Geoff,
I saw that same post and have been eagerly awaiting their post and McIntosh comparison.
Final Beta Review/Thoughts:
After approximately 200 hours of burn-in with the amps, and many additional listening sessions, the following represents what I will consider my final thoughts/last review on the M1200s.
At 100 hours of burn-in (review at 197), I had a criticism on the sonics of the amps that the highs could sometimes sound a touch bright. To address this, I changed tubes as mentioned in the manual which shipped with the M1200s: “changing to a different 12AU7 tube can result in a sound that is more to one’s preference and allows the opportunity to optimize the system’s synergy”
I ordered and rolled in a pair of matched and low microphonic/balanced triode Golden Lion (new stock) 12AU7s. This wasn’t without some sonic tradeoffs, but I preferred the Gold Lions and have kept them in.
Listening now at 200 hours, the issue I had with the occasional amp brightness is largely gone. The highs are clear and airy, the mid-range pleasant, and the bass excellent.
I will give a few other positive comments on it with song context, as I listened to different music for this final review (largely acoustic instruments and dominant vocals). Aaron Neville’s Rainy Night in Georgia was a lot of fun. I could hear the vocal cords work as he changed his range, he sounded in the room and lifelike. Neil Young’s Cowgirl in the Sand – Live – I forgot where I was for a moment and could clearly “see” him on stage. Eva Cassidy’s Fields of Gold , was emotional and rich, my speakers did a disappearing act a couple of times which I hadn’t experienced prior to these amps.
Lastly, the tube change itself. I thought this could use clarification. In review 202 I posted a criticism of tube changing, which I still stand by (albeit with some conditions due to recent PS Audio clarifications).
Judging by Jamesh’s last response (229), this is NOT designed to be a frequent tube rolling amplifier. However, even as a beta tester that messaging was a bit unclear at first. The question for me on that tube change process was one of product longevity. With that clarification, and the relative infrequency of needed tube changes, I don’t see a problem with the current design. However, if people tinker, it might be worth looking at a little bit. But that’s just me – the 200lb gorilla who changed the tubes.
For me, ultimately these amps are great performers.
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You’re right - it was post #84, 11 days ago, and immediately after in post #85 I said right away this would probably be the most interesting comparative data comparing m1200s to the Mac gear. I hope the beta reviewer of post 84 comes through with the review. If the 1200s can hang that would be impressive. If they can’t, will be interesting to hear why. If we never hear anything from that tester, dunno what to make of that… hopefully he/she safe and just taking time to post the results.
Ok, here’s my review of the Stellar M1200 monoblock amps.
Scott sent me an email in February inviting me to be part of the beta test team. I agreed because I’m retired so I have the time to do it and thought it would be interesting because I have never spent any time listening to class D amplification. I have been interested in high performance audio since the mid ‘90s and have always relied on class AB amplification to drive my relatively inefficient speakers (Thiels for many years and now Rockport Artias). Refer to post 74 for details of my current system.
As we rolled into March, all of our lives were changed by the pandemic. The beta test was scheduled for that month and I wondered how COVID-19 would affect PSA’s production schedule. I kept an eye on this thread and we got word from @jamesh that the beta amps would be shipping in early April. Serial numbers 053 and 064 arrived at my home on April 9th. After a 24-hour quarantine, they were placed into service. At the time of this posting, they have been playing music for 100 hours and on (tubes lit, no music playing) for 160 hours. They have been a standby mode (tubes off) for 55 hours. I think users will note a change in their sound during break in. I haven’t noticed any changes in their sound for the past few days so I think my current impressions represent a fully broken in product.
