6AS7 SET amp discussion from Photo Gallery

[daqvin_carter]

The popular use of this type of tubes, like 6336, 6080, etc in the use with cathode polarisation is the hard use of fixed one, But always a good last one could give more efficiency. Many good amps use it. Azazello see it but with patience get better sound and not waste energy in heat.

I have used half cathode bias and half fixed bias with good results on the 6336. I have seen the 6336 run away with fixed bias, so either a servo or partial cathode bias should be used.

 

[mhouston]

I used a 12AU7 driver tube with mine. I thought the amp sounded excellent and so did a guy who bought it. I used 1.7K Edcor OPTs. They are tiny but do the job well. With the 12AU7 there is a little less gain in an amp which already has low gain. The way around this of course is to use a preamp (tube is best IMHO) to get the volume then just let the power section, 12AU7\6AS7 do the grunt work. My6AS7 amp was my first triode amp and the sound came as quite a surprise, pleasant surprise that is. Before that EL34s and KT88s.

 

[TheTubeAmper]

I used a 12AU7 driver tube with mine. I thought the amp sounded excellent and so did a guy who bought it. I used 1.7K Edcor OPTs. They are tiny but do the job well. With the 12AU7 there is a little less gain in an amp which already has low gain. The way around this of course is to use a preamp (tube is best IMHO) to get the volume then just let the power section, 12AU7\6AS7 do the grunt work. My6AS7 amp was my first triode amp and the sound came as quite a surprise, pleasant surprise that is. Before that EL34s and KT88s.

Just thought I'd jump in here and say that I'm happy to hear someone else likes 12AU7's as well.

Both of my tube amp projects incorporate 12AU7A's (same as 12AU7's but with balanced heaters). I just used them because I saw them and bought them one day for my first tube amp project last year.

 

[artosalo]

I just completed a 6AS7 (6N13S) SE amplifier which has been waiting to be built a couple of years. This will give 9 W at clipping point and 8 W at relatively low THD.
Attached some documents and test results.