SSI Powerflex

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SSI Powerflex - Where to start testing? (pic heavy)

Hey all you chip amp guys... Just picked up an SSI Powerflex 5 channel amplifier off of craigslist, and hoping you guys can shed some light on what i've got, and what I can do to troubleshoot some issues.

An externally hosted image should be here but it was not working when we last tested it.


I am planning to build a surround sound system for my PC, building some DIY speakers, and thought this would be the perfect amp setup for it.

An externally hosted image should be here but it was not working when we last tested it.


There is Zip, Zero, Zilch on this thing for a model # as far as I can see.

An externally hosted image should be here but it was not working when we last tested it.


I've looked around on this site, and googled as much as I can, but have been unable to dig up any real information on this device. A past thread on this site referenced an outdated SSI web page, but I have been unable to find it.

An externally hosted image should be here but it was not working when we last tested it.


There are five channels in total, each with an RCA in and and out

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And there seems to be a level adjustment at each channel - I assume this is to match the level at each speaker so that they are uniform at the listening position?

An externally hosted image should be here but it was not working when we last tested it.


No models # at all, but shows as 500w - which made me think it was 5x100w, but I suppose that is 500w electrical, not 500w audio? am I correct in this distinction, or talking hooey here?

An externally hosted image should be here but it was not working when we last tested it.


Taking the case off, there are 5 seperate amplifier modules, fed by one good size toroidal transformer.

An externally hosted image should be here but it was not working when we last tested it.


Taking the case off, I was concerned because the screws had clearly been put back in the wrong spots, and two of the five circuits boards are different colours.

An externally hosted image should be here but it was not working when we last tested it.


Also, someone has clearly been in here marking caps with Xs and √s, indicating they were testing maybe?

An externally hosted image should be here but it was not working when we last tested it.


The power supply seems pretty simple...

An externally hosted image should be here but it was not working when we last tested it.


The amp is based on the TDA1514A, which I gather is 50w.

An externally hosted image should be here but it was not working when we last tested it.


Anyway, after having a good look at everything, I used a couple speakers from a TV set (rated at 6Ω and 10W) that I had kicking around, and my mobile phone with a stereo 1/8" plug to RCA adapter, as the source.

I plugged the amp in and turned it on with all the level adjustments at the lowest setting, and my phone set to mute.

I had a speaker connected to the first and second channels. I adjusted the level up a touch on each channel, and then proceeded to up the volume on my phone. Channel one was playing just white noise.. that's it. Channel two had weak audio with lots of distortion.

I continued through the rest of the channels in this manner, and found that 3, 4, & 5 were putting out nice clear sound. Upon connecting back to channel 1 and 2, channel 1 was now putting out clear good sound, and channel two had absolutely nothing on it at all.

So here's where the questions come - thanks if you've stayed with me this far . Does anyone know where I would begin to test for failures with this chipset and board design? Do you think this is a reference amp design for the tda1514, or do you think SSI has made it their own?

I'm fairly handy with a multimeter, and would love to troubleshoot it a bit. My guess is that with 4 working channels, I can start poking around and comparing resistance, voltages, etc between the presumably dead channel, and the known working channels?

do you think I would be doing damage to the amp to have it powered on, but no speakers connected?

Thanks for any help, or direction to any websites you might know of.
 
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Ohh my god!
That one is one hell of a 5 channel chipamp!
But i think the Powersupply caps are too damn small...
the wireing of each board is hilarioous, seriously... several thin wires running across each.. very unbalanced but fine...

I thought that was odd myself - powered in series, rather than in parallel. If the amp circuit closest to the PS is at full draw, does that mean there is less power for the amps further away? Or is my thinking wrong here?

On the topic of power - I get 52v coming off the PS to the amp circuits - how is that possible? The caps are all 35v rated and the tda1514 is built to run at 18v?

The tda1514 reference notes that caps should be 4700uF/35v, but all the caps on this thing are 2200uF/35v... Is this el cheapo, or am I not getting something here?
 
>update<

I've been playing with the amp a bit tonight... had my phone again connected to channel 2 & 5 playing some music. Channel 2 is definitely not functioning, but i noticed that the heat sink was warm on channel 2, as it was with channel 5. So even though I wasn't getting any sound out from it, it seems like the amp is functioning (ok well, producing heat as though it was functioning...) does that tell me anything? lol.. sorry guys, i'm stabbing in the dark here being a total newb ;)
 
Looks like funny beast :)
Regarding the power supply - I suppose You measured these 52V between + and - somewhere.
Looking at the pictures I'm pretty sure the amp uses "bipolar" supply: the chassis ("zero" point called the ground) is in the middle between the + and -. So this is + 26V and - 26V regarding the ground. And the caps are suitable for this.
If so, the capacitors are ok - they are seeing one of the polarity only.
Could You measure the Volts between chassis and the + rail (then chassis and -)?
 
Probably not the bast explanation, but hope it helps:
Very often many parts are connected to the same potential or signal - for example, to the terminals of the power supply. At the output terminals of the power supply there are (in Your case) most likely positive and negative voltage compared to the chassis.
The positive wire, going to all the appropriate connections, are called "positive rail", etc.
In devices with simple power solution (the car, for ex :) ), there are 2 "rails" - positive (+ from the battery), and - = the ground rail (body (chassis) of the vehicle.
Looking at the photos it's even easier to visualize, because there are the flat cable with 7 wires in it, feeding all the channels in parallel - here are the "rails" connecting the parts with equal voltages.
Hope it helped a bit...

Are there some printed marks near the flat cable sockets on the printed boards? Probably there would be some +; -; 0v or gnd (for "ground") labels - this indicates the polarities of the sully voltages.

As for the chassis grounding - sometimes it's made on the bottom side of the printed boards - the area are simply connected to chassis by means of metallic spacer and nut.

If You have found the points where the 52 V difference is, You could, check these 52 V, then, not moving the + lead of the multimeter, touch the chassis with the - wire: I''m almost sure, that You will read about the half of 52. The second half of the 52 You vill find then withe + wire on chassis and - on the - You used to measure these 52 V.

If it will be so, You could make the further measurements using chassis as the reference ("ground").

Please, do the measurements with caution!
 
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