Metropoulos Forum

Started mounting caps and transformers on Thursday, then got around to doing the actual build Saturday, finished up Sunday

Anyhow, I noticed two oddities...

1) Voltages on the preamp B+ section take a while to come up - I noticed it mostly on V1A - minutes...and even then, I'm not sure they are coming up all the way where they should be (since I went on to probing other areas, where the voltages are in check) This was with the 12ax7's in it, which I need to test it with them pulled to see if they pop right up or not.

2) It plays what goes into the input, however, I have noticed some slight volume shifts, and occasionally, a slight distorted sound on the decay of the note. This is with the volume WAY low, since I don't have an attenuator or earplugs (and my cab is only rated for 80w)

Pics to come soon...

Also, I forgot how stupid loud these amps are - lol. PPIMV or JCM 800 conversion coming soon, but I want to make sure things are right with this first

You're already on the right track to check voltages.

As for the "slight distorted sound on the decay of the note" issue, check for possible bad solder joints and make sure the bias hasn't shifted.

Maybe try moving wires around with a chopstick or similar while sustaining a note. This may help locate the problem. As always, it could be a tube too. Good luck.

What's wrong with stupid loud? What? What?

Finally pulled all the tubes, on the B+ for V1...

It kept climbing and climbing and climbing...I finally stopped measuring when it went over 500 - in fact, all the B+'s measured around that high, or higher (538 is what I read on one socket...)...

Then I blew out my meter by trying to measure a resistor while the amp was draining voltage - or my meter just decided to go south...not sure which...

Anyhow, I played it, and it sounds fine. I guess it's OK?