Before I address their sound, I have a few “operational” observations. First, the packaging is very good. They are shipped individually in double boxes with tight fitting foam inserts. The tube is factory installed. Not all manufacturers do that, but for a single tube unit this well packed, it should work fine. There’s a paper sticker covering the power connector warning the user to make sure the power switch is off before plugging in the cord. The paper sticker is probably fine for the “maiden voyage” but I suggest PSA add a permanent warning label as a reminder to the user later. I liked the speaker terminals. It was easy to clamp down on the spade terminations of my speaker cables using a finger tight twist. The case is functional, nothing fancy and I assume it is of similar construction as PSA’s other amps in the Stellar line. The metal used for the case isn’t perfectly smooth. It slightly dimpled. The tube (12AU7s) is accessed from the back panel via a removable panel held in place by two spring loaded screws. My amps were shipped with Psvane gold pin tubes. The amps come to life by first flipping the mains switch in the back then pressing a blue square button on the front panel. The button first flashes for about 20 seconds while the tube warms up then is solidly lit when ready to make music. Aesthetically, I would have preferred the button in the center of the front panel, as I think it looks more symmetrical with floor mounted amp stands (see my post 76) but YMMV. When fully on, there is an ever so slight buzzing sound coming from the amps (not the speakers) but per the manual, this is normal. I had to put my ear right up to the vents on the top panel to hear it. No way you’ll hear it once they start making music. Regardless of how long or how loud I played my music, the amps never got more than slightly warm.
At this point, some of you are probably thinking “OK boomer, tell me something I don’t know” so I’ll move on to my impressions of their sound. As stated in an earlier post, I have no aspirations of starting a second career as an audio reviewer. I made a commitment to young James to post a review of this product and I can assure you I’m neither a shrill nor a troll. Even while under a stay at home order, I got better things to do than take on either of those roles. During the review, I made no other changes to my system; same upstream and downstream components, cables (power, speaker and interconnects) and power conditioning. The last change I made to my system was over 6 months ago and I listen to it nearly every day so I think I know it well and can recognize any deltas caused by the M1200s.
First off, these are incredibly powerful amplifiers. I can’t imagine any speakers that these amps can’t properly drive without any hint of strain. I played the most dynamic music I have, and my Rockport Artias were always there to deliver the goods. Two examples of the amp’s dynamic power were Yes Fragile (the whole album!) via the Mobile Fidelity One Step 45 RPM LP and Freeway Jam from Lee Ritneour’s 6 String Theory CD. I really enjoy the One Step version of Fragile. Until this release I felt the recording was not as good as the material itself. MoFi has eliminated the gap with this release and the M1200s did an excellent job of handling the dynamic swings of this album.
It’s not all about power though. Assuming the speakers are positioned properly (yup, mine are), one should expect high quality amps to present a clear 3-dimensional soundstage. I used The Sidewinder on The GRP All Stars CD to evaluate soundstage. It took a while for the M1200’s to lock in the soundstage. The left to right soundstage was there from the start but it took about a week of break in for it to become 3-dimensional. It was good but not as good as I enjoy with my Levinson 536 amps. The soundstage did improve even more when I swapped the Psvanes for a NOS pair 1969 vintage GE 6189 tubes. These are a low noise variant of 12AU7s made for the military back in the day. They were tested and transconductance matched to within 2% triode to triode and tube to tube. I’m not wishing to fan the flames of controversy surrounding M1200 tube rolling. I did it before it became a hot topic on this thread and my version of the instruction manual seemed to encourage it:
Changing to a different 12AU7 tube can result in a sound that is more to one’s preference and allows the opportunity to optimize the system’s synergy.
Yes, I got a better optimization of my system’s synergy (more 3-dimensional soundstage) by swapping the Psvanes but YMMV. I predict a “M1200 tube rolling” thread with hundreds of replies once these amps are available to the public.
To my ears, the amps had great linearity across the the entire audio band. The bass wasn’t boomy, the mids were crystal clear and the highs were clean without being too soft or screechy. This frequency linearity was independent of power levels. It was especially impressive at lower levels. I think the M1200 were actually better at low power level linearity than my Levinsons. The 536’s need a little volume to really shine in this regard.
