I picked a '90's Princeton 112+ "project" amp. Replaced knobs, reverb pot and spring reverb tank.
Two issues I'm hoping someone can assist me with:
1. At "zero" position on reverb pot there is no reverb. On "one" I get full reverb. No difference between 2 and 10.
2. The amp (reverb off) seems quite "hissy" to me.
Any suggestions (other than scrapping the amp!) will be greatly appreciiated!
Two issues I'm hoping someone can assist me with:
1. At "zero" position on reverb pot there is no reverb. On "one" I get full reverb. No difference between 2 and 10.
2. The amp (reverb off) seems quite "hissy" to me.
Any suggestions (other than scrapping the amp!) will be greatly appreciiated!
I assume you already got the schem and the manual.
Just in case not:
1)Schem: http://support.fender.com/schematics/guitar_amplifiers/Princeton_112_Plus_schematic.pdf
2)Manual:
http://support.fender.com/manuals/guitar_amplifiers/Princeton_112_manual.pdf
As to problem 1: Sounds suspiciously like "wrong pot" that means either
wrong resistance (It should be 50 k) or wrong taper (>"B")
since this product is of (more or less) US-origin this should be a "linear" one , not one with audio/log tape. (In Europe this is someway different)
As to 2) : Right now I can only guess.
I'd check first: what else did you replace ?
then : Proper solder joints
then: all small caps back in place correctly ?
Hope this helped.
Greez
Simplex
Just in case not:
1)Schem: http://support.fender.com/schematics/guitar_amplifiers/Princeton_112_Plus_schematic.pdf
2)Manual:
http://support.fender.com/manuals/guitar_amplifiers/Princeton_112_manual.pdf
As to problem 1: Sounds suspiciously like "wrong pot" that means either
wrong resistance (It should be 50 k) or wrong taper (>"B")
since this product is of (more or less) US-origin this should be a "linear" one , not one with audio/log tape. (In Europe this is someway different)
As to 2) : Right now I can only guess.
I'd check first: what else did you replace ?
then : Proper solder joints
then: all small caps back in place correctly ?
Hope this helped.
Greez
Simplex
Finally got around to opening up the P112+ to start the MODS you all have been helpful to suggest. Of course I wanted to check out my reverb problem again. I found the problem. When I initially removed the PCB a few months ago I intentionally cut the the reverb send-rec cable to make it easier to remove the PCB. When I soldered back together I assumed (I know- never assume) that the "grounds" were common. I checked the schem today and nope - they are not common! Voila! Reverb working!
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