Bell Pacemaker PM33 to bass guitar amp

[texasaudio]

Hello all,

I have been a member for some time now and have not ever posted. I have experience with tube radios and but not much audio (replaced a filter cap here and there). I picked up a Pacemaker PM33 recently and have decided to convert it to a guitar amp. Here is a copy of the schematic I found on another thread.

http://i263.photobucket.com/albums/i...3schematic.jpg (thanks wildthing)

I will be playing my bass through it and like to mod it accordingly. I will connect it to a Fender cab with two 12" speakers. I have gone through the amp and checked all the voltages and everything is on the numbers.

First question is should I recap it any way? If so what type of caps should I use?

Next question is can I just remove one of the mic connectors and replace it with a 1/8 inch phono plug and start playing my guitar through it? Or should I use the phono input?

From there I am open to any suggestions.

I will start with that and see where we end up.

Thanks in advance for your help.

matt

[tboy]

Next question is can I just remove one of the mic connectors and replace it with a 1/8 inch phono plug and start playing my guitar through it? Or should I use the phono input?

For Bass I'd definitely try the phono input; the mic inputs have much more gain than you need, and would likely distort in an ugly way. Replace the phono connector with a 1/4" phone jack and try it.

[Intergalactic Tourister]

Replace the two prong plug w/ 3prong plug of course.

Tboy is right about the gain. I can't see the schematic super clearly but it may be worth lowering R5 and R7 (4.7meg) to see how it sounds. Compare what it sounds like at 500k and go from there. I did this before with a mic pre to help with the gain.

Also, concerning you play bass, the phono input will probably be the more bassy input.

First question is should I recap it any way? If so what type of caps should I use?

Well, this is an early 60s amp. If it sounds bad (60/120hz hum) the can capacitors could be replaced if it has one.

Wow, I can't read the schem... but it appears C1, C2, C3, would be the first candidates for replacements. It looks like they say 40mfd, 15mfd, 30mfd, respectively.