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Anyone by chance have a schematic of this 1958 amp. Just picked one up on fleabay, will need to be gone through!!!

If I end up buying schematic. will scan and upload here.

Thanks!

i've got an old Bell amp from the 60s with 2 el34s. if you find a source for schematics, i'd love to know.

Get me the model number, and I'll look for it while I look for mine.

will do. it's actually a pretty damn cool amp. besides having the dual el34 o/p section, it's got multiple cap rotary switch very similar to an Orange. it sounds pretty fantastic when it's working properly(no mods!), but itis a bit sketchy once in a while- which sounds like bad elytics to me. the only funky thing is, that it has one of those old multicaps for filtering. it most definitely needs to be replaced, among other electros. so I might have to either build a new board, or find some sort of new production replacement. which, I would honestly rather do- even if it does cost twenty bucks- just for the simplicity factor. I really would love to get this guy kicking, along with a couple 10in bulldog speakers from a found AC15 combo with a missing head that i might have my buddies at emperor build up for me with possibly another low power 12in for some added speaker grime. I've has this thing for a while, I'd love finally get it up to snuff. I want to say it's a PA-75? but I'll confirm that when I get home. anyone else know anything about Bell amps?

Hi RnFr,

Sorry if I´m writing a little out off topic, but you can rebuild these multiple section capacitors merely by opening by its bottom seal and placing inside several discrete electrolytics of the nearest value and voltage, using the old aluminum can.



All you need is to tie all the ground leads to one single wire, and add pieces of wires at each positive lead to exit thru the existing insulator. Look at this link to read all the procedure:

http://www.nmr.mgh.harvard.edu/~reese/electrolytics/

The chassis of your amp will maintain its original look, but with fresh components.

Cheers,
Jose

From googling, probably a PM75 Pacemaker. It seems these were sort of a budget line built by Bell Sound Systems in Ohio. I think the one I bought has a similar tone control. I wonder if the preamps are the same, with different output sections? I found a hand drawn for the PM20 (not complete). The Sams pamphlets for both are on ebay, and other places, about $7 each. Will keep looking for freebies! If yours uses 1 12ax7 and 2 6av6 in the preamp, then they are likely the same.

Bought the Pacemaker as known to be not working. Bought the SAMS for it as well as some extra tubes and fuses. The the seller tested the tubes and disclosed the rectifier tube and one preamp tube as bad. The amp is basically
6Av6 (mic preamp)-->6AV6 AF amp-->Tone Control circuit-->1/2 12ax7 AF amp--> 1/2 12ax7 Phase inverter--> 2X 6v6 PP output.

What I found when delivered:
1. Fuse had been replaced with a wad of foil, and the 6ax5 rectifier was listed as bad by seller. Makes sense. (Hope power tranny isn't fried!)
2. Wire was shorted between the speaker common and the 4 ohm tap. (Hope output tranny isn't fried!)

Here's the deal, I only half ass know what I need to do with this thing. Looking for someone to walk me through this. I was thinking that if this is well documented it could be a guide for people in the future.

I am thinking of starting by pulling all tubes, replacing fuse, and testing pt voltages. Am I on the right track?

I know this forum is primarily for stompboxes, but over the last few years, I see that a number of the regulars here are
"multitalented". If someone capable is willing to walk me through this, that would be great! I do know the basics of discharging caps etc.

Anyone game?

Link to the PM20 schematic. Rnfr, this is probably the same tone control you have on your amp.

http://www.flickr.com/photos/37501189@N ... otostream/

just saw this- thank you spammers!

yes indeed, that looks like the same voice control as in my amp. as far as being a budget version- that could be, but the iron in this amp is massive, and of very high quality. it could easily be over 50w, possibly the 75 as advertised, but that would be pushing it for the 2 el34s. it's really a great, high quality amp. I'd love to get it rebuilt some time.

ppluis- thanks for the tip on the can caps! I'll check that out, but after thinking about it, I will probably like to upgrade the values when I recap so I'm not sure if it will fit. hopefully that won't be a problem.

What would happen if a pacemaker were to disappear from the body? Say a person had a pacemaker installed and one day as he was going about his business the pacemaker ceased to exist--just disappeared from within the body. How would the man feel? What would be the immediate effect on the person? Would he die immediately? Would he clutch his chest in pain?

And the spammers bump this thread again, and shame me more for not progressing on this project. Hopefully this summer vacation!! You gotten anywhere with yours, RnFR? As far as budget, I have read they were considered that back when they were made. Maybe when compared to a McIntosh<sp>?? Yeah the iron on mine looks nIce also, probably not that many companies making audio transformers then. So they took what they could get on the market.