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Ok, so I know a few things about the differences between countries of manufacture. Chinese, Russian, Czech, American vacuum tubes. Cheap to expensive. Not that American are the best, but they have usually been the most costly to me in my buying experiences (which are very limited, I might add). The Chinese tubes are the cheapest I have found, they use inferior materials it seems, and some of the Chinese tubes I have had have gone microphonic rather quickly, or burn out, just stop working and give up the ghost..... The Russian tubes were better. Groove Tubes were pretty tight as I recall. I used to like Mojotone, as they let me buy tubes wholesale, and they had a pisspot full of different tubes at one time.
So, if anyone has any special insight into different international tube makers, that would be helpful.
However, my main question is as follows. I have mainly encountered 6L6 power tubes and 12AX7A preamp tubes in the amps I have owned. Mostly, that is. I have owned a limited number of amp models and makers, I must admit. I know that some power / preamp tubes have similar properties but different numerical designations, and some can be interchanged, but some shouldn't? Some have various sonic qualities and sought after differences?
If anyone cares to elucidate, pontificate, speculate or simply throw in their 2 cents about vacuum tubes, go for it......
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12-30-2015 02:29 AM
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I like Roger Modjeski. I have been a fan of his Music Reference hifi amps since about 1988. This is his RAM Labs Tube Store: Tube Audio Store - Home of RAM Labs & Music Reference . You'll find better prices and better quality tubes than those stores or shops catering for guitarists.
$12 per 6L6? 6L6G .
http://www.tubeaudiostore.com/suitof6dfora.html
(The other hifi tube amp guy I really like is David Berning. I use 'tube' in deference to them because they are Americans.)Last edited by Jabberwocky; 12-30-2015 at 03:05 AM.
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I bought a complete set of TAD (tube amp doctor) tubes for my old deluxe and they completely transformed the amp. I was very surprised. I don't know if it's because the old tubes were so shot that it made such a huge difference, or if they are just really good. At any rate, I am very happy with them.
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I use mostly JJ and Sovtek pre amp tubes, and like them fine. Their price / performance meets my expectations and I've never had a user complain about them. Recently I began to test the Electro Harmonix tubes and similarly I have no problems with then either.
Here's a link to pre tube reviews you may find helpful. I agree with their assessments.
www.thetubestore.com - 12AX7 / 7025 Tube Reviews
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On a similar note, what has changed in tube production between 50 years ago and now to make the quality of the older tubes so much more desirable?
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Hey Doc,
I've been lucky with J&J tubes, which I get from the guys at Eurotubes - Vacuum Tubes by JJ Electronic - ECC83, 12AX7, 6L6. 6L6GC, EL84, EL34, KT77, KT66, KT88 - Eurotubes Inc. . My latest amp, though, came with TAD 6L6s, and they're working fine!
"Most" amps that are designed for one power tube type (i.e., 6L6) can't take other types (6V6, EL34, etc.); others, like Frenzel, are designed to take anything. Preamp tubes probably have more flexibility; for jazz, especially, some say that 12AX7s are "too gainy," so replace the first tube (V1) with a 5751 or something. I just had this conversation, though, with an amp builder, and she said, "Well … it depends!" due to the wide variability of tube quality, etc.
Are you looking to replace some tubes, or just curious?
Marc
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I only use vintage tubes.
more $, but they last forever.
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His preamp tubes are pricy starting at $30 for "standard". He says he tests and rejects 60% (suggesting other dealers sell his rejects), so that's partly what you are paying for.
Originally Posted by Jabberwocky
He doesn't state that the $12 6L6G tubes are equivalent to 6L6GC. I'd check that before trying them. Also, check dimensions, since some 6L6Gs won't fit in all amps. If they are equivalent to 6L6GCs, it's a great price.Last edited by KirkP; 12-30-2015 at 12:54 PM.
