need help with soundtech ps802 amplifier

bt242

Member
2005-07-25 4:49 am
no
I have a soundtech ps802 amplifier sitting in front of me. It has a foreign plug on it. specs say a hybrid switch mode power supply? back says 120v 60hz and below that 230v 50hz. I am wondering, can I lop off the Euro? plug and put on an us plug and have the amp function? the fuse in back panel is the 230v rated fuse but it says what the value should be for 120v aswell. Amp is class H. Some have said give it a try. Some say transformer would have to be replaced. Some say transformer would have to br rewired. I opened it up, it has a rather small round transformer. I was going to buy a step converter/transformer to make it work but was wondering if there is an easier and/or more permanent solution for making it work as it should but on 120v.....??? I included a picture of the back if you can see the markings I'm talking about. Someone said that is probably standard on all the amps. Should I post a picture of the inside of amp? anyone have any brainy thoughts? thanks very much
 

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Hi !
Yes, the plug is european...
Rewiring the transformer in a switchmodepowersupply ? That nuts...
It's not uncommon for smps to work with 110v-250v, so my guess
is you can replace the plug and everything should be fine.
But you should replace the fuse, and if you have a manual, study it.
Be sure it has this hybrid-smps !

But only a guess,
Mike
 

fooserjeff

Member
2010-10-25 4:35 pm
Soundtech PS802 Repair Kit

I have put together a repair kit that fixes every audio problem I have seen if you have no audio on channel(s), intermittent audio, weak channel etc. If you have a lit power LED. This kit is not for blown fuse symptons or "dead" units (no power LED). Complete step by step instructions for replacing parts (parts included) and pictures. Kit is available on Ebay or email me directly [email protected]
Kit is $24.95 Schematic is available for additional $10.00.
Free shipping to U.S., $5.00 outside U.S.
 
A little late answering this post........but they are designed to work with both voltages with no re-wiring. You could have bought a european to US plug adaptor and set your voltage switch accordingly. I just got finished repairing close to 50 of these amps if anyone has anymore questions.
[email protected]
There is not a voltage selector switch on PS802 amps (was thinking of a different model). However they definitely have SMPS's capable of handling both voltages.
 
On a related note I have a PS1600 240v amp that I've been trying to revive. I changed JP1 so the two primary windings are in series and the linear power supply appears to be 100% functional ie the 12v/15v/zener power supply deliver 12v/15v/-10v respectively. Unfortunately the PWM SMPS rails are running at 25v/45v instead of 50v/90v. Did Soundtech change the SMPS output transformers for the 120v model or am I missing something obvious? All my fuses are good and the amp powers up with the green power LED and no protection faults. Both output boards are factory original with no mods or repairs.
 
Its definitely a SMPS using a Samsung PWM chip and a dual transformer arrangement so the "hot" section is completely isolated from everything. The design doesn't have any feedback from the output voltage so it wouldn't know if the output is 50% low. The final output transformer is a custom toroid. Either they designed for 120v and cut the output by 50% for the 240v by limiting the PWM drive or they used different transformers.

The fuses shouldn't affect the SMPS output voltage so that's a non-issue.
 

kwesi588

Member
2010-02-23 9:57 pm
On a related note I have a PS1600 240v amp that I've been trying to revive. I changed JP1 so the two primary windings are in series and the linear power supply appears to be 100% functional ie the 12v/15v/zener power supply deliver 12v/15v/-10v respectively. Unfortunately the PWM SMPS rails are running at 25v/45v instead of 50v/90v. Did Soundtech change the SMPS output transformers for the 120v model or am I missing something obvious? All my fuses are good and the amp powers up with the green power LED and no protection faults. Both output boards are factory original with no mods or repairs.
no it is configure for 220v