OctalSocket
Active Member
Just recently rotated my Sherwood AM-7040 back into use after more than a year of storage. I brought it up gently with a Variac, and heard an approximately one to two second"bzzzp" as I was bringing the voltage up past 50 or so VAC. I assumed it was the speaker relays buzzing until they got adequate supply power to the coils.
Once powered up, the amp was dead quiet when putting my ear close to the tweeters and woofers of my Bose 601s. Ran some music through it, and all was well. Shut it down after a while, no pops, thumps, etc.
The next time I turned it on (straight to 117V, no variac), I noticed a mild pop in the left channel speaker once the protection circuit light shut off and the speakers came online.
I have the service manual, downloaded from HiFiEngine, but am barely proficient in reading such a schematic. I know what most all the symbols are, and I assume there may be a cap somewhere around the speaker relays that may provide a soft start of sorts, but I have no idea which one it could be, if that's even it.
Any tutelage and advice would be greatly appreciated. This is a pretty darn good power amp, and I don't want to be damaging anything, especially a speaker relay that may be arcing, causing that mild pop.
Once powered up, the amp was dead quiet when putting my ear close to the tweeters and woofers of my Bose 601s. Ran some music through it, and all was well. Shut it down after a while, no pops, thumps, etc.
The next time I turned it on (straight to 117V, no variac), I noticed a mild pop in the left channel speaker once the protection circuit light shut off and the speakers came online.
I have the service manual, downloaded from HiFiEngine, but am barely proficient in reading such a schematic. I know what most all the symbols are, and I assume there may be a cap somewhere around the speaker relays that may provide a soft start of sorts, but I have no idea which one it could be, if that's even it.
Any tutelage and advice would be greatly appreciated. This is a pretty darn good power amp, and I don't want to be damaging anything, especially a speaker relay that may be arcing, causing that mild pop.