Holo Audio Serene Preamplifier

[GoldenOne]

Figured it'd be worth starting a thread on this given as there doesn't seem to be one at the moment.

The Holo Serene preamp is now available


Links:
Wildism: https://www.facebook.com/wildismaudiohk/
Magna: https://magnahifi.com/holo-audio-serene-l1-balanced-discrete-pre-amplifier/
Kitsune: Not yet posted

Specs:
 

INPUTS:
3x Single Ended RCA (Cinch)

Largest Value 12Vpp (4.25Vrms)
Impedance 3.9 KOhm
2x Balanced  XLR

Largest Value 24Vpp (8.5Vrms)
Impedance 7.8 KOhm
OUTPUTS
1x Single Ended RCA (Cinch)

Largest Value 16Vpp (5.65Vrms)
Output Impedance 33 Ohm
2x Balanced Output XLR

Largest Value 32Vpp (11.3Vrms)
Output Impedance 66 Ohm

WEIGHT    9 kg
DIMENSIONS    430 × 260 × 55 mm

Measured performance:
Third party measurements here: https://www.l7audiolab.com/f/measurements-of-holoaudio-serene-preamplifierpre-retail/
Key specs:
>120dB SINAD (2nd and 3rd harmonics both below -145dB)
>140dB Dynamic range

Features:
- XLR-1 outputs can also be used as a 3 watt @ 32 ohm headphone amplifier (apparently holo will later be releasing a dedicated full-size headphone amplifier unit as well)
- Relay controlled volume adjustment in 1dB steps
- Chassis is the same as spring 2 / may and will stack perfectly if you have those (additionally the remote control works for both the serene and the spring 2 / may DACs)
- Fully discrete 8 channel amplification, with one module for buffering and one for amplification on each channel (two channels, balanced, with two modules each, so 8 modules total).
- All outputs driven simultaneously

[Holzohr]

Hmm..  updating from my Spring 2 to May or purchasing a Serene. That's the question. *scratching head*

[GoldenOne]

7 minutes ago, Holzohr said:

Hmm..  updating from my Spring 2 to May or purchasing a Serene. That's the question. *scratching head*

Personally i'd say go for the may. What preamp are you using atm?

[Holzohr]

I have a Oppo HA-1 for this but at the moment I use the Spring 2 without preamp. The HQPlayer volume control does a very good job.

[StreamFidelity]

12 minutes ago, Holzohr said:

Hmm..  updating from my Spring 2 to May or purchasing a Serene. That's the question. *scratching head*

Don't you go into your B&M Prime 6 with digital volume control from the HQPlayer? The 4.1 Vrms output should be enough. See measurements: https://www.audio “science” review/forum/index.php?threads/review-and-measurements-of-holo-audio-may-probably-the-best-discrete-r2r-dac.10161/

 

[Holzohr]

2 minutes ago, StreamFidelity said:

Don't you go into your B&M Prime 6 with digital volume control from the HQPlayer? The 4.1 Vrms output should be enough. See measurements: https://www.audio “science” review/forum/index.php?threads/review-and-measurements-of-holo-audio-may-probably-the-best-discrete-r2r-dac.10161/

 

 

Yes, exactly. The volume input knobs of my Primes are set to minimum. No need to turn them up.

[Diavolo]

Take my money! They did! I am waiting for "Serenity Now" 😁 

[John Hughes]

I have a Holo May and love it.  The Serenity looks amazing, though I'm not sure I would find it worth the $$$ in my system. I wish it had a great phono stage at that price :)

[Diavolo]

6 minutes ago, John Hughes said:

I have a Holo May and love it.  The Serenity looks amazing, though I'm not sure I would find it worth the $$$ in my system. I wish it had a great phono stage at that price :)

You know there are no great phonostages that are included with a preamplifier. They are all separates, costing thousands of dollars.  You may get a good one, but not great. 

 

(none of this is true 😁) 

[John Hughes]

That is true for mid-level preamps!  I have heard what a great active preamp can bring to a system.  I'd give my left nut for this: 

http://www.shindo-laboratory.co.jp/English/Giscours.html

 

But alas, that is not to be.  I'll wait to hear what your reviews have to say :)  I've been designing my system around not needing a preamp.  I'd have to get a lot of goodness to add something like the Serenity with all those circuits and cables etc to my minimal path.  

[Diavolo]

2 minutes ago, John Hughes said:

That is true for mid-level preamps!  I have heard what a great active preamp can bring to a system.  I'd give my left nut for this: 

http://www.shindo-laboratory.co.jp/English/Giscours.html

 

But alas, that is not to be.  I'll wait to hear what your reviews have to say :)  I've been designing my system around not needing a preamp.  I'd have to get a lot of goodness to add something like the Serenity with all those circuits and cables etc to my minimal path.  

Gorgeous piece! I'll know pretty fast since I run source direct now, but it's not ideal for certain apps or web sources of content. Works great with roon and hqplayer, not so great for YouTube Music, Pandora, etc. 