The last thing I noticed was how the amps performed during complex music music passages i.e. “Organizational Skills”. For example, when Spoon is layering all kinds of percussive instruments in You Got Yr. Cherry Bomb (Ga Ga Ga Ga studio version on Vinyl), can the amp allow the listener to hear all of what’s going on? In this particular example, the M1200s performed well but at times I felt I was missing some of the action. Not totally missing, or out of control, just not as well delineated my current amps which is a totally unfair comparison. I noticed this with the Psvane and GE tubes. Readers should not interpret this observation as a ‘dis on the M1200s. When I posted my system info to this thread, a member was anxious for a comparison of my current amps to the M1200s. It’s not reasonable to do a value judgement of the two devices because they are totally different technology and price classes.
At the conclusion of a component evaluation, I like to revisit the system using the previous component to confirm my observations. I reconnected the 526s and listened to the Spoon song again. Yes, things were a bit more delineated with the Levinsons. Then I put the Psvane tubes back in (I have long thin fingers so I’m not struggling with this task) and the next morning gave the The Sidewinder another listen with the M1200s. Not quite as full and 3-dimensional soundstage. Yup, I heard what I heard.
In summary, I think the Stellar M1200’s are excellent performers. They are extremely powerful and I think they can drive any speaker that is connected to them. There is a clean and linear sound across the entire audio band at all volume levels. Based on my experience, the M1200s are good candidates for tube rolling for those so inclined. I enjoyed having them in my system and am glad I waited until now to spend some quality time with a class D amp. If you are looking to spend this kind of coin, or perhaps as much as twice more, on your amp, give these an audition. What’s to lose with the PSA 30-day free in-home trial?
Lastly, I think Paul should give Darren a raise.
Stay healthy everyone.
Jeff C
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Nice review, thanks! Sounds like the m1200’s held up well for their cost. Appreciate the comparison to the Levinson’s. Sweet system, BTW! Stay healthy!
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I am guilty as charged!
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So the $6000 dollar question is which is staying the 526s or the M1200s ?
I also own Levensons but unfortunately was not chosen as a Beta tester .
How does the Anthem compare to the B&K? I am just curious, and a long time Anthem owner.
Paul/James
Obviously there is no substitute for personal audition!(and I hope to do so whenever they are available)
In the meantime,I would be interested to learn your views on the feedback you’ve received so far from the Beta Testers? Also,have any ‘Professional’ reviewers had a chance to audition?
Thank you
Why not both? One system is never enough…
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First off, I want to say a huge thanks to all that have put so much effort and time into their reviews and comments. It certainly is good timing for people to have ample time to hang out and enjoy some tunes.
I’ve been doing a lot more listening lately and find myself getting really deep into the music. Each album I put on takes me through another story, more exciting and exhilarating to me than a decent movie. The thought of peeling myself from the listening chair to write an exhaustive review even close to the quality of those in here is fairly daunting. So again, a deep thanks to the folks that have spent their time to do so!
Darren and I chatted on the phone a few days ago and he’s very happy with the feedback so far. He mentioned some of the reviews were better than he expected.
No professional reviews yet. We don’t expect those to come until we officially launch the amps in a few months. We don’t ship review units until they are in full production.
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It’s been a lot of fun. I’m now listening to my M1200s in what I consider a normal manner. By that I mean putting them in stand-by when not listening to the system and turning them on 15 to 20 minutes to let the tubes warm up before listening. The M1200s continue to impress. One thing that gets me every time is how clean the bass lines are. More than once I’ve heard a bass line and started thinking, “Have I heard that bass line before in that song?” To test it out I would go to one of my other systems and play the track. What I find is that yes, the bass line is there, but it’s a little muddied and blurs with the rest of the music. Being able to cleanly hear the bass makes the song that much more enjoyable.
When you start sending out units for professional review, send a pair to Ron Bernay at New Record Day. I’ve bought equipment based on his reviews in the past and have agreed with his assessments. I told him he really needs to get a hold of a pair of these.
