Beta Test Impressions of the New Strata

Darko’s product announcement on the Strata says the the Amp is Class A biased Mosfet?
I thought that it was Class A input to Class D amp?


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Good afternoon. I am starting to post my Strata beta test notes. Here goes:
PS Audio Stellar Strata Beta Test Notes

5/3 Unit delivered at approx. 5PM. Good condition. Unassuming outer brown box not calling attention to what it is. See photos. Can’t upload photos.

Went into cardboard isolation for 3 days.

5/6 Unpacking unit in garage. See photos
Utilitarian packing. Nice to have the clean white inner box. Content sheet lists stickers that aren’t in the box?

Front panel logo is loose. During setup, I learn that it is a button.
The rotational feel of the volume knob is somewhat crude and rough. The knob itself is nice.
There is a power connection warning over the IEC connector. Funny, unit shipped with switch on.

Through the vents, I did notice the small fast-on terminations to the binding posts inside the unit and the thin, commodity style internal speaker wire used. Plus the binding posts are available on Parts Express. Low perceived quality even though this is meant to be a value priced piece of gear.

I’m setting the unit up in a family room with a high ceiling, hardwood floor with area rug, upholstered furnishings and window treatments. Using Revel M106 speakers on stands, a Sony Blu Ray player as a transport (digital out via coax and toslink) and streaming Qobuz and Spotify from an iPad via WiFi. I will add a Revel B110 subwoofer soon.

This Strata is nicely finished on the outside with no visible flaws or defects. The back panel is well organized. It appears to be well made and of high quality. The industrial design is clean and simple.

I’m going to follow the Owner’s Reference page by page to set up and get the Strata operational. I think I’ll start another post so that a single post doesn’t get too long. Stay tuned …

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PS Audio Stellar Strata Beta Test Notes cont’d:

If I don’t mention a manual page #, I had no issue with the setup instructions or information provided.

Unit setup page 6- Remote button labelled “HT”, which is not mentioned in the description. It’s called a Fixed Volume Button. Assume the HT is Home Theatre.

There are two volume controls on the remote. I think that’s odd though I have a theory as to why that is.

10 The phase button… this isn’t worded well.

Nothing mentioned about installing batteries, what type, not supplied with unit.

page 8- manual numbering should match or reference the rear panel connector numbering.

page 9- paragraph 3 could be worded more clearly.

page 11- at this point, the system is operational with CD. The system sounds good. No clicks, pops, buzzes or hiss. I did notice the volume control attenuation issue and raised it directly with James. IMHO, this must be addressed before shipping production units. A brief A/B between input 5 coax and input 7 toslink revealed the coax to sound better, better bass definition and high end extension but this may be a function of the Sony BR player transport and digital audio or the cables. Glad that the Strata revealed the differences.

Per the manual, I read up on Spotify Connect and got that working easily with input 9. At this point, all the gear in the system, which has never been used sounds like it needs to warm up and break in, so I just let it play and play, then left it powered up overnight.

More to follow.

One more wireless streaming issue to report-I was streaming a Grateful Dead concert, Saint of Circumstance (Qobuz) thru the #9 input and experienced gaps between each song. I then went on my computer and played the same Qobuz concert via a DAC and headphones and validated that no gaps exist.

More listening notes, now in the downstairs system with Focal Electra 1028BEs and fed by my DSD and innuous.

Sounds pretty glorious to me, given good source material from Quobuz. There is a feeling of effortless acceleration, like riding a very lightweight bicycle or the automotive equivalent. Swells sound natural. Another manifestation of this is a lightness of touch, in a pianistic sense.

If you have to downsize. from a lot of boxes and stuff, the Strata makes a lot of sense, without the need to feel like you are sacrificing a lot. It also works well aesthetically in a rack of other PS gear.

I am a happy guy.

My apologies, I just downloaded a new version of Qobuz and now it plays gapless, at least on the album I am playing now

Thought you might enjoy a system picture.
The potential “retirement system” sitting in front. Paragigm Atom Monitors with an old velodyne sub I got at garage sale. Some Duland wire twisted pairs (quite good acually) for speaker cables.

It’s not bad, but I’d probably move this speaker set up back to the office and get something a bit better.


Sorry to say I think there is an issue with streaming.
A: We were watching a movie last night, optical cable from the TV to the Strata. Keep having real quick audio cut outs. Happened maybe every couple minutes and were real quick, maybe half a second.

B: Listening to music today, Ethernet connection, using JRiver. It was playing just fine till the last couple tracks started cutting out for a second or so. Switched back to the Direct Stream/Bridge II, still using JRiver and it’s been working just fine.

