Hi -
new to the forum, and only recently realized how much of an audience PL had and still has in 2020. Audio lover forever, audio gear guy only more recently. My uncle worked for PL in the 70s (not sure in what capacity, he passed a number of years ago), and I can still recall the massive Phase Linear stack he had.
Recently acquired a Phase Linear 400 and a 4000, both series 1, from a local fan of Phase Linear, awesome guy. The 400 is mostly cosmetically perfect, sounds good. I'm a tinkerer and wanted to give it the imlay, speaker protection + white oak treatment when funds allow, so it's shelved for a minute. The 4000, I'm having a little more fun with...a few small quirks with it. I got it for a good price, with problems with the peak unlimiter circuit (a board swap fixed that, the same seller had spare boards, eliminated the distortion I was getting) and with what I assume is the Logic circuitry (toggling into "stereo" from "mono" and into "4-channel" from "2-channel", both will eliminate sound from the same channel). I've read plenty of opinions on how the 4000 can be a service nightmare, but sentimentality says I keep it.
At any rate, glad to discover the the Phoenix Audio community here and I appreciate everything I've learned thus far from "lurking." Happy listening!
new to the forum, and only recently realized how much of an audience PL had and still has in 2020. Audio lover forever, audio gear guy only more recently. My uncle worked for PL in the 70s (not sure in what capacity, he passed a number of years ago), and I can still recall the massive Phase Linear stack he had.
Recently acquired a Phase Linear 400 and a 4000, both series 1, from a local fan of Phase Linear, awesome guy. The 400 is mostly cosmetically perfect, sounds good. I'm a tinkerer and wanted to give it the imlay, speaker protection + white oak treatment when funds allow, so it's shelved for a minute. The 4000, I'm having a little more fun with...a few small quirks with it. I got it for a good price, with problems with the peak unlimiter circuit (a board swap fixed that, the same seller had spare boards, eliminated the distortion I was getting) and with what I assume is the Logic circuitry (toggling into "stereo" from "mono" and into "4-channel" from "2-channel", both will eliminate sound from the same channel). I've read plenty of opinions on how the 4000 can be a service nightmare, but sentimentality says I keep it.
At any rate, glad to discover the the Phoenix Audio community here and I appreciate everything I've learned thus far from "lurking." Happy listening!
The joints on my 4000, both where the daughter/smaller circuit boards plug into the mother, and where the mother board joins the face plate board, all looked pretty good to me, although I understand my naked eye isn't the best judge of micro cracks or cold solder joints. I reflowed the solder in a few select spots on the underside of the motherboard, and then worked the face circuit aboard apart from the mother board, sprayed connection points with contact cleaner, and then engaged and disengaged the boards a few times. I powered up again, and the left-channel drop-out issue when "4-channel" is engaged went away...but the more annoying problem of the same drop-out in "stereo" persists. I've got plenty of more reliable equipment, so not losing any sleep over the 4000, but i'm still having fun trying to give it a little love every few days. 
