Tung Sol 12AX7... the modern day Mullard?

[Variable]

Just got four from Doug and swapped two into my Guytron. Prior to today I was running a TS 12ax7 in V1 (which only is an input buffer for the gain channel, V2 is the clean channel). Added one to V2 for the clean channel, another for the master tone stack, and holy BALLZ did that make a big difference! The clean channel was great before, but now it's got this whole new 3D thing going on where the notes just bloom forever. Dynamics all over the place.

I also swapped a Penta Labs 12AX7, which is an R9 Chinese tube made specifically for Penta Labs. I put it in V5, which is the second 2 gain stages for the gain channel. Prior to that I was running an R9 Chinese. I wasn't expecting a big difference, but it seems to have added a bit of a hi-fi sort of sound to this channel. Added a little more 3D to this channel's sound-stage as well. I tried running all Tung Sol for V1 & V5, but it ended up being too smooth sounding. Almost like it was too much to Tung Sol to handle. The Penta has more grit to it. I'd say the Penta is a cross between the TS and an R9 Chinese. Like the "audiophile" R9

I also picked up an NOS JAN/GE 5751 to try out. It's around 70-80% the gain of a 12AX7. It was cool in the V5 position... kinda gave the gain channel more of a "classic" sound. I also tried it for the clean channel but didn't like it at all. Sucked all the warmth out. I yanked it out all together and I'm going to throw it in my Nomad to see if it can remove some of the mud.

I'd love to do some clips of my GT100, but I'm having the hardest time getting this amp recorded with my SM57 and AKG Perception 200... hi-gain sounds flubby.

-Russ

 

[RockStarNick]

I don't know if I'd call it a modern day mullard. BUT... I think it's safe to say that the Tung Sol is as close as it gets, so far, for a modern-production tube.

Totally, totally different flavor than the C9s. The C9s are spongy, gainy, warm. They're good at what they do, but to my ears, not as "complex" sounding as the Tung Sols, which are stiffer sounding, crisper, more immediate attack.

That being said, the Tung Sols are definitely not as rich sounding as a real deal NOS... and I've only tried some $20-30 NOS tubes. I can only imagine how good a $100 mullard reissue sounds.

 

[duesentrieb]

Since they won't handle "standard Marshall layouted CFs", not even close to Mullard IMO.

 

[Marshall Freak]

They're OK sounding tubes, but for new production tubes, I'll take the C9's and even EH's over TS's every time I've tried them. They sound "Big" and they're clear, but they're almost too clear and kind of sterile sounding, too hi fi sounding maybe. They're a huge step up from Sovteks, but they're not even close to Mullards or just about any other NOS tube I've used.

I do like to use them in conjunction with other tubes, but an amp full of them? No thanks.

 

[fearhk213]

They're ok IMO. They sound very good in V1 of my HG Jose. It adds some clarity and opens up the sound a bit. On the over hand, the C9 definitely sounds better in the Uberschall though. The highs sound very smeared in that amp with the TS. There not one of the tubes that sounds good in everything, but in the right situation the can work really well.

 

[jkdsteve]

Since they won't handle "standard Marshall layouted CFs", not even close to Mullard IMO.

What does this mean..they shouldn't be used in certain circuits?

Is this issue similar to the Sov 12ax7LPS issue with Cathode Follower?

 

[RockStarNick]

Since they won't handle "standard Marshall layouted CFs", not even close to Mullard IMO.

What does this mean..they shouldn't be used in certain circuits?

Yeah, someone please enlighten me.

Please explain what the heck a cathode follower dues, in a circuit, and why a TS can't work.

IN DUMMY TERMS PLEASE!!!!

 

[duesentrieb]

They cannot stand (like other Sovteks) the big voltage difference of cathode followers. Thats V2 in a 2203 or 1959 or V3 and V4 in a SLO (two CFs). Just some examples.
If one "elevates" the heaters (tech) this problem of modern tubes can be solved though . . .

In the last couple of weeks I had two Tungs dying in a Shiva (during a gig of course) and one of my own designs. Both were CF-positions.

 

[RockStarNick]

What are the best current production tubes for a CF position?

 

[duesentrieb]

No probs with chinese (Shuguang, Ruby, TAD, TubeTown) tubes here. Or JJs.

 

[fuzzyguitars]

i dont like em

prefer chinese and rft's

and of course mullards.

 

[titanamps]

just to help make a little more sense of the CF issue:

in non CF stages, the cathodes of the tube (that's the part that goes to ground through a small resistor) generally have 4V or less on them. in cathode follower stages, the cathode resistor is much larger, so the voltage on the cathode is much higher.

the filament in the tube actually heats up the cathode so that electrons will boil off of it. this means that the cathode must be physically close to the filament. in the case of the sovtek LPS, tung sols, etc. if you get a high enough voltage on the cathode, like more than 150V, you'll actually get an arc between the cathode and the filament...sorta like a spark plug. this is bad news. most cathode follower stages have 200V+ on the cathode, so these tubes won't survive in those positions for long.

in many amps, whichever tubes drive the FX loop and tonestack are usually cathode followers. obviously, plate driven tonestacks like those found in fenders and mesa marks are not a problem.

hope that helps

 

[Anonymous]

When I want to try something different...I just dump one of about 4 or 5 boxes of tubes out on the floor and start rummaging and testing

 

[jkdsteve]

That helps a lot actually...the dealer who I bought my Tung-Sols from told me I was nuts and that he'd never seen a failure (yeah right!) but I'd had 50% failure rate on mine (3 out of 6)...and am guessing this is the reason.

Would the tube show signs of excessive heating?

 

[duesentrieb]

No. It just stops working.

 

[GuitarGuyLP]

I am very glad that I read that. My peters has some CFs, and I just put tung sols in every position!!!! I will have to open my amp up, and find out which tubes are in CF circuits, and try some different tubes in there!!!!! I will do this next week when I install power scaling in that amp

BTW I think it is great that there are so many people here who have a good amount of knowledge about amps, and there are no A2M/gape comments, or parody threads. I can't stand Harmony central any more (except for using their classifieds)

 

[eternal_idol]

OMG...

this thread might just save me 3 weeks wait on my boogie!!!!

I have 2 LPS' and a TS in my DR, been running that why for awhile...

BRING out the testers!!!

THANKS SOOO MUCH!!! seriously!

 

[MrDan666]

Yikes about the Tung-sols.... I have them in V2 and V3 in my Cameron Aldrich and Jose'. Noth amps sound really good too...

Dave, it should be fine in the Aldrich V2.. That amp doesnt have a normal cathode follower and its probably got elevated heaters being a 4stager

The Jose does have a usual Cathode Follower though, so be careful.

 

[MrDan666]

Thanks for clearing that up. I thought the Aldrich had a normal CF. Dang, the Jose sounds great with the TS's in V2 and V3. Maybe I will just pop back in the C9's (or just let the TS die... )

Ya know.. i had C9's in my modded JCM800 rebuild and the amp just felt very stiff, and to be honest kinda harsh in the upper mids/treble.

I swapped out the C9's and put in some Sovtek 12AX7LPS and holy shit what a night and day difference.. The amp sounds smoother in the top end, but also the amp has this nice balance in feel thats somewhere between being tight and being totally saturated/looser.

Mike Fortin told me i would love the TungSol so im gonna order some this week to try!

 

[MrDan666]

I thought the LPS's had issues with CF's as well? I have a TON of NOS tubes, but I hate to use them Maybe I will just crack some out and test.

The LPS does have issues in the CF position, so i just threw a Chinese 8th gen in V2, but kept LPS's in V1 and V3. Rocks!!!