I'm playing KPAC-FM, the classical music station, and it is delightful.
The F-26 tuner is hooked to a Sonos Connect input, then the digital output of that very same Sonos feeds a Belden cable (terminated by Blue Jeans Cable with Canare "true 75 ohm" RCA's) carrying SPDIF digital to my Tact RCS 2.0 Preamp. Thus is an "analog source" converted to digital for processing by my DSP's for crossover and EQ and time delay.
Actually, for high class sources, I prefer to digitize through my Lavry AD10 digitizer at 24/96. The Lavry feeds a Geistnote AES cable to the Tact RCS.
However, a long time ago, back when I had all the equipment in front and was playing the Krell, long before the Capacitor Service in March 2017, I was playing a Pipe Dreams show on KPBS, using the Lavry instead of Sonos to digitize the output of the tuner. And the Krell shut down. That is the very first time I remember such an incident. I figured right then that there was a motorboating DC or high frequency burst that is not nice. And digitizing through the lowly Sonos somehow suppresses it.
Perhaps it's just a matter of 96kHz vs 44.1kHz sampling. Or it could be transparency to DC, quite likely the consumer friendly Sonos has a steep high pass keeping DC out of the system, whereas perhaps the Lavry goes deeper in the low Hz.
I resumed the Lavry connection, praising it as far superior, in May 2017. And that was actually the first time a shutdown occurred since I got the Krell back from Capacitor Service. It was a few days before the high power incident that blew speaker fuses and which I still believe was responsible for a fundamental bit of destruction that has been causing many, if not all, of the shutdowns.
Right then, I figured the problem playing the F-26 through the Lavry was AC power limitation, with the subs demanding current at the same time as the amplifier to meet some demand caused by a presumed low frequency burst (which I've never heard...since the amp just shuts down). The Krell must be allowed to scale up it's AC power consumption fast to meet any higher bias plateau level the computer with in it demands. If there is any glitch in scaling up the power consumption, it will shut down for "inadequate AC power." Actually, this happens when the rail voltage regulators, which are rare in any power amplifier (but there are a few other very high end amplifiers, such as the Mark Levinson ML2, which have this feature), run out of regulator margin...which is precisely because the AC hasn't kept up.
Anyway, it is quite possible that the problem tracking down the problem with amplifier shutdowns is that there is more than one process involved that causes the shutdowns. One might be that running the F-26 through the Lavry simply creates a problematic signal. The other one, which I believe must have been caused by the high power accident, has yet to be determined, but as of the beginning of this weekend was hoped and believed to be the LF transformers inside the Acoustats.
Well, so I was thinking Sunday morning as I started playing KPAC through Sonos, with the LF transformers in the Acoustats disconnected. This was surely the issue, more than one cause of the shutdowns, and by avoiding the F-26/Lavry input, and disconnecting the bass transformers, I had isolated both of them.
And I was so sure of this, I started writing this blog post after it had been playing for 90 minutes.
And then, there was a shutdown, a shutdown that could not be explained by either theory.
I have noticed that sometimes, also, that Sonos blanks out for about 1-2 seconds, or maybe it's the tuner blanking out. Perhaps that happens when Sonos is suppressing some DC from the input or something.
Anyway, this result doesn't disprove the idea that I should avoid the F-26/Lavry input. That was known to be problematic in the distant past.
But for years and years I played the F-26 through Sonos without shutdowns. So that is most likely the "new" problem I am trying to find.
At this point, sadly, I'm out of good theories. Back to there being a malfunction in the Acoustat attenuators???
I concede it could also be a problem with the Amplifier, though the amplifier was just checked out at the factory. But I won't make any headway with that until I have a consistent explanation of the problem. I may need to measure voltages in and out. Which would be another major challenge...I'd have to build a custom attenuator to protect my measuring recorder inputs.
The F-26 tuner is hooked to a Sonos Connect input, then the digital output of that very same Sonos feeds a Belden cable (terminated by Blue Jeans Cable with Canare "true 75 ohm" RCA's) carrying SPDIF digital to my Tact RCS 2.0 Preamp. Thus is an "analog source" converted to digital for processing by my DSP's for crossover and EQ and time delay.
Actually, for high class sources, I prefer to digitize through my Lavry AD10 digitizer at 24/96. The Lavry feeds a Geistnote AES cable to the Tact RCS.
However, a long time ago, back when I had all the equipment in front and was playing the Krell, long before the Capacitor Service in March 2017, I was playing a Pipe Dreams show on KPBS, using the Lavry instead of Sonos to digitize the output of the tuner. And the Krell shut down. That is the very first time I remember such an incident. I figured right then that there was a motorboating DC or high frequency burst that is not nice. And digitizing through the lowly Sonos somehow suppresses it.
Perhaps it's just a matter of 96kHz vs 44.1kHz sampling. Or it could be transparency to DC, quite likely the consumer friendly Sonos has a steep high pass keeping DC out of the system, whereas perhaps the Lavry goes deeper in the low Hz.
I resumed the Lavry connection, praising it as far superior, in May 2017. And that was actually the first time a shutdown occurred since I got the Krell back from Capacitor Service. It was a few days before the high power incident that blew speaker fuses and which I still believe was responsible for a fundamental bit of destruction that has been causing many, if not all, of the shutdowns.
Right then, I figured the problem playing the F-26 through the Lavry was AC power limitation, with the subs demanding current at the same time as the amplifier to meet some demand caused by a presumed low frequency burst (which I've never heard...since the amp just shuts down). The Krell must be allowed to scale up it's AC power consumption fast to meet any higher bias plateau level the computer with in it demands. If there is any glitch in scaling up the power consumption, it will shut down for "inadequate AC power." Actually, this happens when the rail voltage regulators, which are rare in any power amplifier (but there are a few other very high end amplifiers, such as the Mark Levinson ML2, which have this feature), run out of regulator margin...which is precisely because the AC hasn't kept up.
Anyway, it is quite possible that the problem tracking down the problem with amplifier shutdowns is that there is more than one process involved that causes the shutdowns. One might be that running the F-26 through the Lavry simply creates a problematic signal. The other one, which I believe must have been caused by the high power accident, has yet to be determined, but as of the beginning of this weekend was hoped and believed to be the LF transformers inside the Acoustats.
Well, so I was thinking Sunday morning as I started playing KPAC through Sonos, with the LF transformers in the Acoustats disconnected. This was surely the issue, more than one cause of the shutdowns, and by avoiding the F-26/Lavry input, and disconnecting the bass transformers, I had isolated both of them.
And I was so sure of this, I started writing this blog post after it had been playing for 90 minutes.
And then, there was a shutdown, a shutdown that could not be explained by either theory.
I have noticed that sometimes, also, that Sonos blanks out for about 1-2 seconds, or maybe it's the tuner blanking out. Perhaps that happens when Sonos is suppressing some DC from the input or something.
Anyway, this result doesn't disprove the idea that I should avoid the F-26/Lavry input. That was known to be problematic in the distant past.
But for years and years I played the F-26 through Sonos without shutdowns. So that is most likely the "new" problem I am trying to find.
At this point, sadly, I'm out of good theories. Back to there being a malfunction in the Acoustat attenuators???
I concede it could also be a problem with the Amplifier, though the amplifier was just checked out at the factory. But I won't make any headway with that until I have a consistent explanation of the problem. I may need to measure voltages in and out. Which would be another major challenge...I'd have to build a custom attenuator to protect my measuring recorder inputs.
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