PART 4 - IMPRESSIONS of CEntrance M8 V2 WITH Grado HF-2, HiFiMan HE-1000 v1 and HE-1000se, and HiFiMan HE-6 V1 OG:
THE Tl;Dr VERSION - it drives all of the listed headphone quite well, as well as the ones I've previously posted about in Part 1, 2 and 3 - some better than others, and depending on the app used for music even the HE-6 V1. The M8 V2 is Highly recommended. Buy one ASAP before the price goes up when they start shipping.
I’ve got my final impressions of the CEntrance M8 V2 and I can now stop gushing about the test unit and send it back for the final version USB switching control mod and final firmware. The primary noticeable change will be it showing up as "CEntrance M8" on your devices' output switcher, instead of being listed as “CEntrance M8 V2”. The 2.5mm jack will also be a little more forward and flush with the case. And, if the M8 V2 USB becomes unplugged while using it for data you won’t have to switch out of USB mode and back to USB to use it again. Everything else was perfect.
They are starting production and everything is finalized, with no changes to the audio and amplification being done before production. The way the M8 V2 sounds for us five reviewers is how they will ship, and I would not have asked for any changes in the sound quality or frequency response - it’s that good.
I spent several hours today finishing my impressions of the M8 V2 using my HiFiMan HE-1000 V1 and 1000se, single ended and balanced, on the cold side and hot side. I also tried my stock cabled Grado HF-2 on the hot side and cold side with a 3.5mm Grado adapter. And just for grins I tried my inefficient HiFiMan HE-6 v1 OG, via 4-pin balanced stock OCC copper cable and stock 1/4” pigtail adapter.
I used Tidal lossless streaming app with everything for the first 6 hours of the day, and then at about 5PM, after chatting with Michael about my HE-6 v1 impressions, I switched to Apple Music in Mac OS Catalina to try some of my lossless CD rips and HD Tracks hi-res downloads with my HE-6. I felt like a fool because I’d written a full page and a half about it’s power output with HE-6 V1 while using Tidal, only to discover that Apple Music on Mac and iPhone has a higher output level going out to the DAC (as well as Tidal for iPhone). That changed a lot of what he and I discussed, for the better. I had to spend several more hours listening, to help me correct my findings.
Therefore, this writeup got very complicated midway through todays review, and I did my best to fix it and clean it up; but please forgive me if I was repetitive or not clear. By 10:30PM I was just getting to the point cleaning up my first draft - I’ve been going at this for about 14 hours by the time I hit the post reply button!
I started out with my
Grado HF-2 on the stock cable and pads. I thought that they sounded slightly better on the hot side at higher volumes, rather than via the cold side with a Grado 1/4” to 3.5mm adapter, but not by much. And at lower to moderate volumes I thought the cold side was great with the HF-2.
The Grado house sound signature has a midrange that can be a little “shouty” at louder volumes, and a treble that can be a little grainy at times. A more powerful amp hides some of these flaws at louder volumes, as do tubes. Usually my favorite amps with the Grados have about 2 watts into 32 ohms and tubes to smooth them out and make them sound more euphonic, such as my Eddie Current ZDT. They’re even better on a Millet Hybrid which gives them a nice bass bump as well. But with many SS amps like the Nuforce HDP or HAP-100, CEntrance M8 V1, or DACmini the HF-2 can sound a little lighter and grainier. (I never got around to trying them with our Schitt Audio Magni 3 or HiFiMan EF-100).
With the HiFi M8 V2 the Grado HF-2 actually have a more balanced and neutral presentation, while sounding smoother than on my other SS amps, just like with the HD800/800s. My son owned the HF-2 for a while, but sold them a few years back in favor of the HD600 on the DACmini or Nuforce HDP. But the M8 V2 is warmer and smoother with the HF-2, such that even my son liked them this time around. He would still prefer a pair of balanced HD600 with the M8 V2 if he was on a budget, but he felt the HF-2 + M8 V2 was a good match. I would agree.
I might prefer the Grado’s bass when using flat ear-pads more than the standard pads with the M8 v2, which does give them a little bass boost. But using the flat pads for more bass comes at the expense of a smaller soundstage and a too-forward midrange. So I nixed the flat pads. A better option was flipping the M8 V2 bass boost switch ON, which makes the HF-2 sound nearly perfect with the stock pads, on hot or cold sides at any volume - preventing that typical “wall of sound” and forward mids that I’d get from the flat pads.