Awesome. Thanks. Yeah, Strata’s that pretty much perfect all in one box. Glad you get it. Glad you got it.

I received Strata on Tuesday 5/4/2020 and have been having a lot of fun getting to know the device better.

For a bit of background, I have two KEF LS50 systems at home. One PC based system in my home office with a near silent PC running Roon/Audirvana/Tidal > Audioquest Carbon USB > Matrix X-SPDIF > DirectStream Sr > Sennheiser HDV820 as preamp/headphone amp >Crown XLS2502 amp > KEF LS50’s + REL R218. The bedroom system is a DirectStream Jr (Bridge II) > PS Gain Cell DAC > Crown XLS 2502 > KEF LS50 + two Infinity 8" subs.

I also have other systems at home and have owned/currently own various other components including M700’s and a BHK Pre.

I started for the first couple of days in the home office and had some really enjoyable listening sessions. Some memorable songs that really moved me using the Strata + LS50’s: 1) If Only For One Night - Luther Vandros 2) Various Funkadelic/Parliament songs 3) Voyage to Atlantis - Isley Brothers 4) Concentrate on You - L.T.D. 5) Purple Rain - Prince 6) True - Spandau Ballet. I then moved Strata into my bedroom and replaced 3 separate devices (Gain Cell DAC + DSJ + Crown amp). Really enjoyed watching Guardians of the Galaxy Vol 1 with its classic soundtrack.

Positive Aspects & General Comments:

  • Sounds great! Strata is the first Sabre based DAC/Integrated that I could honestly live with as my primary music playback device if I could only have one.

  • Plenty of power to make my KEF LS50’s sing.

  • The PS Connect app for iOS works well and is visually appealing. (Love the spinning album graphic - nice touch!)

  • I love that I can control Strata’s volume using the hardware buttons on my iPhone (also covered below)

  • Great build quality.

  • Surprising good headphone output. Not quite enough power or perhaps not the greatest synergy with my Hifiman Arya’s BUT Strata offers the best headphone amp pairing that I’ve found with my Meze Empyreans. What a magical listening experience with the Empyreans! Headphone jack sounds better than my Sennheiser HDV820 Amp or Sony TA-ZH1ES headphone amps.

  • Dead silent background with LS50’s.

  • I prefer setting Windows at 44.1 with Strata vs preferring 192 on my DS Sr.
    Did I already say great sounding device? :slight_smile: Really good built in USB DAC. Just a really enjoyable device to listen to. Lots of toe tapping, head bobbing and grooving without any listening fatigue.

Issues/areas for improvement:

  • Wired ethernet works as expected but I simply could not get wifi to work after multiple router reboots, WPS connection attempts, and manual setup attempts using the buttons + dial on the front of Strata. It sees my 2.4g network but fails to obtain an IP address from the router. I’ll call PS Audio support next week to see if they can help.

  • Please make it so that the device automatically wakes up and switches to the Bridge input from the PS Connect App and Spotify Connect App without having to use the remote.

  • Installing the app for iOS is a bit kludgy but I suspect that will soon be resolved when an official app gets published to Apple’s app store.

  • It would be great if you can make the volume jumps a little less drastic when using the physical iPhone buttons. I believe it jumps about 7 steps with each button press when compared to the remote control.

  • Why doesn’t the volume continuously go up/down when holding down the volume button on the remote like on the Gain Cell DAC, BHK Pre, DSj, DS SR? Raising and lowering volume requires many clicks on the remote. Very irritating!

  • Filter button on the remote doesn’t work.

  • I was getting a low level and fast thumping or pulsating sound with my REL R218 (also tried my REL T7i) in my home office system. I did not experience this issue in my bedroom where I use dual 8" infinity subs so not sure what’s causing this in the office as the issue goes away when I put the Crown XLS 2502 (also class D) back in the chain. Also tried using the ground connector on the Strata but issue persists. Not noticeable when listening to music.

I now have some tough decisions to make after having heard how great Strata sounds in the home office as the first unit that I purchased was intended for the bedroom :slight_smile: Again…really great job PS Audio. You have a real winner on your hands here!

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These are my initial impressions of the Strata beta test unit’s sound. I am actually looking to trade in some equipment for a new integrated (more on that later). Which means a box should soon be going a few miles northwest from my house. The question is whether it will be addressed to PS Audio or to The Music Room.

I will be comparing it to my current system, and I am nervous about going from class A/B to class D. My philosophy is I need to hear a clear difference to report it, not “I swear amp X sounds better if I put on a tin foil hat”.

