Hello & Apogee Schematic Needed

Hello & Apogee Schematic Needed


This is my first post, so I want to say hello and that I'm impressed with all of the DIY enthusiasm found here. I also enjoy reviewing all of the posts and the variety of skill levels put forth. Having worked in both professional audio, and having been an avid audio hobbyist for almost two decades, I hope to be able to contribute in a positive manor.

Does anyone have schematics for an Apogee DA-800 (or similar DA series) amplifier, or more specifically, the power amp stage? I recently purchased an output power stage for a DA-800 off eBay and would like to avoid the time and effort of reverse-engineering it (though I’m about 20% done). The output stage I bought includes the positive and negative power output stages with class-A drivers and a PCA with the differential input stages and current sources. The output boards use a two-step supply voltage system similar to class-G topology, but I’m not sure if it switches rail voltages based on the load and drive current, or simply runs class-G to reduce heat during “average” operation. It’s quite beefy with a forced-air-channel heatsink and enough paralleled output devices to deliver its rated 800WRMS quite easily. I may build it into a dedicated sub-amp for the fun of it. Any help is much appreciated and I’d be happy to post my project here.

As a side note, I “acquired” fairly complete sets of schematics for the now defunct Linear Power car audio manufacturer. The schematics are from the 1980s and 1990s and are not to be confused with the current Linear Power products being produced (I must add this little disclaimer as not to upset the near-illiterate person now repairing some Linear products as I don’t want to receive their foul-mouthed, incoherent babblings again as I did when I sold some copies on eBay. I’d be concerned about posting some copies here, but I don’t think the cranially-challenged individual who lambasted me could comprehend this site or its/my content). I’d be happy to trade some for some of the before mentioned Apogee schematics or will simply post some for interested enthusiasts. Some of the DC-DC converter information is interesting, but trust me, the amplifier sections are not very complex or suitable for home use.