# Tube amp repair??



## NJPCRX (Jul 25, 2012)

I have a Planet Audio 754 hybrid tube amp (made by Zed) that is in near mint condition that does not work. I've had this since new in the late 90's. Recently I dug it out when I learned my friend at work had a tube tester. The tubes are good. I am an Avionics guy in the Airforce, so I took it over to the base back-shop where my friend tinkers with broken amps when they are not busy and he kept it for a couple weeks. He said he couldn't find anything obviously wrong with it and gave it back. It powers up and the lights light up. As soon as the tubes heat up and it switches to the output side, it goes into protect. There are no places around here that fix amps. Is there somewhere I can mail this thing and have it repaired for a resonable price?? I miss this thing and would like to run it again someday.


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## thehatedguy (May 4, 2007)

Send it back to Zed?


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## TrickyRicky (Apr 5, 2009)

I could check it out. Did your tech/friend check the protection circuit?


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## NJPCRX (Jul 25, 2012)

I wasn't sure if the new ZED was associated with the old school ZED anymore other than just the name. I would be honored if you checked it out TrickyRicky. I saw your name mentioned on another thread about fixin amps. What do you think it would cost? I'm not sure if he checked the protection circuit, he pretty much did a visual inspection of the board for obvious problems. I don't think he is too experienced with car audio amps, but they have the means to micro solder and replace circuit board components there, so he gave it a shot. I'll shoot you a PM ricky, and see if we can't work something out.


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## TrickyRicky (Apr 5, 2009)

Got the amplifier yesterday...repaired it today...ready to ship by Monday. Unless OP want it shipped tomorrow.

Good thing I saw and read this sign when I was in there, lol.


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## minbari (Mar 3, 2011)

NJPCRX said:


> I wasn't sure if the new ZED was associated with the old school ZED anymore other than just the name. I would be honored if you checked it out TrickyRicky. I saw your name mentioned on another thread about fixin amps. What do you think it would cost? I'm not sure if he checked the protection circuit, he pretty much did a visual inspection of the board for obvious problems. I don't think he is too experienced with car audio amps, but they have the means to micro solder and replace circuit board components there, so he gave it a shot. I'll shoot you a PM ricky, and see if we can't work something out.


looks like you got it fixed anyway, but ya, Steven Mantz is still the owner of ZED audio.


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## TrickyRicky (Apr 5, 2009)

I emailed him hoping they would share schematics....NO LUCK but I was expecting that, lol.


BTW there are two tiny lamps (bulbs) next to the cut out where the tubes are located. Thought it would be neat to switch to a blue neon color but not my amp  and probably should stick with the original yellow glow.


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## Mack (Jul 27, 2007)

TrickyRicky said:


> I emailed him hoping they would share schematics....NO LUCK but I was expecting that, lol.
> 
> 
> BTW there are two tiny lamps (bulbs) next to the cut out where the tubes are located. Thought it would be neat to switch to a blue neon color but not my amp  and probably should stick with the original yellow glow.


I asked for the same amp and got nowhere too. I fixed that problem, but now I have a noisy channel with the RCAs disconnected. Got it troubleshot as far back as near the tubes but haven't nailed it yet.


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## CDT FAN (Jul 25, 2012)

TrickyRicky said:


> I emailed him hoping they would share schematics....NO LUCK but I was expecting that, lol.
> 
> 
> BTW there are two tiny lamps (bulbs) next to the cut out where the tubes are located. Thought it would be neat to switch to a blue neon color but not my amp  and probably should stick with the original yellow glow.


What is the "watch out" stamp for? Does the amp run high voltage?

Great job on repairing the amp. I know who to send mine to now.


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## TrickyRicky (Apr 5, 2009)

Those tubes require high-voltage to power up. I believe I measured over 120v (peak-to-peak) for the power supply going to the pre-amp board.

Mack- have you check the input caps (signal, before and after). If you got as far as the tubes, I would have those checked out...I was going to purchase a tube tester but haven't done so yet, so can't even test them for you. But the OP may be able to help you on that since he tested his.


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## JuiceMan88 (Jun 13, 2012)

TrickyRicky said:


> Got the amplifier yesterday...repaired it today...ready to ship by Monday. Unless OP want it shipped tomorrow.


That's beautiful! I think the blue lights would look good for sure, yellow isn't shabby either though. Great work man.


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