MDAC first listen (part XXIII)

[jirij]

FYI - the Neutrik 5W XLR's I bought for Jiri (RS 694 9409) have a detect switch (the original plastic moulding appears to have been hand milled and the switch glued into position)!!! Like you I'd never seen a XLR with detect switch so it was a nice surprise - I'll use the switch to detect "XLR inserted" and thus select between front or rear headphone outputs.

As we discussed in the car, using the switch on the back-panel-mounted XLR socket wouldn't be a good idea if one wants to use the front jack to switch between rear 5-pin XLR and rear dual 3-pin XLRs. Unless there's some logic I'm not seeing, the only possible solution to that is to have two states based on the status of the front jack socket switch:

1. front socket empty - output goes to dual 3-pin XLRs - and - RCAs (ie. speakers)
2. front socket occupied by "something" - output goes to 5-pin XLR - and - front headphone output

You can't really detect whether there's a dummy jack in the front socket or if somebody plugged in unbalanced headphones. Not without somehow taking Tip vs Sleeve or Ring vs Sleeve resistance into account.

Or is the idea based on expanding the "front socket occupied" state by another condition

1. back 5-pin XLR empty - output goes ONLY to front headphone output
2. back 5-pin XLR occupied - output goes ONLY to back 5-pin XLR output

? ... (still allowing the output to 3-pin XLRs + RCAs if the front socket is empty)

That could actually help with possible issues caused by the front dummy plug.

 

[PhilCTTE]

I knew it all along, you're just a slacker John.

Yea couple of hours sleep , be careful I spent a week with 2 or 3 hours sleep each night , fixing a software application years back . And was then ill for a week afterwards.

 

[jirij]

Not at all – trust me! I lived though the years that RS232 reigned supreme! RS232 was originally a 25W connector but it could be wired in many orientations (it could be the terminal or the CPU) - you never really knew if you need to use the DTR or DCD pins... M/F should have set the orientation but this was more often violated then not.

The 9W "RS232" was a I believe first introduced by IBM (was it for the AT?) many years later to allowing x2 RS232 connectors to fit on one rear panel expansion slot.... the 9W was more standardised then the earlier 25W variant! It really was a standard that was "Not". I believe that the first RS232 used +/- 25V signals, while IBM on there PC used +/- 12V signalling (or was it +/- 5V)? – some older Telco Modems (300 Baud rate!!) would not work correctly with 12V signals… I’m showing my age, and FAR off topic here!

I remember the 25W version as the technology here in czech rep was always several years behind US, but I never had any problems with it - no DIY though, just connecting to black&white terminals for "remote management"

Yes indeed back to work John! - cooled down here in Czech rep. - the lab was 32 Deg C this afternoon - I slept though it!

See? The advantages of working at night! One of them anyways. And people think we're crazy.

 

[JohnW]

Or is the idea based on expanding the "front socket occupied" state by another condition

1. back 5-pin XLR empty - output goes ONLY to front headphone output
2. back 5-pin XLR occupied - output goes ONLY to back 5-pin XLR output

still allowing the output to 3-pin XLRs + RCAs if the front socket is empty

Yes thats the logical conditions I'm suggesting.

 

[mbaudis]

I have an idea to use M-DAC with active monitors (Adams A7X for example, maybe A5X with subwoofer) - not for mixing but for home listening. Is it a good idea ? I hope so because I'm looking for clean, non-fatiguing sound, I prefere listening on low volume levels and I like especially acoustic music (classic, jazz, baroque, human voices) and my hifi room is small (16m2, ~2m base/distance). M-DAC will be used as preamp but only for corrections - basic volume limit should be set on monitors.

I have both Adam Artist 5 + Sub and Artist 6, connected do separate MDACs. I like both combinations; A6 seem a bit more "airy" and obviously lack the very low end the sub provides (well, one could add one there, too). With the 5/Sub combo, I am very happy reg. both detail & depth, clearly better than my floor stands before. The sub is used on a v e r y low level, other speakers on neutral with DAC level -40 - -20 db ( I've tried attenuators but didn't like them). Nice set ups.

 

[jirij]

Yes thats the logical conditions I'm suggesting.

Great, thanks again for going yet another extra mile.

Let us know when you finish and compare the Fusion's fusioned unit with JohanH's unit.

 

[arthur]

Are there enough dedicated HP users to make it all worthwhile given the quality of the original plug? Especially since the sq will already be upgraded with the l2/toy/fusion modifications any way? If that bits right.