  • In the blue corner: Onkyo CD/SACD player + Schiit Bifrost Multibit DAC + Stellar P3 + Exposure 2010 S2 integrated + Wharfedale Jade 3 + Kimber cables. A great system, very good tonalities. The Exposure is a Stereophile class A rated amplifier and the Strata is going to have to work HARD to beat it. Jade 3’s are rated B.
  • In the red corner: the Onkyo + P3 + Strata + Wharfedales.
    I also have a Sumiko subwoofer. I originally planned to use it, however I ran into practical issues. Unplugging / plugging cables from one amp to the other + turning on the amps, adjusting volume etc. takes too much time if I also must deal with the delicate sub cabling / grounding wires. So, I tried going the RCA to LFE route instead. But then I realized the two amps output quite different gains(?) to the sub, so I would also have to level match the LFE volume each time. That was simply too much trouble, so I decided to leave out the sub altogether. That way perhaps I will also get a cleaner impression of what the amps can do.

Amps level matched beforehand with an app. The Exposure/Schiit were warmed up long before the test. Strata had burned-in for 60h (and I may go back after a few hundred hours). All tracks are CD into digital input.

• Kei Koito – Organ Before Bach (incidentally, with a subwoofer this CD will rattle your martini glasses in the next room). Strata actually seemed a little less bassy but in fact it was more airy, controlled bass, less mushed together. There was more space and you can tell that we were in a church. From a bass standpoint, different but a tie. The Strata gives a much better impression of being in a church (reverb?). Also, I noticed a shocking difference. I was suddenly hearing all the clicking and clacking of the organ pedals. I had never heard that before. I then heard it (less) on the Exposure/Schiit but only because Strata had revealed it to me.
• Bill Evans, The Hilversum concert – Nardis. The bass seems deeper on the Exposure but it could be an illusion as it probably goes down as deep on the Strata, which has bass a bit more dispersed and airy, less concentrated. The Strata gives better bass textures: you can better hear the pluck of the strings and the wood of the instrument. This one is a tie: more texture and detail in the bass for Strata vs. more energy and fat in the lower bass for Exposure/Schiit.
• Blade Runner OST – opening title. For the Strata bass goes as deep but it is more spread out; there’s more air, better sound stage for the bass. Strata is more resolving in the bass. May not be as warm but it is also less mushy. This is a tie / a slight win for Strata.
• Harry Connick, Jr, 25 – On the Atchison, Topeka and Santa Fe. Both machines sound very nice here. Strata has a wee bit more texture than Exposure. Incidentally, when Harry sings “…and they’ll all wants lifts to Brown’s hotel” there is an instant when he sings with pursed lips or under his breath. I had never noticed that before; can be heard on the Exp./Schiit as well but only because I heard it through Strata first. A tie on bass.
• Chesky reference CD – bass track 27. Same: extension is similar, Exposure sounds fatter but better bass detail / textures for Strata. It’s a matter of taste and matchup with speakers and room.

• Bach, Suites for solo cello - Pierre Fournier. The Strata clearly reveals more details. It sounds much more like horsehair on strings. Fournier’s fingerwork on the strings is much more apparent. With bright speakers the revealingness could actually be a problem. This is a clear win for Strata.
• Bob Dylan, Blowing in the Wind – Freewheelin’. The Strata has more detail in the strings but less bass extension on the guitar. As a result Bob’s voice takes over a bit too much and the guitar recedes. Strata wins on sounding more like strings but Exposure wins on presence of the strings. This is a tie (dependent on taste). RANT: I cannot fathom why, in an otherwise beautifully recorded solo track, Bob’s voice comes from the center while his guitar comes from the right and his harmonica from the left??

• Bill Evans, The Hilversum concert – Nardis. Strata has more detail in the drum thwacks but Exposure sounds great too. A tie.

• Harry Connick, Jr, 25 – Didn’t he ramble. Strata has less mushiness, more contrast, more details. Sounds more like a piano. Incidentally Strata exposed a short hum Harry makes. Win: Strata.
• Erik Satie – Gnossiene (Aldo Ciccolini). Can hear Ciccolini breathing in a few spots; that was new as well. Here Strata was beautifully piano-like and clearly more defined in the textures, airier. However Strata’s ruthless revealing nature gets a little bit in the way here. Exp./Schiit had a more “compact” sound with more midbass weight and was overall the smoother operator. Exp./Schiit wins this round. This one I might revisit in a few hundred hours as it strikes me as the sort of characteristic that could evolve.
• Debussy – Girl with the flaxen hair, from Preludes (Alain Planes). Strata sounds airier while Exposure puts more weight in the midbass and feels like rich Corinthian leather ; ) Both are superb. This is a tie.
• Bill Evans, Live at the Village Vanguard – Gloria’s Step. After solo piano, time for not solo piano. Strata has better high frequencies, makes piano less muddy and stand out more vs. bass and drums. Win Strata.