The bass boost switch with the HF-2 also makes the HF-2 a lot more fun sounding without hurting the sound, because the bass does a better job of keeping up with the midrange. With the bass switch turned on, I thought that the cold side with the 3.5mm Grado adapter was every bit as good as the hot side with 1/4” jack. Even flipping on the treble boost didn’t make the HF-2 too sharp sounding, but made extreme low volume listening more enjoyable. So the HF-2 is a good match for Stamina Mode, while being slightly better on the hot side (while the HE-560 planar magnetic perk up quite a bit on the hot side).
I then moved to the
HE-1000 v1 and HE-1000se with the stock single-ended and balanced cables, and also used my Moon-Audio Black Dragon mini-xlr cable for the HE-1000se, using 2.5mm, 3.5mm, 1/4”, and 4-pin XLR pigtails. I usually prefer the HE-1000se over the HD-800/800s, because the HE1K has more bass impact and foundation, and they are smoother without losing any detail or transparency. In general, the HE-1000se are also more fun sounding while staying true to the recording, while the HD800s tend to be more analytical, airy, and out-of-head.
Even with the stock HiFiMan balanced cable the M8 V2 with either version of HE-1000 blew me away!
While the M8 V2 was a great match for the HD-800/800s, it’s an even better match with the HE-1000 v1 and 1000se. The sound is extremely transparent and crisp, with rich tones and textures, plus fast and tactile bass, making them sound simply amazing. The HD-800/800s still have a more etherial and spacious soundstage vs the HE-1000se, but the M8 V2 brings the HE1K that much closer in terms of a large soundstage, while sounding more punchy, exciting and energetic than the HD-800s.
Unbelievably, connecting my HE-1000se to the 2.5mm balanced output was quite remarkable, and the M8 V2 can drive them with ease from any output, including just the cold side in Stamina Mode! The M8 V2 has more power than I could ever ask for with the HF-2, HD600/6XX/800, and Edition-X, and it’s no different with the HE1K v1 and 1000se. With gobs and gobs of power on tap I could not ask for more from a portable DAC/amp when using the HE1K; and like with many other headphones, it could be my only DAC/amp in the house and I’d be a happy man.
After being blown away by the M8 V2 driving the HiFiMan HE1K v1 and se, I rested my ears for a bit and then
switched to the HiFiMan HE-6 V1 OG in balanced mode on the 4-pin XLR output. These headphones are notorious for their power hungry appetite, thriving on a 50+ watt/8 ohm speaker amp, with about an 84-85 dB/mw sensitivity. I consider them to be a good torture test any time I try them on a new amplifier.
I started out with HE-6 v1 using the Tidal lossless streaming app for Mac, not knowing that Tidal’s output levels with an external DAC are often a bit lower than when you are using the Apple Music app on a Mac or iPhone. Regardless, I was impressed.
The HE-6 V1 on the M8 V2 sounds good at normal/medium listening volumes. It has good bass and treble extension, solid presence, vivid midrange vocals, good detail and air and space, and the soundstage is open. Overall sonic balance and frequency response is excellent and still closer to the HE-1000se than it has a right to be after all these years - but with a smaller soundstage than the HE1K v1 or se. Yet the HE-6 soundstage still sounds bigger and more spacious than with my HE-5LE, HE-500 or HE-560 on any amp.
At normal listening levels with most music, with my eyes closed I might not know that I was listening to a portable amp, and even with Tidal lossless streaming app the HE-6 gave no sign that the M8 V2 can’t drive them, until I found out that I was already at about 75-80% of max volume - whoops!
Going up from there to 100% volume adds at least 3+ dB with Tidal, where it’s a few dB louder than I would normally be listening with HE-6, although not at levels that would make my right ear tinnitus act up. If listening at max volume for a while, once my ears adjusted to the higher volume then there was no way to go up if I needed more, except via software. This did not happen often, and could be cured with taking a break and letting my ears rest before coming back to listen.
It’s not that big of a problem because
most of the time the HE-6 v1 volume levels were more than adequate while using Tidal to play thru the 4-pin XLR output. And the bass depth and “feel” didn’t make me feel like it was struggling at all. but, it just can’t reach slamming impact levels with the M8 v2 like it does with a 50 watt speaker amp.
