[pianoguy]

I had an interesting thing happen this evening as I was listening to my system.  I have the B100 SST.  I have two digital inputs - one from my Cambridge Audio 840C, the other from a Squeezebox Duet.  I also have two analogue inputs, from my Rega turntable and a small receiver which I use as a tuner and to power outdoor speakers.  I also have the BR1 remote.

I switched on the B100 with the intent of listening to Internet radio through the Squeezebox. When I hit the increase volume button on the remote, the B100 turned off.  I turned the integrated back on and hit the decrease volume button and the B100 turned off again.  This process must have been repeated 5 or 6 times.  I then adjusted the volume by manually turning the knob on the B100 several times without incident.  I went back to the remote and everything seemed to be fine, but then, after moving the volume up and down several times with the remote, the B100 shut off again.

I then put a CD in the CD player and had a similar experience.  I was able to turn the volume up and down several times using the remote, but then, out of the blue, the amp would turn off in the middle of a volume adjustment.  I put on a record and tried to reproduce the problem.  I could not.  I turned on the Cambridge receiver (tuner) and tried to reproduce the problem.  Again, I could not.  The issue seems to only occur with the digital inputs though I have not done near enough testing to state this with 100% certainty.

To review: at the beginning, when I first turned the B100 on, the amp would turn off every time I tried to adjust the volume (either up or down) with the remote.  It was only after I manually turned the volume knob a few times that the problem seemed to stop.  However, if I continued to adjust the volume up and down several times using the remote, the amp would every once in a while shut itself off in the middle of a volume change.  Also, this only seems to happen when being fed a digital input and I cannot seem to reproduce the problem when manually turning the knob.

Any ideas as to what might be going on?

[James Tanner]

HI pianoguy

Could be low voltage?
Please send this to Mike Pickett at Bryston - mpickett@bryston.com

james

[pianoguy]

Thanks, James.  I've just sent an email off to Mike.

[pianoguy]

Just as an update, I measured the line voltage while I did some more experimenting with the volume changes using the remote.  The B100 still continues to shut down but the line voltage is pretty constant and hovers between 108.8 V and 110.0 V.  I think I read earlier that the shutdown voltage is 105 V, so I doubt this is the problem.  It's also definitely only occurring with the digital inputs.

[niels]

A silly thought, but could it be the battery in the remote?

[pianoguy]

Hi Niels:

I have been discussing this issue with Mike Pickett and we've come to the conclusion that it is likely a low voltage shutdown problem.

He informed me that when combined with the use of the internal DAC and the volume control (both of which pull down the power supply), it is quite possible that the B100 is detecting low voltage and shutting off.

What's more, I have one of the earlier B100 DA units and apparently, the low voltage reference was set higher than that of the current units. As a result, mine might be tripping at a higher voltage.  He has offered to reduce this voltage to avoid further issues.

The other thing is that I have my electronics on a dedicated line.  This was put in when we had renovations done on our home.  Unfortunately, this dedicated line appears to share a "leg" of the incoming service with other high-draw appliances, including the microwave and the air conditioner.  Because of this, I have seen the voltage in this dedicated line as much as 5 V lower than other outlets in the same room.  Mike informed me that an electrician could redistribute the circuits so that the audio system isn't sharing this leg with the a/c, so this is another option.

In the meantime, I have temporarily plugged the B100 in to another outlet and am keeping an eye on it.  So far, no issues!

[alexone]

Hi Niels:

I have been discussing this issue with Mike Pickett and we've come to the conclusion that it is likely a low voltage shutdown problem.

He informed me that when combined with the use of the internal DAC and the volume control (both of which pull down the power supply), it is quite possible that the B100 is detecting low voltage and shutting off.

What's more, I have one of the earlier B100 DA units and apparently, the low voltage reference was set higher than that of the current units. As a result, mine might be tripping at a higher voltage.  He has offered to reduce this voltage to avoid further issues.

The other thing is that I have my electronics on a dedicated line.  This was put in when we had renovations done on our home.  Unfortunately, this dedicated line appears to share a "leg" of the incoming service with other high-draw appliances, including the microwave and the air conditioner.  Because of this, I have seen the voltage in this dedicated line as much as 5 V lower than other outlets in the same room.  Mike informed me that an electrician could redistribute the circuits so that the audio system isn't sharing this leg with the a/c, so this is another option.

In the meantime, I have temporarily plugged the B100 in to another outlet and am keeping an eye on it.  So far, no issues!

that's interesting.

al.

[patrickm]

I had exactly the same problem with my B100 DA.  However, my issue was not with internal house wiring but the supply coming off the external grid.  On hot summer days, the supply into my house was sub 110V due to the local drain.   Called the local power folks to inform them and after much discussion + investigation, my supply now hovers around 120V +/- 5V.

In the meantime, I picked up a Torus CS15 AVR which regulated the power to 120V... at least I could listen to my music during the summer [and I was looking for a power conditioner anyway].