travelfotografe
pfm Member
Since it is a digital pre-amp (all done mathematically), selecting 0db is equivalent to disabling the pre-amp mode.
MDAC first listen (part IV)
- Thread starter adamlau
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TwoSeventy
pfm Member
Once you have rotated the selector knob to select fixed output you then have to press it in. I had the same problem. The manual omits this step!
I believe I did try that and the settings were still not sticking for me. I'll try it again when I get my replacement today (hopefully) and report back. Thanks.
Sorry, I wasn't clear - the A80 is an integrated amp. I was putting the MDAC through it to get the power to drive the speakers.
I am going to go through all the suggestions and will report back. Thanks again.
John_73
pfm Member
Are you using lossless files, or MP3s? The MDAC is very revealing.
MartinFXDX
Member
Yes I found that not to work too. I tried it a number of times including pressing the vol control. It stayed firmly stuck in preamp mode
In the end I did a factory reset and I was able to change the "mode" to preamp disabled.
Hope that helps
Thanks to all.
Worked through all the suggestions methodically and also tried USB connection just in case. Nothing made a significant difference to the sibilance issue as I perceived it. In the end I got a second and third, unbiased opinion and while they could tell the difference between DAC A and DAC B they did not mention any sibilance issues.
As an aside, I was actually quite surprised by how little difference (none of us could detect anything) having two active pre-amps made. Equally, switching between the MDAC preamp and the Integrated preamp did not produce any obvious difference with the reference tracks I chose.
I settled on disabling the MDAC preamp because, in the absence of noticeable difference in sound, it is the logical setup for the equipment I have.
In summary...perhaps I just need to get used to the new equipment.
Thanks again to everyone for your help, it is appreciated.
Worked through all the suggestions methodically and also tried USB connection just in case. Nothing made a significant difference to the sibilance issue as I perceived it. In the end I got a second and third, unbiased opinion and while they could tell the difference between DAC A and DAC B they did not mention any sibilance issues.
As an aside, I was actually quite surprised by how little difference (none of us could detect anything) having two active pre-amps made. Equally, switching between the MDAC preamp and the Integrated preamp did not produce any obvious difference with the reference tracks I chose.
I settled on disabling the MDAC preamp because, in the absence of noticeable difference in sound, it is the logical setup for the equipment I have.
In summary...perhaps I just need to get used to the new equipment.
Thanks again to everyone for your help, it is appreciated.
Hi John,
Just wanted to let you know that I got my replacement MDAC today and it sounds beautiful. Thanks again for designing such an amazing product and I am hoping that it continues to be a solid product long term. The one question that I have, is that the voltage shows at around 21v using the 110v PSU you kindly sent over from Vegas. Is this within spec or is it on the high side? The reason I ask, is that the first MDAC was showing around 15v using the UK plug via the step up converter and other people have posted around 16 or 17 volt readings. Is there anything to be concerned with?
I also look forward to the M-PAX to complement the MDAC which I have asked some questions on earlier in this post. Hope you can respond as I would be very interested in purchasing one of those too.
Hope this finds you well and look forward to hearing from you soon.
Cheers,
Vin.
Just wanted to let you know that I got my replacement MDAC today and it sounds beautiful. Thanks again for designing such an amazing product and I am hoping that it continues to be a solid product long term. The one question that I have, is that the voltage shows at around 21v using the 110v PSU you kindly sent over from Vegas. Is this within spec or is it on the high side? The reason I ask, is that the first MDAC was showing around 15v using the UK plug via the step up converter and other people have posted around 16 or 17 volt readings. Is there anything to be concerned with?
I also look forward to the M-PAX to complement the MDAC which I have asked some questions on earlier in this post. Hope you can respond as I would be very interested in purchasing one of those too.
Hope this finds you well and look forward to hearing from you soon.
Cheers,
Vin.
JohnW
pfm member
Hi Vin,
I'm glad your MDAC has arrived.
21V is a little high, its odd because I used the same PSU in Vegas and it was about 17V - says something about the mains supply in Vegas!
Maybe best to try with the original UK PSU + stepdown transformer.
You can atleast compare sound quality - I'm guessing you should not find much difference.
At 21V I'd worry about long term reliability.
Sorry its so high - this is whats happens when I trust other engineers to test something for me! (at the time I was packing my lab to ship back to Europe) I'll get an M-PAX out to you ASAP.
John
Hi John and thanks for the quick response on this. Is this to suggest that this PSU is not designed for the MDAC but maybe for another Audiolab product? What doesn't help, is that there is no label on the PSU so I can't share what the actual voltage output/input details are for review.
The sound seemed very good (open, detailed and punchy) to me and luckily, I only ran for 2-3 hours and powered off for the evening. I will use the UK PSU with the transformer for now as I don't want to potentially kill this one that now seems to be working with a good display for me!
I am very interested in the M-PAX and as soon as you have one available for me, please let me know via PM and for payment etc. Do you have a rough ETA as to when I may receive?
Cheers,
Vin.
MartinFXDX
Member
Well I borrowed a M-DAC for 4 days and compared it to my TAG DVD/AV32DP/Calliope setup. I used identical cables and the by-pass inputs with the M-DAC in "preamp disabled" mode.
In this way I was able to easily switch between the internal TAG DACs with their synch link to the DVD transport and the M-DAC
I found the differences between some of the filters quite noticeable. Optimal Transient XD was, at first a little like engaging the "Loudness" button on an old amp! Though to be fair, the effect did seem to be less pronounced as time went on. Maybe I got used to it or maybe the unit was still settling in. I found the best use of this filter to be with dull and lifeless masterings and in this role it worked very well.
Getting back to how it compared with my TAG setup I found that the Optimal Sectrum filter produced results very similar to the the TAG equipment using the synch link and better than digital sources without the synch link.
So, an impressive performance on the part of the M-DAC but one that didn't improve on what I already have as my non synch link digital sources are in the main AV ones. However the choice of filters would be useful for "correcting" poorly mastered CDs and for adding extra high quality digital inputs.
Hi John,
Just to provide some further information based on your suggestion to go with the UK PSU using transformers of which I have two:
110-220v regulated transformer gives 15.1v on the MDAC
110-230v non-regulated gives 17.5v on the MDAC
Which one would you recommend the safest bet to use while I wait for the M-PAX?
Cheers,
Vin.
JohnW
pfm member
Hi Vin,
Both are OK - so what every sounds the best
The "dropout voltage" is around 14.5V, so 15V "regulated" should be OK.
The M-PAX will supply 15VDC to the M-DAC.
ETA 's about 2 months for first M-PAX units, I've just completed the "design and simulation" of the PSU section - if the the simulation results are to be believed then its certainly ultra high performance - I hope it equals a SQ benefit...
John
JohnW
pfm member
Hi Aloft.
The first production batch pre-orders have been "sold out" - but I believe that a couple of "pre-orderers" have decided for the CD/CDQ updates instead.
I'll add you to the pre-order "waiting list"...
John
klipschman70
Active Member
JohnW
pfm member
Hi Harry,
The M-PAX has a 115V/230V voltage selector - but it is officially for European sales only - you would need someone in Europe to ship the unit to you in the US.
John
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