With some albums like Jack Johnson “Sleep Through the Static” the volume levels in Tidal were close to that of Apple Music. With others like B.B. King and Eric Clapton “Riding with the King” or Chris Jones “Roadhouse and Automobiles” the volume was a little quieter, but still very useable between 60 to 100% volume out of the 4-pin XLR. With Rutter Requiem by Timothy Selig and Turtle Creek Chorale, sometimes with some songs the volume was too low for the HE-6 V1 (e.g. Pie Jesu), more so if I had been listening previously to other music at louder volumes for a while.
Taking that short break to “reset” my hearing allowed me to go back and listen to this quieter recording again.
With Tidal and some quiet albums, the M8 V2 with HE-6 V1 doesn’t run out of steam so much as it runs out of gain. Regardless, the 4-pin XLR jack was a must with Tidal for Mac and the HE-6 V1, when using the software as intended.
Rogue Amoeba SoundSource software for Mac - As noted, with Tidal and some classical music with HE-6 V1 I’d sometimes wish for maybe 3-4 dB more gain, but later things got much better by using the Rogue Amoeba SoundSource app, or switching to Apple Music for Mac or iPhone which plays louder. I can use the Rogue Amoeba SoundSource app on my MacBook to bump the gain as much as 400% in overdrive mode, setting the amount to be boosted on an app by app basis. So, I can have it only boost the gain for the Tidal app to 200% but not boost it with the Apple Music app.
With overdrive mode at 200% and using Tidal, the M8 V2 will just continue to give me more and more volume and power thru the HE-6 v1 without complaint, to a limit. With louder masterings the software overdrive will put its foot down and say no more, which helps prevent clipping the signal. So with Infected Mushroom “More of Just the Same” it’s already pretty loud without overdrive, and going to 300% overdrive did not result in the music getting any louder than 200%. But that 200% overdrive resulted in a noticeably louder playback while staying pretty clean, and at a volume that was fairly loud and higher than I would normally listen, without degradation in sound quality or any change in sound signature.
So, with Tidal, some very quiet classical genre recordings that are well below -0 dbfs will benefit some software gain boost with the HE-6. SoundSource overdrive does a good job of predicting how much gain boost is safe before clipping, but it’s not flawless. You might click on the 2x button for 200% boost and then need to turn it down to 150% or 175% manually for the cleanest sound. Note: I did not use the “Magic Boost” switch in the software, which compresses the quiet passages to be louder while giving about 150-200% boost in gain overall.
Again, with most of the music in my Tidal playlists the HE-6 v1 was fine without any software gain adjustment. Despite that, using overdrive could make the HE-6 sound more fun with many songs at higher volumes, like Infected Mushroom, Jonas Brothers and Katy Perry. And the M8 V2 with HE-6 v1 can take quite a bit of bass EQ via the SoundSource app before anything distorts. It was just a little disappointing with HE-6 V1 when trying to play a quiet song in Tidal for Mac, without using a software gain boost app like SoundSource.
Fortunately, nothing like this is needed for Apple Music or on the iPhone. When
I switched to Apple Music on Mac to hear my ripped CD’s and hi-res music, everything changed! This is where I found out that different music apps on the Mac can have different volume output levels with an external DAC/amp, even with the same album or songs. While Tidal doesn’t play as loud as Apple Music in Mac OS Catalina, this is not the case with the iPhone, where Apple Music and Tidal both play at the same level, regardless of whether using USB with a Camera Connection Kit (CCK) or Bluetooth Audio.
When I switched to Apple Music on MacBook (or iPhone) and played the same music through the M8 V2 I found that it drives the HE-6 V1 OG noticeably louder than Tidal for Mac, making me check a few times that Tidal’s volume was not turned down.
At no time when listening to music in Apple Music for Mac, or on the iPhone, did I need to use any software cheats to get more volume out of the HE-6 v1. I was happy with what I got.
Prior to this discovery, I was trying to talk to Michael about whether there was any way that CEntrance could add another 3 dB to high gain on the hot side, in order to drive the HE-6 slightly better, but it was too late to make that type of change. Adding more gain overall to both hot and cold side might be easier but could risk exposing the noise floor in low gain, harming some IEM in high gain, or allowing the M8 V2 to distort at max volume when the bass boost switch is turned on, so I’m glad we couldn’t go forward.
