Tube Advice

[Indie P Bass]

Ok... I just dropped 16 bucks on a single 12AX7... I feel so dirty. In anycase, one of my tubes went microphonic on my last night, is it safe to mix 1 russian tube with 2 chinese tubes? Beyond that... can I mix the czech JJ's with the GT sovtek? would that be doable? thanks in advance.

 

[bvc310]

Re: Tube Advice

When it comes to preamp tubes, anything goes. you can mix and match to your hearts desire with no ill will granted they are the same type of tubes. Russians mixed with Chinese are fine as well as JJs mixed with Sovtecks. However, for power tubes, it is highly recomended to use the same tube style and manufacturer for all of the set. But if you change power amp tubes its best to have a tech redo the bias as it will probably need adjustment too.
Good Luck,
Brian

 

[Indie P Bass]

Re: Tube Advice

yeah, I'm leaving recto and power replacement to my tech's. Preamps, I'll handle my own.

 

[Quencho092]

Re: Tube Advice

what if you buy the same brand and grade power tube and put it in your amp to replace the same brand and grade tube? i dont think that needs biasing. isnt biasing for when you go from el34 to 6l6gc or another tube type that carries a different wattage?

 

[plexible]

Re: Tube Advice

what if you buy the same brand and grade power tube and put it in your amp to replace the same brand and grade tube? i dont think that needs biasing. isnt biasing for when you go from el34 to 6l6gc or another tube type that carries a different wattage?

Just buy a matched pair, or matched quad.

I myself ALWAYS check the bias.
Once i bought a ´matched pair´ JJ el34. Put ´em in my amp and checked the bias. turns out they weren´t matched. one tube would draw, say 43ma and the other 48ma.
So you wanna make sure they are matched.
As for the el34´S, I like JJ´s and Svetlana.

 

[Benjy_26]

Re: Tube Advice

ElectroHarmonix makes a very good power tube. Their 6L6GC's compared very favorably to th RCA Blackplates I had in my Bassman. Their el34's sound very good as well. I liked them better than the Siemens EL's that came in my Duncan Convertible.

 

[Hellion]

Re: Tube Advice

I've had good results with Ruby Tubes, Groove Tubes, Sovtek and even some old Sylvanias that I found in a small town TV repair shop. Biasing is the key. Those were power tubes, and you need to keep those as similar as possible, since they work together. Pre-tubes, again, Ruby Tubes, Groove Tubes, whatever.....