I was checking the '62 Princeton 6G2 Chris Stapleton and comparing to the schematic I noticed his actually has a bia pot. Any idea on how to implement this mod with the tremolo?
Also noticed an extra fuse for the PT and another for the heaters...
'62 Princeton 6G2 Chris Stapleton
Moderators: pompeiisneaks, Colossal
-
Bombacaototal
- Posts: 1675
- Joined: Thu Oct 06, 2016 5:53 am
1 others liked this
'62 Princeton 6G2 Chris Stapleton
You do not have the required permissions to view the files attached to this post.
-
Bombacaototal
- Posts: 1675
- Joined: Thu Oct 06, 2016 5:53 am
Re: '62 Princeton 6G2 Chris Stapleton
A couple more pics..
You do not have the required permissions to view the files attached to this post.
-
Bombacaototal
- Posts: 1675
- Joined: Thu Oct 06, 2016 5:53 am
Re: '62 Princeton 6G2 Chris Stapleton
Briliant! Many thanks. It is not the same circuit as the Hoffman is a Blackface and the Stapleton is a Brownface but I will see if it can help me on the implementation....sluckey wrote: ↑Tue Jan 07, 2020 10:20 pm Look at this...
https://el34world.com/Hoffman/files/Hof ... Reverb.pdf
-
norburybrook
- Posts: 3290
- Joined: Mon Jan 06, 2014 12:47 am
- Location: London
- Contact:
Re: '62 Princeton 6G2 Chris Stapleton
don't try and Bias it with the trem onBombacaototal wrote: ↑Tue Jan 07, 2020 10:11 pm I was checking the '62 Princeton 6G2 Chris Stapleton and comparing to the schematic I noticed his actually has a bia pot. Any idea on how to implement this mod with the tremolo?
Also noticed an extra fuse for the PT and another for the heaters...
!!!M
-
Bombacaototal
- Posts: 1675
- Joined: Thu Oct 06, 2016 5:53 am
Re: '62 Princeton 6G2 Chris Stapleton
Yes! It will fluctuate 2mA + and - I think.....norburybrook wrote: ↑Wed Jan 08, 2020 11:51 amdon't try and Bias it with the trem onBombacaototal wrote: ↑Tue Jan 07, 2020 10:11 pm I was checking the '62 Princeton 6G2 Chris Stapleton and comparing to the schematic I noticed his actually has a bia pot. Any idea on how to implement this mod with the tremolo?
Also noticed an extra fuse for the PT and another for the heaters...
M
I am trying to understand how I could potentially incorporate this into my 50W Dumble and keeping control of the bias as his amps are the most bias sensitive in my opinion...
And the second worry would be how to protect the PT from blowing up...maybe why they have the extra two fuses on the Stapleton amp?
Re: '62 Princeton 6G2 Chris Stapleton
Extra fuse on the B+ line at least is needed for the amp to be EU certified hence why they use one (beside the extra protection this will provide).
Don’t know if a fuse for the heater winding is a necessity by the book for that certification, could be, but HT fuse is one.
Take a look at current production amps with worldwide coverage and volume (Fender, Marshall, Friedman, etc). HT fuse, specific marking on the back plate, snap-on isolates connectors one the power lines, metal grid on the back to avoid direct contact with tubes, ROHS components, lead free solder, etc are all requests for safety and needed to obtain those certifications.
The bias can varie a lot on bias trem amps hence why a lower bias without trem working is safer than a higher bias (won’t go as high oscillating). On one of my fave amp, the brown Vibroverb, featuring a bias tremolo the trem effect didn’t really kick unless you bias it rather cold (the oscillations seemed wider working more On/Off as the bias will go lower). I prefer the amp bias around 70% plate dissipation but doing so the trem effect is very subtle with little to no perceived tremolo oscillation and bias went up on positive execution quite close to red plating (around 60mA).
That amp trem is a two triodes trem. The Princeton used only one triode (you need less bias variation for the same trem feel on 6V than 6L) so maybe it’s safer but always good to mesure bias while the trem is one to have an idea.
Bias trem could be use on cathode biased and fixed bias amps.
Don’t know if a fuse for the heater winding is a necessity by the book for that certification, could be, but HT fuse is one.
Take a look at current production amps with worldwide coverage and volume (Fender, Marshall, Friedman, etc). HT fuse, specific marking on the back plate, snap-on isolates connectors one the power lines, metal grid on the back to avoid direct contact with tubes, ROHS components, lead free solder, etc are all requests for safety and needed to obtain those certifications.
The bias can varie a lot on bias trem amps hence why a lower bias without trem working is safer than a higher bias (won’t go as high oscillating). On one of my fave amp, the brown Vibroverb, featuring a bias tremolo the trem effect didn’t really kick unless you bias it rather cold (the oscillations seemed wider working more On/Off as the bias will go lower). I prefer the amp bias around 70% plate dissipation but doing so the trem effect is very subtle with little to no perceived tremolo oscillation and bias went up on positive execution quite close to red plating (around 60mA).
That amp trem is a two triodes trem. The Princeton used only one triode (you need less bias variation for the same trem feel on 6V than 6L) so maybe it’s safer but always good to mesure bias while the trem is one to have an idea.
Bias trem could be use on cathode biased and fixed bias amps.