Metropoulos Forum

I have been playing my 5E1/5F1 amp and overall been happy with the sounds, but felt it needed a bright cap. I was reading around the net and found a couple mods I wanted to try. I put in a 22K input resistor for input 1, (vs 68K). I changed the cathode bypass cap to 10uf vs 25uf on the first stage. I added a .0012uf bright cap on volume pot.

Overall, I think I have it very close. Now at loudish volume the amp sounds great. With volume pot rolled down, it is a little bright and thin, but most of the use with be with the volume up.

Anyhow, my question is on the low input. Previously I had a 68K resistor with a .022uf cap piggy back. I took that and was just going to replace with 68K. I ran out of 68K resistors so I found a 56K, resistor. I felt this was close enough.

The low input has very very low volume?? Is there a problem with using 22K for high and 56K for low? Will check tonight for a faulty solder connection, etc. But is there something going on with these resistor choices??

Mike

with those values for sure you have much less low input.
you can keep the 68k pair,that won't affect much highs with your guitar volume on full,and its not a problem if it has treble bleed.

OK, thx. Back to 68K then. I just need to get a few more first.

Mike

Resistor turned out to be a 2.2K not 22K...LOL. Anyhow, changed them both to 56K, (as that is all I have for now). Changed the bright cap on the volume control to .022uf. OMG the amp is a monster. Loud, lots of gain and easily controlled with the volume control on guitar. Will continue to test it out with various guitars, but with my Les Paul it sounds terrific.

Mike

BTW - it is interesting how much the bright cap increases the overall volume and gain of the amp. I guess with so few stages and no tone stack, the easier path for the signal to bypass the volume pot and hit the 2nd stage is very pronounced. Amp is really loud, (for its 5w) at 2-3. Before I needed to crank it to maybe 6 or 7 to get similar results. It makes the amp lively at lower volume, where before it was sort of anemic until you cranked it up. With the lack of a tone stack, careful selection of coupling caps, and bright caps can really taylor the sound.

It is cool that the amp is so simple, yet sounds so nice.

Mike