Upgrade Nakamichi PA 7All power amp with mono blocks

@ellajeanelle thank you for your thoughts.  PS Audio sounds like a  decent upgrade for me.  I am also interested in their Stellar Gold pre-amp.  Have you used the Tyr mono blocks, or is your concern with other items in their portfolio.  I found the Bifrost 2/64 compared favorably with more expensive DACs.  That is my only experience with their equipment though.  I was not impressed with the Schitt pre-amp reviews.

@decooney funny you should mention the Elector.  It is on my short list for pre-amps along with the PS Audio Stellar Gold.  I will think about it.  My Crossover came from London (a real hassle, but worth it in the end).  I believe HiFi Heaven stocks the Elector here in the states.  I purchased my turntable and cartridge from them.  They are great.

@decooney thanks for the offer.  My unit was refurbished two years ago.

@ellajeanelle ​​@decooney I have decided to explore upgrading the pre-amp first.  Too many people have said the PA-7AII may be the strong point in the system and that the NAD may be the weak link.  I am focusing on the SPL Elector and the PS Audio Stellar Gold.  Others may get in the mix, but for now these are my focus.  Thank to both of you for your suggestions.

@decooney 

We seem to have similar taste.

I am picking up a used Benchmark LA4 preamp this weekend.  I leveraged the purchase to also pick up a pair of PS Audio M700 power amps used.  I suspect the LA4 will be my long-term preamp, but I will do some a/b testing with the NAD just to comfirm.  I have some interested parties in the NAD so it will be easy to sell.

I will also do some a/b testing with the M700s with both preamps just because the equipment will be here.  I expect I will leverage them into something else, but if I love them then I will leverage the Nak into something else.

My streamer/DAC journey was a mess.  I started out with a Cambridge CXN v2.  The sound was just OK and the app was not user friendly.  Never could get it to work consistently.  I returned it to the dealer and tried the Node N130.  The app was a little better and the sound was about the same.  I upgraded the N130 with a PD Creative SMPSU in a LPSU interface.  The sound improved dramatically.  Really loved it.  While this was happening I ordered an Eversolo DMP A6 based on all the great reviews.  By the time it arrived the upgraded Node was working great.  I was going to return it, but decided to go ahead and do an a/b test.  Turns out the streamer portion of the Eversolo worked better than than the Node.  Additionally, the app was amazing (still is).  The DAC portion was a bit shrilly, but it had very good stage and instrument separation relative to the Node.  I kept the DMP A6 and moved the Node to a secondary system.  The Node is still very good.

I listened to a friends Lumin D2 and liked it, but didn't love it.  The sound was great but the app was not as user friendly as the Eversolo.  It was also too expensive for me at the time.  My friend suggested the Bifrost 2/64.  He had one on his 2nd system and said the DAC was the equivalent of the D2.  I listened in his system and liked it so I ordered one.  I was prepared to return it if I was not blown away in my system.  I was.  It was a huge improvement over the DMP A6.  

So, what did you try in terms of DACs and where did you end up?  Did you try the Schiit Yggdrasil LIM or MIL?  Any suggestions for the future?  Did your try different streamers too?

@yyzsantabarbara The M700 did a great job of separating the channels.  Very good stage left to right.  The Tyr improved the stage L-R slightly and also had a boost in the high bass (over 80 hz).  I felt the Tyr didn't quite handle the treble as well as the M700, but the hard clipping might be influencing my judgement there.  Both sets of mono blocks were good.  

I am set with the XA25 until a mono block version is released.  I tested a CODA #8 and was not impressed.  I was comparing it to the Schitt Tyr at the time.  The #16 was out of my price range so I did not consider it.

I also took a look at the Coda 07.x but liked the LA4 better.  Mostly due to the quiet sound floor on the LA4.  There was just a slight sound out of the speakers with the 07.x with the volume turned up, but nothing playing.  The LA4 was dead quite.

Have you looked at the following pre-amps relative to the LA4?

• Pass Labs XP 22 or 32
• Luxman C 900 U
• Bricasti M20
• Townshend Allegri Reference Mk2

Thanks

@yyzsantabarbara thanks for asking. The Benchmark LA4 worked out great. The PS Audio M700 mono amps not so much. The Acoustat 1+1 speakers get down to 0.5 Ohm at high frequency. The M700s had a screeching sound at 85db and above indicating a hard clipping. I sold them and tried a pair of Schiit Tyr mono blocks. They had a hard clip and actually shut down at the same point in the music. Quickly returned them to Schiit.

In the mean time I had sold the Nak, so I had to put my old NAD 2700 in. The NAD has a soft clipping feature so I monitored it with the same music passage. It actually flickered at the same passage and if I listened closely there was a bit of muffling. The soft clip NAD marketed way back when actually worked. I just never noticed because the Acoustats rarely draw 0.5 Ohm (I think it only occurrs with a signal above 17k).

I reached out to Nelson Pass and asked if there were any plans for a dual mono XA25 in the future. He had a pair custom built for himself, but none were planned for release. He said the XA25 would handle the 0.5 Ohm signal without a hitch, but that high volume might be an issue if I drove the speakers very loud. On his recommendation I purchased one and it is amazing.

I then decided to upgrade the PS Audio Direct Stream Mk1 DAC. I noticed better detail from friends systems. I tried several including a Chord Dave with an M-Scaler, a HiFi Rose M130, and I borrowed a Tambaqui. I ended up with a Bricasti M1S2 DAC which is amazing in detail and sound (multiple filter choices depending on music type). A benefit I did not expect was it sent a ’louder’ signal to the LA4 which passes the increase along to the XA25. Hi volume is not longer an issue. I am very happy.

I am just starting to explore other pre-amp options, but I am not certain that I will be able to find a suitable upgrade to the LA4. For now I am definitely enjoying the music.