MDAC first listen thread

[arthur]

Lo rtrt.

Actually, it might be better to whop the Mdac up to near max and using the A400 as volume control. So far as I know if the A400's pre is being used at all it may as well be used that way to allow the Mdac room to breathe as it were.

 

[Plutox]

D3E is only active with source material lessthen 24bits - it will not be inactive with 24Bit data.

Fascinating - thanks. I have one particular record (what's the word for a collection of tracks that used to be a CD?) which, due to a mastering oddity, jumps intermittently between 24 & 23 bit. That explains why D3E lights up when it flips to 23bit!

 

[Blurpapa]

MDAC is connected to my old A400 for now.

the Pioneer A400? Wow. That was my first amp and something I wished I hadn't loan to my friend. Haven't seen it since

 

[rtrt]

I have a silver unit and it has a black remote - the unit I heard at an open day also had the same remote. I just checked the XLR sockets at the back of my MDAC. They are identical on mine and a secure connection results for both channels - with the usual slight play on vertical and horizontal axes. The connection is better than average I'd say. I guess you have checked with two sets of leads? I'm using el cheapo Farnell-CPC cables.

Thanks for the quick feedback - appreciated.

Re the balanced socket issue - thing is I dont have any xlr cables. Though there's definitely a possibility of me going there in 2012, as the attraction of minimum boxes is definitely taking hold. Based on the posts here, there are some active speakers or simply a power amp in the plan for next year.

 

[JohnW]

Picked up the MDAC on thursday evening but not been able to listen till this evening. Have been rediscovering some old stuff and just generally enjoying myself. Favourite 'oldie' so far (listening again now) A secret wish - Propaganda.

Pro
Sound
Using USB from an old iMac. Detailed presentation with lots of space around the different instruments in a mix. Particularly enjoying headphone listening.
Also enjoyed amp/speakers too, only used at around - 40 db so far. Not sure about taking it up to -15 to 20db as John recommended - think our neighbours would be round pd quickly!
Bass seems fine - tight and well defined - think my room is simply too small for it to be anything better than that.
Bit of sibilance at times but since it seems less prominent on my phones then i'm putting it down to the amp/speakers.

Other
Display is as good as I hoped - crystal clear & good enough to read from across the room. If there was some way to read the tag info from the Mac across the USB interface that would just be the icing on the cake!
Remote - simple and elegant with access to the key functions. Enjoy the ability to control the player (VLC), skipping back and forwards in a playlist and have even used the balance control to good effect - was sitting off to the side at the desk earlier!
Filters - dont really know how much of a pro to be fair, as I haven't done any real evaluation - but will have a proper play later.


Con
Sound
Nothing really - only the sibilance, but as I mentioned an amp/speaker upgrade some time in the new year will hopefully address this one.

Other
Had assumed the remote would be silver to match the silver unit - I have a black one - can other silver owners confirm?

The only thing that is actually bothering me, in what is definitely a keeper, is to do with the balanced output for the right channel. The connector isn't seated flushly in the chassis - the top is 'pushed in' to the chassis by a few mm. Suspect it might prevent some cables engaging properly. I know it will niggle at me so i'd like to get it addressed, but thing is - knowing how few there are in the country and not wanting to be without for a few more months, i'm not sure the best path to take. Think I'll contact Bartletts and assuming they haven't got stock to spare, see if we can agree on me holding onto this unit and then sorting a replacement once stock stabilises. I'd appreciate peoples views on this point tho pls.

rtrt,

What amplifier are you using, are you using Balance or XLR connections?

If your normal listening level's around -40dB, then I suggest using inline attenuators, say 18dB to 20dB, you have too much digital attenuation going on for serious listening.

Inserting 20dB attenuators will bring the volume Level to around -20dB, which is a good operating point.

I'd guess when you listen via headphones the levels set higher.

http://www.rothwellaudioproducts.co.uk/html/attenuators.html

As for the XLR connector being misaligned, its a simple job to correct - Bartlett’s will be able to correct it for you. I'm sorry for the issue, it sounds like the Top "Lip" of the XLR connector has caught itself on the rear panel hole-cut out as it was being tightened - a quick 5 minute job to correct.

 

[JohnW]

I think you'd benefit from some attenuators there. -40dB is low enough to lose some information I think.

Exactly, you beat me to it!

 

[rtrt]

rtrt,

What amplifier are you using, are you using Balance or XLR connections?

If your normal listening level's around -40dB, then I suggest using inline attenuators, say 18dB to 20dB, you have too much digital attenuation going on for serious listening.

Inserting 20dB attenuators will bring the volume Level to around -20dB, which is a good operating point.

