peavey mace low power

[tsor]

Picked up an old peavey mace combo on ebay. Not sure if the problem is the amp or the speakers. volume is very low. pre-amp gain volume sounds fine but post gain (Like a master) volume doesn't go up at all. Thinking it was the tubes I replaced 4 (It has 6). From left to right, the first two tubes light up bright, the next 4 have very low red light to them. I wasn't sure if it might be the speakers half shot or something with the amp. Should all 6 tubes light up bright? I was planning on sending it out for repair but wanted to see if anyone might have an idea of potential issues. Appreciate the help.

[determined2play]

which input are you using? The normal or the Automix or one of the two effects? My Mace, which I just picked up from a pawn shop was a wreck when I got it. But with doing some searches here I have been able to reviveit a bit. Still trying to optimize it. I noticed that all my tubes, whether I run 2, 4, or 6 do not all glow the same. The best I have got it to match is running 2 so far. I am interested to see what others chime in and say. Best of luck. Oh, BTW what speakers are in yours?

[tsor]

same issue on all inputs. interesting that only 2 of your tubes glow as well. speakers are not labeled. they look old and have the straight edges in the front like some of the older peavey's but not sure if they are black widows or the originals. If there a way to test the speakers with a meter to see if they are shot. that way there i might be able to isolate the problem. I think I might just send it out for repair and see what they say.

[determined2play]

Did you try to use a digital Mulitimeter ste to check Ohms? To see what kind of impedence they are checking in at?
I am sure someone here knows the answer to the volume issue.
I had a bad TL604 IC in mine, I ended up using a jumper wire to bypass the switch, because it was gonna cost me like 30 bucks to get a new one shipped here, they are obsolete.

[Enzo]

COnnect only one speaker at a time for a listen. Better yet, connet the amp to a different speaker cab. Then you will know if the amp sounds funny or the speakers.

If your speakers have a rather wide mounting flange of brushed aluminum, squared off like a stop sign, they are PV Scorpions.


Probably original speakers.

Black Widows are PVs heavier premium speakers. They also are cast framed, but they are round with a narrow flange, no flat edges.

I don't know what you mean about tubes lighting up. DO you refer to the little orange glowing heater in the middle of each tube? Or are you talking about the dim bluish glow inside the glass? Are the tubes ALL the same exact type and brand? if the tubes are not matched, then I don;t doubt they might look different. If you mean the gray metal structure suspended inside the glass gets red hot, that is a problem - shut the amp off immediately.

[tsor]

OK. seem to be getting closer. I hooked up the amp to my 2 10 inch speakers in my music man 130 and it is much louder. Sounds like I would expect. Yes the speakers in the peavey are prob scorpions as they appear as you describe. tubes are all groove tubes and matched. No the metal inside is not hot, tubes glow at top and bottom. I wonder if the speakers are partially blown. either way it sounds like I should either put in better speakers or the wiring to the speakers which I did myself might be messed up. I used 16 guage speaker wire. I think I will try and pick up the ohm meter at radio shack and see if that tells me anything about the speakers.

[Enzo]

Are the speakers wired in phase? That means do they both move the same direction? Briefly touch a 9 volt battery to the speaker plug. Pull the plug from the amp jack first, of course. The speakers should make a little pop sound and move one direction a little ways. Watch which way the cones move. DO both move the same direction? If not, one is wired backwards. And that will sap the sound out of the system.

Did you try connecting just one Scorpion at a time to test them individually?

[tsor]

Both pop out when I use the 9 volt. I have them wired in Parallel but rather than have the pos and neg go right from the amp to each speaker I have the positive from the second speaker comming off the positive from the first speaker and the negatie for the second speaker coming off the negative from the first speaker. Since both pop outward should I assuming the wiring is correct? If so, then is the only other option to check the ohm reading using a meter or would anyone suggest wiring the pos and neg for the second speaker directly from the amp and not the first speaker? I did it this way because that is how it looked on my music man. I can also try wiring in series if anyone thinks thats an option?

[Enzo]

Your wiring is fine.

So try just one Scorpion at a time. Test them individually. If one is screwed up it could be holding down the other.

[tsor]

So I tried each speaker individually and they both sound the same. I have the pre-gain on 10 and if I turn the post gain from 1 - 10 there is very little increase in volume. Like I said, when I hooked up the amp to my 2 10's in my music man, it was much louder. I didn't want to turn it all the way up because I didn't think the 2 10's could handle the watts from the mace even though the music man is 130 watts.

Anyway, this might be a strange question but I found a photo of the scorpion speakers on a web site and I noticed there is some gold thing at the center of the magnet. I took a photo of the scorpions in my amp and as you can see there is no gold thing. Could that have something to do with it?

[dwhutchens]

I belive the "gold thing" you are referring to is the voice coil. I think the pic you found on the web is just a replacement basket minus the magnet. That allows you to replace the cone and voice coil assembly and reuse your original magnet. I belive your magnet is bolted to the basket with three bolts.

David

[Enzo]

The left photo - same photo I linked earlier - is of a Scorpion basket only. There is no magnet mounted on it. it is not a complete speaker. I used the image to show the shape of the mounting flange. Your other photo is of a whole speaker with the magnet bolted onto the basket.

[tsor]

OK got it. Appreciate the education on this. I guess my last step is to pick up one of those meters and check the ohms. I assume it is possible that both of these speakers are somewhat shot and only putting out a little sound.

[Enzo]

Connect them to some other amp for a listen then.

[tsor]

Well here is the latest as to what I tried.

Hooked up the speakers to my music man and same low volume. No increase when you crank the master vol.

Ohm meter. Not sure if I am using this correctly but I put the red lead on the red dot wire of each speaker and the black lead on the black. meter went to about 1 ohm but also bounced around a bit all the way to the left of the meter at times. I tried the same thing on my music man to see if I was doing it right and basicly got the same thing.

Is it possible that the voice coils are bad in the peaey speakers?

Thanks

[dwhutchens]

Originally Posted by tsor

Hooked up the speakers to my music man and same low volume.

Sounds like you got your answer. Your voice coils are most likely partially melted, they overheated and melted the insulation on the wire shorting some of the winding together. Sounds like you got an analog meter, does it have a needle on it. An 8 ohm speaker will only read around 6 ohms or so. That can be hard to read on this kind of meter if your not familiar with using one and if its not zeroed correctly. Its probably bouncing around because your not making a good connection on the speaker terminals, could be a little corrosion on them.

David

[Enzo]

Also, when reading resistance of speaker voice coils, it is important to remember that speakers can also act like microphones. Move the cones and small voltages are generated. This can confuse a meter. Always set a speaker down so it isn;t moving before making a reading. And turn off any relatively loud sounds in the vicinity.

[tsor]

That sounds logical since I've read that Skynard replaced the scorpions with JBL's since they couldn't handle the loud volumes these amps produce. I guess I'll replace them with black widows and hopefully this think will be done.

Thanks for all the help

[Don Moose]

Well, an ohmmeter can really only tell you if the voice coil is open (broken wire) or not. A radical difference between the ohmage - with one much lower than the other - would suggest that the lower one may be shorted.

You did have the amp off and speakers unplugged at the time, right?

Your experience driving them with the MM amp says they are probably toast - you tried them one at at a time?

From Enzo's picture, it looks like you can replace the basket/cone/coil assembly and keep your existing magnets if you want to go that way.

Hope this helps!