In the same way that any component will have synergy, or not, with the rest of the gear in a system, I think the same will be true of tubes. And in fact that's certainly true of power and small signal tubes, so why not rectifier tubes? I don't think anyone can tell you what will be best or will match the quality of your output tubes with any authority, given its your system, environment and ears. But it's pretty clear that the early Mullard 5AR4/GZ34 are held in high regard by a large percentage of those who weigh in with opinion, myself included. The earlier manufacturer series f30 and f31 tend to get the most love but I've both experienced and read that the the f32 are essentially every bit as good. I have an f31 and a couple f32 and cannot tell any difference. Of course the very early metal base are said to be the ultimate, however that may be lead by pride and elitism. Or maybe I just think so due to jealousy! The point is, you really can't go wrong with a pre-1970 Mullard GZ34 and if you don't care for it (hard to imagine) it will be easy to sell on to someone else. Remember that Mullard made them for a wide variety of other companies, so don't get too hung up if its branded differently assuming you trust either your research or the seller or both! My f32 are Daystrom branded. Cheers, Robert
Robert, Khorn and any other current/prospective owners of the LS100, I don't want to discourage anyone with my comments on this fine piece. The LS100 is a feature rich, full flavored Preamp. I only had the one glitch and that was it, it performed flawlessly for close to four years after that. I only moved on for the same reason most do, I simply wanted to try something different.
@Khorn … sorry if this ends up going a little far afield of your original question. I’ll stay within the 6SN7 realm, though, and try to keep it broadly applicable to folks interested in this tube type, OK? Sorry, fellas—I shouldn’t have used the “J” word. I didn’t mean that anyone literally threw away GTAs … only that they were likely to be replaced. (There was actually a real stigma against GTAs and Bs as “TV tubes.”) Likewise, my comment was more in relation to the $200/pair price than it was to sound quality. In context, that’s a mind-blowing price to me; but, if Sylvania GTA beats all the competition in an amp, then there’s only one thing to do. I didn’t mean to question taste. Just keep in mind that all of this relates to a time when builders would use 6SN7 specifically because NOS was so cheap and plentiful. Even an amplifier built to a strict budget might specify two 6SN7s and then operate only one triode of each—wasting the other. That wasn’t done because 6SN7 was considered sonically superior to all (or even any) of the single triode “equivalents times two”; it was done to capture the advantage inherent in the 6SN7 supply glut at the time. Obviously, though, I need to update my thinking from the “ancient wisdom” of Sound Practices, Vacuum Tube Valley, Glass Audio, and the like. Those days are long gone. In terms of what specifically was preferred 20 years ago, just name it. You had your pick, because they were all available. (Begging the question, where did they all go? 6SN7GT(A)(B) was a major military and then computer and television tube, and I’m skeptical that a bunch of fringe audio nuts caused that supply to evaporate over the last 7000 days or so.) In terms of what might be preferred today and going forward? I hope no one read me to be saying that I know of a fantastic 6SN7 for cheap. I don’t. That’s why GTAs are apparently a hundred bucks a pop. I’ve explored lots of other options, though—and have been successful enough that I don’t need to (or even want to) use 6SN7 anymore. Here’s an amplifier that illustrates just a couple of the many 6SN7 workarounds: First stage (center tube) is spec’d for a single 6SN7—thereby utilizing both halves for stereo and leaving somewhat limited options. Second stage (one from center on both sides) was also spec’d for 6SN7 but utilized only one triode in each tube, which left all the options. To break this down: In the first stage, a simple 6F8 adapter allows for the use of one the finest 6SN7s ever made (or at least its sonically-identical predecessor) for about the price of one of those Sylvania GTAs. Don’t like adapters? Pin reassignment is simple. (I just need to get around to it.) On the other hand, if you don’t mind adapters, they can open up a world of alternatives by splitting a twin triode into two singles like so: These are military 7193s, but 2 x 6J5 (and tons of similar single triodes, few of which use those top caps) is an excellent way to go—I just don’t have a photo Speaking