2. amps-preamps
  3. 189201-124012

Bryston amp, pop sound at power down.

I have a Bryston 4BSST2 amp that has been wonderful except for a "pop" sound at power down. It is not enough of a pop that I think it will hurt the speakers, but I find it a little annoying. I also worry that it will have a reduced resale value some day as I will have to reveal that fact. 

It is still within the 20 year Bryston warranty period, but when I called a couple of years ago they were dismissive of the issue, stating that it is just the last little bit of power being released, no big deal. 

Does anyone else have an issue with amps making a pop sound at power down? If you did, were you told it was normal? 

Do you knowledgeable electronics people think there would be a way to correct the issue?

I'm debating if I should be more forceful with Bryston. Maybe responses here will push me a bit.

Thanks!

 

 

128x12861falcon
erik_squires
15,667 posts
 

Turn amp on and measure DC at speaker terminals. 

Also, disconnect inputs and see if problem persists

erik_squires
15,667 posts
 

Of course, turn off your amp before playing with the inputs.  

Also, do you have a tube pre?

bslon's avatar
bslon
2,043 posts
 

My 20 year old 4bST would send a quiet, dull thud sound to first the left speaker, then the right on shut-down, no matter what the preamp’s volume setting. I was told by my dealer and by Bryston’s James Tanner this is normal operation for that amp. I would not describe it as a “pop”.
I now have a 4b3, no more thuds on shutdown.
Send an email about it to James Tanner, he’s responded promptly to me in the past.
 

61falcon's avatar
61falcon OP
101 posts
 

No tube preamp. I've tried the amp with two different solid state amplifiers and with no inputs at all and the pop still occurs. I noticed that it seems to be an equal pop on both left and right channels. 

I will perform the dc speaker terminal test tonight and report back

Thank you Erik.

61falcon's avatar
61falcon OP
101 posts
 

I measured DC voltages at speaker terminals on the amp and both channnels measured .000VDC. This measurement was with a fairly decent fluke meter and had the volume set to zero on preamp and speakers disconnected. 

That's how to do it, correct?

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