Ok, so I have this monstrosity finally up and running. Still needs some wire rerouting and final mounting, but everything seems to work. It is using the TDA7293 x 4 BTL module found frequently on Ebay. I think it may be manufactured by Yuan Jing Audio but sold by several resellers.
One standout in the design. Two of the electrolytic caps near the voltage regulators for the NE5532 are underrated. The specs say you can run the boards at 35V, these caps see near rail voltages and were rated at 25V. I didn't notice until I saw them bulging and got suspicious. So double check these if you get this board and swap them out if your going to run it above 25V.
It has a good turn on thump, so I put in two Velleman K4700 protection kits. Since the output is bridged, you need two of these. No more thumps or squeaks on shutdown.
I was getting some hum but was able to eliminate most of it by rotating the 500VA torroid and routing the DC power to the boards further away from the transformer.
Listening: These boards put out a lot of power. I've been using a Rotel RB-981 prior to this and it compares fairly well. The Rotel seems might have more detail in the mids, but overall these TDA7293 x 4 BTL mono boards are good sounding amps. The heatsinks remain <45 deg. C unless I turn up the volume louder that I care to listen to it.
Time to tidy things up, find good placement for the Vellemans and finish the case.
One standout in the design. Two of the electrolytic caps near the voltage regulators for the NE5532 are underrated. The specs say you can run the boards at 35V, these caps see near rail voltages and were rated at 25V. I didn't notice until I saw them bulging and got suspicious. So double check these if you get this board and swap them out if your going to run it above 25V.
It has a good turn on thump, so I put in two Velleman K4700 protection kits. Since the output is bridged, you need two of these. No more thumps or squeaks on shutdown.
I was getting some hum but was able to eliminate most of it by rotating the 500VA torroid and routing the DC power to the boards further away from the transformer.
Listening: These boards put out a lot of power. I've been using a Rotel RB-981 prior to this and it compares fairly well. The Rotel seems might have more detail in the mids, but overall these TDA7293 x 4 BTL mono boards are good sounding amps. The heatsinks remain <45 deg. C unless I turn up the volume louder that I care to listen to it.
Time to tidy things up, find good placement for the Vellemans and finish the case.
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