Tube Amp Archive

Billy, nice amp! Very clean.

By any chance, have you ever tried a 500pf disk in place of the stock 5k Lenco? My '74 JMP50's was removed when I got it. I have to reform the caps and go over everything before I fire it up. Planning to temporarily mount a 3-position bright switch to test both values.

Lummox, before you change the topology of your 1987 circuit, there may be something you can try. In his book and on his website, Merlin Blencowe has suggested "bootstrapping" the buffer stage to the cathode follower for a gain increase. I think the stock buffer stage has a gain around 50-60 before i...

OK, I get it. I look too deeply at this stuff sometimes. In the middle of making a conversion chart for my Maxi-Matcher, so it's all about the numbers for me at this time.

Good bias thread. Excuse the interruption.

-Allan

Redshark, did Ken really specify #4 GT-EL34s for the Express? I was under the impression that he preferred high current draw EL34s, I figured a 7 or an 8 in Groove Tubes terms. I know a #6 is usually at the Mullard /Philips spec for current draw. I did however read somewhere that Ken liked a #4 rati...

Could I please have a copy also? Thanks in advance.
-Allan

admacmil@verizon.net

Excellent Glen! I understand what you mean by slightly darker. Works well in this instance.
Great job!

-Allan