Hello all,
Many years ago, I had purchased a brand new Carver PM 1.5a. Was a great amp. Used it very rarely. I ended up selling it about a half decade ago. I've been lamenting this poor decision ever since.
So, I've been keeping an eye out for 1.5a', 1200's, 2.0t's, etc. And I came across a 2.0t for sale by a used music equipment reseller. The price was reasonable for what I assumed was a reasonably sorted example.
When I received the amp, I quickly connected 8 ohm speakers to each of the channels, and ran a line level input into both channels. I plugged the amp in and let it charge up for a few minutes before powering it up.
And that's when my troubles began.
I noticed multiple issues.
1) The power supply is making a high pitched whine. This is not on the speaker output. This is directly from the power transformer. I am aware that these amps use a unique switching PSU design. But this amount whine is above what I'd expect.
2) The output is very low. Yes, it does pass audio on both channels, but the frequency response is poor, and the output volume is very low. It should be breaking the drywall at half volume, but instead its barely audible.
3) The VU meter doesn't move.
4) The fans don't run in either switch position
5) After testing the amp for a couple minutes, I could smell hot electronic. Pulled the cover and checked the PSU components with an infrared thermometer. The transformer was hot (120*), as were the diodes in the middle of the PSU board.
I'm trying to decide what to do. I do have the full service manual. I also have the necessary test gear. Trying to decide if I should run through the low voltage tests on this unit, or if I should just ship it back and get my money back... I have talked to the seller, and I think I could probably make a deal to get a partial refund since its non-operative.
A visual inspection showed that the labels on several of the caps have melted off or been damaged by heat. I'm wondering if maybe the issues could be fixed by re-capping the PSU.
Has anyone heard of a Carver 2.0t having a high pitched whine? Anyone have an opinion on whether I should just ship it back, or take the time to try to revive it? I like the Carver amps due to their lightweight design, and the quality output. My other go-to amp has been a Peavey CS800X, but they are so heavy in comparison..
Thanks,
Brad
Many years ago, I had purchased a brand new Carver PM 1.5a. Was a great amp. Used it very rarely. I ended up selling it about a half decade ago. I've been lamenting this poor decision ever since.
So, I've been keeping an eye out for 1.5a', 1200's, 2.0t's, etc. And I came across a 2.0t for sale by a used music equipment reseller. The price was reasonable for what I assumed was a reasonably sorted example.
When I received the amp, I quickly connected 8 ohm speakers to each of the channels, and ran a line level input into both channels. I plugged the amp in and let it charge up for a few minutes before powering it up.
And that's when my troubles began.
I noticed multiple issues.
1) The power supply is making a high pitched whine. This is not on the speaker output. This is directly from the power transformer. I am aware that these amps use a unique switching PSU design. But this amount whine is above what I'd expect.
2) The output is very low. Yes, it does pass audio on both channels, but the frequency response is poor, and the output volume is very low. It should be breaking the drywall at half volume, but instead its barely audible.
3) The VU meter doesn't move.
4) The fans don't run in either switch position
5) After testing the amp for a couple minutes, I could smell hot electronic. Pulled the cover and checked the PSU components with an infrared thermometer. The transformer was hot (120*), as were the diodes in the middle of the PSU board.
I'm trying to decide what to do. I do have the full service manual. I also have the necessary test gear. Trying to decide if I should run through the low voltage tests on this unit, or if I should just ship it back and get my money back... I have talked to the seller, and I think I could probably make a deal to get a partial refund since its non-operative.
A visual inspection showed that the labels on several of the caps have melted off or been damaged by heat. I'm wondering if maybe the issues could be fixed by re-capping the PSU.
Has anyone heard of a Carver 2.0t having a high pitched whine? Anyone have an opinion on whether I should just ship it back, or take the time to try to revive it? I like the Carver amps due to their lightweight design, and the quality output. My other go-to amp has been a Peavey CS800X, but they are so heavy in comparison..
Thanks,
Brad
Send it back immediately and demand a full refund. Stop your credit card payment if necessary.
Hi Brad,
Agree with Rayma 100%. They should give you a full refund.
