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Bryston 7B SST

Hi There,

First post of many I hope.

I am using a PS Audio Directstream into a pair of the above monoblocks running into B&W 802 diamonds. The Brystons have a 1v/2v gain setting and a switch for balanced input (XLR) or single ended.

On adding a PS Audio BHK Preamp I noticed a lower relative volume in the right speaker and after checking inputs / isolating components / cutting back to just the Directstream and testing I find that:
On single ended leads, both speakers have equal volume on 1v (1v is louder than 2v)
On single ended leads, both speakers have equal volume on 2vOn XLR, one speaker is louder on 1vOn XLR, one speaker is louder on 2v
So it seems that using XLR, one of the monoblocks is putting out more volume on both of the gain settings relative to the other.

I can run them on single ended leads on the 1v setting to get equal volume, but I can’t help thinking that I’m missing out somehow.

Anyone have any ideas as to what may be wrong or maybe has experienced similar?
Thanks,
Marcus.
astonmartinv8
10 responses Add your response
astonmartinv8 OP
4 posts
 
Yes I flipped gain switch back and forth to make sure it was not faulty. Initially it made no difference on one of the blocks, then it did! May have been both switch and XLR cable. All good now.

Thanks very much to everyone for taking time out of your day to respond.
Marcus.




mike_in_nc
1,139 posts
 
It looks like you've solved the problem. I would also flip the Bryston's gain switch back and forth a few times, in case it's intermittent.

(I used a 14BSST for years -- a similar amp to yours -- and it is one of my favorite amps ever. Now I'm using a 4B3, which also is excellent.)
noble100's avatar
noble100
2,419 posts
 
Hello astonmartinv8,

Yes, room acoustics are very important. It also will be beneficial to move your right speaker as far away from the corner as possible. if you’re able. Just moving both l+r speakers further away from the wall behind them should also be beneficial, again if you're able to.

Tim
arcticdeth's avatar
arcticdeth
1,572 posts
 
Great!

 I bought my first pair of audioquest XLR cables , god, must be 30 years ago,
 one day I hooked them up, this was 4-5 years ago now, and something was wrong, happens there was a single wire which was broken in the one cable.
  I sent them to audioquest, and their warranty is one of the best in the business, they received, repaired, sent back, no charge.
  Amazing company, amazing!

 They were 20 years old when I sent them in for repair, and everyone was friendly, and wicked cool., I will continue to buy audioquest cables.  Great company!

also, my right speaker, seems to have more output, louder than the left,
 left speaker is 3 feet from a large opening to the stairwell, and hallway and rooms,
right speaker is in a corner, and puts emphasis on the right side, which makes it seem louder, has tighter bass, took me a while to get used to it.  
 I put pillows behind the right side, and it helped a bunch!

 Room acoustics is a huge part in audio as always mentioned!

 
astonmartinv8 OP
4 posts
 
Its a weird room shape, which didn't help in the troubleshooting, but the cause was a faulty (new) XLR cable, which was a great surprise as I'd run through this and thought it had checked out. After replacing all cables with new XLRs it is working very well now.
arcticdeth's avatar
arcticdeth
1,572 posts
 
Is one speaker in a corner?
 Or did you get it all figured out??
astonmartinv8 OP
4 posts
 
Went to the local dealer and replaced all the cables. Ooops. I think the issue is in one of the XLRs. It sounds pretty awesome now I have to say.
limomangus's avatar
limomangus
1,363 posts
 
Yes check out the cables.
astonmartinv8 OP
4 posts
 
I don’t think it is the BHK as When using the DS as a preamp I had the same issue. It could possibly be the XLR cable (will test this later). 
auxinput
2,920 posts
 
Something is definitely wrong with the BHK. It could be one of the tubes that is faulty or it could be the Class A output stage. I am guessing the BHK is not providing gain for the "inverted" signal pins on the XLR balanced output. This is likely why one of the amps is quieter when using XLR inputs.
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