[Ilkatze]

Hello, Everyone.

Today I received XLR cables from Bryston and connected my BP4 preamp to my new 4BSST2 amplifier.

By pure chance, I turned off the preamp first--leaving the tuner and amp on--and sound continued to come from the speakers for several seconds.  Maybe 5 seconds or more is how long the sound lasted.

Is this normal?  It did not happen with the unbalanced (RCA) connectors.

The rear amp switches are in the balanced position (for the XLRs), the gain is set at 1v, and the mode is set at "Individual".

Also, there is now a rather noticeable (loud?), very low-pitched "thump" when I turn on the preamp.

I'm wondering whether I have something connected wrong or set incorrectly.

In closing, I'll mention that the speakers are both connected out of phase (because of a difference in XLR pin assignments on the preamp and amp).

I'd appreciate any thoughts you all might have.

Michael

[drummermitchell]

I usually turn my prepro on first and then the amps.
If I shut them off, shut the amps off first,then components,I'm not surprised you got a nasty thump.
I've only shut my gear down once(last year)2week holiday.I have all my gear on except my 4B-sst and 7B-sst(centre)My mains(7b-ssts )are always on and ready,and soooon my 28s will be READY.
TURNING OFF,AMPS FIRST,COMPONENTS LAST,TURN ON PRE FIRST AND THEN THE AMPS
Your speakers will love you for it .

[James Tanner]

Hello, Everyone.

Today I received XLR cables from Bryston and connected my BP4 preamp to my new 4BSST2 amplifier.

By pure chance, I turned off the preamp first--leaving the tuner and amp on--and sound continued to come from the speakers for several seconds.  Maybe 5 seconds or more is how long the sound lasted.

Is this normal?  It did not happen with the unbalanced (RCA) connectors.

The rear amp switches are in the balanced position (for the XLRs), the gain is set at 1v, and the mode is set at "Individual".

Also, there is now a rather noticeable (loud?), very low-pitched "thump" when I turn on the preamp.

I'm wondering whether I have something connected wrong or set incorrectly.

In closing, I'll mention that the speakers are both connected out of phase (because of a difference in XLR pin assignments on the preamp and amp).

I'd appreciate any thoughts you all might have.

Michael

Hi Michael,

How old is the BP4?

james

[James Tanner]

Hi Michael,

I checked with engineering and apparently the early versions of our preamplifier's (BP4 included) only had the mute relay on the RCA outputs not the Balanced outputs.

So the best course of action is to make sure you turn the preamp 'on before' the power amp and turn the 'power amp off' before the preamp. You are not doing any harm using the preamp once it stabilizes.

james