of 6J5, and having said that this amp originally had a “1/2” 6SN7 second stage, it was a simple matter to rewire that socket for single-triode use. (The adapter that I used originally could have been a permanent and much easier solution, but it’s wasteful of 6J5s.) With that, the vintage MOV L63s that are currently installed represent about the most you can spend on “half a 6SN7”; and they’re available for roughly the quoted price of the Sylvania GTA. And speaking of Sylvania GTAs, these are their great-grandfathers: Sylvania metal-base, round-plate 6J5GTs. I’m sure I didn’t pay more than 10 bucks for these … as a pair. ( I mean, they’re “off-branded” ) When I tried them on 2 x 6J5 —> 6SN7 adapters, they beat every 6SN7 in that second stage—even the fancy, near-unobtainable ones. And they should have: these are considered closest to (half) the Sylvania metal-base VT-231. Only the British L63 has been sonically superior. Listen, this could go on and on … my only intention was to demonstrate that with a little bit of strategic thought and effort, you can enter the world of 6SN7 royalty in a financially realistic way. But again, if you place Sylvania GTA in that category, then you’re already where you need to be. For the rest of us, the alternatives to expensive 6SN7s are probably more numerous than any of us has time to explore.
@Khorn Regarding tube reliability and what manufacturers use in their equipment and why the use of new production tubes is based on availability more than anything. You have to spec tubes you're going to be able to reliably source over the life of the product you create. But any tube can be unreliable and go bad on you it makes no difference if it's new production or NOS. As far as a rectifiers going in a well designed piece of gear damage should be minimal. In 15 years my amp twice had rectifiers blow the two instances were 10 years apart. First time the rectifier fried a resistor easy fix I used that as an excuse to do a cap upgrade. Second time it took out a fuse I popped a new fuse in and the amp worked fine. Obviously ever piece of gear is different and your talking amps vs preamps, all I really mean to say is don't be afraid of NOS rectifiers they do sound so much better than current production tubes that I've heard.
@Jim Hodgson I think we understood that what you were saying is the current pricing of the bog-standard GTA was what was most shocking, not that they were literally being disposed of. But the query was really, back in the day, what was kicking the GTA to the curb? You indicate any and all which, then, is not entirely unlike today. While many like this common tube, there are many others who are ga-ga over plenty of other choices. I completely agree that prices are at silly levels for many of these tubes. I've not seen those Sylvania GTA at the $200/pair levels - mine have been closer to $80/pair - but it's not surprising given the price of 6SN7W or Melz 1578, Tung-Sol "round plate", the red base RCA - all of which approach $200-400 per tube! Are the dubiously named (and dubiously "identified") Sylvania "Bad Boy" tubes seriously 5 times better sounding than a more common OS tube? For some I suppose... This is far off-topic, but you clearly have some great experiences that could be helpful and interesting to those using 6SN7-based gear. I wonder if you could post some of this on the dedicated thread discussing this tube... I, for one, am certainly open to trying some of the alternatives you mention but would need some guidance, along with a ton of reading! Shootout of Nos 6sn7 tubes Cheers, Robert
I was buying some tubes today and passed on a BAT box of two EL84's. Did I make a mistake? There was also an original Mullard GZ34 but I set it aside for next time. Instead I got two boxed NOS Raytheon RK807's (I needed them), two Magnavox branded 6550's and four Mullard EL84's. I also passed on two NOS boxed Amperex metal base EL34's. I didn't want to spend the money at the time. But I also set those aside for next time.
u audio folks i'm sure are familiar with looking for etch codes on vintage valves to confirm actual plant/type etc. below is a solid link i've used as a musician for sussing out a vintage valve (got educated yrs. ago on the long defunct PlexiPalace forum). for players, mullards, valvo, philips and many other solid mfrs. will always be the gold std. in guitar tube amps. not to exclude rca, westinghouse, ge in the usa. the 2nd is the old 60's philips etch code list that i've used for decades to identify the type/mfg. plant data. u may already have/be familiar with this. Tube Classics - Philips Audio Tubes http://www.audiotubes.com/PhilipsCodeList.pdf TA!
