Valves/tubes etc ... what do you use and like?

[Despot]

A while back I managed to snag an early '70s SF Princeton.

It's a beauty of an amp, but unfortunately it's begun to act up a little bit, primarily due to a tempermental power amp tube.

The original amp had a Brimar and GE each in the power section. I suspect that the GE is the one that's been acting up. I managed to source a pair of original Sylvania 6V6GTs to replace the tubes ... but somehow the sound just wasn't quite the same as with the original valves.

But, as luck would have it, I found a stash of Brimar 6V6GTYs on the Irish version of craiglist ... and they arrived today. I haven't had a chance yet to try them in the Princeton, but I have high hopes given that they'll be a matched replacement for the current set, and should at least be decent.

The other nice thing was that I managed to find a pair of Mullard ECC83s as well - '70s production, but still as rare as hen's teeth to find. The Princeton came to me fitted with Mullard ECC83s ... so these will be a like for like replacement for when the current valves die.

I know it's probably being super picky to get to this level of twitchiness about sound ... but I really can hear the difference between putting in a set of JJs or Groove Tubes and something old/NOS like the Sylvanias, or Brimars, GEs etc. For some reason it seems to be easier to find old 6V6s as well compared to EL34s/6L6s - which is another reason I like the Princeton.

I could easily get a decade out of the replacement valves, but I do feel sad that eventually my ability to source replacements will run it's course and the amp will never sound exactly the same.

So - anyone have any preferences in terms of valves used in their amps, and if so what have you preferred and why?

[beauzooka]

I have a lot of old 12ax7/ecc83's and I always go back to the old Mullards. Maybe a little less top end and an more pleasing with distortion. I have put them in the P1 position in all my amps. I'm not quite savvy enough to date mine yet so not sure what eras they are.
I bought some GE 6V6's for my princeton but I haven't installed them yet.

[eigentone]

Preamp: I've just stockpiled a mix of old tubes over the years. I mix them until I get something I like. I'm not buying the most desirable NOS tubes or anything very high priced. I have many amps and keeping them loaded with the best glass would be a considerable investment. I occasionally buy a specific tube or work with dealers. 5751s to taste, depending on function.

PI: Highest likelihood of burnout IME, so nothing terribly desirable. Often 5751.

Rectifier: Smaller stockpile. Often wind up buying from a dealer. Old, with the exception of the Gold Lion GZ34 in my AC30.

Power: A mix of old and new. Basically, old unless cost prohibitive. I'll let somebody else have that quad of NOS EL34s for $1000+ USD.

Reverb: Same as preamp and power.

So I aim to use old and it's not unusual to drop a good amount more than one would on current production tubes, but I'm not out spending hundreds on a single tube.

That said, I'm somebody who prefers to work with several good amps at hand - rather than one perfected amp.

[beauzooka]

I got all the Mullard 12AX7's together that I could find and dated them. All 4 are short plates: 1961, 62, 65 & 69.
I have an Amperex too but there are no codes on it. Looks to be almost identical construction to the mullards.
I also have a couple of Dynaco branded Telefunken's but I don't think they sound that great in gtr amps, imho.

[Despot]

I guess I've splurged a little bit on this amp because it's the only old amp I own these days, and given how good it sounded with the original valves I wanted to try keep that sound.

I'm also stockpiling a little bit, as 6V6s don't appear to be in as short support as some other valves and you can still get some pretty good ones for not a huge amount.

You need to have some perspective though - I mean, the Princeton does seem to benefit from putting in decent valves, but my other amp (a Swart AST Master combo) is running JJs in every socket from day one and sounds great (also runs whisper quiet). It's all a question of what the amp needs I guess...

[Ursa Minor]

I can tell the difference with certain tubes and certain amps. This topic is pretty dear to my heart.

I like old RCA or GE preamps in my Princetons. I was buying used old stock 6V6s pretty cheap a few years ago with very little issue. Sure they may not last as long and occasionally you get a dud, but generally speaking I've been happy not paying a premium for them. The saving allows me to shop around and try different ones too. I'm a big fan of grey glass RCAs from the 50s and mid-late 1950s Sylvania in my 6G2. You can also find some RCAs that are under different manufacturers too which might lead to a bit of savings because the label might say Delco instead of RCA.

