The Amp Garage

. Best sofar are the 550v axial series designed for Frag Jan Zuerst, very punchy and musical. i just ordered a lot of them.. i like 550-600V margins at first place, but needed them a lot for ampegs (525V) That’s exciting , I like the numbers . Gonna have to try out F&T: different series comes with ...

F&t : shrill and thin in the midrange , even if they are bouncy and fun to play . Sprague: warm and loose . Not very fast articulate , but punchy ARS: my favorite . Punchy lows and clear treble . A little soft in knocking midrange in comparison to the LCRs they say they replace . JJ: dull sounding ...

I may try the TAD Gold Cap series. They are slightly larger than the same F&T cap. Although it maybe that F&T is actually making those caps for TAD! G the TAd gold caps are made in asia and sound good but I've had to replace a few that did not last long. https://www.tubeampdoctor.com/en/tad-product...

The F&T type A caps are intended specifically for tube amps but the AH type is not apparently: https://www.ftcap.de/fileadmin/user_upl ... _11_16.pdf

200k works well with the 2k7 cathode.

cf. https://www.ampbooks.com/mobile/amplifi ... alculator/

seveneves wrote: ↑Sat Jan 20, 2024 9:11 am BTW, what do you all think of this solution?

yes series might be better. note that the ac30/4 used 10nf PI coupling caps, which reduces blocking distortion and bass mud. Personally, I am using 15nf (had plenty of these caps) and it sounds great with more than enough bass for guitar.

70uf caps in series for a total of 35uf is really on the low side. normally, that is not desirable, unless you want plenty of sag and perhaps even a slight ghosting (suitable for blues and some low-fi sounds with a slow attack). still, the tad audio series made in germany offers great 70uf caps that...

The resistors in the original Marshall were probably 10% tolerance and I highly doubt anyone was sorting for matched pairs. The output tubes also likely had a bit of a mismatch, same with the PI. I wouldn’t sweat that amount of difference, but “optimal” is subjective. If the amp sounds good to you,...

CC is the best to use in that place because of non-inductance, good RF properties, so just replace for new cc's one day how about resistive hiss? wouldn't CC grid resistors in the first preamp gain stages add unnecessary hiss? no on grids because there is no current passing, i put cc everywhere, bu...

bepone wrote: ↑Fri Jan 12, 2024 5:17 pm CC is the best to use in that place because of non-inductance, good RF properties, so just replace for new cc's one day

how about resistive hiss? wouldn't CC grid resistors in the first preamp gain stages add unnecessary hiss?

what kind of amp or application?

with an express, the v-type and creamback 65w seems better than v30s, g12hs etc

Would I use the same Screen and Input Grid Resistors from the 6L6 when switching to KT66? The amp I have uses 470R for the Screens and 2.2K at G1.. hardly, since a real kt66 draws more screen current than a 6L6 … I never even seen a real MOV KT66, nevermind tested an amp with them to see how they p...

leadfootdriver wrote: ↑Sat Jan 06, 2024 2:41 am Would I use the same Screen and Input Grid Resistors from the 6L6 when switching to KT66?

The amp I have uses 470R for the Screens and 2.2K at G1..

hardly, since a real kt66 draws more screen current than a 6L6. What is the voltages and the Z?

https://www.tube-town.net/ttstore/en/co ... tisection/

not exactly right but in the ballpark