that's a great chassis. the only trouble may be that they are worth over a grand on ebay if in working order. I got my sx-3700 for 125 cdn several years ago.
There is a relay on the sansui? board behind the amp boards that may be protection circuitry. you will have to connect the new amps to that system if you want it to work. Did you have to connect directly to the outputs to get sound?
found a schematic, it does have basic speaker protection built in as well as a separate 57v regulated supply for VAS stage.
There is a relay on the sansui? board behind the amp boards that may be protection circuitry. you will have to connect the new amps to that system if you want it to work. Did you have to connect directly to the outputs to get sound?
found a schematic, it does have basic speaker protection built in as well as a separate 57v regulated supply for VAS stage.
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Yes, the value was a consideration but I couldn't resist the build. 
There is an Omron relay for speaker protection but there are some other connections on the existing Sansui boards that aren't used with the new driver and ops boards. So there are some "to make it work" kind of connections. An amp control board would just finish the build nicely I think. If there is room.
Then of course stencil a little "Powered by Vzaudio" logo in a corner of the top.
There is an Omron relay for speaker protection but there are some other connections on the existing Sansui boards that aren't used with the new driver and ops boards. So there are some "to make it work" kind of connections. An amp control board would just finish the build nicely I think. If there is room.
Then of course stencil a little "Powered by Vzaudio" logo in a corner of the top.
The VZ control board looks like a great option if you can fit it in there. THe problem becomes the VAS power supply board that look like it shares the same PCB.
You may be able to cut the board removing only the Protection circuit but I doubt it would be that easy.
with a little extra work, it may be possible to remove all the protection parts and piggyback the VZ control board on top of the Sansui board
You may be able to cut the board removing only the Protection circuit but I doubt it would be that easy.
with a little extra work, it may be possible to remove all the protection parts and piggyback the VZ control board on top of the Sansui board
Whoa!
I really like the build, as well as the fact that this good old piece of metal from the legendary brand has got a new life The chassis is in good condition - the whole thing looks very cool to me.
Jeff will consult on the control board options - I think we've got some rather compact ones, designed for VHex+ amplifiers, normally occupying relatively compact 2U cases.
We will quickly add the required board to our new website then - not all of them are in place at the moment
Couldn't I just disconnect the 33v taps to the protection board and disable it. The only connection between the driver supply and the protection board which appears to be a ground connection for the protection circuit.
I don't need the space left by the unused protection circuit. I added 2' to the length of the chassis for the driver and ops board installation. So there is about a 4" x 5" space by the speaker outputs.
I don't need the space left by the unused protection circuit. I added 2' to the length of the chassis for the driver and ops board installation. So there is about a 4" x 5" space by the speaker outputs.
The old protection circuit and the driver supply are on one board with separate transformer taps and only 1 connection between them that appears to be a ground connection. So I believe I can disconnect the existing protection circuit.
I have a choice of 2 locations for the new protection. One is near the speaker outputs and is a space 4" x 5" with maybe 2" height clearance. The other is at the front of the amp to the right of the meters but separated by steel panel. This space is about 5 1/2" x 5" and
1 1/2" height clearance.
I have a choice of 2 locations for the new protection. One is near the speaker outputs and is a space 4" x 5" with maybe 2" height clearance. The other is at the front of the amp to the right of the meters but separated by steel panel. This space is about 5 1/2" x 5" and
1 1/2" height clearance.
Please keep in mind that this test is about the IPS(pulled AD744) NO OUTPUT connected!
Yes the protection board itself is 4" x 4". You would need to use a couple speaker relay boards and temperature sensor boards to complete the protection system. Those speaker relay boards would work fine of you have the space. We have smaller boards that can mount right on the rear of the binding posts if that would work better too.
I can't get this IPS in working conditions.
The problem with the i. C solved but now i have an oscillating unit even if i add 22pf//22pf on the vas stage.
OK, I'm with you - thinking. This is the most interesting part of testing the circuit that has never been live-tested before
I can't see any oscillation after 22pf added when tested as stand alone unit.OK, I'm with you - thinking. This is the most interesting part of testing the circuit that has never been live-tested before
I can't see any oscillation after 22pf added when tested as stand alone unit.OK, I'm with you - thinking. This is the most interesting part of testing the circuit that has never been live-tested before
Before overcompensation the IPS oscillation was present even as stand alone.
Yes now oscillate when OPS connected.