Other Amps

6SL7 Octal Tubes

1

For all you octal preamp folks, a nice old 1961 Ampeg M12 Mercury came my way recently and I found that most of my old stock 6SL7 tubes were microphonic; the worst being the stubby GEs. So, I bought three of the new JJs at about half the price of the new Tung Sols, and they are great. Just holding them one has a sense that these are solid, quality made tubes. The best part is that they ARE solid, with no rattles, and are dead quiet when running in the amp.

The other 6SL7 that seems fine is the Russian 6H9C; exactly the same tube, and can sometimes be found labelled as 6SL7 and sold by Sovtek. I honestly can't hear any difference in tone between the JJ, 6H9C, GE, and Sylvania tubes, only performance wise, the JJ and Russian tube are perfect.

I've noticed the prices on the 6SL7 going up over the past couple of years, due I'm told, to the audiophile folks discovering how great they sound and creating demand; the Russian 6H9C is a deal for the time being.

2

I never had probs with octals... some people dismiss them as 'not hi-gain' as if that is some kind of negative.

Ampeg used them to good effect for sure

3

good info!!! always a fan of jj tubes..last of the european tube manufacturers...nice to know their octals are also worthy

octals have a different harmonic distortion than the 12ax7 type tubes...not as smooth...more jagged...react with guitar volume nicely...a real '40's-'50's vintagey sound

enjoy that ampeg...great amps in the non fender tradition

cheers

5

There’s some Gibson amps running 6SL7s that are steals by vintage standards.

6

I’ve used silicone dampeners to tame many a microphonic tube, shown here on two of the worst tubes on the planet. They work great.

7

I’ve used silicone dampeners to tame many a microphonic tube, shown here on two of the worst tubes on the planet. They work great.

– Powdog

I never thought of trying tube dampers; maybe I'll hang onto the old tubes and try some. Aren't those 'two of the worst tubes on the planet' swanky and expensive?

8

Opinions are like vacuum tubes......

9

Opinions are like vacuum tubes......

– Powdog

I was just curious about those; was reading something about them lately. The seller was suggesting that they were so exceptional that some manufacturer(s) were making counterfeits. Wat's your impression of them?


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