Looking for advice/counsel...I recently purchased an Aiyima 04 amp with the standard TI NE5532P op-amps. Using with a 24v/5a power supply. One of the Amazon review posters sung the praises of swapping in OPA627AU amps...there were a number of alternative ones mentioned as being "better" or "warmer" than the stock chips, so I thought I'd give that a try.
Found a seller that looked credible with those chips mounted to dip8 sockets, at a good price. Got them today and swapped them in, being careful to get the pin orientation correct. Upon powerup, got a high pitched noise from the amp, powered down immediately. Inserted old chips back, fortunately, the amp seems fine at least.
Did I get bad units or does the squeal indicate some sort of voltage mismatch? The chips don't have a TI or BB logo, just marked as BBOPA 627AU 0008.
Found a seller that looked credible with those chips mounted to dip8 sockets, at a good price. Got them today and swapped them in, being careful to get the pin orientation correct. Upon powerup, got a high pitched noise from the amp, powered down immediately. Inserted old chips back, fortunately, the amp seems fine at least.
Did I get bad units or does the squeal indicate some sort of voltage mismatch? The chips don't have a TI or BB logo, just marked as BBOPA 627AU 0008.