Peavey Mace Question

[dlb]

Hello Everyone,

First post here, I appreciate the help in advance.

I picked up a non-working Mace a few years ago and it's been sitting around since. I just pulled it out and I am thinking about trying to repair it.

I just noticed that someone has added two jacks and have tapped into a resistor and capacitor.

Below are pics of this. Does anyone have an idea what they were attempting to do?

Thanks again!






Looks like there was a little heat near the top also...

[Amp Kat]

Looks like an effects loop possibly but I would eliminate it for troubleshooting and revert it back to original. What's wrong with the amp ? Looks like the power resistor in the pi circuit got pretty hot but the board looks ok for an amp of it's age. Be careful there are voltages that can kill in there and 6 /6L6's get very loud when cranked. We should be able to get you going.

[dlb]

Thanks for the response.

I have removed the modifications. I borrowed the 6L6's from my working Mace VT Series and powered on... Immediately blows the fuse.

I found two diodes that are shorted. I'll go ahead and replace the four of them then see what happens.

Thanks again.

[Amp Kat]

Do yourself a favor and give it a recap job for the power supply filters for a first. Those caps are about 40 years old and have been dried out for years. You'll notice a huge difference in sound and if you change them all (e-caps) it will sound awesome and you'll have basically a new amp. That Mace you have looks to be in pretty decent shape so with some tlc it could be a very durable loud ass monster from hell or heaven depending on how you want to look at it. If it's blowing fuses it's because something is shorted. You really need a lighbulb dimmer for this but the flip side is you'll have to use several fuses until you find it. I would waste one on trying it with all of the tubes out and seeing if it blows and if it does you have a power supply short somewhere and verifying the power transformer is good would be a good place to start. Try http://www.geofex.com and follow the precedures for checking a transformer. One more tip is you don't need all the tubes in to see if it works. The Mace will run with 1 tube on each opposite end.

[oc disorder]

The Peavey site has the owners manual in the archived manuals section.
The last page has the schematic with the transistor pre-amp which dlb has.

http://www.peavey.com/media/pdf/manuals/80347000.pdf

I recomend changing the power supply capacitors as Amp Kat says.

I had one ages ago which had already been serviced used by a pedal
steel player (he could hardly lift it) and he couldn't believe how good it sounded when fixed up. He just needed a big clean sound and was overjoyed
at the fact he could now drown out the band if he wished....

160watts RMS into 4 ohms !

[dlb]

Here's an update... replaced the diodes and systematically powered up without tubes in standby, then installed tubes... standby then off standby...

Things seem to be okay. Sounds good, no hum/static. Didn't crank post gain very much, didn't want to crack the windows.

Filter caps are in the plan to replace next...

What would cause the diode(s) to short? Shorted or bad tube? I guess it's possible that something else could rear its ugly head?

[Amp Kat]

Shorted tubes are the most likely culprit or leaky bad filter caps. Glad you got it going now you can rattle the windows to no end .

[cmattdabrat]

I had a Peavey Rock Master which was similar, but was 120W. Loud amp, but my OT gave out and I couldn't find a replacement. Even the peavey repair man couldn't get a hold of one cause it was made in 81' and they no longer made parts for it. I wish I would've known about this forum before I sold it. I sounded great mated with my 1960a.










I still have the schematics for this one laying around if anyone would ever like to attempt a clone.

Matt

[Enzo]

I have a Rock Master head myself, but it is nothing like the Mace. The Mace has the six 6L6 output tubes for a whopping 160 watt rating, but the rest of the amp is solid state. The Rock Master is all tube. It is loud and raw sounding.

Welcome to the forum, by the way.

[cmattdabrat]

Thank you for the welcome!

I knew the Mace has the 6 6L6 tubes, but I didn't know the rest is solid state. Thanks for the heads up. Gotta love those old school Peavey amps though.