Review and Measurements of Holo Audio May --- Probably the best discrete R2R DAC

[Wino]

I am trying to choose a preamp to sit between the Holo May KTE and Dual Benchmark AHB2's. I would prefer to use the Topping Pre90. Has anyone used this with the May? I am also considering the Serene (long wait and expensive) and the Benchmark LA4 (expensive). Are there impedance issues running balanced between Holo May and Pre90?

Thank you

 

[sq225917]

Topping works fine between smsl400 and benchmark power amp. (Circa 600 ohms output impedance, smsl400)

 

[Wino]

Topping works fine between smsl400 and benchmark power amp. (Circa 600 ohms output impedance, smsl400)

Thanks. I ended up pulling the trigger on the LA4. Figured it would pair will with the AHB2's.

 

[Dgob]

I am trying to choose a preamp to sit between the Holo May KTE and Dual Benchmark AHB2's. I would prefer to use the Topping Pre90. Has anyone used this with the May? I am also considering the Serene (long wait and expensive) and the Benchmark LA4 (expensive). Are there impedance issues running balanced between Holo May and Pre90?

Thank you

I was going to suggest the Holo Audio Serene, as that makes a wonderful combination with the May (or, in my case, the Spring 3 KTE). I was very pleasantly surprised when I swapped out my Pre90 for the Serene.

 

[Wino]

I might have gone with the Serene if the wait wasn't so long. Benchmark shipped the LA4 this morning. Would have been 5-6 weeks for the Serene. Regardless, I think the LA4 will match well with the AHB2's.

 

[Dgob]

I might have gone with the Serene if the wait wasn't so long. Benchmark shipped the LA4 this morning. Would have been 5-6 weeks for the Serene. Regardless, I think the LA4 will match well with the AHB2's.

I totally understand. Fortunately, Magna Hifi get it to you within 2 weeka here in the UK. At least they did in my case, and so that was not really an issue for me.

Happy listening.

 

[RustyGates]

@WolfX-700

Did you run the SINAD test with the 555 output running at 44.1kHz and not 192kHz?

Also what is the analyzer output rate for the 90kHz bandwidth test? Should be set to 48kHz as Amir does.

 

[Jimbob54]

@WolfX-700

Did you run the SINAD test with the 555 output running at 44.1kHz and not 192kHz?

Also what is the analyzer output rate for the 90kHz bandwidth test? Should be set to 48kHz as Amir does.

SINAD dashboard is at 192. Don't know about the 90hz test

 

[RustyGates]

SINAD dashboard is at 192. Don't know about the 90hz test

Yep, I see it, just wondering how much the 20kHz BW SINAD will be torpedo'd if running 44.1kHz sample into the May in NOS mode, similarly with 90kHz BW.

 

[zhgutov]

View attachment 40938

View attachment 40939

OK, wow, those are spectacular. What are we looking at and what do you learn from it? <need popcorn >

This is just clipping in the test signal.
Even not the overshooting as a result of interpolation/filtering.
You can see three sequential samples for 44.1 kHz which means clipping.

 

[MediumRare]

This is just clipping in the test signal.
Even not the overshooting as a result of interpolation/filtering.
You can see three sequential samples for 44.1 kHz which means clipping.

View attachment 228213
View attachment 228217
View attachment 228218

Yes, but the question is why do these test signals generate this clipping and would that ever happen IRL?

 

[zhgutov]

Yes, but the question is why do these test signals generate this clipping and would that ever happen IRL?

This clipping is inside the test signal itself. My screenshots are made from the source files.
If the test chain is accurate enough it will show the similar result, and this is expected.

 

[Eagle3333]

Folks, I apologise, I'm not awfully tech savvie and hope you can help with following.
My Mirus Resonessence Pro DAC output stage has died. The makers are no more. In the absence of a repair I'm looking at the May as a replacement on the basis of pricepoint and (circumspect) reading of reviews/commentaries.
Can you answer following question: Will the May's 5.8v output and its output impedence be safe and satisfactory to use with my Gryphon Essence pre amp - input impedence on XLR 50kΩ? Gryphon dacs have output around 4.3v and 30ohm output impedence. With the Mirus, my best sound came with output at approx 2v. At 4v sound became a bit harder edged - so I'm worried how 5.7v will sound. Thanks.

 

[Extreme_Boky]

I am sure that any competent electronics technician/engineer would be able to get (any) DAC analog output stage going again.

May's analog stage is a bit hot, especially on XLRs. I use HQPlayer volume control with my amplifier.. so it is not really an issue. However, May's low output impedance (working in a class A mode, burning 60W of power at all times) will easily match any pre-amp input impedance... even a really low one of around 10kOhms. Your pre-amp input impedance is 50Kohms balanced, so not a problem.

You could also reduce the pre-amp gain. Contact Gryphon and see what they have to say. It can't be that hard... If this is a no-go, then just use a volume control inside your player/streamer.

 

[Eagle3333]

Thanks very much for that. The pre has 18db of gain but I'm ashamedly clueless about quite what this means and whether it's adjustable. But it sounds like it would be an ok, technical match, regardless.
I've put some feelers out but it's very hard to know the true competency of the few repairers I've found. If anyone here in the UK has any recommends for skilled tech's I'd be grateful to know about them. Thanks again.

 

[Killingbeans]

I am sure that any competent electronics technician/engineer would be able to get (any) DAC analog output stage going again.

+1

@Eagle3333 What does "output stage has died" mean in this case? Complete silence on all outputs? Or just one? Noise? Intermittent error or constant?

Judging from the few pictures I can find, the actual DAC + output stage is a realtively simpel design with some relays at the very end. It wouldn't be a surprise to me if one or more of those relays have crapped out.

 

[Eagle3333]

+1

@Eagle3333 What does "output stage has died" mean in this case? Complete silence on all outputs? Or just one? Noise? Intermittent error or constant?

Judging from the few pictures I can find, the actual DAC + output stage is a realtively simpel design with some relays at the very end. It wouldn't be a surprise to me if one or more of those relays have crapped out.

Thanks a lot for the effort. There's zero sound on both XLR and RCA outputs. The DAC sees the signal, recognises the resolution and plays - there's just no output. it's a constant.

 

[Killingbeans]

Then my guess would be that it's not actually the output stage that has failed. More likely some control logic has failed and is muting the outputs.

Hard to tell without poking around a bit inside. Either way, can't possibly cost more to fix than the price tag on a new Holo May

 

[Eagle3333]

Then my guess would be that it's not actually the output stage that has failed. More likely some control logic has failed and is muting the outputs.

Hard to tell without poking around a bit inside. Either way, can't possibly cost more to fix than the price tag on a new Holo May

This chimes in as much as there was no noticeable 'event' preceding the failure. I just turned it on after turning it off the evening prior and nothing came out. Your suggestion motivated me to re-install its firmware - I happen to have it saved - but still no sound.

 

[sq225917]

It's just a simple iv stage into the output, textbook ess stuff, as they were ess staff. Any good tech can fix it.