• Grieg – Peer Gynt. P. Jaarvi. On Solveig’s song (female) and the male Peer Gynt’s serenade, both amps were superb. Tie.
• Bizet – Carmen. (Callas / Gedda / Massard). Strata’s details are perfect but Callas’ voice has more bass which gives it more depth and more color on the Exposure. Ditto for Massard’s phenomenal Escamillo. Exposure wins.
• Diana Krall, Live in Paris - the look of love. Both amps are beautiful here, I hear no difference. Tie.
• Harry Belafonte, live at Carnegie Hall – Cucurucucu Paloma. Both amplifiers sound superb. With Strata Harry’s voice hangs holographically at about 6 ft height; it’s almost eerie. Win: Strata, but not by much.
• A.C. Jobim – Agua di Beber. Both sound great. Tie.

• Miles Davis, Kind of Blue – Flamenco sketches. I was expecting Miles’ trumpet to sound shrill with the Strata but it did not. Coltrane and Cannonball’s saxes are a little more treble forward with the Strata’s, this is a matter of taste. Tie.

And now for the important bit:

My primary interest in the Strata was to see if it could make orchestras sound more dynamic, while remaining musical (not exactly class D’s reputation). I listen to a lot of symphonies and large orchestral works. When I increase the volume, sound goes up but it seems something is missing. Listening carefully, I would say that while the bass and the treble go up, it is almost like the midrange goes up less. That’s when I went back to the Stereophile review of the Jade 3’s (rated class B). I used to ignore J. Atkinson’s incomprehensible measurements, but finally took the time to “educate” myself and I now think the Jade’s might be harder to drive than I thought: the 6ohm / 86dB speaker actually measures at 83.5dB and although JA finds the phase angle benign, the impedance nevertheless spends its time at 3.2-4 ohms throughout the midrange. I think this is really a 4 ohm speaker. Turns out Exposure does not list a 4 ohm rating for this amp. Some bloke online measured 80w into 8ohms but only 105w into 4ohms + called Exposure and they did not recommend using it with 4ohm speakers. Could this be my problem?

• St Saens – concerto pour piano n2 – Cecil Licad. Strata spreads the energy wider and taller but it’s a little light for my taste here. Exposure concentrates the energy too much in the center. This is a tie.
• Beethoven’s 5th. R. Chailly (Decca). Finally an improvement with big orchestral music! It’s hard to explain why but Strata has better instrument separation. Less mush. The soundstage is 2 feet taller and music more “effortless”. This is THE win for Strata!!!
• Smetana’s Moldau. F. Fricsay (DG). The Exposure seems to be playing from a 1 m circle in the middle. The Strata seems to be playing from a 3x2m rectangle. Cymbals at the end were small and coming from the floor on the Exposure while Strata’s were airier and had more bloom. Another win for Strata.

A few more tracks for enjoyment, not listening for any aspect in particular.
• M. Jackson – Billie Jean. Exposure has more midbass impact. Strata a bit more detail. Both sounded good. A slight edge to Exposure.
• B. Dylan, Freewheelin’ – Corrina, Corrina. Both great. Strata’s drums sounded a bit more like hollow objects (a good thing). Tie.
• Lalo Schiffrin, Bullitt OST – opening titles. The openings bass line is “angrier” with Strata which befits Bullitt. Win Strata.
• Dire Straits – Six Blade Knife. Exposure sounds great. Strata reveals just a smidge more clarity and detail in Mark’s guttural effects. Win: Strata by a hair.
• Duke Ellington and John Coltrane. While sax and drums sound fine, to my amazement the Duke’s piano is muffled and in the background. WTF? I have a hard time hearing it, it’s almost like he’s playing with a soft pedal. Moving to the Exposure I hear it too now but I guess I had never noticed it before. Something is wrong with this recording and it took Strata to hear it. I’ll call this a win for Strata and the CD will be my second CD to go into the trash after B. Evans’ Portraits in Jazz.
• J. Brown – Papa don’t take no mess. Both sound good but there is a little more clarity and detail from the Strata’s while the Exposures sound is a little bit more like tubes. This is a tie.
• J. Brown – Sex Machine. Very interestingly, the Strata is more revealing of Brown’s vocal idiosyncrasies. “Stay on the scene, like a sex machine” on the Exposure/Schiit becomes “Stay on the sceneh, likah a sexah machineh” on the Strata. Win: Strata.