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Tubes are no longer manufactured by companies that use them in their own products (e.g., GE, RCA, etc) and/or supply them to large-volume customers that can impose very strict spec's and QA/QC requirements (e.g., the US military). So, there's essentially no warranty-driven or demand side pressure to keep quality up. At the same time, because it's an obsolete product outside the tiny niche of guitar amps and audiophile components, highly qualified technicians and engineers don't participate in the industry, so there's a shrinking knowledge base for product improvement. It's only a viable business at all because there are old factories/equipment in places like Eastern Europe and China that have low labor costs and loose environmental and safety regulations. All that said, suppliers who know how to match tubes (and throw away the bad ones) can get you a pair of power tubes for reasonable cost that perform well. Decent quality pre-amp tubes seem to be even easier to come by. I've been reading predictions of the imminent demise of tubes for 35-odd years; hasn't happened yet. Originally Posted by wzpgsr
To the OP, there are lots of charts out there showing which tubes are equivalent to which (e.g., this one: Russian and Chinese Tube Substitutes). I've had amps with 6L6, 6V6, and (IIRC) 6BM8 (in an oddball Univox), and played through lots of 6V6, 6L6, EL84 and EL34 amps. I can hear differences among all of these amps, but I don't know how to tell how much is due to the tubes themselves vs the overall circuit differences. I currently have two 6V6 amps (a PR, and a Galanti-branded Valco/Supro). They sound very different from each other, but they're entirely different amps (one is class A/B push pull, the the other is SE Class A, different tone stacks, different speakers, etc).
Way back when tubes were cheap (e.g., a couple of bucks a pop in surplus electronics/junk shops), I used to just buy new ones at random intervals and swap them in without re-biasing, or getting the amp serviced. I would hear differences, but then I learned about how amps need to be biased and serviced, and discovered that the differences I was hearing between two brands of the same tube were probably more a matter of the amp not being biased for one or the other.
Over the last many years, I've given up on just swapping tubes and taken amps to a good tech when they're either broken or I perceive the sound to have started to crap out. I find that if I describe the quality of tone and degree of break-up I'm looking for, the tech can pick tubes, set the bias (and do whatever voodoo he does with other stuff inside the amp) to meet that. That works better than my specifying the tube brand/source.
John
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Originally Posted by marcwhy
Marc,
Good info. Thanks.
I have found enough small Fender SS amps (well, maybe one more under $100 if I see one on CL). The couple I end up gigging with will need speakers. Then my tube amps need speakers. Except for the Fender Concert amp that lives in the closet under the stairs. I like that speaker. The amp is soooooo heavy, however it does have castors. I put Groove Tubes in it way back when.
That leaves me my 60 watt valve tube amp. The tubes are Russian I believe and still work good. However they do fizzle out from time to time. I need to back up my tube array. I also have a red knob Super 60 that was abandoned at my place. If I can get it firing up properly, maybe some new tubes and definitely a new speaker, I may keep it here on a salvage title....
I will require four or five 12" inch jazz speakers. Buying 6 at one time would make me a dealer in most cases. So, if I can utilize the same manufacturer and buy direct, that would be good. Or, hook up with a tubes, speaker and parts distributor and get dealer pricing on whatever I need in those area. That would be good too. Like I mentioned I was a dealer for Mojo a dozen years back. Some of these companies are happy to keep that dealer status open for you. "Yes, sir, I see you are still a dealer. What would you like to order?"
Other companies are not so forgiving. "Sorry sir, you did not meet ANY of the minimum yearly order amounts for the past dozen years. If you would care to apply again, and buy $5,000 worth of product as an opening order, just sign here...."
Puff, puff....
Ok, you asked about tubes. Yes, I want to get some replacement tubes, back-up tubes and learn more about tubes. I love damn tubes. I would like to know more than just plugging and unplugging them into the amp. Also, where to source tubes and other parts. In the new year, I plan to be a bit more proactive in gigging, writing, and in moving more acrhtops and maybe even some vintage amps. (or vintage styled amps). Nothing on a grand scale, but I have done this Internet audio stuff since 1995 and I have managed to keep a good rep online. I have a cool domain archtopjazzguitars.com sitting there that would look really good after I win the lottery, and plug in a million in vintage jazz guitars and a million in Peerless jazz guitars.
