|
Tube DIY Asylum Do It Yourself (DIY) paradise for tube and SET project builders. |
For Sale Ads |
Use this form to submit comments directly to the Asylum moderators for this forum. We're particularly interested in truly outstanding posts that might be added to our FAQs.You may also use this form to provide feedback or to call attention to messages that may be in violation of our content rules.
Original Message
RE: 20B
Posted by dave slagle on January 18, 2017 at 18:57:48:
1. The only issue with using the 6C6 triode strapped is that to get near full output, the preamp volume knob needs to be turned all the way up. With the preamp at full throttle, the output is about 90% of max output (just a guess, but close enough for the sake of this conversation). So, is there a way to get the 6C6 triode configuration to get more output from the power amp? If so, how?
If your preamp puts out 17V like you mentioned and your 6C6 is giving a gain of 15 (fair guess for a resistive loaded tube with a mu of 20) then something is seriously amiss if you can get anywhere near full volume on the linestage since 3V into the amp will run the 6C6 into A2 current and clip the output tube.
Your removal of the cathode bypass cap on the 2A3 may be what is "saving you" since the clipping behaviour looks a lot more polite without it in place. (even though the distortion is still upwards of 10%)
In any case, going from tube A with a µ of 20 to tube b with a similar µ isn't going to change your lack of gain.
dave