage, more diffuse whereas the brown base staging is more round with more clearly defined boundaries.
Since I already had them in and I was so impressed, I kept going and compared them to the gray glass GEC L63, can't believe it, maybe tastes are changing, but I prefer the black base Fivre...so they stay. Guess I have a new daily driver, maybe it is tube synergy or just my mood, I am seeking a sort of "easy on the ears" sound lately, which isn't to say the L63 aren't, but the Fivre are very chill and smooth.
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GEC (Mullard made) 6C5G | (photos: L0rdGwyn) |
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Ken Rad 6C5G | d (photo: RoyGB) | The key thing that stands out to me with this tube is how ‘soft’ it sounds. It retains a good amount of detail but is lacking microdetail of solidstate.
It can almost be psychoacoustically confused with soundstage because it does make music sound ‘further away’ in the sense that microdeail is equally gone from all ranges creating a soundstage-like sound. Contrast with many tubes where it seems like a certain range has certain characteristics like loss of microdetail.
That being said on my 9200’s I don’t inherently perceive this as a bump in soundstage as I did the Marconi’s.
The best way I would describe these tubes is soft. Granted, once again to what degree is the hard part to describe. Enough to matter, not enough to overwhelm. Whatever that means. It feels like it retains a very good amount of solid state detail, but with smoother edges, music seems to flow and slur a bit more, but still keeps good instrument separation. The smoothing seems to take place within the instruments themselves rather than across the spectrum of music. Once again this is with Denon D9200’s and SVS Ultras. Expensive gear that already has good separation and clarity.
Dynamics are also a bit behind solidstate but I don’t know how much of that is the softness making me perceive a loss of dynamics due to less slam and fast decay and how much of that is actually lowered dynamics. The answer probably lies somewhere in the middle.
As far as FR characteristics go. Treble seems just a touch splashy with hi hats, snare drums, and cymbals. This feels bothersome to me. But I feel that this is subjective to both the person and the gear. I am not getting as much as a ‘tube treble’ feel with this tube as I do others. I do not like this tube for drum heavy music where that splashiness just tends to get to me a bit too much. Granted it is very subtle, and I believe halfly due to the other characteristics of this tube changing other bits of the music my perception of drums relative to everything else. It does really well though with vocal and lounge tracks and music that does not have heavy emphasis on drums, or the treble instruments are mastered so their levels are neutered significantly so they are not prominent in the music.
Changing over to the 650’s the softness is still there. This makes the 650’s very soft and very mellow. Meanwhile, the splashiness is a non factor with these. In fact treble seems more articulate although still very 650.
There might be some part of the midrange or upper bass with a slight lowering. No idea though. Might just be the general softness changing characteristics enough.
Easily distinguishable from SS Tubey Average noisefloor. (RoyGB) |
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Super Silvertone (National Union) 6C5G | (photos: Slade01) -unique construction -possibly National Union/Arcturus tube from 1939 | ||
RCA 6C5G |
(photos: JKJedi) | . Don't know what year these are and they sound golden to my ears, kinda the same flow as the Zenith 6J5G, very close, I don't think I could tell them apart in a blind test. As good as all these 6J5 variants are ..may never roll a 6SN7 on this amp again. (JKJedi) |
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Tung Sol 6C5G | (photo: tintinsnowydog) -coke bottle shaped -top mesh ring | -COMPARISON to the TS 6F8G and BGRP -ever so slightly attenuated but still amazingly extended treble compared to 6F8G, but still bright; certainly not thin. Both are inevitably fatiguing over long periods at high volumes on a bright system, 6C5G less so (6F8G calmed down a bit after burnin, less harshness). No perceivable loss of detail; if anything less treble helps reveal more in mids. I am hearing better spatial separation+definition in orchestral recordings, about the same amount of air between notes/musicians. -bass sits perfectly between BGRP and 6F8G. It is well extended, textured and appropriately impactful without bringing any excess attention to itself or colouring the rest of the presentation. The result is better weight than the 6F8G but not as diffuse as the BGRP. -slightly wider but possibly shallower soundstage. Imaging and layering of sound is still superb across all 3. -all the good qualities of the 6F8G, but better linearity and even more realistic presentation. -My favourite of the 3. -Both share the same beautifully natural, transparent and clean presentation. Less bloom and warmth than the BGRP but at the same time very musical and faithful across all registers. Superb articulation and details. -very realistic midrange! Light and delicate → high treble. Brittle in a good sense. Sound reproduction feels more efficient. Like looking through a polished tube envelope. Vocals some of the best I’ve heard. -shines on acoustic/live recordings and genres -differences lie in amount of treble, and bass quality. May be due to amount of use, but dual triodes may take the edge in overall clarity, 6C5G has a softer, more open and slightly less technically detailed presentation. -TS BGRP: huge, visceral and resonant bass that is well extended into lower mids. Dynamic, punchy, amazing technicalities and micro-details. Airy, well weighted, engaging, highly musical sound. Treble is strong, but never overly bright even at high volume. Mids sweet and highly realistic. All the refinements KR 6SN7 was missing. This is the most musical and fun tube of the 3. -TS 6F8G compared to BGRP has noticeably more extended, cleaner and more quantity yet leaner sounding treble, noticeably deeper and slightly wider soundstage, even sweeter and addictive mids, much tighter bass and slightly less overall weight/body. It is prone to noise. It is more balanced and linear sounding IMO than the BGRP which feels bass-boosted and more diffuse (in a euphonic way) in comparison. That may have contributed to a bit of bleeding into the mids. It sounds faster, cleaner and there is more overall micro-detail, likely due to enhanced treble. The bass is certainly just as well extended, if not more so into the subbass, but is less diffuse, less bloom, overall less body and weight. The overall presentation is slightly further back; while the BGRP surrounds immerses you in sound from all directions, the 6F8G places the sound on the stage in front of you with you in the front row. The enhanced treble gets a bit fatiguing over a longer period- was sometimes reaching to lower volume in heavy treble sections. It is slightly more airy, noticeably more refined, leaner, and a bit drier in presentation than the BGRP. Differences were still apparent even at -3dB. BGRP: fun, euphonic and musical. 6F8G flat plate: accurate, hyper-realistic and controlled. - |
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Hytron 6C5GT | (photo: chrisdrop) -metal skirt -solid metal shield | They are supposed to be good sounding tubes in general - I think Phantaminum liked the treble in a Hytron 6SN7. (mordy)
I was also a really big fan of Hytron 6C5's. But my pair has a pretty bad gain imbalance so I really don't use them
These tubes are like skydiving. Fun and unlike anything else. But you best hope that everything works.
The predominant sound characteristic of these tubes is their dark sound signature, and how tubey they sound. They sound great. IDK exactly what it is about these tubes but they do some wonderful things to the sound.
Out of every tube I have tried so far these change the sound the most. Bass sounds different, vocalists sound different, these tubes give a completely new flavor to the music. Once again, sanity check. Completely different, but still very much the same.
There is definitely a dark shift to things but overall I have no idea how to describe these tubes due to just how much they change. I really don’t know how to put my finger on it. Detail is reduced but I don’t care with these tubes. It does not matter because they are doing something else really well.
Bass is elevated, and treble is reduced more than average.
Tubiest tube I have heard. Easily distinguishable from SS Has some of the theremin effect. Noisefloor is about average.
(RoyGB)
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Raytheon 6C5GT | (photo: CAJames) |
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Sylvania 6C5GT | (photo: CAJames) -metal base -no getter flashing -fully enclosed metal cylinder shield | Sound is a lot like the metal 6C5s: detailed, a little cool and lacking that last drop of bass. Nice enough. (CAJames) |
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Russian 6S6S = 6C5 | (photo: RoyGB) |
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Mazda 6C5 | (photo: leftside) |
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GE 6C5 | (photo: mordy) (photo: chrisdrop) -black metal | These tubes sound great and you can get them for a few dollars each, especially if you buy them in small lots.
Some people claim that GE tubes in general aren't good sounding tubes. Maybe so, but these (and some others) are the exceptions. (mordy)
I have a pair of GE 6C5s that I think are also really good sounding tubes, and were so cheap it is amazing. Recommended! (chrisdrop)
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Ken Rad 6C5 | (photo: bcowen) | ||
National Union 6C5 | (photo: CAJames) -black metal |
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Nedtron 6C5 | (photo: leftside) |
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Super Air Castle (!) 6C5MG | -a rebrand, but by whom? | ||
Tung Sol 6C5 | (photo: CAJames) -black metal | I've been listening to them for about an hour and they are fantastic! Probably the my best sounding drivers, beating out the Sylvania "bad boy" tall bottle 7N7s. Liquid (but not lush) and detailed for days. (CAJames) |
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CV1932/6P5/76 |
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??? CV1932 | Picture incoming |
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RCA CV1932 | -(photo: chrisdrop) -black metal (but usually glass shaped=CV1932) | -I didn't particularly fancy this pair. IMO it is hard to 6J5s wrong, especially the "ugly duckling" metal can ones, which are usually good sounding. Now, in all fairness - they are almost free, at ~$5 each, but still - usually the metal 6J5s are pretty good.
