Coda #8, Pass XA25, or Schiit Tyr to replace PS Audio M700

I recently upgraded my power amp from a Nakamichi PA7Aii to PS Audio M700 monoblocks.  I honestly expected to flip the M700 pair quickly because I did not think they would be better than the PA7Aii.  The M700s actually provide a wider and more detailed soundstage.  I sold the Nak.

I listen (often passively) for several hours each day.  I began to identify a 'shrill' on the high end.  Since I had upgraded my DAC (DirectStream Mk1) I initially thought that could be it.  I rotated three DACs through the system (DS, N130, and Eversolo DMP-A6).  All of them had the shrill.  I then put in an old NAD 7600 and the shrill went away along with a lot of the detail.  Put the M700 back in and used the EQ from the DMP-A6 streamer to limit extreme high end.  Ended up with a -1 Q starting at 19,500 Hz that solved the shrill, but also muddied the high end detail.  I don't trust the EQ a lot and figure more is being impacted than the targeted range.

This led me to consider upgrading the M700 pair.  I have a  pair of Acoustat 1+1 speakers with low sensitivity efficiency (81 to 86 depending on who the source is) with a pair of Rythmik F12SE subs and an active crossover at 100 Hz controlled by the SPL Crossover.  My budget is around $6K.

Looked at the Pass XA25.  Not certain there is enough power there although a Pass representative encouraged my to try it.  I was hoping to get two used and use them as mono blocks.  

The Schiit Tyr has been on my short list for awhile (prior to buying the M700).  The Schiit AI tool actually stated the Tyr was not a good match and suggested other Schiit amps.  This seemed strange to me.  I sent an email to Schiit seeking clarification, but have not heard back.  I may go to there store in LA this week to talk to someone live.  

The Coda #8 came up as an option as I was exploring.  I looked at other Coda used products, but #8 seems to match up best. (Well, the #16 matched up best, but was more than double my budget).  I will go take a look at it later this week.  Not a mono block but could work.

I am essentially seeking the last 1-2% of the detail the Acoustats can provide.  Any suggestions would be greatly appreciated.

One final note.  I am not interested in tube power amps.  I don't like the fussiness of tubes and the Acoustats seem to pick up the hum from tubes. I know it shouldn't happen with their sensitivity, but I notice it.  It could be my prejudice, but please no tube suggestions.


Suggest you call Coda and talk to Doug Dale. See what he thinks in terms of what product and bias match up with your needs.

As you are probably aware, the Coda 8 can be biased 3 different ways depending upon how much power you actually need in Class B and how large the Class A envelope is. If you do get the Coda 8 and need to have the bias adjusted you could always send it back to Coda.

I have a Coda CSiB, which is essentially a Coda 8 with an integrated line stage driving Thiel CS 2.4 speakers and am very happy with it. I chose the v1 in order to have more power in Class A. The amp grips my speakers like a vice.

As you may also know, Doug Dale and Nelson Pass worked together at Threshold and have similar design philosophies. If anything, the Coda amps are even more high current than the Pass. My CSiB is rated at 130 amperes. I believe the Coda 8 is rated at 150 amperes.

Good luck with whatever you decide.


OP, the XA25 is not bridgeable, as an fyi. A pair can be used to horizontally / vertically passive bi amp, or actively bi amp through an electronic crossover. Do you have the 1+1s in a room with low ceiling height. The problem can be the speakers with the room, or just the speakers. Have they been updated / rebuilt since they were new ?...the panels and / or the power supplies. I mean no offense to you. My best, MrD.