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How about vs the BHK250 and 300? 
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Great idea Rons awesome
Craig here…My Beta M1200s have been on since 9th April. My initial impressions with the stock PSvane tubes are available above. Summary: Amazing improvement over my previous M700s which are packed up and ready to trade in (JamesH?). They are different league and they are not leaving. I predicted that I would want to try other tubes, since I’ll bet that in this configuration (tube input stage feeding directly into the ICE 1200 stage bypassing the ICE input stage) that the tubes could/would have a definite influence on how they sound.
So, for reasons to follow, on 23 April, I installed a set of NOS 12AU7 Mullard UK made/1958 matched pair…zero hours except for the measuring/matching. I’ve listened to them every day, but respecting the prediction that they would take some hours to settle in, I’ve waited until now to report.
Bottom line: The input tubes in the M1200s CAN make a difference.
Part of my reason for experimenting: In my room, my system, my ears…etc, my Dunlavy speakers have a small up-shelf in the upper midrange/lower treble that has bugged me for years…especially after improving their response with latest PSA gear and more revealing Iconoclast cables. So, over the years I’ve experimented with EQ, (Schiit), speaker placement, toe in, etc. Given their reputation for ‘warmth’, I’ve replaced the tubes in my BHK Pre with NOS Mullards as well. So, I tried the same in my new M1200s. Result: (in my system…etc) GOT IT!!
I’ve played my old poorly recorded CDs, better SACDs, and lots of vinyl, both poorly recorded old stuff, and great Direct to Disc stuff from the ‘70s, and just my favs from more recent times. My upper midrange shelf is successfully dealt with some ‘warm’ NOS tubes.
I have notes on my personal listening experiences, but, I’m happy with my experimentation.
For now, let me just recommend, to those so inclined, Roll On!!
Let us know what you hear…
Thanks, Craig
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Thanks ‘Calord’. Was there ever any doubt that changing tubes could make subtle changes to the sound! Those who regularly ‘tube roll’ have alluded to this fact for years. What I do find questionable when reading these people’s reports, is they would have us believe they constantly ‘roll’ tubes in the middle of listening sessions! What!? Are they seriously suggesting they switch off, wait for the tubes to cool off,change tubes, switch on, wait for tubes to warm up, all whilst in the middle of a listening sessions!!?? Possibly their interest is more about ‘the tubes’ than ‘the music’
It is also well known , that the first tube is the most important(input tube in the Pre)
The personel at PSA obviously know this , hence the BHKs !
I currently own Croft Pre and Power Amps,both of which I’ve changed the tubes to something I like and leave it at that! I then only buy the same tube to ensure a future supply. The M1200 is a similar hybrid construction. I look forward to the comparison.
For those concerned about changing tubes. I’m no whizz kid when it comes to the tech bits! For those who have no experience, changing tubes is not a problem! All that’s needed is a bit of common sense!
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I completely agree with your observation on the bass line. I have had mine on for about 20 hours of play time, and the improved bass notes were definitely noticeable. The track that made my jaw drop was the first track on Fleetwood Mac’s *Tusk. John McVie’s bass has never sounded that good in my system. Enjoying every minute of the M1200s
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A late review from a fellow beta tester. Chet R.
"4-13-20 Day 1 - received new M1200’s, moved M700’s out of the rack and hooked up the 1200’s. Turned them on around 1500 (3 pm) and played Bocelli’s, Music for Hope released on April 11, 2020 just made available on Quobuz. System sounded rough, had gain up to 50 on BHK pre-amp, REL subs on and the sound out of my B & W 683’s was raspy and sounded very compressed. Listened to some other releases by Bocelli and sound somewhat improved but still sounded sharp and raspy. Finally, played my reference vinyl song, Loggins and Messina in Concert, Vahevala. Still sounded compressed and not nearly as loose and clear as with the M700’s. Stopped for the day and let the system continue to play Jazz24 streaming radio at low gain (6 on the dial) all night. As I thought the matter through, it seems that when I first set up my M700’s I had the same impressions. Perhaps burning-in does make a difference as described in Paul’s U-tube’s dated February 19, 2018 and April 7, 2020. I plan to find out!
