Converting Peavy Deuce amp

[beasleybodyshop]

Hello everyone, Im new to the forum here, and pretty much new to amp building as well. I found an old Peavy Deuce 2X12 combo for cheap a few months ago. I was considering gutting the amp and buying a Marshall JMP 50 watt clone kit and fitting it inside the peavy chassis. It looks like I would need to cut out a square hole for the transformer, as well as some holes for the preamp tube sockets - All within my ability. The chassis measures 24 1/2" long by 8" wide and 2" deep. Will this accommodate a JMP build? Any pitfalls I should know about regarding using this chassis?

[martin manning]

Plenty of room for a JMP50 or even a 100W in that box. You can probably get a stand-up transformer and save yourself the trouble of machining cut-out, as long as it will clear the speakers.

[beasleybodyshop]

Thanks for the info. By stand up transformer, do you mean one that just bolts to the bottom side of the chassis? I didn't even consider speaker clearance...hmm. Also, would its "upside down" orientation affect the potentiometers i would need to get? Most JMP kits look like the are oriented tube side up, whereas this one is going to be tube side down. Is this going to be an issue?

[ampdoc1]

I'd find some way to use the original xformer. In those days Peavey had them made in Chicago. They are hell for stout, and usually mounted on a think metal base instead of the thin wing type bases most companies used. Worked on lots of Peaveys in my tech days (usually easy fixes), and doubt I ever saw a dead transformer.

a'doc1

[JazzGuitarGimp]

Thanks for the info. By stand up transformer, do you mean one that just bolts to the bottom side of the chassis? I didn't even consider speaker clearance...hmm. Also, would its "upside down" orientation affect the potentiometers i would need to get? Most JMP kits look like the are oriented tube side up, whereas this one is going to be tube side down. Is this going to be an issue?

No worries about the pots. As far as orientation goes, pots are pots: you turn them clockwise to increase volume, bass, treble, etc. If you get the unit wired and the pots are working backwards, just swap the wires going to the outside lugs of the pot. With a bit of study, you should be able to get the pots wired correctly out of the gate.

Welcome to TAG!
Lou

[beasleybodyshop]

Would using the stock transformer work? At this point I don't know if the spec is similar enough or have enough taps at the right voltages for what a JMP circuit needs. The transformer looks pretty rusty. Can I bench test it?

[martin manning]

Thanks for the info. By stand up transformer, do you mean one that just bolts to the bottom side of the chassis? I didn't even consider speaker clearance...hmm. Also, would its "upside down" orientation affect the potentiometers i would need to get? Most JMP kits look like the are oriented tube side up, whereas this one is going to be tube side down. Is this going to be an issue?

Yes, so-called X-mount, typical of later Marshall's. If the control layout across the front panel (which side the power switch is on) is the same as the tubes-up JMP, doing it tubes-down makes it a mirror image, so you would have to put the components on what was the bottom side of the circuit board. The pots are just rotated 180-degrees to orient the lugs toward the open side of the chassis. If the layout is reversed, then it's just flipped upside down.

[beasleybodyshop]

Thanks for the info. By stand up transformer, do you mean one that just bolts to the bottom side of the chassis? I didn't even consider speaker clearance...hmm. Also, would its "upside down" orientation affect the potentiometers i would need to get? Most JMP kits look like the are oriented tube side up, whereas this one is going to be tube side down. Is this going to be an issue?

Yes, so-called X-mount, typical of later Marshall's. If the control layout across the front panel (which side the power switch is on) is the same as the tubes-up JMP, doing it tubes-down makes it a mirror image, so you would have to put the components on what was the bottom side of the circuit board. The pots are just rotated 180-degrees to orient the lugs toward the open side of the chassis. If the layout is reversed, then it's just flipped upside down.

So in short, if I am looking down into the open chassis, the pots will need to be lugs up facing me, and the turret board will need to be flipped upside down?

[martin manning]

The board isn't flipped, the components are just mounted on the back side. This is only required if the input and power supply ends of the chassis are in the same left-right orientation as the Peavey. If they are opposite, then the whole thing is just flipped over.

[beasleybodyshop]

The board isn't flipped, the components are just mounted on the back side. This is only required if the input and power supply ends of the chassis are in the same left-right orientation as the Peavey. If they are opposite, then the whole thing is just flipped over.

I think I see what you are saying. So all the resistors, caps, etc will be facing downward, and the back side of the turret board will be facing up? Will this make future servicing and maintenance difficult? Could I just rotate the board 180 degrees?

[martin manning]

The board isn't flipped, the components are just mounted on the back side. This is only required if the input and power supply ends of the chassis are in the same left-right orientation as the Peavey. If they are opposite, then the whole thing is just flipped over.

I think I see what you are saying. So all the resistors, caps, etc will be facing downward, and the back side of the turret board will be facing up? Will this make future servicing and maintenance difficult? Could I just rotate the board 180 degrees?

The components would be on the top of the board looking into the open side of the chassis, but that side of the board would be the bottom side in a tubes-up layout. The input end of the board has to remain on the input end of the chassis, and the front edge has to be stay towards the front, so you can't flip it or rotate it.

[beasleybodyshop]

Ok. I see what you are saying now. Luckily the peavy has 4 input holes drilled along with a plethora of potentiometer holes. I can cover everything else up with a custom plex amp plate.

In your opinion, what would be a good speaker complement for the 2X12 combo? I would need at least 2 25 watt speakers right?

Any opinions on buying components a la carte or investing in a kit? I have good soldering skills and a good Fluke. I think it would be cool to make this amp a total sleeper - still look like a beat up rusty Peavy on the outside but totally scream!

[Phil_S]

I suggest contacting Peavey directly to ask about the transformer specs. You have nothing to lose and everything to gain. They will probably tell you what you want to know. I have heard good things about Peavey customer service.

[MGW]

Call em on the phone. They will take the time and tell you anything. Really great folks over there.

[beasleybodyshop]

Tried to call Peavy and shot them an email, they are out until the 8th for vacation (That must be nice that the whole company can take off! I wanna work there lol...)

In the mean time I am gonna look into bench testing the transformer - the larger one is the PT right? If I check its resistance and get anything other than infinity than it should be good right?

Anyone have any experience with Triode Electronics JMP kits? Ive been considering purchasing from them.