[GoldenOne]

I can't seem to edit the original post but in case anyone missed it Kitsune has the serene listed now :D
https://www.kitsunehifi.com/product/holo-audio-serene-preamp/

[GoldenOne]

Two things I am curious about though, (maybe @Bimmer100 might be able to shed some light on these? Figured it'd be better to post here as i'm sure others may want to know as well)

1) Can the serene do balanced to single ended conversion safely? I know this isn't the case for all preamps (and of course you can't do it with a passive adapter without risking damage to your DAC/Source)

2) The XLR-1 and XLR-2 outputs have fairly different specs, with XLR-1 having 3 ohm output impedance and XLR-2 having 40 ohm output impedance. What is the difference between these two outputs? And for a single-amp system is one preferable to the other?
(Additionally, can we use one of the XLR outputs and the RCA output simultaneously without sacrificing CMRR on the balanced? I'm guessing maybe XLR-1 is a separate circuit to XLR-2/RCA?)

 

[GoldenOne]

Also, seems that the initial specs Magna had listed have changed both on there and on Kitsune.

Max output voltage is now higher, higher input impedance, lower output impedance, so that's pretty nice!
No manual available yet so will probably have to wait to find out more but it looks like an absolutely stellar device!
 

[lpost]

@GoldenOneNearing review time?

 

I use a May dac into PS Audio BHK hybrid preamp into a BHK hybrid amp. I very much like to be able to experience different tubes and their contribution. I've run my previous DAC direct to amp (it had volume control) and while it was very 'clean' it lacked life or soul that the tube preamp adds.

 

I might need another preamp...

[GoldenOne]

15 minutes ago, lpost said:

@GoldenOneNearing review time?

 

I use a May dac into PS Audio BHK hybrid preamp into a BHK hybrid amp. I very much like to be able to experience different tubes and their contribution. I've run my previous DAC direct to amp (it had volume control) and while it was very 'clean' it lacked life or soul that the tube preamp adds.

 

I might need another preamp...

Review is up on my patreon atm and will be on youtube at the weekend.
Honestly it was really tricky to review because it sounds so ridiculously transparent......

Normally I think that 'transparent' isn't an appropriate description for gear.
You can't listen to something with no DAC, so you don't have a reference point with which to compare a DAC and claim it is the same and therefore transparent.
Same with amps.

But preamps are the one area where you CAN take it out of the chain and listen without it. To see if it is indeed different.

Previously I was using the Goldpoint SA2X attenuator.
Objectively, it measures like a wire, literally, and subjectively, I was never able to tell a difference whatsoever between having my DAC connected directly, vs using the goldpoint.

The Serene is SO GODDAMN CLOSE to the goldpoint it's nuts. Like, the difference here is way more subtle than the differences between most DACs.
I guess maybe I should have expected that given the insane objective performance but wow....this thing sounds good.

And by this I don't mean its "clean" like a lot of the well measuring opamp based stuff is. Headphone amps like the A90 or 789 measure very well but sound cold/clinical/analytical to me. That's not happening here.
(A90 also functions as a well measuring preamp but sounded flat and meh)

The one area where the serene is a little different from the goldpoint is in the lowend. Lowend/bass is just a sprinkle more dynamic and 'punchy' than with the goldpoint. And I love it.
Additionally, there have been times where I feel like I might have heard a slight difference in the midrange which I'd best describe as if someone had added 5-10% of that tube holographic signature to it. But its so subtle that i'm not confident it wasn't placebo.

And as a headphone amp....well, its beautiful. Dynamic, engaging, open and spacious without so much as a hint of glare or sibilance (and not hiding ANY detail or smoothing things over whatsoever). Its absolutely stunning.

With Susvara specifically I prefer my AHB2 because they really do benefit from the power. But Arya or HD800 are absolutely sublime on the Serene and I really cannot wait to hear the dedicated headphone amp version with Susvara.

The serene is quite frankly incredible and if one of the other high-end companies had released it for £10,000 people wouldn't bat an eyelid because it absolutely meets that standard and expectation.

Well done Jeff Zhu

PS: Tube preamps are imo a bit of a different area. With a tube preamp you are looking to add a specific flavour/signature to the sound. So its not really a direct competitor in that sense. This is not a coloured preamp. But it most certainly isn't flat, dull, grey or anything of the sort. Regardless of if I'm using it as a pre, or a headphone amp, I can't help but smile, it's fantastic.

[lpost]

4 hours ago, GoldenOne said:

PS: Tube preamps are imo a bit of a different area. With a tube preamp you are looking to add a specific flavour/signature to the sound. So its not really a direct competitor in that sense. This is not a coloured preamp. But it most certainly isn't flat, dull, grey or anything of the sort. Regardless of if I'm using it as a pre, or a headphone amp, I can't help but smile, it's fantastic.

True, but there are so many choices in the two tube families my preamp supports one can flavor as much or as little as desired plus the ability to mix it up is fun.

 

I'll have to try a Serene in my system to know...as we all know.

