Thanks guys!!
I had to change the cathode resistor for the 3rd stage of ch1. I had put a 10k there, changed it to 1k8 and all of the nervousness and exaggerated compression went away. Now I don't know which channel is better. I really love how the ease of balancing the channel volumes turns out to be... Very useful.
Here is a quick and dirty clip.
Using a Friedman Mic No Mo' --> Behringer UMC202HD --> Cakewalk. I think the recording was a bit hot, but you get a good idea from it. I don't want to compress it by exporting to mp3 but when I export to wav it is too big to upload. I'm not sure if SoundCloud defeats the purpose. Whatever.
I'm playing a '95 Les Paul Classic on the bridge pup, both volumes and both tones at 10. 1st 20 seconds are ch2. Then ch1 until 1:00. Then back to ch2 1st pass with bridge pup then switch to neck at 1:08.
Settings (Presence and Resonance were both at 5, LNFB switch was disengaged):
https://soundcloud.com/anthony-dorris-2 ... al_sharing
I must say that this is possibly the quietest amp I've heard in quite a while. Amazing dynamics all around!
UP Bassman Main Board Layout
Moderators: pompeiisneaks, Colossal
- dorrisant
- Posts: 2628
- Joined: Tue Sep 21, 2010 1:27 pm
- Location: Somewhere between a river and a cornfield
- Contact:
1 others liked this
Re: UP Bassman Main Board Layout
You do not have the required permissions to view the files attached to this post.
Last edited by dorrisant on Fri Mar 31, 2023 12:20 am, edited 1 time in total.
"Education is what you're left with after you have forgotten what you have learned" - Enzo
- dorrisant
- Posts: 2628
- Joined: Tue Sep 21, 2010 1:27 pm
- Location: Somewhere between a river and a cornfield
- Contact:
Re: UP Bassman Main Board Layout
Here's another clip... Master turned up to 7 1/2, guitar volumes at about 6.
Just some chords for a feel.
https://soundcloud.com/anthony-dorris-2 ... al_sharing
Just some chords for a feel.
https://soundcloud.com/anthony-dorris-2 ... al_sharing
"Education is what you're left with after you have forgotten what you have learned" - Enzo
-
- Posts: 83
- Joined: Thu Feb 09, 2006 10:46 am
- Location: São Paulo-Brasil
- Contact:
1 others liked this
Re: UP Bassman Main Board Layout
i reduce voltage in V1a and V1b more Juice sound ...dorrisant wrote: ↑Fri Mar 31, 2023 12:16 am Thanks guys!!
I had to change the cathode resistor for the 3rd stage of ch1. I had put a 10k there, changed it to 1k8 and all of the nervousness and exaggerated compression went away. Now I don't know which channel is better. I really love how the ease of balancing the channel volumes turns out to be... Very useful.
Here is a quick and dirty clip.
Using a Friedman Mic No Mo' --> Behringer UMC202HD --> Cakewalk. I think the recording was a bit hot, but you get a good idea from it. I don't want to compress it by exporting to mp3 but when I export to wav it is too big to upload. I'm not sure if SoundCloud defeats the purpose. Whatever.
I'm playing a '95 Les Paul Classic on the bridge pup, both volumes and both tones at 10. 1st 20 seconds are ch2. Then ch1 until 1:00. Then back to ch2 1st pass with bridge pup then switch to neck at 1:08.
Settings (Presence and Resonance were both at 5, LNFB switch was disengaged):
Clip Settings.jpg
https://soundcloud.com/anthony-dorris-2 ... al_sharing
I must say that this is possibly the quietest amp I've heard in quite a while. Amazing dynamics all around!
145v 135v vs 190v 200v
Marks Amp
- dorrisant
- Posts: 2628
- Joined: Tue Sep 21, 2010 1:27 pm
- Location: Somewhere between a river and a cornfield
- Contact:
Re: UP Bassman Main Board Layout
I will try this when it is burned in for a bit.m.alexander wrote: ↑Fri Mar 31, 2023 11:57 am
i reduce voltage in V1a and V1b more Juice sound ...
145v 135v vs 190v 200v
"Education is what you're left with after you have forgotten what you have learned" - Enzo
Re: UP Bassman Main Board Layout
Just to check, on the schematic the bright caps on the volume pots are drawn wrong?
it should be on pins 1-2 not 1-3?
or maybe they are not bright caps
it should be on pins 1-2 not 1-3?
or maybe they are not bright caps
- dorrisant
- Posts: 2628
- Joined: Tue Sep 21, 2010 1:27 pm
- Location: Somewhere between a river and a cornfield
- Contact:
Re: UP Bassman Main Board Layout
Which schematic are you referring to?
I didn't install a bright switch but I did install a rock/jazz switch.
https://ampgarage.com/forum/viewtopic.p ... 73#p450373
"Education is what you're left with after you have forgotten what you have learned" - Enzo
Re: UP Bassman Main Board Layout
this one:
check capacitors on each 1M pot
check capacitors on each 1M pot
- dorrisant
- Posts: 2628
- Joined: Tue Sep 21, 2010 1:27 pm
- Location: Somewhere between a river and a cornfield
- Contact:
1 others liked this
Re: UP Bassman Main Board Layout
Yes, I agree that the bright cap is wrong on that schematic. But that is not what I built. I did end up putting a 47pF cap across the gain pot of channel 1, but none of the pics even show that. The front panel switches are for rock/jazz and channel switching. I am not so sure I have the R/J switch wired correctly either. I haven't had any desire to play this amp on anything but the rock position. I feel that the PAB position (on-off-on switch, middle position) sounds very thin. Unlike any R/J I've ever built before. When time permits I will revisit. Until then, rock it is.
"Education is what you're left with after you have forgotten what you have learned" - Enzo