Upgrade Nakamichi PA 7All power amp with mono blocks

@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?

@thriftyaudio I see so you’ve partly been down the dac merry-go-round. I ended up leveraging a bunch of friends and colleagues to narrow down my lists a bit more. You or others might prefer something different in terms of DACs, I was following along with folks at Schiit for while, and almost went down the Yggy path, yet had some insight to go a different way, and was trying to stay a way from a huge dac footprint, and a few I compared with that owned Yggy had downsized to BF 2/64. Dont get me wrong that dac has decent deail, separation, just not the velvet and musicality I was looking for. (note: I’ve had modded MHDT Labs tube tube dacs before as well). Note Schiit Yggy, probably a little smoother yes, yet maybe a different sound from BF 2/64. For streamers, nothing special, an older/updated Arcam unit I won’t let go of, and have compared it to a few different Bluesound Node units through friends. I was looking for a particular result, and a certain magic for my modded Pass/Forte SS amp and my upgraded Quicksilver Mono 120 tube amps. This eventually came about through my Border Patrol SE-I dac with the upgraded power supply, specific phillips TDA1543 chip, and Jupiter caps that come with SE-I version. Its the only dac I’ve never modified or needed to. The Tube is not in the signal path, which I like for my needs - its part of the power supply circuit and you can turn the tube on/off for different sounds too. Gary Dews built it for me and super happy pairing it with my particular pre/amp system setup. It responds well to different cables, and now my digital woes are over. Have not looked back since. Some people try it and rotate it too fast without letting it fully settle in. After 45 days of solid play time, it opened up more, and it bested my other dacs in a nice way. Let me say its a "preference" thing, and does what I want and need for my system.

I do believe so much of this is system/speaker dependent and finding a good match for your current and demo amps in the way of the right dac for you can be a game changer. It was for me. 👍

@thriftyaudio How did the LA4 and the M700 work out together. I am thinking of raising funds for a headphone and replacing my Sanders Magtech for a M700 to use with my HPA4 preamp. This seems like something that may work. It is for a Magnepan Mini office system, so some compromise is OK.

BTW - I have the Yggi+ OG and the Yggi+ LIM. I love the OG and would buy another in a second if I could find one. The LIM is OK with a brighter system, but it is rolled off on top. That does not work in my new setup so I am in the queue to convert the LIM to a MIB. I may even sell the LIM and see if I can get a used Yggi+ OG. I have not heard the MIB but a review and some comments indicate it is closer to the OG and not the LIM.

@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.

@thriftyaudio Thanks for the response. I now remember reading your take on the m700 in another thread (late night reading yesterday). I think I am going to take a chance on the m700 since my office Magnepan Mini does not drop as low as your speakers.

With regards to your LA4. It is a keeper. I had the LA4 and the HPA4 (2x) and it is not something I will replace. I have 2 systems, and I bought the Holo Audio Serene preamp instead of a LA4 since I had the HPA4 and wanted to try out something else. It is an excellent preamp too and sounds and measures like the LA4. It is just a bit warmer and a lot of people like that over the LA4. In retrospect I should have gotten the LA4. First world problems.

If you want to go for an even more powerful XA25, I am going to be selling my CODA #16 amp in a week or 2 along with my Audience FrontRow speaker cables I use with it. I need to raise funds for a headphone and new speaker. I think we are both in Southern California if you want to have a listen.

How did the Schiit Tyr mono blocks sound when they did work on your speakers. I am thinking of getting a used pair to hold me off until I raise fund for the CODA #16's replacement or just do not use the speaker connected to the #16 until I get a proper replacement. The new speaker (second speaker I will keep) will work with 8 watts.