The Strata is quite a revealing little machine… At 60h, it is already an excellent amp: musical, with great soundstage. The details you get out of this thing are insane: it’s making me throw away a CD for god’s sake. If anything, the bass was a bit less full/fat than Exposure/Schiit but more detailed (and with the sub back in, it won’t matter). I think the boys from Boulder have crafted a wonderful integrated; as far as I am concerned the class D myth is busted wide open.

So…unless things change I think The Music Room will be getting a box. Thanks to the Whiz Kid for allowing me to pick up a Strata.

One last thing: I have a philosophical nitpick with Strata. I am not really the target market for this amp, which is, I think those who contemplate integrateds like the Hegel P120-190 and stream a lot. I couldn’t care less about streaming – I’m no luddite but I just don’t have the patience to troubleshoot all the stupid gadgetry. Despite its impressive performance, I therefore cannot help but wonder how much wifi, streaming, screen gadgetry noise bleeds into the Strata’s signal. Would it sound even better without all that? And how long before all this schtuff goes on the fritz or needs some “firmware update”? When changing inputs, it has already crashed twice – flashing blue logo – and needed a hard reboot. When I press the input button too quickly half the font temporarily goes yellow or purple. The Exposure has one -hardware- button (power), no screens, no antennas, no extraneous controls… I like simple. Simple works, simple is reliable. Simple is peace of mind. To each his own. Given the Strata’s musicality, detail, and power however, it will replace my current set-up, and I trust PS Audio’s design prowess and quality will change my mind about antennas and screens.

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The Ethernet bridge is absolutely susceptible to switch and PS variations.

There is a SQ difference on my end between Netgear GS105 and Cisco SG-110D.

I mixed and matched the SMPS’ from each. The Cisco PS sucks and alters the sound a bit and is a little fatiguing. Cisco PS sounds bad on both switches but worse on Cisco.

Netgear PS is much better. Get this, I hear a significant SQ difference between the Netgear SMPS plugged into wall vs. cheap power strip. Netgear SMPS (At wall)+ Cisco switch might be my fav so far.

These effects were also noticed while watching TV over Toslink, the Cisco + Cisco SMPS was making it a little off.

In summary, the better SMPS from Netgear sounds quite flat plugged into cheap power strip with other devices in it. Really holds the sound back, getting it to the wall makes a pretty big difference… surprisingly so. I am excited to get a linear power supply in here.

The sound ranges from best case - speakers disappearing beautifully, to sound being ok but kinda flat, to worse case sounding scooped and etched.

Wow, kudos to the reviewers for the time and effort they are putting into these reviews.

It was his wording that’s not exact. It is a class A biased MOSFET on the front end of the Class D on the output.

Thanks. This is an excellent report and another example of how valuable beta testing is for us. Your comments and critiques are much appreciated. We’re on it!

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That ain’t right. Mine works normally at any rate.

Dumb questions: Peeled off the plastic on the remote? Fresh batteries? Unobstructed view to front of unit? Etc.

Is that the case with both the up/down arrows and the “regular” volume control below it?

These types of “revealing details” are what I look for as well when evaluating/noting an improvement in my system. Great catch/observation.

Another beta tester here. Strata arrived yesterday, two days early. The usual PS Audio double boxed and well cushioned for the trek. The unit has some heft to it along with excellent fit and finish. The black unit looks great in the family room rack.

I had the speakers and cabling in place already. Unpacking, hook up, manually set up WiFi, down loaded Connect app on iPhone and iPad and listening to music in under an hour with no issues. Strata instantly found and indexed all music on my NAS drive. Have listened to some of my music, Spotify and Qobuz. Also connected to TV via optical cable.

Size of the unit is just right and I appreciate the minimalist design. Volume knob has great tactile feedback; I like feeling the volume clicks. Menus and sub menus work just fine. Not the most intuitive but no problem using the manual to set everything up.

I just wanted to give my initial “unboxing” report, listening reviews to follow. I will say out of the box this thing sounds amazing. I was up early this morning listening to new music on Qoboz and the imaging is spooky good.


That’s encouraging to hear that yours doesn’t exhibit the same volume behavior. I double checked all of the things that you mentioned. Changing volume requires one click on the remote = one tick on Strata’s volume. Holding down the volume up or down button does nothing on my Strata. Same thing with arrow buttons. I see the little red light blinking on the remote but no luck.

I also tried the remote from my Gain Cell DAC and same issue.

I’ll see if support can help with this when I call about the wifi issue.


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