Seeking advice re: Pine Electronics (Pepco) 5 watt amp (70's Canadian amp)

[Stratdan]

I recently acquired an old Pine Electronics (aka-Pepco) amp that is in need of some TLC and I'm an absolute novice who is looking to gain some knowledge about guitar amp workings. I do know enough not to get electrocuted and am doing some reading, but my experience is at virtually beginner level.

This amp has an old cap can, that I believe is 3 caps in one, that is marked as such:
Plessey UK
20-10-10uF
Red outer - 20
Plain inner - 10
450V max wkg
525V surge
CE 8641/13
Dec/67

The tube compliment is : 2 X 6AV6 ; 1 X 12AX7; 1 X 6V6; and a 5Y3 rectifier.

What I would like to know and get advice on, is what if anything should I do to possibly bring this amp up to speed. It does work, but sounds a little lackluster and I think the 6V6 cathode resistor is blown, as it looks as such and it reads apprx 230 ohms, it should be (I think) 470 ohms. This amp came in a monster cabinet with 2 really crappy original 8 ohm 12" speakers wired in series to take the 4 ohm output from the OT. I put the chassis in a small ARC brand cab, also made by the same Montreal manufacturers of this amp and hooked it up to a new Weber 8" 4 ohm SIG8S speaker, that sounded so very much better than the 12" ones.

Firstly, I think I should replace the 2 prong power cord with a 3 prong and would like to know if I should reconfigure how the present incoming leads are wired , I do know that the new ground wire will have to go somewhere on the chassis. Also, should I remove the cap going from the fuse to grd? Is this what is known as a "death cap", because there is no ground lift switch, which is usually present with that type of cap, am I correct?

I am especially concerned about the age of the main capacitor(s) and was wondering if it should be replaced due to it's age and if so, should I get a similar style cap can or 3 individual caps and just secure them to the chassis, thus avoiding messing with a heavy duty soldering iron needed for the big can replacement. If the 3 singles are the way to go, could someone tell me what kind of value caps I should use and exactly how to wire them in relation to the existing can terminals. I realize that this is similar to a Fender Champ style amp and know it is primarily a practice amp, but I feel it's a good place for me to start learning, as the wiring is so basic and accessible. Also, I'm thinking of adding an on/off switch, currently the volume pot is serving that function. Should I bother with that, as I thought I might put new pots in anyway? I also am not interested in the tremolo feature, which really sucks anyway, should I remove that. What is the exact function of the 6AV6 tubes? I have a lot more questions than knowledge.

I am posting some pics and if anyone has any suggestions of any kind, I would really like their input.

Dan

[Enzo]

I am assuming the lower right hpoto is of the power tube and rectifier tube sockets. Yes? So the left tube is the power tube. Is that resistor right in front of the socket the cathode resistor? If so, why do you think it should be 470 ohms? I can see the first color band on it is red, which means it more likey was a 220 or 270 ohm resistor. Since resistors seldom go down in value, I'd bet it was a 220 ohm. Personally I might like to see a somewhat higher wattage resistor though.

Yes your can cap is three sections. 20-10-10uf. SInce they identify the one with the red terminal as the 20uf section, the other two are 10uf, and it doesn;t matter which is which. I can see the red on in the photos.

You could find a can cap of similar values, and replace that one. Myself, I;'d leave it there for appearance, and install three discrete caps. You can see most of the circuit parts oare on three terminal strips. I'd mount a couple new terminal strips near that can cap, and mount three new caps betwwen them, and wire to the rest of things. Move the existing wires from the can over to the new terminal strip. The little resistor on the can, I'd probably replacec instead of trying to get it off and reuse it. Resistors are cheap.

I like two parallel terminal strips with caps stretched between, but you could ground all three caps to the can cap ground posts, and just one terminal strip for the cap hot ends.

Three wire mains cord? Yes, the ground wire goes to chassis, to its own lug, under its own screw.

Then the hot and neutral basically go where the two power wires used to go. The old two wire plug could go into the wall either way, so there was no knowing which side would be hot. SO they often sent one side to the switch, and the other side to the fues holder. But now that we will know which side is hot, we SHOULD wire the hot lead to the fuse holder, then from there to the switch, and on to the power tranny. The neutral wire should go direct to the other tranny wire. Unles you wanted to use a DPST switch and break both sides of the mains.

Yes, remove teh cap from AC wiring to chassis once it is all grounded nice.

[Stratdan]

Thanks for the help Enzo, you helped me out with a previous post re my SRRI.

