Lower Volume from One Monoblock

.the seller refused to allow me to inspect them at his place prior to finalizing the deal...

Sounds like he made you an offer you couldn't ACCEPT ;-) IMO, looks like you dodged a bullet.

Well it turns out I couldn't close the possible deal on the Brystons...the seller refused to allow me to inspect them at his place prior to finalizing the deal...

I did remove the cover and check the fuses...they were okay. I will just send them back to Cary (not too far from where I live) and let them check them out.

Russ offers good advice. If a fuse blows on one side of the Cary MB's you will get a much lower volume (really low) out of that amp. Its always worth a try taking the cover off and seeing if there is anything obvious.

Just for kicks, try putting in new fuses. Sometimes it's something simple.

My only thought was that since the 20's don't really go too low that in the bass it might work.

Stickman451, you need to trust Al on this one. I've had some experience with an impedance mismatch, and bass was not the only issue with the sound. It also seemed lifeless, dull, and lacked dynamics. An amp with the correct input impedance, and only a 1/4 of the power of the mismatched amp was actually more dynamic. Both amps sounded great with a properly matched preamp.

As far as sound goes, what do you think if the Cary's? You don't say how long you had them for. Did you hear them before the problem? If you can use the Cary's as a reference, it may be helpful in the search for a new amp.

My only thought was that since the 20's don't really go too low that in the bass it might work.

So, you don't think it would match well at all?

I wouldn't recommend it. It MIGHT sound fine on most recordings, since what would be adversely affected to the greatest degree is mainly the bottommost octave. But why introduce a known issue into your system when there are other choices available?

Regards,
-- Al

Almarg, thanks for the info and response. I too have read that Stereophille review and the Hovland does have a very high impedance. So, you don't think it would match well at all? I am using Magnepan 20.7's too.

Stickman, I haven't tried any of the Bryston amps in my set up. It's been all Cary for a long time now.

Stickman, I doubt that the 28BSST2 would be a suitable match for your Hovland preamp. As with a number of other Bryston amps, its input impedance is lowish, in this case either 15K or 16.5K for its unbalanced input, depending on what document is looked at. From JA's measurements of your preamp:

Despite the claim that the HP-100 uses a cathode follower output stage, its source impedance was high at 2.4k ohms, rising to 4.3k ohms at 20Hz. The partnering power amplifier would best have an input impedance of at least 47k ohms if the bass is not to sound lean.

Regards,
-- Al

I've been looking at the Bryston 28B SST2. I tried the new version of the cary 500's but they had some sort noise problem via the single ended inputs; talked to cary but could not work it out. Not really sure what caused that noise issue.

Have you tried the 28B sst2?

Stickman, it's been a while so I don't remember what I replaced the mono's with, sorry.

Stickman, If you are thinking about replacing the Cary's you might want to give some thought to the CAD 500.1t's. In most respects, the 500.1's are much better amps than their predecessors. They don't come up for sale very often though.

Foster_9, curious what did you find to replace the Cary's? I am driving Magnepan 20.7's and need all the power I can get!

I will contact Cary Monday and arrange to send them both amps for a 'check-up'...

I repalced the Cary's temporarily with a stereo SS amp and all is good now, images are centered correctly; definitely something going on with the Cary's...

Having had those monoblocks before, and dealing with Cary service before, you might find they'd say that one or both amps need to be re-biased.

After reading Tls49's response, I think I may have missed something.

"Swapping the monoblocks left to right the louder sound swapped too. The left channel is now lower in volume."

Did you actually swap the amps so that the IC's going from the preamp to amp remained connected to the same channel, or did you just swap the IC's? If its the former, then Tls49 is right. Disregard everything in my 1st post except the part about the Balanced/SE switches.

The Bal/SE switches should be checked, however, interconnects and other components will not be the problem. Since the reduced sound moves as the amp is moved, it can only be the amp.

Make sure the 2 switches for Balanced/SE operation are both in the same position. If you have one on SE and the other on Balanced, the volume for each channel will be different. After that, swap the IC's going from your source to the preamp. Its possible that one of the other components is the problem.

Have you tried reversing the interconnect cables? Try swapping the cables from the preamp to the mono amps to eliminate the possibility of the preamp causing this problem. Also, are your cables of the same length and same kind? I had a similar issue as you, until I used the same length interconnect.

Good luck,
Audioquest4life