My PR is less sensitive to power tubes it seems. I used to get the nicest old RCAs but now have settled on JJs and think they sound pretty damn good. I dont miss my old 6V6s in there at all.

[Despot]

I've found the same Nick - I managed to snag a few RCAs that were branded National for small enough money a few years ago (unfortunately they were sold with the Gibson GA20 amp that I'd used them in!).

Brimars are good solid valves in my opinion - and sound really really good. They're a little more common on this side of the pond as they were British made. I'd equate them to the RCA - my Princeton was running one of each before the Arrival of the Hum & Pop. Thankfully the two I've just stuck in were shiney/spanking new, so I should get a few years of use from them. That's another thing I've found - old Fenders like old valves and are less likely to fry older valves that are better able to deal with higher voltages. Newer valves, even good ones, burn out quicker.

I put a full set of NOS valves in my old Vibrolux over a decade ago - and that was my gigging amp then too. It's gotten less use in the last few years (It lives in my parents place so I've something to play when I head home) but when I fired it up two weeks ago and gave it a good bit of use over the weekend it was still running well (and no hum, popping etc). Got to love that.

[sookwinder]

Amps that use 6V6GTs and GTAs are my cup of tea.

Sylvania 6V6GTs are good, way better than any new valves, but for my ear not quite as good as RCAs or GEs (I haven't ever tried Brimars)
Given the SF Princeton is cathode bias, you won't need to reset the bias and there is no real need to have "matching valves"... that terminology didn't even exist for valve amps back in the day.

I always like to have a good rectifier like a Mullard GZ34. They were used standard in the fenders in the 60s, and sometimes in the 70s on these smaller amps.
The Mullard GZ34 is just THE rectifier to use.

While Mullard 12AX7 and 7025 were used as OEM parts for the BF Princeton, RCAs were also used. "Grey plated" RCA and GE 12AX7 are perfect to use in this type of amp. The more expensive "black plate" (circa late 1950s) RCA and GE 12AX7s sound a little, too "Rocknroll", 50s RnR for my liking... I would stick with the 60s or 70s Mullards, GEs or RCAs...even some 60s Dutch AMPEREX 12AX7 sound great,

[Despot]

Thanks for that David.

I didn't realise that about the Princeton (re: biasing) - good to know! That does mean that I could always stick that lovely old RCA 6V6GT back in there if I need to.

I agree on the RCA/GE being sort of the top of the pyramid of 6V6s (funnily enough every amp I've really loved has been a 6V6 amp - Deluxe, Princeton and even the Swart). I can tell the difference using the Sylvanias (it's not as pronounced as using modern tubes like JJs) - but I can't notice any real difference between the Brimar/RCA combo and the NOS Brimars I've put in there. I'd put the Brimars up there at the same level as GE or RCA - I think they're just a little harder to find outside Europe/UK - so probably not something you'd come across on your side of the globe.

NOS GE/RCA tend to run about fifty euro a tube - Brimars run about forty euro mostly... so thankfully none of them are terribly expensive.

The rectifier is a 5U4GB at the minute - that's how it was rewired when the solid state mod was taken out. It's a Fender badged tube, but I believe it to be a Sylvania. The Mullard in the preamp slot is a 70s production (later type blocky shield logo). I've found two more locally and they're on the way as spares - that way I can keep this thing running for quite a while without having to worry about valves.

I might swap out the rectifier if I find something worth getting to replace it - what would you recommend apart from a Mullard Sook?

[sookwinder]

Kevin,
I know this might sound a little uncompromising, but get a Mullard GZ34. it will last a life time...as Brad often says, even a slightly to medium used Mullard will last a lifetime.