4-22-2020 Day 9: up to this point I have listened to the system but have not done any critical listening. Just low gain and background music. The 1200’s have not been turned off and have been getting a signal, mostly streaming Jazz24 for the entire period of around 216 hours burn in plus 48 hours of burn in prior to leaving PS Audio. One single impression during the burn in period. The system has been continuously on and has not been turned off a single time, I am now experiencing increased presence with the very low end, more so than with the M700’s.
Oh BTW my system is as follows:
• Stellar Phono Pre about 3 months old
• BHK Pre about 3 months old
• PS Audio P12 Power Plant about 3 months old
• Direct Stream DAC about 4 months old
• A set of used B & W 683’s (arguably the weakest link in the hardware chain). They are located about 10 feet away from the walls both back and side.
• Junk speaker cables
• All component interconnects are built with Mogami cable as per Paul’s balanced recipe from the PS Audio website.
• Two REL T9/I subs about 7 months old
• Fluance T-Table with Ortofon Blue cartridge about 5 months old.
• My listening room is a finished basement that’s 24 x 48 x 8. Mostly hard surfaces with not many rugs. Floor is hard tile. Its “bright”.
Day 9 Critical Listening:
• Bocelli’s Music for Hope (Quobuz): The bottom end, pipe organ, was very full all the way down to the lowest note. After listening to the first three cuts from Bocelli, I can say that the sound quality was very much improved, but I am still sensing a raspy quality to his vocals. Perhaps it’s the recording quality, my speakers or “bright” listening room.
• Loggins and Messina in Concert, Vahevala, Gain on BHK Pre at 41: Clean bottom end, no booming, heard the tambourine for the first time, it was clean and in proportion. Oh BTW, I’m a drummer since 1971 and still play, I could not determine if the tambourine was being hand played or if it was attached to Merel Bregante’s (drummer in band) hi hat. The more I listened; I think someone in the band was playing it by hand. I could hear Merel playing his “ride” cymbal and it sounded like he was using plastic tipped sticks. That’s pretty “revealing”. No problem with soundstage and separation. Listened to the album a second time and turned gain on BHK Pre to 50, first time I hear distinct background rumble from album.
• Next Critical Listening: Quobuz: Yudo Mabuchi Plays Miles Davis. 24 bit/88.2 kHz, never heard of her but what a great album. Very clear, transparent and full range. Plenty of low end.
• PS Audio P12 power plant. With all the components listed above drawing power thru the P12, the readings were well within the green. I did some measurements with the M700’s before removing them from service because I was worried the M1200’s might require an upgraded power plant. Don’t think I’ll need to do that.
April 27, 2020: Its now been two weeks of “burn-in”. I’ve switched speakers from the B & W 683’s to a completely restored set of AR-3a’s. The single thing I’ve noticed about the M1200’s is that now, at low listening levels (around 5 on my BHK pre-amp) I’m experiencing the low ends and the highest ends that I didn’t have prior at very low listening volume (gain) levels. It’s almost like switching on the “loudness” control that older integrated amps have.
Final assessment, I’m happy with the new 1200’s, I’m going to keep them. They don’t appear to draw any more power thru my P12 than the M700’s. At low listening levels, it’s like having the “loudness” control on. Big difference now that I have two weeks of “burn in”.
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Yup, but it says ‘afventer frigivelse’ (awaiting release) in small print. So it’s just a flag for an upcoming product. PS Audio in Sweden also has them (74,000 SEK/pair) but fails to inform that they are not yet released.
You should indeed give consideration to Darren Myer’s phono preamp. It’s great! Tried one at home and just decided to keep it.
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