[GoldenOne]

Review is now up :) 

[Gavin1977]

Great review @GoldenOne, and nice lead in - many people will benefit from the introduction on different methods of attenuation.  I fully agree with you on the Pre90 - I bought one and it does sound as you describe.

 

I also agree with you on how you feel about the Holo vs passive attenuation.  I have a similar issue with my Audio GD-Master 9 which is marvelous - it adds something that makes it better and yet it's difficult to put it into words.

[Gavin1977]

Do you have a review up of Holo May / Spring?  I would be very interested to hear your thoughts.  Your MQA video was an amazing amount of effort.  Well done.

[GoldenOne]

19 minutes ago, Gavin1977 said:

Do you have a review up of Holo May / Spring?  I would be very interested to hear your thoughts.  Your MQA video was an amazing amount of effort.  Well done.

I don't yet but will have one for the may soon.
If you want the TLDR though: It's the best dac I have personally heard. Even when I had the DAVE+Mscaler here for a bit they ended up unused most of the time because the may was better imo.

From an objective and engineering standpoint it's absolutely insane as well. Absolutely EVERYTHING has been thought of and overdone even stuff that most people wouldn't think nor care about.
Even just how crazy the PLL is. 

It's absolutely fantastic and the only dac i've tried that MAYBE beats it is the dCS vivaldi but that was in a system I was not familiar with so can't really give a proper comparison. Would LOVE to get a dCS dac for review though.

 

[happybob]

On 5/1/2021 at 11:57 AM, GoldenOne said:

I don't yet but will have one for the may soon.
If you want the TLDR though: It's the best dac I have personally heard. Even when I had the DAVE+Mscaler here for a bit they ended up unused most of the time because the may was better imo.


 

I'm anxiously awaiting your Holo May review! That said, I'm wondering if you've ever had a chance to listen to the Dave + MScaler combo BUT with the Dave having the Sean Jacobs DC4 linear power supply? This is what I have and I can say it's a big step up from the stock Dave (with MScaler also have an LPS). Here's a review you might be familiar with. 

I'm not saying this beats the Holo May or a top of the line dCS, but it sure does give a big boost to the Dave... 

 

 

[GoldenOne]

18 hours ago, happybob said:

I'm anxiously awaiting your Holo May review! That said, I'm wondering if you've ever had a chance to listen to the Dave + MScaler combo BUT with the Dave having the Sean Jacobs DC4 linear power supply? This is what I have and I can say it's a big step up from the stock Dave (with MScaler also have an LPS). Here's a review you might be familiar with. 

I'm not saying this beats the Holo May or a top of the line dCS, but it sure does give a big boost to the Dave... 

 

 

I've not tried that no. I do like better power supplies and in some gear it can make quite a noticeable difference. Though once you put that on the DAVE you've both invalidated your warranty and also are now looking at a nearly £20k setup just for the DAC alone (assuming you have MScaler). So it's a bit of a different ball game at that point as you could be looking at a dCS vivaldi or something. 

I would absolutely love to try that combo though!

I've actually filmed most of the May review, but it's going to be a LONG one cause there is just so much to talk about, and lots of different ways to use it. (R2R PCM, OS PCM, HQP PCM, OS DSD, HQP DSD etc)
 

[justthemusic]

GoldenOne,

Great job on the Holo May and Serene reviews. I’ve ordered the May and I run a pair AHB2s into speakers. I was wondering if you have more information about the upcoming headphone amplifier from Holo that you mentioned here and in your YouTube review. I understand that the Serene’s XLR outputs have very different output impedances. 

Will the upcoming Holo headphone amp be a new version of the Serene pre with a beefier headphone section or a separate unit entirely? If it is the latter, could I still use the Serene as a pre amp / source switcher with one set of balanced going to my speaker amps and the other set of balance outputs going to the headphone power amp. The answer to my question may be obvious but given that the XLR outputs on the serene are different, would it work like this?

[GoldenOne]

Just now, justthemusic said:

GoldenOne,

Great job on the Holo May and Serene reviews. I’ve ordered the May and I run a pair AHB2s into speakers. I was wondering if you have more information about the upcoming headphone amplifier from Holo that you mentioned here and in your YouTube review. I understand that the Serene’s XLR outputs have very different output impedances. 

Will the upcoming Holo headphone amp be a new version of the Serene pre with a beefier headphone section or a separate unit entirely? If it is the latter, could I still use the Serene as a pre amp / source switcher with one set of balanced going to my speaker amps and the other set of balance outputs going to the headphone power amp. The answer to my question may be obvious but given that the XLR outputs on the serene are different, would it work like this?

From what I understand the bliss will be released later in the year. Its a dedicated headphone amp unit not a preamp. 

 

Originally Jeff wanted to make a combo unit but felt that he could do a better job separating the preamp and headphone amp into different products. 

 

Headphone amp will have much more power, probably much lower output impedance, and 6.35/pentaconn/xlr out on the front. 

 

No idea if it will also function as a pre or not