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RE: The Very Best LM3875 Gainclone

Posted by gordguide on October 19, 2017 at 23:07:35:
Op-Amps can sound great, or not so great. The basic knock on many is they were not designed specifically for high performance audio use ... many are general purpose amplifiers that are not ideal for our use.
The LM38xx family are designed for audio. Therein lies the difference.
With a gainclone type amplifier, layout is critical to sonic performance. You can't just cobble together a PCB and expect stellar performance. As techs go, many are not layout savvy, preferring to build a PCB in a way that is convenient rather than optimized.
Always buy your semiconductors and passive components from known good suppliers with a paper trail for component sourcing. Needless to say, although it's painting with a wide brush, offshore suppliers are suspect and should be avoided. You won't really save much anyway; there is little point in the first place.
A lot of eBay amps just use the basic design notes as supplied by the chip manufacturer. This is a starting point, not an end point. But if further development isn't done, they will sound average and possibly worse.
Do the math and insure there is sufficient, and don't be afraid of over-sufficient, heat sinking. This is one area where design of chip amps is critical and is often overlooked by offshore offerings (heat sinks are heavy and expensive, two areas Chinese vendors strive to minimize).
Now, not all of this matters if you're buying a premade unit. But it does reveal why better sounding examples cost more than a casual perusal of the BOM might suggest.