Krell S1200 or Yamaha CXA5100?

Unfortunately, I do not have a definite list.  I know that the Theta Casablanca will limit everything to 96khz, which is really good (but it's not going to be the same as a 192khz DAC).  I believe that I read the Classe SSP-800 will automatically convert everything to 96Khz before it sends the data to the DAC chips (they state that 96khz is the best rate for those specific DAC chips).

There are many processors that will use an off-the-shelf DSP board or similar.  These DSP boards have a backplane data bus that is limited to 48Khz.  This means that everything is automatically "sample rate converted" to a maximum of 48Khz regardless of the source media.  Most receivers will do this and some processors, depending on what the manufacturer is doing.  This is perfectly fine for home theater and movies as blurays will not be produce higher than 24bit / 48Khz (except maybe for 1 out of 10,000).  But it will still be a limiting factor if you are trying to use the processor/receiver to play 2-channel hi-res audio (such as 24/96 or 24/192).  This has been going on for years.

It's difficult to say what is really going on inside a receiver.  This may be changing as manufacturers may be implementing better DSP modules and backplanes.

If you are primary using a processor for movies or analog preamp, you're fine.  You can use an dedicated external DAC for doing any of the critical 2-channel music.

hi maella.  Yes, I have had the same problems with responses from Krell.  I think they are very busy sometimes.  You just have to keep on them and keep calling if you want a response.  Krell has their own "Flashloader" software that will upgrade the firmware using a normal RS232 serial cable (NOT a NULL MODEM cable).  Firmware is specific to the serial number of the unit as there are many versions of firmware for the S1200 / S1200U / S1200U-3D.

Actually, all the above problems I have documented were fixed by a DSP board replacement.  I think the problems may have been bugs or bad components in the original "Gen 1" version of the DSP board, as several others have documented the same problems on their S1200 units.

Your unit has the Gen 1 Dual DSP board, which can no longer me made because the DSP IC’s were discontinued by the manufacture. This forced us to do some minor redesign work to the Dual DSP board, thus creating the Gen 2 Dual DSP board. This will work fine for your application but will require new faceplate software to be loaded up into the unit after the install.

That was one of the responses I got back from Krell.  I think your best bet is to fill out a Service Request form and send your S1200 in for repair.  I would specifically request the installation of the Gen 2 DSP board.  Actually, once I did a service RMA request and sent the unit it, it was fixed pretty quickly.  Right now, the service department might be backed up because I have another friend who has been waiting about 4 weeks for his Krell preamp to be repaired.

http://www.krellonline.com/service-request-form.html

My Krell S1200U was still under warranty, so they did not charge me for the Gen 2 board.  I don't know what the cost would be if you had to buy it.  I think it could potentially be a couple thousand dollars.