 

[arthur]

I have both Adam Artist 5 + Sub and Artist 6, connected do separate MDACs. I like both combinations; A6 seem a bit more "airy" and obviously lack the very low end the sub provides (well, one could add one there, too). With the 5/Sub combo, I am very happy reg. both detail & depth, clearly better than my floor stands before. The sub is used on a v e r y low level, other speakers on neutral with DAC level -40 - -20 db ( I've tried attenuators but didn't like them). Nice set ups.

Have you tried the 6 with the sub? I think that would be a very viable hifi on the end of the M-dac, modded or not.

 

[mavwong]

I think John have enough work on the mod already, let's not distract him with more balance HP jack thing with plug in detection.

I have been a HP user for the pass few years. There's no standard in the balance connection for HP frankly but generally 3 pin xlr is more common now a days. Personally I would mod my current single ended plug to 2 - 3pin xlrs and plug directly at the back of the MDAC. This 3 pin xlr plug could plug into any other preamp with xlr out as well. So the key is compatibility with other preamp/HP amp. It's the most direct path anyway.

John hope you have found out what happen to Johanh unit, I work in the failure analysis line and non measurable fault is hardest to fault isolate.

Mav

 

[JohanH]

John hope you have found out what happen to Johanh unit, I work in the failure analysis line and non measurable fault is hardest to fault isolate.

Mav

I don't want to start a discussion but since it is so clearly audible it surprises me that the fault cannot be measured.

 

[JohnW]

I don't want to start a discussion but since it is so clearly audible it surprises me that the fault cannot be measured.

If only it was so simple - Id have the problem resolved by now.

I beginning to suspect it could be the Phase noise performance of the Clock oscillator - if this is the case I cannot measure with significant accuracy the Phase noise close to the carrier (I've a Wavecrest SRi3000 system which despite costing over $200,000 lacks the performance required for audio grade measurements) - Close in carrier noise could help explain why the Bass seems "Soft" - I'd need to be able to measure down to -130dB to -160dB from 10Hz to 100Hz... its a very challenging requirement.

Standard audio measure will not measures one difference we heard during our listening session!

I've just powered up Fusions unit for the first time, trimming the audio section... and will check to see if I can make it go unstable (The x4 100pF Cap. are not fitted).

 

[Akasha]

I don't want to start a discussion but since it is so clearly audible it surprises me that the fault cannot be measured.

nobody have yet come up with measurement technique for sound quality, subtle differences will be even harder to measure, still not knowing what to look for

 

[JohanH]

nobody have yet come up with measurement technique for sound quality, subtle differences will be even harder to measure, not knowing what to look for

I didn't mean measuring sound quality (although that is probably what it will come down to) but measuring a fault; there is a difference between 2 units that shouldn't be there. More resolution in the measuring equipment might solve this I understand.

 

[Akasha]

I didn't mean measuring sound quality (although that is probably what it will come down to) but measuring a fault; there is a difference between 2 units that shouldn't be there. More reolution in the measuring equipment might solve this I uderstand.

only if you know/find out exactly where to look, it's like the needle in a haystack

 

[bh69]

Excellent idea. My adam compacts are mighty fine indeed. No hint at all of fatigue, and as clean as they come.

Thank you, it's encouraging.

I have old Marantz PM44 with Dynaudio Audience 10 nowadays and it's on edge to say diference between old Denon CD player and M-DAC. And sound becomes more tiring/annoying last years (I feel some sound distortion, probably amp is not in good shape after years). I heard few new amps (NAD, Hegel) and passive loudspeakers but despite quite high price I never had a "wow feeling". And I have felt that such solution is not ideal for near/mid-field conditions and low-level listening.

Can you tell me more about this ? Are actives (Adams) significantly better by low volume and microdynamic than common passive loudspeakers ?

And what about subwoofer - is it difficult to join it together ? Is it enough to have one SW or its better to have two for proper stereo image ?

 

[WAD62]

Hi John, just wondering if my 'Toy' upgrade resistors have shown up yet...

They were ordered on Friday, and I believe shipped air mail, so shouldn't be too long now...

Cheers,

Will

 

[simonom]

Mine, too, John. Have they arrived?

 

[Steven Toy]

Mine took 2 days to arrive at John's although I have no idea where they are now

 

[tunkejazz]

It would be interesting to listen to this song with the upgraded units (I have the FLAC). It is sounds terrific even with my old DacMagic

spotify:artist:7okwEbXzyT2VffBmyQBWLz

 

[PhilCTTE]

Are there enough dedicated HP users to make it all worthwhile given the quality of the original plug? Especially since the sq will already be upgraded with the l2/toy/fusion modifications any way? If that bits right.

Headphone users are the biggest growth area in Hifi. If this balanced option is made available, then it will really put the icing on the cake IMHO.

Correct me if I'm wrong but it's not just sq, but balanced output will allow, longer cable runs and improved output to drive difficult loads.