I was Canadian warranty for Carver and repaired my share of PM 2.0t amplifiers. It's one of the few Carver products I have seen bad power transformers in. This one works more like a car amplifier than a mag coil design. It's lighter and puts out more power as a result. You could have anything from shorted fan motor diodes to a toasted power transformer.
If I were to buy one for home, I would buy an M-1.5t and modify it a bit. These turn out to be amazing for sound quality. No fan noise to deal with either. If I had a ton of money, it would be a TFM-75. Those are really "pretty" amplifiers. I did have a Lightstar series 1 for a while and can still repair those.
-Chris
Agree with Rayma 100%. They should give you a full refund.
I was Canadian warranty for Carver and repaired my share of PM 2.0t amplifiers. It's one of the few Carver products I have seen bad power transformers in. This one works more like a car amplifier than a mag coil design. It's lighter and puts out more power as a result. You could have anything from shorted fan motor diodes to a toasted power transformer.
If I were to buy one for home, I would buy an M-1.5t and modify it a bit. These turn out to be amazing for sound quality. No fan noise to deal with either. If I had a ton of money, it would be a TFM-75. Those are really "pretty" amplifiers. I did have a Lightstar series 1 for a while and can still repair those.
-Chris
Thank you both for the advice. I've requested an RMA # be provided.
I intended on using the amp for mobile sound reinforcement purposes. Didn't want to have to lug around a couple CS800X's. But on the flip side, I didn't expect to have to try to diagnose a Carver amp, with their idiosyncratic design.
So, back to the seller this amp will go.
I guess I'll continue to search for a PM 1.5a or 2.0t that is in working order. Or, forget about Carver's and deal with a design I'm more comfortable with.
Thanks again for the reality check.
I intended on using the amp for mobile sound reinforcement purposes. Didn't want to have to lug around a couple CS800X's. But on the flip side, I didn't expect to have to try to diagnose a Carver amp, with their idiosyncratic design.
So, back to the seller this amp will go.
I guess I'll continue to search for a PM 1.5a or 2.0t that is in working order. Or, forget about Carver's and deal with a design I'm more comfortable with.
Thanks again for the reality check.
Hi Brad,
The only thing about a Carver amplifier you have to watch is to provide a good AC power supply. Also, they work great as bass or full range. High power mid or highs only duty will kill them as the commutators will lock up and it will go into thermal runaway - eventually causing a failure.
If you have a half decent tech, their maintenance is low and a blown channel often very inexpensive to fix. An idiot tech will generally destroy a Carver amplifier, but that is true of all amps.
Any amplifier you buy with this many years under it's belt is going to need service. Don't kid yourself that just because an amplifier is running, it's good to go. Everything should be maintained and have some sort of schedule for routine maintenance. Many amplifiers as old as the PM-2.0t are scrap by now. So the point I'm making is that being a Carver isn't the problem. It shouldn't have been sold to you in that condition (unless it was an as-is sale). The problem is really the fact that you expected an old amplifier to be in good enough condition to go right into production. Always expect to fix amplifiers this old - they need attention, even a BGW-750C needs service at this point in time.
-Chris
The only thing about a Carver amplifier you have to watch is to provide a good AC power supply. Also, they work great as bass or full range. High power mid or highs only duty will kill them as the commutators will lock up and it will go into thermal runaway - eventually causing a failure.
If you have a half decent tech, their maintenance is low and a blown channel often very inexpensive to fix. An idiot tech will generally destroy a Carver amplifier, but that is true of all amps.
Any amplifier you buy with this many years under it's belt is going to need service. Don't kid yourself that just because an amplifier is running, it's good to go. Everything should be maintained and have some sort of schedule for routine maintenance. Many amplifiers as old as the PM-2.0t are scrap by now. So the point I'm making is that being a Carver isn't the problem. It shouldn't have been sold to you in that condition (unless it was an as-is sale). The problem is really the fact that you expected an old amplifier to be in good enough condition to go right into production. Always expect to fix amplifiers this old - they need attention, even a BGW-750C needs service at this point in time.
-Chris
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