Hello,
Sony STR-DE197 100 watts x 2 receiver died. I would like to salvage to the power components for a DIY subwoofer 2 channel amp project to drive 2 15" subwoofers (mainly for learning and fun). I removed the big heavy transformer 1-443-188-11 and measured the A/C voltage between various output lines of 88.2v, 74.8v, 43.7v, 30.3v, 12v across various pins. I can also try and salvage 2 71v 6800uF capacitors and a rectifier RBV-602 HTTP 301 This page has been moved.
What type of board/chip would you all recommend for such a project? Any reliable sellers on ebay for such a board?
Sony STR-DE197 100 watts x 2 receiver died. I would like to salvage to the power components for a DIY subwoofer 2 channel amp project to drive 2 15" subwoofers (mainly for learning and fun). I removed the big heavy transformer 1-443-188-11 and measured the A/C voltage between various output lines of 88.2v, 74.8v, 43.7v, 30.3v, 12v across various pins. I can also try and salvage 2 71v 6800uF capacitors and a rectifier RBV-602 HTTP 301 This page has been moved.
What type of board/chip would you all recommend for such a project? Any reliable sellers on ebay for such a board?
Maybe 1 sub. ... sony trafo is kind of "weak" for subwoofer duty.
PS - sony lies - that amp is barely 50 "true watts" per channel !!
OS
PS - sony lies - that amp is barely 50 "true watts" per channel !!
OS
You need to do more than this.
disconnect the transformer completely.
Isolated every end from all others.
Use a continuity meter/ohm-meter to identify which ends connect to any others.
Some windings may have more than two tappings/ends. Label them.
Measure the resistance of every tap to tap.
Work out from the resistances which tappings are near the middle and which are actually at the ends.
Then apply mains power to what you think are the correct primary tappings through a Mains Bulb Tester.
Now measure the voltages on ONE winding. Record each tapping to tapping voltage. And record the mains primary voltage. You will need this later.
It is possible that the transformer you have is a centre tapped secondary with two intermediate tappings. But at this stage that is just guessing and inspiration. You need to be more thorough than that before you commit to powering ON via the Mains.
Your life (and that of any other occupants) is in your hands.
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Yep, AndrewT is right. You need to check it all thoroughly.
The connectors (provided you didn't cut them off) will also provide hints along with the wire colours. They should be in logical sets which should aid in figuring out what is what.
On the Sony you will probably find a centre tapped set, with two higher voltage pairs for power stages (possibly Class-G type stages) and then one set that is intended to feed op-amps. Then on a seperate connector, you will find various voltages suitable to feed various bits of digital electronics.
The connectors (provided you didn't cut them off) will also provide hints along with the wire colours. They should be in logical sets which should aid in figuring out what is what.
On the Sony you will probably find a centre tapped set, with two higher voltage pairs for power stages (possibly Class-G type stages) and then one set that is intended to feed op-amps. Then on a seperate connector, you will find various voltages suitable to feed various bits of digital electronics.
I would of recorded the amps rail voltages at the big caps and marked the wires before taking it apart. but you obviously know where the primary is , oblivious to some other posters.
2X 71V caps seems strange but can be low as 63V for solid 100W operation.
2X 71V caps seems strange but can be low as 63V for solid 100W operation.
71V caps - sony is chinese junk . They are running 60-65V rails with little de-rating.
The trafo is cheap and designed for massive rail sag to allow the use
of a single pair of (soa starved) mt-100's and to make the 1 year warranty period.
Then they have the gall to call it a 100W/ch amp !
The sony's use as parts for a sub - maybe 1 8"-10" (mono) efficient driver powered by a small 2 pair mt-100 output stage.
I've used 2 of these (sony /pioneer) e-waste trafo's (dual mono) to build a stereo 80W per channel unit.
Even with over 20kuf per channel - much rail sag.
OS
The trafo is cheap and designed for massive rail sag to allow the use
of a single pair of (soa starved) mt-100's and to make the 1 year warranty period.
Then they have the gall to call it a 100W/ch amp !
The sony's use as parts for a sub - maybe 1 8"-10" (mono) efficient driver powered by a small 2 pair mt-100 output stage.
I've used 2 of these (sony /pioneer) e-waste trafo's (dual mono) to build a stereo 80W per channel unit.
Even with over 20kuf per channel - much rail sag.
OS
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