Yes that is the output and rectifier tubes, I wasn't sure about that power tube's cathode resistor value, but I just assumed from what I've read about Champ values and thought that it would be the same (still learning). What value wattage would be recommended for that resistor?

I really think going the way of 3 discrete caps is what I'm going to do and the idea of 2 terminal strips makes sense. Now given my complete lack of experience, could you please tell me about the proper polarity of the replacement caps in relation to the existing wiring to the old can. Also, I notice the existing terminal strips are riveted to the chassis, how should I mount new ones, screw down?

Re: the mains cord, just to make sure I got you right, I should wire the hot (blk) of the new cord to the end lug of the fuse holder, then connect a wire from the side lug of the fuse holder to the 1st lug of the switch (vol pot) and then from the other switch lug to the tranny and then the neutral (white) of the cord direct to the tranny, sorry if it sounds like I'm just repeating what you said, but I want to get it straight in my mind. Is this correct?

I will snip out that AC to ground cap once I've rewired the mains. I did edit the original post, so it may look a bit different. Thanks Enzo!

[Enzo]

Never a good idea to change a post after we have responded to it. Very few people go back and read posts again just to find out if they have changed.

Yes, wire the mains just like that.

The can caps have all sections with a common negative terminal, and that negative terminal is the metal case. That case is grounded to the chassis. The three little solder lugs on the end are positive terminals. So wire the negative ends of your discrete caps all together and ground them. Best to ground right wher the can cap is grounded. We might find better places, but I don't think that is within your level of expertise. We will just rely on the original design. Then the positive ends of the new caps are wired to individual termnials on the strip for connection to the circuit.

An alternative would be to follow the wires from the can back to the circuits elsewhere, and wherever those wires go, you could solder the + end of the new cap there, then remove the old wire. In this case, the new caps would not be side by side, they would probably be here and ther.

[Al Grech]

I have the same amp, I'm just changing to a 3 wire cord, I assumed I could just wire it in like the exising 2 wire cord aside from adding the ground to the chassid ?. Thx....Al

[Stratdan]

I have the same amp, I'm just changing to a 3 wire cord, I assumed I could just wire it in like the exising 2 wire cord aside from adding the ground to the chassid ?. Thx....Al

Hi Al,

Yes, that is correct, wire it like the existing cord, making sure to properly attach your ground cable to the chassis.I ground off some of the top layer of the chassis, to ensure that I was making proper contact with bare metal. I'm no pro like some of the guys on this site, but it's pretty simple, be sure to read the entire original post, as I mention the "death cap" that I removed and your amp may have that as well. Enzo, gives the correct answer to this procedure in the OP.

Good luck.

[olddawg]

Never a good idea to change a post after we have responded to it. Very few people go back and read posts again just to find out if they have changed.

Yes, wire the mains just like that.

The can caps have all sections with a common negative terminal, and that negative terminal is the metal case. That case is grounded to the chassis. The three little solder lugs on the end are positive terminals. So wire the negative ends of your discrete caps all together and ground them. Best to ground right wher the can cap is grounded. We might find better places, but I don't think that is within your level of expertise. We will just rely on the original design. Then the positive ends of the new caps are wired to individual termnials on the strip for connection to the circuit.

An alternative would be to follow the wires from the can back to the circuits elsewhere, and wherever those wires go, you could solder the + end of the new cap there, then remove the old wire. In this case, the new caps would not be side by side, they would probably be here and ther.

And... As has been mentioned many times before, you can always hollow out the can cap and stuff it with new caps. You just have to take care to insulate the leads properly and hot glue, or silicon them in place.

[Stratdan]

And... As has been mentioned many times before, you can always hollow out the can cap and stuff it with new caps. You just have to take care to insulate the leads properly and hot glue, or silicon them in place.

Thanks olddawg, but I repaired this a long time ago, I removed the can and wired in some new caps on to terminal strips and it works and sounds fine! I posted here yesterday, simply to respond to someone spotting this thread, with a similar amp, wishing to upgrade to a 3-prong power cord. Thanks again though, I did consider reusing the can, but more trouble than it was worth.

[olddawg]

Thanks olddawg, but I repaired this a long time ago, I removed the can and wired in some new caps on to terminal strips and it works and sounds fine! I posted here yesterday, simply to respond to someone spotting this thread, with a similar amp, wishing to upgrade to a 3-prong power cord. Thanks again though, I did consider reusing the can, but more trouble than it was worth.

Lol..I'm always necroposting. Since I use my phone I never see the dates, lol!