RCA changed their logo in what looks like 1968 according to this link. That makes these newer build tubes than the older "beach ball logo" versions
(chrisdrop) |
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Wizard (rebranded ?) 6P5G | (photo: CAJames) | None of the hardness of the P5GTs, and more liquid than the Tung-Sols, albeit with a slight loss of transparency. Also dialed down the gain with the 6BL7 power tubes as I hoped, these are going to stay in the WA22 for a while. And handsome to boot. (CAJames) |
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Silvertone 6P5G | (photo: chrisdrop) |
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Tung Sol 76 | (photo: RoyGB) -round plates | These are my current favorite tubes. Tung Sol 76's Lot's of tube character, warm, lush, with good dynamics. //
These are tube tubes. Lush, good bass dynamics, retains a good amount of detail while still providing a fair bit of tube character. More smooth than warm, but is on the warmer side of neutral. The defining characteristics are definitely the tube character that these provide. These tubes sounded wonderful on everything. These are my default tubes and have a near permanent home in my ember.
Below Average Noisefloor Very Tubey Easily distinguishable from SS (RoyGB) |
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Arcturus/National Union 76 |
(photo: RoyGB) | I have a few pairs of 76 tubes like my Arcturus (National Union) 76 tubes that have close to solid state levels of noisefloor. And the trend is that they are on average the quietest type of tube that I have. And I have like 4-6 pairs. This is before I further ground things out and sheild the tubes. This was at max volpot, high gain, with 24 ohm Denon D9200's. Not all but some.
See RCA 37 below for the audio characteristics. Dead quiet noisefloor. Probably the quietest tube that I have heard in terms of noisefloor. Blue lettering is also cool.
(RoyGB) |
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Marconi 76 | (photo: RoyGB) | When I hit the play button on my music for the first time after slotting these in my Ember I immediately said aloud “whoa soundstage”.
I have yet to hear a tube do soundstage better than these tubes. They excel at soundstage.
This is mainly accomplished through a reduction in midrange dynamics, reduction in midrange FR, as well as a blanket reduction in microdetail. I have not heard the Sennheiser HD800 lineup, but from what most reviewers say, they don’t have the best midrange, but they do have incredible soundstaging. I think these tubes do a similar thing. That midrange reduction leads itself to a soundstage like experience. Then again, I could just be spewing nonsense and have no idea what I am talking about so that is your disclaimer.
They sound good. Worse articulation than SS, and feels a bit slow but overall, very pleasant with great presentation. This is another one of the instances where detail is gone but it really does not matter with these tubes because they do it so well. There are some tubes where that is almost a dealbreaking feature, but these do it to an extent that it works really well with the character of these tubes.
These tubes do have a bit of ‘tube character’ as well. They are more smooth than warm, but there is a twinge of warmth in their presentation. They have less tube treble than most tubes but do take a small amount of the edge and harshness out of the treble.
Midrange is not nonexistent. It is still there; it just sounds somewhat damped. Dynamics and extension are excellent. Overall wonderful tubes.
Exceptionally low noisefloor Tubey Distinguishable from SS (RoyGB) |
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RCA 76 | (photos: CAJames) (photo: RoyGB) | My first impression was that this was another soundstagey tube. But wholly different than the Marconi. But after more and more listening I began to realize what that presentation was. It was middle to upper midrange that was harsh and elevated.
So why did I think that this was a soundstagey tube?
Have you ever been to an outdoor event at like a park, house party, or wedding and they had a DJ or a band with music going? That is what these sound like. The bass is lackluster and dead because it does not have nearly the power or displacement needed to make impactful bass in an outdoor environment. Likewise, the treble is not the best because it’s a high frequency and it decays a bit to quickly and has no room reflections like you would get with speakers indoors. This just leaves you with a mid heavy presentation. That is the best analogy I could give into how these sounds and why it can be confused with soundstage. Because we have all heard what this sounds like before.
