Ampeg PF 500 Service Help

#21
Did you get a fault light, or did she just cut out with no other indications?
Like Beans said, try to return the board for a refund.

I don't know what power module is being used, but, whatever it is seems pretty dodgy somehow. Low output forces us to crank the volume way up, and according to my latest emails with Ampeg tech support, that's not how these particular class D amps (PF-500 and PF-800) are to be driven.

I love the tone stack in these amps though.
 
#22
beans-on-toast said:
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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Several things are in the control area- the power cable is factory original. I used a very high quality, better than OEM speaker cable, brand new. The amp, as you noticed, had more than adequate 'breathing' room, and it was probably about 70* onstage last night. The power in the CVI has never been an issue, I've been playing there now for about 15 years, with at least 5 different bands. I've used all sorts of amps and speakers there. There is one possibility- the specs show that this amp will run at 4 ohms. There are two Carvin current gen neo tens in it, both 8 ohms- in parallel. The impedance was checked after the replacement, and it registered about what my other 4 ohm cabs do, a little under 4. But, I don't think that was the issue.
Did Full Compass send me the same board that was already in it? Is there a newer revision that is known to work?
At this point, I'm ready to either adapt a different Ampeg head to it, or just sell this thing as is to someone that can find the issue and spend the time. I'm almost 65, I have instruments I need to do at home.. two major string bass repairs to do. Taking amps apart, is kinda fun... but it's like someone who doesn't usually eat steak having one once in a blue moon. I'm just going to contact the needed parties- Loud, to tell them what occurred...and Full Compass. I have never heard of anyone accepting electronic parts returns, once they've been installed.
THANK YOU for your recommendations!
 
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#23
A trivia note here, some already know this- I grew up in Woodside, Queens, N.Y. City. Sound familiar? Yup- the home of Ampeg. I used to rehearse at The Roosevelt Avenue Boys men's club, under the #7 IRT El, at 54th. St. Guess where Ampeg was? RIGHT across the street! It was in a storefront type of building, not a factory like you might think. I never knew they were there! That location, is a coffee shop now.
Here's what an old school regular Ampeg user cannot get out of my mind.
I owned the following Ampeg products. '67 BT-15C, '66 B-15 with a JBL, '64 B-15, '69 SVT with both a flatback and a towel bar cab, '77 B-410, B-410 HLF cab, V4-B head. This is over a 45 year period.
I had preamp overload issues with the B-410, Replaced the power transformers in one B-15, and the BT-15, but other than that, those American made amps and cabs were workhorses.
I wonder just how Ampeg, with it's history, could allow a product with this really lousy design flaw to tarnish my, and others view of their business practices. Is saving money by using foreign manufacturing THAT important? Wow... I think I just answered my own question.
 
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#24
I can understand your frustration.

If what Full Compass sold you has an issue, it doesn't hurt to ask them about getting a replacement. If you tell them that it went into fault mode at a gig, they should make it right, give you your money back or a replacement. It certainly doesn't hurt to try.

Since, based on what you described to them, Loud customer service recommended that you buy the board and that it has an issue, why not let them know where things stand. Tell them that something odd is going on and this isn't normal for this product. Ask if there is anything that they can do to help you. Again, worth a shot.
 
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#25
beans-on-toast said:
I can understand your frustration.

If what Full Compass sold you has an issue, it doesn't hurt to ask them about getting a replacement. If you tell them that it went into fault mode at a gig, they should make it right, give you your money back or a replacement. It certainly doesn't hurt to try.

Since, based on what you described to them, Loud customer service recommended that you buy the board and that it has an issue, why not let them know where things stand. Tell them that something odd is going on and this isn't normal for this product. Ask if there is anything that they can do to help you. Again, worth a shot.
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Thanks, that's what I always tell MY repair clients to do regarding defective instruments. When I return to Reno, I'll get in touch with loud, and Full Compass.
 
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#28
Update.. Full Compass has offered to either replace the board, or give me a full refund. I opted for the replacement. An amp without a main board is useless. I'll give this amp one more try. If it fails again, after that, it's up for sale as a project. Of course, it's now Veterans Day, so it won't go out until Monday.
I'll keep all of you informed as to the progress of this adventure. Have a good holiday, and... Thanks to all of our Veterans.
 
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#29
As an aside you spoke about warbling and installing ports on the cab. Let me share this with you.

