Yes IN is connected to amp OUT, 200W/8R but you can use 10k pot instead 4k7 resistor and set different value.
hi wiljj78,your work is great for diyer.i have one request for you.will you make pcb of that apex traic based speaker protecter?i need that circuit for my speakers.if you make then it will be great help for me.i love your pcb.
6 pairs at 80vdc rails. 5 pairs will also do if your trafo is less than 700va for both channels. it depends how much the rails sag.... be safe go with 6 pairs. 7 pairs with 800va, 10 pairs with 1kva. This should cover 4 ohm loads. I had a Forte Audio model 3A with a 700va trafo with 5 pairs, it had 5 pairs and ran on 78vdc rails and ran 4 ohm loads without issues. Clipping at 8 ohm was about 240watts just to give you reference. You should go with some extra safety margin.
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hi apex sir,you are very naughty guy.please please please share pcb file of that vu meter.
If you are looking for more wattage.... you would need a massive transformer (i.e. if you wanted 600w into 4 ohms at 80vdc) you are looking at about a 1.5kva trafo per channel.
Some examples:
I stuck a 1kva trafo in an Adcom 555ii and changed all outputs to MJ21195/96; jack up the supply to 86vdc. I got about 370watts into 8 ohms at clipping and 575 watts into 4 ohms with only one channel running.
The Adcom 565 uses a 1.2kva trafo with 83vdc rails and it can do 610 watts into 4 ohms at clipping into one channel.
So if you want 600w using only 80vdc... you need a huge power supply
and many pairs of C5200/A1943... in the range of 8-12 pairs
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If they are not blown up yet, and are hot at 95vdc, that might denote inadequate heatsinking. If you had breached the SOAR, the devices would have failed prior to them heating up the heatsink.
If you are very price sensitive, and cannot afford many Devices, then agree on running the amp at 8 ohm loads only, this way, 4 pairs at 80vdc will be ok assuming a moderately regulated power supply like 500va with 15000uF per rail.... . But if you run 4 ohms with 4 pairs, you could blow them up. At 80vdc, the c5200 is like a 50watt device, so extracting 400 watts from 8 devices is right on the edge.... derate that with temperature and you have already exceeded the SOAR.
By the way, are you sure the 2sc5200/A1943 are not fakes? Since originals will not be a whole lot cheaper than the MJ21193/4's, and the 3281/5200's are one of the most counterfeited devices out there... so there is a chance these are fake devices.... consider this as well.
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thank u,
i think my transistors are original, because i checked with 95v dc with full volume, clipping around 60vac on out,
load 4 ohm dummy load
9 pair outputs,
the temperature of the transistor ceramic body is over 90 degree, but not blown.,
but with the two fans cant reduce the heat.
heat sink also very hot, over 90 degree,
voltage drop to 84v dc.
This is impossible.
If the supply voltage dropped to +-84Vdc ( "voltage drop to 84v dc" ) then the output cannot be 60Vac ( "clipping around 60vac on out " )
Since 60Vac is equivalent to 84.85Vpk
The supply rail voltage would need to be greater than approximately +-90Vdc while the output was delivering 60Vac.
If your supply voltage dropped from 95Vdc to 84Vdc, then for 60Vac you would need quiescent supply rails of ~ +-101Vdc
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if supply is down to 95v to 84v it mean your tranformer is poor quality.voltage should never down to 3v or 4v at load.with poor data and material transformer on chassis can also dispatch the heat to heat sink.in that case you have to insulate transformer with bakelite sheet so it does not touch the chassis.