[DRC]

I have a question for all SP3 owners that have used their SP3 in 2 channel bypass and feeding it an analogue signal from a phono preamp. I have identified an issue that has been confirmed by Bryston and will be corrected. Unfortunately in my case it was a little late because I blew a driver in my Usher's.
The issue is a large transient "popping" when the SP3 receives a signal from a phono stage that might be higher than 2 volts. Although the SP3 is supposed to be able to accept up to 4 volts in 2 channel bypass it has an issue in handling anything approaching its maximum.
The suggested work around is to run in "stereo" versus 2 channel bypass. "Stereo" is not 2 channel bypass and does not sound anywhere close to pure analogue 2 channel bypass.
In my case I have a an Ortofon Cadenza Bronze with a .4 mV output. It feeds either an EAR 834P or a Parasound JC3. Each has a 68 dB gain for MC. At 1000 hz this would produce a 1 volt signal.
I have had the EAR for over 10 years. In fact I had the same front end going into an SP1.7 before the SP3 as well as Proceed, Levinson, Arcam etc and never had an issue.
I have had the SP3 since December 2011 and posted many rave reviews including one on this forum. I did not experience this issue for the first 6 months. In fact for the first few months I was trying to find the source of my loud transient popping I ruled out the SP3 and looked at everything else in the signal chain. It was only when I sent the SP3 back to Bryston that we confirmed this is an issue with the SP3 in 2 channel bypass. I sent the EAR to them and they used it on other SP3's in stock and had the same result. Although they said the gain in the EAR was high they did confirm that the SP3 should not behave they way it does.
When I went back and looked at all the published reviews from Stereophile, Widescreen Review, Home Cinema Choice, Inner Ear none of them used the SP3 with a phono based source. Only Home Theater (Fred Manteghiam) tested with a phono front end. The review did not mention any details on the source components.
This is why I am reaching out to other SP3 owners that have a phono front end to see if anyone else has experienced this symptom.

Thanks

[DRC]

Update March 11, 2014 from DRC

It was suggested I move this to the official SP3 thread which I am doing and also for an update.

In December Bryston installed what they are calling a "level limiting modification" to my SP3 for 2 channel bypass mode. After chasing the cause Bryston engineering in October identified "Engineering has nearly finalized a solution for this that eliminates the voltage spikes when the level control chip is overdriven".
I am happy to report that the modification has not only eliminated the problem but most importantly HAS NOT DEGRADED THE SOUND in 2 channel bypass when being fed an analogue signal from a phono stage.
I am satisfied with the support from Bryston for this issue. Unfortunately it did take almost 6 months to confirm that my problem was not unique. My position was always that running a .4mv MC cartridge into multiple phono stages (including Bryston) should not cause the SP3 to cause loud popping transients. In my case it blew a driver in my Usher Mini Dancer DMD. I originally posted this question to identify other SP3 owners that have had a similar experience and hopefully prevent this happening to anyone else.