Metropoulos Forum

The Tung Sol RI in V2 in my JTM45 lasted about 2 months and 12 gigs till it started to go on the last 2 tunes of my gig last weekend. It slowly died. I had to keep turning up the amp. I swapped it out remembering this thread and sure enough the amp was all good again.

What do you guys use instead of the Tung Sol in V2. I am not a fan of the JJ's so what else is there that will hold up besides NOS?

Dan

DNeafsey wrote:What do you guys use instead of the Tung Sol in V2.

In my own amps I'm exclusively using NOS glass, so there this problem can't arise at all.
But in 'the other amps' of my customers, especially in the Marshalls in the case of an amp service I'm usually using the Chinese 12AX7 or the JJ ECC803S in the V2 spot with good results.

But also avoid the Sovtek 12AX7-LPS as V2, because this tube might have the same issue!
The Sovtek EH IMO is too much compressing and the JJ ECC83S sometimes too brittle.

Larry

I second the Shuguang 12AX7 from China , great new stock tubes. Get the from a reputable dealer. TAD, and Ruby are good reseller/testers of these tubes.

I like the Chinese tubes as they seem to have no to few issues. I also had good experience with the JJ803S in the PI. I didn't like them as much in V1 as they tend to be a bit microphonic. Didn't try them in V2 yet.

Cheers Stephan

I've got a 5F6A (59 fender bassman) circuit I built - as you know, this circuit became the JTM 45 when marshall built it using Brit parts. But both amps tend to cook one of the cathodes on V2 with around 180 vdc. I had a lot of trouble with tubes here too, especicially the tung sols, which do sound sweet and seem to do OK in V1. The tell tale sign is a loss of volume - means v2 is dying...

But I found the 12ax's with the shortplates do much better in the V2 spot. Also tried those new Techtubes being built in what used to be the mullard factory in England.

http://www.techtubevalves.com" onclick="window.open(this.href);return false; -check 'em out. At least they're trying to build new tubes.

So far that one is doing OK, too. I live in Taiwan, and was able to get some old RCA short blackplates, those sound sweet and can take the heat in any spot.

Be it an 5F6A bassman or JTM45, it's one heckuva circuit, sounds amazing, imho still the best after all these years.

Dredging up an oldie here, but I have a question: I have RI Tung-Sols, I bought a few months ago, in V2 and V3 of my '74 Super Bass (V1 is sporting a NOS Mullard CV4024). Recently, I've noticed that the amp seems to lose volume during practice as the evening wears on. Is this a sign that the tube in V2 is on the way out?

Thanks.

Cheers!

More likely the power tubes. The tungsol problem usually involved them dying pretty quick in v2, but I haven't heard of it happening for a while now.

demonufo wrote:More likely the power tubes. The tungsol problem usually involved them dying pretty quick in v2, but I haven't heard of it happening for a while now.

I hope it's not the power tubes... they're fairly new JJ KT88s.

Thanks for the reply.

Cheers!

I had a very similar problem with my '84 4104 for several months before the OT finally went totally dead on it.
I hope for your sake it isn't that!

I only mention this because the problem cleared itself after I replaced the OT.

demonufo wrote:I had a very similar problem with my '84 4104 for several months before the OT finally went totally dead on it.
I hope for your sake it isn't that!

I only mention this because the problem cleared itself after I replaced the OT.

It's not a major drop in volume, but noticeable after playing for a while. I had the OT on my '73 SB go on me. Got it rewound by Marstran, and the amp sounds better than it ever did. If the OT goes on the '74, I'll go that route again. But, it isn't experiencing the same symptoms as the 73 when the OT was dying on it (which was: MAJOR volume loss and super fizzy sounding).

I have 1 brand new Tung Sol 12AX7, that I'm going to try swapping into V2 tonight, just to see if it makes any difference.

Cheers!

Clammy wrote: It's not a major drop in volume, but noticeable after playing for a while.

Mine wasn't major either. I had to think quite hard as to whether or not I was imagining it at times.

demonufo wrote:

Clammy wrote: It's not a major drop in volume, but noticeable after playing for a while.

Mine wasn't major either. I had to think quite hard as to whether or not I was imagining it at times.

Well, I swapped in the new Tung-Sol, and the volume stayed steady throughout the jam. Interesting... I have a bunch of NOS RCA 12AX7s on the way from Tube Tramp, so I'll be removing the Tung-Sols altogether soon.

Cheers!

Clammy wrote:

demonufo wrote:

Clammy wrote: It's not a major drop in volume, but noticeable after playing for a while.

Mine wasn't major either. I had to think quite hard as to whether or not I was imagining it at times.

Well, I swapped in the new Tung-Sol, and the volume stayed steady throughout the jam. Interesting... I have a bunch of NOS RCA 12AX7s on the way from Tube Tramp, so I'll be removing the Tung-Sols altogether soon.

Cheers!

Good move. Those GE 12AX7's he has are a cracking good deal too.

demonufo wrote:

Clammy wrote: Well, I swapped in the new Tung-Sol, and the volume stayed steady throughout the jam. Interesting... I have a bunch of NOS RCA 12AX7s on the way from Tube Tramp, so I'll be removing the Tung-Sols altogether soon.

Cheers!

Good move. Those GE 12AX7's he has are a cracking good deal too.

I installed the RCA 12AX7s in my '73 and '74 Super Basses, and WOW!!! What a difference!! it REALLY made a huge difference in the '74. More volume, rounder tone, more sustain, more "balls"!!! These tubes sound fantastic!!!

Cheers!

those rcas are fantastic that terry has i bought 7 of them for my amps, plus 3 rfts and 4 british valves of his selection, the rcas sound not bad in my jtm 45 reissue but then that needs better parts, rft not tried in my 69sl and the other tubes i put in my marshall super pa and jeesus that thing is insane!