I'd guess when you listen via headphones the levels set higher.

http://www.rothwellaudioproducts.co.uk/html/attenuators.html

As for the XLR connector being misaligned, its a simple job to correct - Bartlett’s will be able to correct it for you. I'm sorry for the issue, it sounds like the Top "Lip" of the XLR connector has caught itself on the rear panel hole-cut out as it was being tightened - a quick 5 minute job to correct.

Using RCA's for now John - temporary pioneer A400 till new year when I'll have funds for upgrade (possibly sooner - but not counting chickens!).

Re the rear panel - just had a quick look to see what you mean. Would you have any objection to my opening it up to see myself John?

I'm very familiar with working with electronics - have built several PC's and was a data comms support engineer (glorified board swapper) in a past life. Still have my anti static zap strap in the tool kit!

Have the correct removal tool for the screws too - looking at the heads. Seems like you've used the same size all round.

Happy to accept responsibility if I damage the unit - whilst feeling confident I wont

 

[JohnW]

Thanks for the quick feedback - appreciated.

Re the balanced socket issue - thing is I dont have any xlr cables. Though there's definitely a possibility of me going there in 2012, as the attraction of minimum boxes is definitely taking hold. Based on the posts here, there are some active speakers or simply a power amp in the plan for next year.

rtrt,

When I'm next in London, I can arrange to fix it for you, or Bartlett’s...

No, Pls. ignore what the manual says, I suggest setting the volume control on the MDAC to -20dB, then adjust the volume control on your A400 to your listening level.

Afterwards you can use the MDAC’s volume control.

This will tame any brightness - you had way too much system gain, and huge Digital attenuation.

John

 

[Dominik]

I did wonder why it seemed to make a beeping noise every time I pressed a button on the remote though as it became a little bothersome when cycling though option screens, or adjusting the volume, and was going to ask if this 'feature' could be turned off. I then noticed that not only did my speakers make this beeping noise when using the MDAC remote but also every other remote I have, so my hifi beeps when I browsing through my TV's programme guide.

It is definitely emanating from the MDAC, as it stops as soon as I cover its infra-red sensor window next to its screen. Do I have a faulty unit, is it system related, or is this really a 'feature' to alert me every time someone sends an infra-red command in the MDAC vicinity?

Cheers!

Sorry to hear about this. It seems the IR bus connection is shorted to a nearby signal, perhaps voltage rail and it's upsetting the unit while there's IR traffic, unsurprisingly. I'm afraid your unit will have to be checked over by IAG Service guys.

Dominik

 

[rtrt]

rtrt,

When I'm next in London, I can arrange to fix it for you, or Bartlett’s...

No, Pls. ignore what the manual says, I suggest setting the volume control on the MDAC to -20dB, then adjust the volume control on your A400 to your listening level.

Afterwards you can use the MDAC’s volume control.

This will tame any brightness - you had way too much system gain, and huge Digital attenuation.

John

John, I think this bit 'No, Pls.' means you'd rather that I dont open up the unit - ok no problem at all.

Re Bartletts and yourself then I think there's a good plan in there somewhere. How about I take it up to Bartletts next time I'm north of the river (dont hold it against me - i know you have a low opinion of South London ) If it's a simple fix then all's good. If not and they can replace the unit - again simply done. If they want to send it to Audiolab UK - leaving me MDACless then I'd rather wait till you're next over this way and we can meet up somewhere.

Re the volume/attenuation setting on amp/MDAC - will follow your and Arthurs advice and set amp to a reasonable value. That way I can still use remote for volume as well as control of track skipping on the mac etc - getting quite used to that.

 

[Dominik]

Hi John,

I must have super sensative hearing then!

No it's not massive. I'm just used to the fiddly buttons on the Tact, which if anything takes too long to change the volume.

Please help me understand - do you find the loudness difference of 1dB step to be too great or is it the rate at which the dB figure changes on M-DAC when you turn the knob and/or press the remote buttons? As John mentioned, the very definition of a decibel is the smallest discernible change in perceived loudness by an average human. It would be possible to change the step size to 0.5dB, but until now I did not think it would be necessary.

Dominik

 

[sq225917]

rtrt, just undo all the bolts on the back panel a couple of turns and also the four on the back of the case. Then tighten them all up starting with the ones next to the xlr sockets. I stripped my unit down yesterday for a look see, reseating the xlrs is easy.

 

[Cereal Killer]

Please help me understand - do you find the loudness difference of 1dB step to be too great or is it the rate at which the dB figure changes on M-DAC when you turn the knob and/or press the remote buttons? As John mentioned, the very definition of a decibel is the smallest discernible change in perceived loudness by an average human. It would be possible to change the step size to 0.5dB, but until now I did not think it would be necessary.

Dominik

hi Dominik, I actually have had both with kit recently and I very much prefer 0.5db steps. Its much more useable for late night sessions.

