Ampeg PF 500 Service Help

LHbassist

LHbassist

Supporting Member
Apr 4, 2003
1,187
1,810
5,341
Reno, Nevada
#1
I KNOW, this amp head and its issues have been discussed on Talk Bass before. I just have a few questions, for anyone familiar with the issue. I just simply, would like to make this amplifier usable. Please don't suggest things like, 'well, you knew it might have issues, you shouldn't have bought it' and such.
I live in Reno, Nevada. There are amp techs here, but they are iffy. I want to contact someone, like how Andy took care of my GB Shuttle 9.0 issues, after going through Talk Bass to contact him, that both knows these Ampeg amps, the issue, and how to actually fix it. I tried the service center contacts, and got no responses. The amp is NOT under warranty.
The amp looks mint, functions, and does the intermittent cut out after a time.
I'm a guitar and bass tech, and have done some repairs to my own amps, like transformer and capacitor replacement and such. If it is a simple module replacement and I can buy the part... I can do the work.
Thanks!
 
#3
The boards are generally swapped out. It is more profitable for a shop to do this. If you can find the right tech, the boards have discrete parts so they can be repaired by changing components.

If you do buy the board that Jimmy referenced, ask them if there is an exchange price. You might be able to get it at a better price if you send in the old one.
 
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#4
Also, you are always welcome to call Ampeg's tech support and talk to them. I'm thinking that by the time you send it to a shop, it's going to cost right around the same price as getting the board, maybe a little less, and those boards all hook up with molex plugs, and anyone with a screwdriver and a couple small wrenches can swap them out easily enough. The tradeoff, however, is if there's a problem elsewhere. But I'm pretty sure there are only two boards...the main one and the preamp board with all the front panel controls.
 
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#5
You figure, if a tech were to repair the board, you have at least a couple of hours of bench time, plus parts, plus elays in having the work done. The replacement board keeps looking more attractive.

I would call loud and ask what the latest revision of the main board is. Ask how much they sell them for. Then call the place selling the board and ask what revision their's are. Also ask if they are new or repaired boards. I wouldn't want an old revision.
 
#6
Thanks, Jimmy. I just e-mailed them. $189. is a lot of dough, it's almost half the retail of the entire head. I paid $250 for the head an a mint PF210 cab. Still cannot use it.
Some trivia for you, Jimmy- I know you're an Ampeg guy. I was born in Astoria, Queens, N.Y. City. I lived in, and grew up in Woodside. I used to rehearse RIGHT ACROSS from the original Ampeg company, under the 'El' on Roosevelt Ave. at 54th. St. in Woodside. And of course, I was using an SB-12.
I've owned a LOT of Ampegs. I even had an early 60's Baby Bass for a while.
 
#7
beans-on-toast said:
You figure, if a tech were to repair the board, you have at least a couple of hours of bench time, plus parts, plus elays in having the work done. The replacement board keeps looking more attractive.

I would call loud and ask what the latest revision of the main board is. Ask how much they sell them for. Then call the place selling the board and ask what revision their's are. Also ask if they are new or repaired boards. I wouldn't want an old revision.
Click to expand...


O.K., I'll call them... anyone have a number handy for them?
 
#8
Ampeg Service Center: 800-898-3211

And very cool you used to rehearse near the Woodside location! A lot of people so closely identify Ampeg with Linden, NJ that they don't know that they started in NYC. But that's where Everett Hull located the company so he could be close to the big jazz players of the day.
 
#12
Update: Today, 10/25/ 2016, I ordered a main board from full Compass. $151.78. when it arrives, and I get a break from my other work... I'll install it and let you all know how it works out.
I DESPISED the factory purple Eminence 10's in that cabinet. The frequency response seemed to literally drop completely off at about 100 hz., and a nasty weird sound ensued. I just bought some second gen Carvin neo- 10's 8 ohms- 300 watts like that came in the BRX 10.2 cabs for a while. here on TB. I installed them, and plugged in my PF 500 and tested it... MAN, what a nice sound, and no problems in the low end anymore. Can't trust the head, though, until I fix it.
 
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#13
O.K., after a busy weekend of gigs and a few repairs.. I swapped out the main board. I was a bit taken aback.. I seem to recall that the newest main board for these was 'Revision J.' The new board I just installed is also a revision 'J.' The difference is- the old board has a black ink mark of '02.' The new one is '03.' (Does anyone know the actual difference between these two boards?)
I'm running the amp at home now. I periodically go over to it, and test functionality, with different basses. So far, so good. I'm playing a gig for three nights this weekend, in Minden, Nevada. It's a low volume R&B/ classic rock gig, but a damn good bunch of players. I'll bring this, and my trusty Carvin BX 500 and BRX 10.2 Neo to the gig, just in case. The results of this quasi- scientific test will appear on, or just after Monday, 11/7.
 
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#15
If someone at Loud could get a peek at the latest schematic, there is a note in the legend indicating what was done between revision J02 and J03. The numbers are minor revisions. J01 for example added a fuse clip to the bill of materials, J02 changed a common TL072 op amp and removed a related resistor. It could be that the resistor was no longer necessary with the new part. Don't know about J03.

Enjoy your gigs!
 
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#16
beans-on-toast said:
If someone at Loud could get a peek at the latest schematic, there is a note in the legend indicating what was done between revision J02 and J03. The numbers are minor revisions. J01 for example added a fuse clip to the bill of materials, J02 changed a common TL072 op amp and removed a related resistor. It could be that the resistor was no longer necessary with the new part. Don't know about J03.

Enjoy your gigs!
Click to expand...
THANK YOU! I will! Rooms, comped meals, nice quiet town.. free Wi-Fi and cable.. and a great band... life is good!
 
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#17
I have been playing this combo for a bit to test it.. there is still one issue not related to the amplifier that might be a problem... for me. The cabinet is sealed. and even with the much better Carvin neos, low end still seems to fall of a bit, as you go below 'A' on the 'E' string. It's there, but not quite like my Carvin BRX 10.2's. Has anyone successfully ported one of these cabinets and experienced an improvement?
 
#19
Arizona Jones CVI 11-3-16.jpg
Well, here I am at The Carson Valley Inn in Minden, Nevada. One gig down. I brought two amps, the PF500 -210 with the neo speakers... and, my proven Carvin BX 500 head with a BRX 10.2 cabinet with Deltalite long x-max 10's from my long gone avatar 4-10 cab. You can see both amps 'on' lights are on. The Ampeg seemed o.k. at soundcheck, no problems. Three set gig. First set- the Carvin rig. Killer sound in a small package. Then, second set, switched to the Ampeg. The combo has a fairly good sound, but the speakers are definitely in need of a port to alleviate the strange 'warbling' on the lower notes. Well, it's a good thing I left the Carvin head on, because about three songs in, the amp cut out- first for few seconds, then, just stopped... I unplugged my bass, and used the Carvin for the rest of the gig.
So, my adventure with the PF 500 is a failure so far. Loud recommended getting the board from Full Compass, and by installing the new main board, they said it would probably fix the issue. It didn't. So 151 bucks, an hour of my time to swap the board, and still not a usable amplifier. I'm really not sure what to do at this point....
 
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#20
If there's a warranty from Full Compass on the replacement board, they might take it back.

You put the amp through its paces at home. A low line voltage will cause the amp to go into fault mode. This can happen at some venues when everything gets plugged in. But your other amp wasn't affected. Too much heat is another possibility. Stage lights or poor circulation around the amp can cause this. Based on your image, it doesn't look like this should be an issue.
 
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