Oops, the needle just fell out of my arm. Just a sec......
Ahhhhhhhhhh. There we go..... nod, nod.... lottery, lottery .... dream, dream..... (drool, drool - had to get the Homer reference in!)Last edited by docdosco; 12-30-2015 at 01:52 PM.
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Here's a chart I have found useful for my petty purposes:
https://www.tube-town.net/info/doc/tt-tubemap.pdf
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Tubes! Tube technology peaked 50 years ago. At that point, equipment and labor abounded to make high quality (internally well aligned) tubes. Alas, tubes expend 50% of their energy as heat into the room. Thus, they are horribly inefficient. For most applications engineers could not wait to replace them with SS technology. Oops! Tubes sound better--outside their linear ranges of operation--than do SS technologies. So, a FEW tubes remained in production. Meanwhile, the equipment and labor to make tubes dwindled from the golden age to today's "meh-age."
So, today's tubes are--on average--not as well aligned as those from the 50s-70s. They don't last as long and go microphonic at a higher rate. That said, EH, TAD, JJ, and Tung-Sol tubes of current manufacture work well for me.
My only deviation is that I use NOS rectifier tubes exclusively. They are so well aligned that they are plug and forget. I have used examples of Mullard GZ34 rectifiers for more than 40 years in some cases.
GT
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JJ's are produced in Czech Republic. No "american made" tubes any more, and haven't been for years.
NOS, and vintage is all there is for "american production tubes."
TAD's are my choice for good sounding "matched" sets, and or guitar preamp tubes. I've also used them on the audio side where 'noise free' is a must.
As to Chinese and Russian tubes, I prefer Psvane's and from China...There like an audiophile's "Shuguang" tube, and worth the additional price over Shuguang's. But make no mistake the Shuguang Treasures put many other high dollar NOS tubes to shame too.
Svetlana Winged C's are as good as it gets on the Russian side for my money. And they're made in St. Pete!
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The best luck I've had has been with TAD brand of power tubes, consistantly. But I've pretty much moved on to Quilter amps for the past year or so!
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This is a good question. Now and then I need new tubes to my Voxes and Fenders and quite often when I am going to buy "the same as last time" I find out that my tube expert's (a Finnish parts etc dealer Uraltone) recommendations have changed.
Sometimes the chinese ones are best in EL84, sometimes russian ones are the best and so on. You have to do a bit of research every time. Although JJ seems to be quite good most of the time. So I trust to my dealer.
Ahh, tubes!... There is so many secrets ands mysterious rites with them... They are so human!
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Groove Tubes were re-branded and could be one of many different brands.
12ax7, 12au7, 12ay7 are interchangeable and have different gain levels. 12at7 is interchangeable with 12ax7 in some/most amps. RE: different designations e.g. ECC83 = 12ax7, one is the European designation.
Some other letters e.g. JAN 12ax7a are for military grade versions.
I'm NOS all the way except my Dumble clones. Big difference in tone to me. My Dumble clones were designed around certain newer tubes so they sound best with those.
I pay about the same for my NOS tubes as compared to current mfr.
Part of the reason the new mfr tubes sound bad are because they're built on machinery that is old and not maintained. That machinery used to build some fine tubes.
There's nothing that comes close to 60s RCA blackplates for 6L6GCs, imo.
Nothing comes close to 40s-50s smoked glass RCA 6V6GT/G VT-107a for 6V6.
Hammond labeled EL84s are a great cheap way to get into Mullard's.
Mullard and Bugle Boy 12AX7s - some of the most sought after - are, to me, not that great for guitar amps. They're very neutral - a bit lacking in character to me. I go with Baldwin/Sylvania's - higher gain, little noiser. $10 a pop. JJ and Sovtek preamp tubes sound cold, thin and harsh to me.
Mullard XF2 EL34s are my favorite though Siemens EL34s are a favorite classic but lack bottom end, and RCA 6CA7s are a great cross between a 6L6 roundness and EL34 mid punch.