Although the portaflex flip top is a cool gadget, the modern re-realization has some flaws which I noticed with mine. First, my lid is warped slightly in the middle and air chuffed out the back of the seal where there are no latches. It kinda of warbled too. I bought an extra latch of the same type and installed it on the back to hold down the lid securely. Secondly, that tiny rubber seal strip is too narrow and thin and the adhesive didn't hold it in place. I bought some 1/4" thick, 1" wide neoprene weatherstrip and the chuffing is done.

As for the head, crank the master up to the noise floor and control volume with your gain. Yes there's a design flaw that the power section cuts if the pre section hits it too hard, but doing this will stop thermal shutdowns and you'll have huge fat tone for days.
 
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#30
96tbird said:
As an aside you spoke about warbling and installing ports on the cab. Let me share this with you.

Although the portaflex flip top is a cool gadget, the modern re-realization has some flaws which I noticed with mine. First, my lid is warped slightly in the middle and air chuffed out the back of the seal where there are no latches. It kinda of warbled too. I bought an extra latch of the same type and installed it on the back to hold down the lid securely. Secondly, that tiny rubber seal strip is too narrow and thin and the adhesive didn't hold it in place. I bought some 1/4" thick, 1" wide neoprene weatherstrip and the chuffing is done.

As for the head, crank the master up to the noise floor and control volume with your gain. Yes there's a design flaw that the power section cuts if the pre section hits it too hard, but doing this will stop thermal shutdowns and you'll have huge fat tone for days.
Click to expand...

I have a lot of basses, many of them are close in output, but some are very hot, active.. I use a Zoom B-3 preamp effects unit. If I switch to an active bass, I reduce the output gain on the Zoom, and unmute it for playing. I LOATHE the input pad switches on most modern amps.
I tried getting the necessary gig volume on the PF500, both by running the gain low, and the master up- as I prefer, and the opposite. I noticed, as I expected, that when setting the input gain higher, distortion was introduced. I backed it off, and just adjusted the master. The amp actually sounds really good, but two things- the lack of porting makes this seem like it isn't as 'loud' or room filling as the Carvin BRX 10.2 that I used before and after it, with a Carvin BX500 head. Same power, 500 watts at 4 ohms, and same speaker configuration two tens- 4 ohms. ... the Ampeg seems to be down on power in comparison. The Carvin was at 10 o'clock on the master, and about 3 on the input gain. The gain was at about 11 O'clock, and the master on the PF500 was at 2 O'clock.
 
#31
What I'd like to do, is convert this from a sealed enclosure, and port the cabinet in front. I do not care for rear ported cabs, I have my reasons.. I dig the Mesa Powerhouse 12 cabinet I have, and it has a triangular corner port. I'd like to know what you guys think about cutting one of those. There is plenty of space to cut one out of the baffle there. I have some free box porting programs- but not really sure how effective they are. Has anyone tried doing this?
 
#32
LHbassist said:
What I'd like to do, is convert this from a sealed enclosure, and port the cabinet in front. I do not care for rear ported cabs, I have my reasons.. I dig the Mesa Powerhouse 12 cabinet I have, and it has a triangular corner port. I'd like to know what you guys think about cutting one of those. There is plenty of space to cut one out of the baffle there. I have some free box porting programs- but not really sure how effective they are. Has anyone tried doing this?
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Like you, I would rather port in the front.
I'm sorely tempted to remove the hf horn from my PF115HE cab. The horn is never used and just sits there and rattles (the baffle just isn't rigid enough, so I've a wooden dowel jammed between the horn driver and the cab floor to stop it from rattling). The resulting hole could then be adjusted to suit, and then install the proper diameter and length of porting tube. One of these days.
 
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#33
Well, I shipped the main board back to Full Compass. Just to let you guys know, the people at Full Compass, unlike Loud- are VERY, VERY cool. I got the Fedex Label from them, boxed it up and shipped it. When I went to pay the clerk at Fedex, she told me it was already paid! How cool is that?
So, now I wait for the new board to arrive. No hurry, really... I have lots of amps and speakers.. I'm hoping this solves the issue. If it doesn't, one thing is for sure, Full Compass is a great company to do business with.
 
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#36
LHbassist said:
Full Compass gets an A+++++. Loud Technologies gets the buck passer of the year award.
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It's pretty sad that the most iconic bass amp brand have such a flippant attitude towards it's customers. Especially when it concerns their "known to have many problems" line of amps like the pf500 and SVT pro 7
 
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