RT3000P powered sub amp not working

jcotterman

I, like many people on this forum, have had my RT3000 amps fail. Originally I only had a single failure a couple years ago but now have the second one fail as well. I have the complete RT5000 set and have never even tried to power the center.

While I have lurked around on these forums for a few days now, I have yet to see where anyone has bypassed the built in amp(s) to power the subs with an external amp. Is this even possible?

I have an extra Adcom GFA-555 amp that I am considering powering either both (stereo) or one (bridged) of the RT3000 subs. My right speaker is corner loaded so the sub output is adequate for my reasonably small space. As I have not been able to get any sound yet, is it even possible to externally power the subs w/o removing the amp to change the wiring? I am using the speaker level input on the RT3000 from the Adcom but still don't have any sound. I have tested the Adcom with a full range input and all is good so I know the amp works perfectly. And I am also using the same sub level output from my receiver to the Adcom that I was using to the LFE input on the RT3000 before amp failure.

Any ideas?

Thanks.

ESavinon

You cannot power the rt3000 subs without bypassing the plate amplifiers.
You will need to remove the plate amps and directly wire the adcom amps to the subs.
You have to keep in mind that the rt3000 plate amplifiers function as an amplifier and an active crossover.
Why not remove the plate amps and have them repaired?
It may be cheaper than having them replaced at $700 each.

jcotterman

I was trying to avoid two things with a repair; 1. The costs of repair for both amps and 2. the time spent without subs while repair was taking place.

As I don't have a separate sub, the loss of the amps would not only not allow the internal amplification, but also the Adcom amplification while the amp plates are out.

Cost is also the reasoning behind using the Adcom instead of repairing the internals. I already have the Adcom and it is more than powerful enough.

Thanks for your response.

Jon

dubradio

Jcotterman,
If you would like give us a call here at polk CS 1-800-377-7655 and we can direct you to our service center for an estimate.

Kyle
PolkAudio
Customer Service
Toll Free : 800-377-7655

dubradio

Jcotterman,
If you would like give us a call here at polk CS 1-800-377-7655 and we can direct you to our service center for an estimate.

Kyle
PolkAudio
Customer Service
Toll Free : 800-377-7655

HT ED

Can anyone tell me what it cost them to have an RT3000P amplifier repaired?

A rough estimate?

I have been having an intermittent problem with one of the amps producing a crackling noise. If there is no drive into the amp, it is quiet. But as I inject a test tone into the inputs, there is a crackling noise present. The more drive, the louder the noise. If I use the test tone (white noise) from my AV receiver, and you know what that sounds like (low rumble), it is accompanied with another noise best described as a loud version of rice crispies!

I swapped the two speaker drivers from my other RT3000 cabinet, so its not the drivers.

Anyone ever have this similar symptom?

I removed the amp and don't see any loose connections or bad solder joints. It appears that the high power transistors DO amplify high level inputs just fine, so I'm suspecting there might be something going on with the op amps on the input board. I received a service document from Polk via email, but it appears to be for a different version board. The one they sent me is for a board labeled B2941, but I need docs for a version B3901 (P/N 62-0684-5900) board.

Can anyone help? Of course, I pulled the damn thing apart on a Sunday, so calling Polk is not an option until tomorrow Morning!

Thanks
ED

HT ED

Got the amp working like new again. Once I removed the preamp board and fully exposed the main amplifier, I started poking around and found that one of the two TO-220 style plastic case transistors was ready to fall off the board. I unscrewed the board from the heat sink, and found all three legs with completely loose / cold solder joints. I also found the center pin of the small transistor which bolts to the heatsink completely unsoldered. Looks like it was never even soldered from the factory! I resoldered the two suspect transistors, reassembled it, and all is good once again.

While I had the tools out, I pulled the other RT3000P apart and inspected that amp board as well. All was fine with that one.

If I had the CORRECT service doc for this version amp, I'd list the part designation numbers, but its hard to do without the document.

It took most of the afternoon by the time I reassembled everything and cleaned up the work table, but now I can once again enjoy the HT without hearing rice crispy like noise during low volume pasages!

HT ED

miner

Good troubleshooting HT ED. I once had a problem with one of my RT20p amps and Polk CS was very helpful. Sent it to them and 6 days later I had it back. All I paid for was shipping. Polk CS is top notched and a pleasure to talk to.

trentbreeding

Looking for Rt3000p powered subwoofer bases