[Guts390]

Okay here's some update! My MMB2 arrived yesterday and I did some testing and listening.

First thing first, volume pot hum.

As previously mentioned it only happens when hand is touching volume pot, if you let go then it's fine. I also noticed that it only happens if I have RCA plugged to a USB powered source that's plugged into PC.

i.e. SDAC = USB Powered, iFi Zen Air Dac = USB Powered.

Then if I unplug RCA and just run the ES9028 Dac Card directly it's fine. But if I plug in RCA, even if PMax is switched to read Dac Card, you still get hum. So make sure you unplug RCA when not in use.

UNLESS....... you're using MMB2, then I get no hum no matter what. My guess is that MMB2 has its own power source (not from USB) so maybe it's fine??? It was late at night I didn't bother to test any further. So this is my initial assessment LOL.

So based on this I'm assuming if you use USB power, maybe use a USB Hub with its own power?

Now back to sound......... I find only SDAC sounded pretty terrible on PMax, ES9028 Card, MMB2, Zen Air Dac all sounded pretty good. Each has its own flavours and pros and cons. But they all sounded good more or less.

I'll compare MMB2 to ES9028 since most people probably would be using either of those.

MMB2 vocal has more subtleties, ES9028 vocal is more detailed but edgier.
ES9028 vocal surprisingly to me is a bit...... closer....??? Maybe because shallower depth overall.
MMB2 is wider sounding, imaging also better.
ES9028 overall sounds more detailed.
Treble/Mids/Bass balance to be honest didn't feel too different. At least upon the quick 1 night listen I couldn't tell a huge difference. There is a difference, just not huge.
Bigger difference lies in the Multibit vs Delta Sigma sound.
Overall MMB2 presents things a bit softer but more 3D while ES9028 are a bit sharper edgier but also higher resolution, but sounded flatter.

I'd say they all sound nice but just really depending on preference.

Let me know if you guys have any questions.

nice write up. This seems to line up with what the folks at superbestaudiofriends were saying. Man I can't wait to get my hands on this thing. But I'm waiting for tax season. Going with the 9028 for sure.

 

[JonM78]

First post here but just ordered the Pietus Maximus last night, shipped today. Can't wait to get it. I currently run a JDS Labs Element III MK2 and usually prefer warm to neutral audio. I've had the iFi Zen DAC V2 and Monolith THX 887 in the past. Honestly have to thank @GadgetryTech for bringing the PMax to my attention. I'm always watching his reviews.

 

[michael2v]

Do the top case screws have some sort of thread lock on them? I'm having an incredibly hard time loosening them with a ceramic driver (I don't want to scratch the paint on the screw head).

 

[Jimmyblues1959]

Has anyone been able to compare the Pietus to the Schiit Mjolnir 3?

 

[Orange5o]

Discussed on sbaf if nobody here has. Consensus seems to be a cheaper way to get 90% of the way there.

 

[Rattle]

Do the top case screws have some sort of thread lock on them? I'm having an incredibly hard time loosening them with a ceramic driver (I don't want to scratch the paint on the screw head).

No evidence of any thread lock on top 4 case screws and they came out easily. The set screw on the pot was tight as hell though ! I installed the ess card yesterday so I got to mess around a bit.

 

[michael2v]

No evidence of any thread lock on top 4 case screws and they came out easily. The set screw on the pot was tight as hell though ! I installed the ess card yesterday so I got to mess around a bit.

Thanks! Was it necessary to remove any internal screws to loosen the PCB in order to get clearance for the ESS card? Some have commented that this was necessary for DAC installation into the Asgard 3.

 

[Rattle]

Thanks! Was it necessary to remove any internal screws to loosen the PCB in order to get clearance for the ESS card? Some have commented that this was necessary for DAC installation into the Asgard 3.

The only thing you have to do is remove the screw on the potentiometer shaft pull off the knob. Remove the 4 top screws and and slide off the top. Only tiny bit of resistance was around the 1/4 jack. Oh and take the sticker off the back blocking the port.

There's a stand off that goes on the board under the card, once you're ready to go, easiest thing to do is line up the pins and get a visual. Take the small plate that has the USB C connector opening and screw it to the ess card not tight. Then slide it in against the back of the case making sure the pins are lined up. Then just push down easily. Once you have the card seated put the screw in the back of the case that holds the plate in. Once you've got it all squared and flat, tighten all 3 screws to taste lol that's what I did anyway. No interference at all and no removal of anything.