I use Mullard GZ34s where possible. Had a brand new JJ/Tesla rectifier blow up on me.
RCA 5Y3GTs - can be had for $9-10 NOS.
Gold Lion KT66s and SED Winged =C= 6L6s (no longer made) are the only newer tubes I've thought weren't terrible. The Gold Lion's were impressive, the SED's were above average.
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On my 6L6 and 6V6 amps I tend to like JJ power tubes but on my EL34 Musicman I like Svetlana's. I go exclusively NOS on preamp tubes mostly Jan/GE or Jan/Phillips as they are still easy to get. I almost always use a 5751 in V1. I have yet to find a new production rectifier tube that I like. Believe me I have tried every tube known to man and have the boxes in the garage to prove it. I am still trying to figure out what I like best after 4 decades of tube swapping. Every time I get a new tube amp it takes me at least a month to find my sweet tube combination but hey that's part of the fun of a tube amp right ? Bias is just as important as tubes. Every amp has its happy tube temperature spot. If you buy a new Fender amp the first thing you must do is bias it as they set them really cold at the factory for the 5 year warranty. A amp biased too cold sounds worse than one biased too hot IMO. Yes too hot you loose headroom but too cold you get tube rattle and a sterile sound. Nothing sounds better than a perfectly dialed in tube amp.
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Greentone and 2bop are the true audiophile experts around here if you need expert advise.
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Yeah, and reading this thread You'll convince You that advise You will need if You purchase a tube amp!
Sorry to say this but according to my knowledge the US NOS is not always what they should to be. Of course it is Your ears that makes the decision but what I have learned "NOS is always good" and "US is always good" are not anymore as true as in past.
"Mystique is all around" would some SS amp afficianado say!
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Alright humor me here. I just got ahold of a hand-wired, single-ended, cathode-biased heavily-hyphenated amp based on the tweed Princeton circuit but with a different tone stack. It arrived with a Mullard reissue 12AX7, Sovtek 5881, and an old used RCA 5Y3 rectifier. It sounds really nice through a Legend 1218, but at the edge of breakup there is a noticeable harshness to the low-pitched notes that sounds kinda nasty. Would I be better suited running a NOS RCA 6V6 instead of the 5881 and a 5751 or 12AY7 instead of the 12AX7?
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If it's a used amp with used tubes with nasty tone, I'd assume some components are defective or out of spec. I'd confirm that's not the case before spending a bunch more money on NOS tubes. One quick check would be to borrow a set of tubes you know to perform well in another amp and see if they clear up the "nasty" problem. Also try another speaker. If its still nasty, a qualified tech should look inside to check component values. Originally Posted by wzpgsr
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Oh, you mean like an amp "set up." OMG, imagine that!? Originally Posted by KIRKP
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Here is a year end blow out at Mojo. There are some some tubes a few pages in. JJ TAD etc. Various grill cloth, some speakers, etc. I don't know if they are really good buys or not.
Folks, this is my very weakest area. I can pick on a guitar with a pick and pick out a guitar with my eye. I know what sounds good. I know what plays good. Amps, however, beyond sticking the phone plug in and twisting the knobs..... well..... I am a damn goober most times.
I am drinking up knowledge from the electronics posts here. Glug, glug! So, my fine fellows, if something looks good, please comment.
Year End Blowout Sale!!
Happy New Year.
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Could you be more specific on what the 'harshness' is? Also, I'm assuming you mean the 5F2 circuit - not sure who built your clone but that circuit calls for a 6V6. Do you know what transformers are in your build? What ohms is the speaker? Originally Posted by wzpgsr
I've had edge of breakup issues with impedance mismatches.
I would be worried about the amp being able to accept a 6V6 now w/o modification since it came with a 5881.
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I have stopped playing tube amps long ago. Still own a Fender Twin, and Boogie Mark III though. I found that some Amps play much harder on tubes than others. A quartet of 6L6GC which worked well in the twin might not sound good in the boogies. The preamp tubes got wasted fast in the boogies, but often were still okay in the twin.
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