 

[rtrt]

rtrt, just undo all the bolts on the back panel a couple of turns and also the four on the back of the case. Then tighten them all up starting with the ones next to the xlr sockets. I stripped my unit down yesterday for a look see, reseating the xlrs is easy.

ok will take a look - thanks sq. have the right tool for the job - checked earlier.

 

[Plutox]

...I very much prefer 0.5db steps. Its much more useable for late night sessions.

That sounds rather like the rate of change on the knob is felt to be too high rather than the step size. i.e. a request for more knob movement to obtain each dB of adjustment.

Personally, I like the 1dB per step approach - it's perfect when using the remote.

 

[JohnW]

That sounds rather like the rate of change on the knob is felt to be too high rather than the step size. i.e. a request for more knob movement to obtain each dB of adjustment.

Personally, I like the 1dB per step approach - it's perfect when using the remote.

Well that's what you would think as 1dB is already a fine step, but I understand it that Moog listens between -20dB to -15dB, but needs more resolution between these listening levels.

I think the "rate of change" on the knob feels about right...

I'll see if we can add a "Fine step size" option in the menu

 

[rtrt]

Hmm - did as you suggested sq and there was no movement of the rh xlr at all - it doesn't look like the lip or edge of the connector has caught behind the panel.

You can see how thick the panel is if you look at the power socket - as that seems to sit behind the panel. I'd say the panel is around 3-4mm thick. Explains why this thing feels so solid!

The xlr socket is at angle, so that if it were a clock face then the 1 o'clock position is where it is furthest back into the chassis - at that point i'd estimate it was 3mm back. Am wondering if it's been mounted at an angle on the production line. If so it might not be the 5 min fix John (and I) was hoping for

 

[JohnW]

ok will take a look - thanks sq. have the right tool for the job - checked earlier.

rtrt,

Be very careful taking your unit apart. There's a flat "Ribbon" cable that connects the front panel the Mainboard which is quite fiddly and can be fragile if not treated with care.

If you want to open the unit, you must first undo the 4 screws that hold the front panel - partially remove the front panel, and release the Flat Ribbon Cable that connects the front panel to the Mainboard.

Once the cable has been released, then you can undo the 4 rear panel screws (2 screws on each of the sides).

Then slide out the from the rear - holding the rear panel. the Main board, PSU board will be attached to the rear panel, and slide out as a single Pcs.

When re-assembling the unit, insure that the Mainboard PCB & PSU PCB are slid into the "rails" on the casework - then slide the whole lot back into the Case.

Then reconnect the front panel cable and attached the front panel - screw the unit back together 8 screws in total, 4 screws rear and 4 screws on the front (these screws are located on the side panels).

 

[rtrt]

rtrt,

Be very careful taking your unit apart. There's a flat "Ribbon" cable that connects the front panel the Mainboard which is quite fiddly and can be fragile if not treated with care.

If you want to open the unit, you must first undo the 4 screws that hold the front panel - partially remove the front panel, and release the Flat Ribbon Cable that connects the front panel to the Mainboard.

Once the cable has been released, then you can undo the 4 rear panel screws (2 screws on each of the sides).

Then slide out the from the rear - holding the rear panel. the Main board, PSU board will be attached to the rear panel, and slide out as a single Pcs.

When re-assembling the unit, insure that the Mainboard PCB & PSU PCB are slid into the "rails" on the casework - then slide the whole lot back into the Case.

Then reconnect the front panel cable and attached the front panel - screw the unit back together 8 screws in total, 4 screws rear and 4 screws on the front (these screws are located on the side panels).

Hi John, I just undid the screws a couple of turns as sq had suggested.

Tho as I say i'm not uncomfortable in this kind of thing - esp when someone is able to spell out the key steps.

With the ribbon - does it have the re-enforcement where it meets the board - i'v sometimes seen that on particularly delicate connectors.

 

[JohnW]

Hmm - did as you suggested sq and there was no movement of the rh xlr at all - it doesn't look like the lip or edge of the connector has caught behind the panel.

You can see how thick the panel is if you look at the power socket - as that seems to sit behind the panel. I'd say the panel is around 3-4mm thick. Explains why this thing feels so solid!

The xlr socket is at angle, so that if it were a clock face then the 1 o'clock position is where it is furthest back into the chassis - at that point i'd estimate it was 3mm back. Am wondering if it's been mounted at an angle on the production line. If so it might not be the 5 min fix John (and I) was hoping for

No, that's still OK. The XLR connector has little plastic "Pips" that align the connector to the PCB.

If you have slid your PCB out, and turn it over, you will see little holes on the PCB under the XLR connectors - where these little black pips push into and thus align the connector to the PCB.

If the connector is not mounted to a rear panel it can move about 3-5mm with little force - so I don’t see a problem in reseating it.