 

[Guts390]

You can also power the hs02 and see if that works. Good luck!

The HS02 works with the modi+. Doesn't seem to matter if I power the hs02 or the dac. Either way it works fine.

 

[solid12345]

Just got mine this morning with the ESS Card. Very interesting amp, never really heard anything like it. Just my impressions off the internal DAC but It almost sounds like you have a DSP-like effect or slight reverb applied lightly to the sound. Vocals come across very ethereal, like they’re singing right in my ear. Separation is very, very good. Note decay is very quick, very nice for pop and EDM. It’s definitely the most ”tube-like” solid state I’ve heard save for my old 70s McIntosh 2505. Everything other amp I’ve heard claiming tube-like qualities but a pale imitation. This is its best selling point IMO is a true tubey sound without the hassle and heat of bulbs. I imagine the ASR guys would have a meltdown poking and prodding it lol.

I will say it’s one weakness is it can get a bit fatiguing, it’s very dynamic and sharp but I’d attribute it to the Sigma dac, I’ve never heard one that isn’t. Will have to try it later with an external R2R.

 

[Slade01]

I will say it’s one weakness is it can get a bit fatiguing, it’s very dynamic and sharp but I’d attribute it to the Sigma dac, I’ve never heard one that isn’t. Will have to try it later with an external R2R.

Maybe give it a few days. I thought so too, especially running this with a 2/64 (where I was warned it could be etchy in the highs), but it seems to have settled more and smoothed out. It was no longer fatiguing to me after a day or so of running the amp.

 

[Jimmyblues1959]

Just got mine this morning with the ESS Card. Very interesting amp, never really heard anything like it. Just my impressions off the internal DAC but It almost sounds like you have a DSP-like effect or slight reverb applied lightly to the sound. Vocals come across very ethereal, like they’re singing right in my ear. Separation is very, very good. Note decay is very quick, very nice for pop and EDM. It’s definitely the most ”tube-like” solid state I’ve heard save for my old 70s McIntosh 2505. Everything other amp I’ve heard claiming tube-like qualities but a pale imitation. This is its best selling point IMO is a true tubey sound without the hassle and heat of bulbs. I imagine the ASR guys would have a meltdown poking and prodding it lol.

I will say it’s one weakness is it can get a bit fatiguing, it’s very dynamic and sharp but I’d attribute it to the Sigma dac, I’ve never heard one that isn’t. Will have to try it later with an external R2R.

The tubey sound is what I like about the Piety. It's not fatiguing at all. IME there's not too many headphone amplifiers under $1000
that aren't fatiguing to listen to after an hour or so. Especially with digital sources. The Schiit Asgard 3, Meier Corda Classic, Cavalli Liquid Platinum and Nitsch Magni Piety are four HEADPHONE amplifiers I would include for under $1000 that offer that fatigue free factor. And now the Pietus.

 

[Rattle]

I don't find the amp fatiguing at all. Even with ess card, listened with BF2 for a couple weeks first. Even with a headphone like focal elex I can listen for hours.

I would say Jot 2 is more fatiguing for sure. Had asgard 3 for a long time as well and sold it. Good amp for $200 when it launched but its not very dynamic and rather soft sounding in comparison. Great thing about PM is you can leave it on barely gets warm, smooths out a bit as well after being on. I don't have any hum or vibrations on mine either thankfully.

 

[Freia]

I’ve mentioned I did liked my Grado better on my Pietus compared to Piety. It’s mostly due to the gain as the Pietus allows more room to turn the knob. As for synergy goes, the headroom or soundstage is a bit too enclosed to my liking although the way it represents music is very mature.

That sucks man. I had to sell all my headphone gear in 2015 due to financial struggles. I got back in the game years later and have now far surpassed what I used to have, but it was a sacrifice at the time.

Curious how does your Corda Classic fare with the Pietus. I’m a fan of Meier‘s crossfeed and the dac I’m using is the Daccord.

 

[J Ottawa]

I wonder how Schiit Midgard compares with Pietus? I’m using RME Adi-2 as a dac.