Fired her up for the first time just now.....
Sounds from the word go..
bit of background hum and slightly more rushing in speakers than I expected. But doesnt get any louder with volume increase.
Using old tubes for testing so will try new set later.
435v on the plates , B+2 = 429v; B+3 = 413v, B+4 = 367v, B+5 = 351v
sounding great - very "present" - no top end loss with the coax - this is bright and glassy
Only issue is my relay - I have plenty of dc supply voltage but when I switch channels the relay momentarily switches, then drops back to OD chanel default. May be a faulty pair of relays ( I used 2 DPST relays I had spare )
Bit of debugging to do but so pleased she firecd up and played first time !!
cill keep you posted on the tweaks.
I've used 150K over 100K trim for OD trim input. Rest is as the schematic I posted earlier.
......a very pleased Pedro
All fired up !!
Moderators: pompeiisneaks, Colossal
Re: All fired up !!
Pete,
You may want to raise the 150k to 180k. See what you think.
You may want to raise the 150k to 180k. See what you think.
Re: All fired up !!
Congrats, Pedro! It's always a great relief when you fire up an amp for the first time and it actually makes sound. Even better when it makes great sound!
Re: All fired up !!
now grounded the speaker out most of the buzz now gone.
slightly annoying bit of noise when the amp is wide open in OD channe but nothing to worry about for gigging.
just going to do the deep switch now.
dogears - have changes OD input resistor to ~182K (5% 1meg and 220K resistors in parallel ) - sounds more focussed.
Still messing with OD trim to get sweet spot - nice to have the CL vol, drive and trim to set up the sound.
Certainly a nice OD sound - especially noticeable on chords where all voices are distinct and no horrible cross-modulation that you get with bad OD circuits.
just need to swap the faulty relay over for a new DPDT 5v jobbie so I can hear the clean channel.
Pete
slightly annoying bit of noise when the amp is wide open in OD channe but nothing to worry about for gigging.
just going to do the deep switch now.
dogears - have changes OD input resistor to ~182K (5% 1meg and 220K resistors in parallel ) - sounds more focussed.
Still messing with OD trim to get sweet spot - nice to have the CL vol, drive and trim to set up the sound.
Certainly a nice OD sound - especially noticeable on chords where all voices are distinct and no horrible cross-modulation that you get with bad OD circuits.
just need to swap the faulty relay over for a new DPDT 5v jobbie so I can hear the clean channel.
Pete
Re: All fired up !!
awesome pedro, glad to hear its working out:) I'm bout 40% done myself... just gotta order push/pull pots and stress bout wiring all those switches:)