[Alfalfa]

Although there does not seem to be too many visitors here, I feel this is the place to ask about the buzzing power supply of my BP20 preamp. My concern is that it could compromise sound quality. Could it? During quiet passages in the music I can hear the power supply in the hot spot. There is also a slight 'hum' in my midranges/tweeters when there is no music playing when I put my ear beside it although I know that Bryston amps are known te be 'dead quiet' when tested this way.

What causes the power supply to buzz? Can it be fixed (if one knows how to open the box?)

The related question is of course about the new power supply of the BP26 pre. Can somebone comment if it improves the sound quality?

In case you might ask: I'm using an earthed seperate mains supply for my audio system and have tried to swap the plug the other way around to no effect. Using alternative cd-player also did not make any difference.


Please don't answer al at once  

[James Tanner]

HI Al,

Do you get buzz from the supply only or through the speakers?
Do you still get buzz through the speaker if you disconnect the preamp with power amp still on?
The buzz can be cause by bad power conditions - have you tried it in another circuit?

james

[Alfalfa]

Hi James,

Thanks for stopping by    The power supply of my BP20 starts buzzing as soon as I fire up my BP20. I tried several mains outlets and got the same result. Before we moved into our current home 'the buzz' was also there in our former house. I connect to the &B ST's through balanced interlinks. My brilliant new speakers are PMC IB2's.

When I slightly press the power supply case, the buzz stops, but when I release it, the buzz is on again.

Is this a problem (could it compromise performance?)

Greetings,

Alfalfa

[James Tanner]

Hi Al,

Sounds like it is just a mechanical problem with the Power Supply. The bolt that holds the transformer in place may be a little loose.
It will not cause an issue with performance but you may want the Bryston distributor to have a look at it.

How do you like your IB2's? How big is your room?

james

[Alfalfa]

My room is about 15 x 15 x 12 feet. It has (en suite) doors to the adjecent room which is about the same dimensions. I have positioned them about 2 meters apart and sit at about 2,2 meters distance. While I'm not sure that the speakers have been fully burned in yet (there sometimes is an occasional 'ssss' when I crank it up) I am astonished at the transparency of this setup. At the same time I am amazed of the termendous powers it can unleash, and the very clean high frequencies. Classical orchestra music is really great, acoustic music is fantastic, pop music sometimes maybe is just a bit too much in the bass and rock/metal quite easily ehh "fills" the room at higher levels so that voices get a bit squeezed. So far my musical preferences..!

I feel this speaker is so transparent ans of high quality that I imagine enjoying it for very long (the rest of my life maybe) and gradually upgrade the rest of the (pre/amplifying) system. The power supply of my BP20 could be the first victim   .