Not as far as I'm concerned. My point with BAT was that he designed around the 6h30 and the best sounding by a wide margin in my line stage--- which is not made by BAT-- is the older production DR Reflecktor. And this is not some ancient tube- the quad I recently installed was from circa 1977. PS: for what it's worth, some people who use that tube in other circuits claim not to hear much difference between these older, hard to get tubes and current production. That makes life less expensive, it may depend on the circuit.
FYI i just finished listening to the Mullard Sittard f30 GZ34 and it sounds identical to the f32 i already own, at least i have a spare in hand.
That's been my observation also, the f31 and f32 Mullards I have sound identical to my ear. Probably because neither of has gambled the money on a metal base version... lol. Still, at least you have a quality OS backup now. Cheers,
Yes, and I am not going to explore the metal base options- even though some Philips versions are cropping up ~ $400 US or so.
As an update the sound of my system became a little bright at the top with more than occasional sibilance. Process of elimination led to the Mullard GZ34 rectifier being the source. Too bad, it did so much well. Now using the Amperex NOS and the sound is excellent. Things changing over time I guess.
Thats cool. Id like to know what it is that makes them sound different. Physical properties? Impurities in the vacuum? Was that Mullard GZ34 bad or did you just end up not liking it? I had at least 3 of them pop for no good reason and they are not cheap but they are very very old now.
different matetials, different plate lengths and construction configurations, mostly a mystery to me. the mullard just changed a little for some reason, possibly lots of hours playing my system every day while working from home.
I just switched the rectifier in my Aric Audio Motherlode II preamp. It can use any 5u4,5u4g,or 5u4gb. I replaced the RCA 5u4gb that came in the pre,for a Winged C 5u4g. I immediately noticed a difference in soundstage. It was deeper than I previously noted. One of the many things I love about Aric’s preamps,is the ability to roll tubes.
there's the rub..all that amazing metallurgy/tech behind the classics is lost/unobtanium now imo. mullard gz34/5ar4 types used in several of my heads are integral to getting great tone off the stage.
And mostly fueled by world militaries, a lost art that was replaced by solid state manufacturing starting in the late 60's. No need for tube anymore.
More 5AR4 / GZ34 rectifier ramblings. My current running Mullard f32 4-notch began sounding noisy with occasional bursts and an overall slightly noisy top-end. Updated my preamp with the f31 version and it sounded overly bright and sibilant. The Amperex rectangle punch pates became fatiguing with certain music because of a pervasive bass peak. Too bad because it sounds great with most recordings. I now have a later version 7-notch Mullard f32 on order, it will be interesting to see how it sounds. Currently running a Gold Lion new production tube with 7-notch plates which seem to resemble the new production Mullards. The Gold Lion does not sound bad at all. Much better than the stock Sovtek which is bland and crispy that makes everything sound like a low-res MP3 file in comparison. Just some observations of the way these sound in my system.
After some listening today the Genalex Gold Lion is a far cry from the F32 Mullard 4-notch. Hard to believe how much impact on the sound the rectifier tube has. Hopefully the 7-notch Mullard will sound great but I have a feeling I might miss the 4-notch.
Received the Mullard 7 notch plate GZ34 and have a few hours on it. So far a very pleasant and pleasing tube. Just a touch dark but smooth and forgiving, no noise or edginess. waiting for another 4 notch which i believe sounds best overall.
SED 5u3c Like the SED EL34 from the 90s, these are excellent tubes. I've used the Mullard 5ar4...it's an excellent tube. So is the SED. The best part is significantly less cost.