By no means should it be made out to be a bad thing. Depending on the rest of your gear I guarantee things will still sound good with these tubes. It is just an analogy to try to give an idea of how these sound. The effect is a lot less than in a scenario that I described above. Bass is still there in plenty. Along with treble. It is just an analogy.
These can very easily be interpreted as soundstagey, and anyone looking for soundstage in a headphone should give these a try.
So how is that midrange… elevated and slightly harsh. It is on the shouty side of things. This is not your HD650 warm vocal type of midrange. This is upper midrange. If you are sensitive to upper midrange frequencies, I think that these could be bothersome. They are a unique listen. My best guess is somewhere around 1k these start to get crazy and tails off in the lower treble. They are not bad tubes and have a character really unlike anything else I have heard.
On my KPH30i’s these provided a ‘fuller’ sound to the music. Which is to be expected. These are a fairly thin sounding headphone in the first place so they appreciated the extra midrange.
Not tubey Distinguishable from SS Below average noisefloor. (RoyGB)
they are fine. Softer than the 6J5 variants, both tonally and gainwise. They have by far the least gain of any tube I've tried. If this was the first single triode I heard I would be pretty excited about the sound relative to the dual triodes I'd been using. But as much as I want to like them, for the looks if nothing else, I just don't find them competitive with others, e.g. 6J5GTs or L63s or even the metal Tung Sol 6C5s. FWIW I tried them with a Type 83 rectifier, to keep it period correct, but it didn't help. (CAJames) |
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Mazda 76 |
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Fivre 76 |
(photos: leftside) (photo: tintinsnowydog) | -I've acquired quite a few Fivre 76 recently. I find the 76 tube to be very similar to the 6C5. Airy and refined. (leftside)
Plenty of warm yet well-controlled bass, singing mids, balanced treble. Good technique and detail wrapped in a really expansive, airy presentation. (tintinsnowydog) |
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Continental (Sylvania?) 6P5GT | (photo: CAJames) | Continental brand 6P5GTs, they look like Sylvania round plates. They sound really nice, although much more like 6J5s than other 6P5s in my experience. A little on the soft side, and natural (not exaggerated) bass. Long time residents of this thread might notice my upgraded adapters. They are very nice indeed, a huge upgrade over the ebay stuff, and definitely helped with the hum problem I was having. (CAJames) |
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National Union 6P5GT |
(photos: chrisdrop) |
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Sylvania 6P5GT | (photo: CAJames) | They still sound good, but a little edgier and with more bass. Zeppelin rocks, but the classical music I listen to most suffers in comparison to the Tung-Sols [6C5 black metal]. They are used so probably aren't going to improve much with use. The tubes themselves are interesting, labeled JAN and with the USN anchor. They have clear tops, bottom getters, 2 hole "bad boy" plates, and no date code that I can see. I'd guess probably 40's or very early 50's. (CAJames)
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Other |
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Marconi MH4 | (photo: L0rdGwyn) | The exception to the sprayed-on coating of the metallized European tubes is what was used on the tube above. This metallized coating, which I have seen on these Marconi MH4 and some Telefunken / Klangfilm REN904, is very thick and is much more prone to oxidation and flaking than the thin sprayed-on type. I wonder if perhaps some other type of deposition process was used in this case, but again, no information that I have been able to find. (L0rdGwyn)
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Sylvania VT-192/ 7A4 | (photo: Paladin79) | I have a couple pairs of '40's Sylvania VT-192's, but I like these Hytrons better. More whomp in the bass and more harmonic info in the mids. A bit smaller soundstage, but the other qualities overshadow that...at least for my preferences. (bcowen) |
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United Electric (Rebranded Tung Sol?) 6L5G |
(photos: RoyGB) | I am unsure who manufactures this tube. My best guess is Tung Sol. These are VERY similar to my Tung Sol 76 tubes. Same micas, same mica fins, same getters, and the rest of the construction is extremely similar.
The biggest standout thing about this tube is its noisefloor. This tube has a very noticeable 60Hz hum and it only gets worse the closer you are to it. Likewise if I ground myself on my Ember by touching the top of the caps, the screws, or the metal base the noise immediately goes away and it almost sounds like you become an electrical shield if you hold your hands over the tubes. A couple of tubes have this theremin effect but it is BAD on these tubes.
The best way I can think to mitigate this would be a faraday cage. Or possibly grounding the ember.
