MDAC First Listen (part 00110000)

[JohnW]

IIRC my PSU will have 4400uF per rail. I think that should suffice.

I even got 8800uF for the "power hungry" digital section, since I'll wire two rails in parrallel.

Yes, one of my thoughts as the AC input board has 4700uF on each of the 5 rails which is located close to the MDAC mainboard - these caps are "removed" when the AC input board is not used - I wonder if this is the cause of my missing sound stage and treble... but I'll listen more tonight after giving time for the calexes to run-in.

 

[paulski]

I've ordered some of these from RS. They're only rated at 35V but that's fine as there's around 28V across the existing caps.

 

[jamjar784]

iansr/misterdog/paulski/Nick1881

I think you are the guys who have already tried the Calex DIY PSU. Am I correct in saying that only Paul (misterdog) upgraded the internal smoothing capacitor to 4700uF, but everyone posted very positive results? Paul (misterdog) did you try the Calexes before upgrading the smoothing capacitors? I'm trying to follow in your footsteps and wondering if this is really necessary Maybe JW will advise his findings too when he has time.

Calex 1000uF electrolytics to be replaced with 4700 µF (2 per PSU) with either
Farnell £2.98 + VAT each, free delivery
or
RS £2.305 + VAT per 2

 

[iansr]

Correct I have not changed the caps. My MDAC Fusion is sounding fantastic.

 

[Nick1881]

I upgraded the caps in all my Calex units, my original one I did a while ago.

 

[Mark Dirac]

Mark,

The cables look nicely made, you cannot really go wrong for the price - please let us know how the headphones work out with the MDAC in balanced operation

Apologies for taking so long to supply a few words in feedback. All my listening evaluations have been contrary to expectations. However I have now been told that I need my ears syringing - and not by a rude pfm-er, but by a nurse.

So please allow me a little while longer to respond.

 

[JohnW]

Correct I have not changed the caps. My MDAC Fusion is sounding fantastic.

Ian,

Can you report you findings with the Calex's WRT L/R sound stage + Treble?

 

[JohnW]

I upgraded the caps in all my Calex units, my original one I did a while ago.

Did you listen before you changed the caps?

 

[davidjt]

JohnW,

FWIW, when I first used 2 unmodified Calexes, I had the same reaction as you, although to a lesser extent as I wasn't running MLs + 2 Subs. I did go back one click on my single sub. There was more detail, which may have masked a decrease in treble. My speaker placement is not optimal and I was unaware of any effect on the soundstage until, after about 30 hours listening I realised that everything had improved significantly, and I turned the sub back up.

Of course, with only two I haven't by-passed the psu board.
Nevertheless I think you're going to be pleasantly surprised, but it may take another day or two.

 

[JohnW]

JohnW,

FWIW, when I first used 2 unmodified Calexes, I had the same reaction as you, although to a lesser extent as I wasn't running MLs + 2 Subs. I did go back one click on my single sub. There was more detail, which may have masked a decrease in treble. My speaker placement is not optimal and I was unaware of any effect on the soundstage until, after about 30 hours listening I realised that everything had improved significantly, and I turned the sub back up.

Of course, with only two I haven't by-passed the psu board.
Nevertheless I think you're going to be pleasantly surprised, but it may take another day or two.

David,

Thanks for the feedback, ATM I'm working on the FDAC so not sure if I'll have a chance to listen again this evening, but it sounds like it might be worth leaving until tomorrow anyway

 

[sq225917]

Misterdog's using quads. Soundstage?

 

[fusion5]

I already hate those tiny JST crimp connectors...

 

[JohnW]

SQ,

I'm not sure which direction your coming from but I've never really heard the Quads sound stage say like the ML.... The Quads are odd in that they almost have a "quantised limit" to resolution - they resolve to a certain level, but then no more.

Don't get me wrong, the Quads are good, and are far easier to integrate them ML (and don't suffer so much from a narrow sweat spot), but then ML can be stunning in the right room and system.

 

[JohnW]

I already hate those tiny JST crimp connectors...

I've always been lucky that we order the cables completed from the vendors - but I can well believe you!

 

[fusion5]

Maybe less crimping and more soldering is the way to go

 

[misterdog]

Maybe less crimping and more soldering is the way to go

It is - just done mine this pm. cut back the long 'wings' which should crimp the cable sheath, tin 4mm of the stripped wire, flux the insert, crimp the tinned wire then solder.

For crimping I use a pair of circlip pliers with a slight flat filed on the inside edges, or a surgical clamp, though long nose fine pliers should do.

PITA they are, but you have to admire the machine that bends them into shape..

Oh and don't forget to wear these

 

[fusion5]

Yeah, I've soldered one without crimping whatsoever. Rock solid.

 

[Goldalene]

Sorry to trouble you John W but I've sent you a PM.

 

[misterdog]

Yeah, I've soldered one without crimping whatsoever. Rock solid.

But crimping is the fun part.

Make sure it inserts into the connector correctly.. The full length of the metal plug needs to insert - click.

Hence the need to cut off the long wings.

 

[jamjar784]

But crimping is the fun part.

Make sure it inserts into the connector correctly.. The full length of the metal plug needs to insert - click.

Hence the need to cut off the long wings.

Thanks for the tip!

Any thoughts on my previous post ... did you try the Calexes before upgrading the smoothing capacitors? i.e. in relation to John's adverse findings on SQ with Calex's?