With Apple Music on Mac or iPhone, or with Tidal on iPhone, the M8 V2 is powerful enough to even drive the HE-6 V1 to good listening levels from the 1/4” singe-ended jack! I actually preferred the HE-6 V1 with it’s lower volumes on the M8 V2 to the listening to the HE-560 V1 at the much higher volumes that they can achieve. (Note - the HD600/6XX/800 on the M8 V2 balanced output also have better synergy than the HE-560.)
Then comes Bluetooth - I have to say that with the previous CEntrance BlueDAC I thought that they did one of the best implementations of Bluetooth audio that I’ve ever heard, through upsampling and re-clocking; and it does the same with the M8 V2 over Bluetooth.
HOW M8 V2 BT SOUNDS - The M8 V2 Bluetooth audio is simply outstanding, whether with AAC on an iPhone or AptX on a MacBook. Today I played a ripped lossless CD via Apple Music through USB on the Mac, and played the same album transferred to the iPhone in Apple Music through the M8 V2 BT input, and switched between the Mac with USB and the iPhone with Bluetooth - I was hard pressed to hear any drop in quality with Bluetooth on any of my open back headphones. I’m not sure that I could tell which was which very easily in a blind comparison, except with my Westone ES60 custom IEM with passive noise blocking that let me hear an increase in air and micro detail. It’s that good.
HOW M8 V2 BT WORKS - When you turn on the M8 v2 it starts up in BT search mode. If you’ve previously paired it with something, it will connect to the last device that it was paired with if it’s within range. If no paired device is within range, then it goes into pairing mode and automatically connects to whatever tries to use it, without needing to enter a pairing code.
First I paired the M8 V2 with both my iPhone and my MacBook Pro. The I used Bluetooth Explorer app on my MacBook to set my Mac to only connect with AAC, or AptX if available, not SBC. When I turn it on the M8 V2 connects to my MacBook immediately using AptX if no other paired devices are around. And the M8 V2 connects immediately to my iPhone 11 Pro Max, presumably with AAC, if no other paired devices are around when I turn it on. And, if several paired devices are nearby when you turn on the M8 V2, then it will automatically connect to the last device that was connected to it previously.
Connections happen super fast. If I'm using BT with my iPhone and want to switch it with my MacBook Pro, I have to go into my iPhone and manually disconnect the M8 V2, and then I can connect to it with my MacBook Pro.
I should mention that with the iPhone that the Apple Music and Tidal apps outputs are volume matched to each other, and using the USB input with CCK also plays at the same volume as when using Bluetooth. On the Mac, switching from BT to USB and back doesn’t result in any volume change, as long as you are using the same app. Also, right now every time you unplug the USB cable on the DAC from a CCK (camera connection kit), you have to switch out of USB mode and back to USB to get USB to work again, and then the iPhone recognizing the CCK might take several seconds - but this is not how it will be with the production units (a small fix was implemented).
It’s only with the Mac that Tidal that plays quieter than Apple Music, and I actually pointed out this Mac vs iPhone volume discrepancy to Michael on the first day of impressions. I just hadn’t compared Apple Music to Tidal on a Mac until today, and the drop in volume with Tidal fooled me into thinking that the M8 V2 wasn’t as good to drive the HE-6 V1 as we’d hoped. Doh!
CONCLUSION: The CEntrance HiFi M8 V2 is now my favorite portable DAC/amp, and it’s quite versatile - my son called it the “Jack of all Trades, Master of Some" and I agree.
I plan to use it often on my MacBook and iPhone with my Westone ES60 and W80, JH Audio Roxanne, HiFiMan Edition-X and HE-1000 v1 or se, as well as my HD600/6xx and HD-800s - via the balanced 4-pin output or 2.5mm balanced output, depending on which cables I am using. I would even sometimes use it with my HE-6 v1. When I some need passive isolation and don’t want an IEM, the light-weight portable CEntrance Cerene dB headphone is also great with the M8 V2.
