Does anyone use a Sovtek 12AX7LPS in V1?

[misterwhizzy]

The EHX I have in mine now is just a little noisy, and I'm looking for different options. I'll probably give Tung-Sol another go, since those are typically pretty clear and bright and have adequate gain, and I've decided the Mullard I had in there before is just slightly on the dark side, especially when miced up. I went to Tube Depot to see what else was available that I might not have tried, and I realized that even though I had used these as PI tubes before, I had never given them a serious shot in V1 of this JCM800 clone I'm running.

Just looking for opinions.

 

[beaubrummels]

Sovteks were always too abrasive to me in V1. The best V1 I've ever used was an international-branded Mullard 10M 12AX7A/ECC83 (second best was an RCA large blackplate 12AX7A). The closest new production to the original Mullard was a TAD 12AX7STR. After that, Ruby, Groove Tubes, JJ ECC83S or ECC803 were really close and really good (I forget which ones are the low-noise small plate). Newer product Tung-Sol and Mullard are fine - they're clear and even IME. The former ones I mentioned had the character I was looking for. There's a low-noise small plate JJ that is really good, a little brighter than my taste, but might solve what you are experiencing. I can't remember which one it was - they make about 4+ variants of 12AX7/ECC83 types.

 

[jeremy]

i like the sovtek lps a lot but dont usually use large plate tubes in v1 since they can be more noisy in my experience

 

[FuseG4]

If you get a low noise tested one I think they are pretty good
my bugera combo doesn't have tube retainers of any kind and I've tried Sovtek LPS in v1 and didn't notice any extra microphonics but that can change with a few car trips across town
Anyways
I think the long plates give a tiny bit better bass and treble.
someone gave me a Russian gold lion and I'll be damned if it doesn't look the same inside and sounds about the same as Sovtek LPS I have. Both sound good to me in v1 with nice bass response. If you don't like it they make good phase inverters too

I'm not sure but the tung sol 5751 I have looks really really similar in the inside too. I wonder if they are the same tube but graded.

 

[beaubrummels]

5751 is a different tube. It's amplification factor is only 70 vs 100 for a 12AX7/ECC83. It also uses a 3v grid vs 2v for a 12AX7. You can swap them interchangably, but it will just give more headroom and break up later. They look the same because they are both twin-triodes in a 9A pinout package. But you can't go by looks with tubes.

 

[misterwhizzy]

Thanks, Beau.

Do you know of a retailer that has TAD 12AX7 STR's available? I struck out with Tube Depot, Doug's Tubes, and the Tube Store.

 

[Gtrjunior]

https://www.tubeampdoctor.com/en/

 

[formula73]

i like the sovtek lps a lot but dont usually use large plate tubes in v1 since they can be more noisy in my experience

My experience, as well.

 

[beaubrummels]

Thanks, Beau.

Do you know of a retailer that has TAD 12AX7 STR's available? I struck out with Tube Depot, Doug's Tubes, and the Tube Store.

Gtrjunior posted the link. I'm not seeing the STR on there (unless you want to count the Premium Selected / Balanced version), but the 12AX7-C should be the same, it just doesn't go through quite the same level of testing/burn-in whatever they do for STR. (Technically, it's a Chinese 12AX7, which are often maligned if you buy the raw whatever 20% tolerance ones cheap, but what TAD does is require tight tolerances and more stringient testing to get the best of the best, and that gets the results: TADs I have are great IME.)

 

[Gtrjunior]

I’ll chime in on the TAD as well. While I’m not currently running any In my amps, I have used them in the past and still have a few on hand. They are a very nice tube. The sound quality is high and they can handle a higher voltage for those amps that runs hot cathode follower like the JVM.

 

[FuseG4]

5751 is a different tube. It's amplification factor is only 70 vs 100 for a 12AX7/ECC83. It also uses a 3v grid vs 2v for a 12AX7. You can swap them interchangably, but it will just give more headroom and break up later. They look the same because they are both twin-triodes in a 9A pinout package. But you can't go by looks with tubes.

I know the difference in gain and that they are interchangeable
I guess I just wonder HOW they get the gain factor different with such remarkably similar construction.

 

[Bogner]

I wouldn't run anything in V1 that I ran in a Phase Inverter unless I was going after super clean sounds. Gain and PI don't mix.

 

[beaubrummels]

I know the difference in gain and that they are interchangeable
I guess I just wonder HOW they get the gain factor different with such remarkably similar construction.

AFAIK Materials, dimensions, spacing. It's similar to how humbuckers all look alike but some are 16k monsters and some are 8k vintage.

 

[Erlend_G]

AFAIK Materials, dimensions, spacing. It's similar to how humbuckers all look alike but some are 16k monsters and some are 8k vintage.

I just learned about tubes- (by watching a youtube video of someone opening up a tube and taking it apart) - that there's alot more inside it, than you can see from the outside .

 

[Mincer]

I just learned about tubes- (by watching a youtube video of someone opening up a tube and taking it apart) - that there's alot more inside it, than you can see from the outside .

What video was that?

 

[Erlend_G]

What video was that?

sorry, I don't remember .

Something about... "inner workings of a 12ax7"

 

[beaubrummels]

Disassembly let's you see the parts inside, but doesn't tell you how it works.

I think this is the video, FWIW

 

[FuseG4]

That's pretty cool stuff! Tube tech is neat stuff.

 

[Jeff_H]

Try KCA NOS Tubes. He has some expensive tubes of course, I recommend the RFT if you can swing them. Otherwise, the Svetlana’s at the bottom of the page are great. $22 each for a high gain rating when you click on the tube selection.

https://www.kcanostubes.com/catalog/4