The good thing is that Mullard manufactured a shit load of these GZ34s for other brands in Europe
For example below is a photo of some guy in (IIRC Bulgaria) who found a stash and was selling them off at about 1/3 - 1/2 the going rate.
I bought a 6 pack for my stash
Notice how in this case they didn't even bother to print the other brand on the glass

When I have time I'll do you a little "how to spot the good Mullards" cheat sheet

[Despot]

Nice!
I've just ordered an Amperex 5U4GB - but I'll scout around for a deal on the Mullards and then changeover.

I used to have a serious thing about wanting an old BF Deluxe reverb or PR, but I'm just smitten with this SF - I'll be happy to just keep it up and running (and sounding) as it does now. It's pretty much the perfect Fender clean sound.

[jorri]

+1 for Mullards or Telefunkens....

whilst i thought this was all gear snobbery...well they've saved me a lot of money on JJs and EHXs, or even the Harma stock, because these old tubes last for years! The sound, can't really say much has changed but the reliability has.

Sacriledge, but for the GZ34 in an AC30...erm, get some diodes...Hasn't sounded better since and of course, it won't break. The mythical sag is not particularly present on an AC30, to me it just sounds like its not getting enough power, and thus enough headroom. Ac30s, i was told produce a constant unchanging sag from their rectifier that doesn't react to playing, unlike the compression characteristics of other amps with tube rectifiers.
First time my GZ34 failed, an SS rectifier was installed...At some point i put a tube back in and kidded myself that i liked that weaker sound...then about 2 failings later, i went back because clarity was lacking and it was back to the old sound i remember. (or of course correct me if i'm wrong, i also love old solid states, so i might just prefer it)

[s_mcsleazy]

i really like most of the JJ's i've tried. im no purist. i play tubes until they feel like their gonna give up the ghost. granted, i only have 2 tube amps so it's hard to say. my bassman has a set of the sovteks at the moment but i have a spare set of jj's which are a wee bit cooler. i usually bring out the jj's for times when i need the amp to stay cleaner. saying that, i've been considering getting my bassman biased to be way cleaner.

[rexter]

Despot: I think I'm running Brimar 6V6GTs in my blackface Princeton Clone now. When I switched to them from Tung Sols there was a noticeable increase in mids, the sound somehow became much fuller.
Rectifier is a NOS Radiotron (Australian made) 5Y3. Sounds so good, that when coupled with prices approaching insanity, it has called off my hunt for a vintage PR (unless i become wealthy or see a great deal)

[eigentone]

Sacriledge, but for the GZ34 in an AC30...erm, get some diodes...Hasn't sounded better since and of course, it won't break. The mythical sag is not particularly present on an AC30, to me it just sounds like its not getting enough power, and thus enough headroom. Ac30s, i was told produce a constant unchanging sag from their rectifier that doesn't react to playing, unlike the compression characteristics of other amps with tube rectifiers.
First time my GZ34 failed, an SS rectifier was installed...At some point i put a tube back in and kidded myself that i liked that weaker sound...then about 2 failings later, i went back because clarity was lacking and it was back to the old sound i remember. (or of course correct me if i'm wrong, i also love old solid states, so i might just prefer it)

Most modern production ACs use SS rectifiers.

Some people prefer the sound of SS. Some don't. These rectification methods have different sounds/feels. SS is more reliable and less expensive, but really it comes down to the sound somebody prefers.

I'm using a tube rectifier in my AC30 because I have other amps with SS rectifiers. If I want that tight/fast/more modern sound - I just choose another amp. That said, that AC30 with tube rectifier has been getting more use than any other amp in my collection. As well, my Mesa has switchable Tube/SS rectifier -- I choose tube more often than SS.

My reason for posting is to say that drop-in SS rectifiers (which plug in to your tube socket) aren't necessarily safe upgrades. Example: Using a diode (where a tube was) can result in a voltage increase to your power tubes. This increased voltage could be higher than specified for the tube - depends on the circuit. As well, not all solid state rectifiers simulate warm up. That's an important detail for ACs (which often omit a standby). Not all drop-ins are created equal. Some can damage an amp and/or its tubes.

So… if somebody prefers the solid state rectifier, I'd encourage her/him to get the Custom series rather than the Handwired series.