It’s very hard to find a headphone or IEM that doesn’t sound good with the M8 V2, and we only managed to find one or two. I was a pleasant surprise just how many picky headphones got along so well with the M8 V2. It’s definitely a step up from the M8 V1 and DACmini with my HD-800s, and has better bass with HD-800s than my $3000 ZDT. And it completely took me by surprise with the HD600/6xx by the amount of power and energy it gave them, giving them new life. The efficient Edition-X and the related HE-1000 v1 and 1000se should have been brutally revealing with the M8 V2, and instead they got along so well with the M8 V2 that it could replace my desktop amps. And, it was the best amp I’ve ever used with my Westone ES60/W80 and JH Audio Roxanne, especially with the cable rolling I was able to do.
The HE-560 and HF-2 that I tried work just fine with it, but they are not my favorite headphones these days - they’re good enough that I would not sell them and I’ll keep them paired with my high-power Eddie Current ZDT desktop amp where they sound best. But my primary issue with the HF-2 is not the sound, which is engaging and fun, but the comfort - I cannot tolerate Grado foam-cup ear cushions for more than about 45-60 minutes at a time. I did not try my HE-500 (packed away) but think would be great with the M8 v2.
The Bluetooth is one of the best, if not the best, Bluetooth implementations for AAC and AptX audio I've tried. I don’t have a compatible device for SDHC, LDHC and LDAC, so I wont complain about the lack thereof, but having AptX HD and LDAC would have been nice to have included for android users and to future proof the M8 v2.
The Bass Boost and Treble Boost switches are subtle but work well, and do not make the amp sound bad or distort. The hi/lo gain settings are good for a vast number of different IEM and headphones (+20dB on high). There are so many full size headphones that can be driven by the cold side that we can use easily stamina mode to double the battery life to 8 hours (not tested), as Stamina mode turns off the hot side amps and LED dB meter. Using it with BT input and Stamina Mode at normal volumes (not max) should let you use it for an entire work day. The unit barely got warm for me with the hot side active, and I did all of my listening for Part 4 in high gain.
I comes in a small black cardboard box with a CEntrance sticker, a SIM card tool to operate the switches, a nice 3 foot USB-C to A cable, and a draw string pouch that can hold the M8 V2, USB cable, a CCK, and a second cable of your choosing. I also got a small CEntrance zipper bag, but not sure if that will go out to all the buyers. I don't know if Michael will also be throwing in a USB-C to C cable yet.
It can be charged via USB-C on either the cold side or hot side, while the cold side USB-C doubles as a data input for the DAC; and if power is connected to the hot side USB-C then the cold side USB-C becomes data-only without having to flip the switch on the panel to disable it. You can use the charge switch to turn off charging from the data input so that it doesn’t drain your phone, and that switch off can keep a noisy PC power supply from contaminating the sound as well. You can easily plug in a power bank to the USB-C to charge it while using it mobile with a phone or tablet, to avoid draining power from the source device. You can also charge it with a 45 watt USB-C wall charger for a MacBook or Chromebook - it will only draw the power that it needs and no more, and it can be charged with as little as a 5v 1a charger. I neglected to ask what is the most that it will draw in order to charge.
IF I COULD CHANGE ANYTHING: (1) I’d have liked a separate gain switch for the hot side that could do +23dB instead of +20dB,
(2) I’d have liked to be able to change the switch settings with a fingernail like with the M8 V1 instead of needing to use a pointy tool or a pen, although it comes with a SIM removal tool to operate the switches
(3) I’d like to have seen it get Made for iPhone compatibility built-in without needing a CCK,
(4) I’d like to have seen color LEDs with it going from green, to yellow, to red as input levels got higher.
Number 1 would not be an issue with anything but using HE-6 V1 with the Tidal app.
Number 2 can be solved by keeping a pen in your pocket if you aren’t worried about painting the switches with ink.
Number 3 can be fixed by buying a CCK or a more compact “Lightning to USB-C data" cable from Penon Audio for $40.
Number 4 can be fixed with colored dry erase markers and some clear tape to cover the LEDs?
But if using a USB-3 CCK since there is no native Apple support (#3), then you can charge the iPhone with a lightning cable while using it to play music via the lightning port to USB, for times when you don’t have access to a Qi phone charger (like on a plane or in a car for a long trip).
I have to stop somewhere, as I’ve been going at this for 14 hours straight, so that is all. As the saying goes, "Stick a fork in me, I'm done."