This may be in part due to how exposed the grid and cathode are as the plate only covers about 70% of the triode. [SPECULATION, no scientific backing to my statement]
So on to the actual audio characteristics. Wider than SS. Kills some of the upper mids and that presents a soundstage-like sound. Typical tube treble. Going back over to soildstate those two areas are immediately noticeable as the presentation seems to close in and clear up. Bass seems slightly elevated on the tubes as well. This may just be from that 60Hz hum though. Which does largely go away once you get music playing. It is still there if you go searching but I can largely ignore it.
The thing is these tubes don’t sound articulate or enjoyable. They are a bit sloppy and I want to say all over the place. It might just be my headphones and my gear, but I do not think these tubes sound all that great. Articulation and instrument separation are nowhere near what it is on other tubes. I am sacrificing quite a bit for tube sound, which I don’t think I need to do, other tubes have better characteristic tube sound while also sounding better at the same time.
Another interesting note is that the Tung Sol 6L5 that I received as detailed in the National Union 6L5 post looks completely different than both the United Electronic 6L5 and the Tung Sol 76. It looks closer to a RCA tube with a similar top mica design. The gentleman that I purchased these tubes from mentoined they were made by RCA but the reasoning that he gave was lackluster at best. (RoyGB) |
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National Union 6L5G (VT-213A) |
(photo:RoyGB) | This is a bit of a weird review. The seller that I bought these from messed up my order and sent over one Nat union tube and one Tung Sol. They are very different construction and they are not audibly identical. They are close enough, and the gain match is good so I still feel like I can glean some impressions out of my one Nat Union. I will post a better impression at the end of the month when the actual pair comes in.
Very technically impressive. It sounds very solid state outside of a softer treble. I would categorize this as strong tube treble in the sense that treble is softer than most tubes I have heard. Detail and articulation are fantastic everywhere else. But I would not consider this tube ‘tubey’. It really does not add much in the way of character. I’m really not getting ‘warmth’ or ‘darkness’ or ‘soundstage’ out of this tube. All I am getting is a softer treble. Which is by no means a bad thing. That’s kinda one of the things tubes do is soften treble. Maybe the bass is slightly elevated, but that could just be an effect of the softened treble. The softness does extend into the midrange, but is still very articulate.
Compared to my left ear Tung Sol, this tube retains more detail and is more articulate with better instrument separation. This might just be a gain difference. I also wouldn’t trust this review too much until my actual pair comes in. (RoyGB) |
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Philco/Sonatron (RCA?) 37 | (photo: CAJames) (photo: Tom-s) -mesh plate | I had to go through a few to find 4 that weren't noisy, and they sound promising on first listen but certainly need more time to cook before I'll pass judgement. (CAJames)
With the volume up (because of the low volume hum), there's beautifully clear dynamic music. Tight bass with good authority, very precise defined high's, good soundstage, nice natural tonality overall. It's very unfortunate that no modern manufacturer is making a mesh plate indirectly heated driver tube (without hum issues). (Tom-s) |
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RCA 37 | (photo: RoyGB) | 7’s are electrically similar (identical?) to 76’s and share the same current and voltage requirements. They are the only other pair of tubes in the 76 family that are direct drop in replacements without worrying about weird voltages and currents like the 56 tubes.
Sexiest tube. For some reason I really dig the look of these things. Photos don’t really do it justice. The bulb tube towers just have something about it that I adore looking at. Bulb tube towers >>>>>>> Coke bottle tube tower.
Soundwise they kill detail everywhere and do not have good dynamic range. An interesting listen if you really want to emulate a ‘old music experience’ for lack of better phrasing. Comparable to the Arcturus (National Union) 76 tubes audibly, but with a higher noisefloor.
Easily distinguishable from SS (but for all the wrong reasons). Somewhat tubey. Maybe??? Average noisefloor. Theremin effect (RoyGB) |
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Sonatron (Sylvania) 227 | (photo: Tom-s) -mesh plate -1920's | This makes it no surprise that these sound close to their Sylvania type 37 brothers i've tried before (similar, but with more Crack friendly 6.3V heaters). The sound is open and airy, clear, detailed but with a touch of floppy bass. Not as good a soundstage as the 37 version but I do like them! (Tom-s) |
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Sylvania/Silvertone 37 |
(photos: L0rdGwyn) |
| $15-20 |
