Mutec MC-3+

[zoltan]

On the topic of replacing the Meanwell PSU with a LPS unit in the MC3+ USB, I was wondering if everybody has soldered the DC cable to the posts and then going straight to the external LPS unit whatever that may be?

I'm thinking of converting my unit soon but thinking of installing some sort of DC-in socket in place of the IEC input so that I can connect different lengths of DC cables if it becomes necessary and also can experiment with different DC cables.   

Has anyone done it that way?

[Kritpoon]

12 minutes ago, zoltan said:

On the topic of replacing the Meanwell PSU with a LPS unit in the MC3+ USB, I was wondering if everybody has soldered the DC cable to the posts and then going straight to the external LPS unit whatever that may be?

I'm thinking of converting my unit soon but thinking of installing some sort of DC-in socket in place of the IEC input so that I can connect different lengths of DC cables if it becomes necessary and also can experiment with different DC cables.   

Has anyone done it that way?

 

Thats what I did, just solders to the solid post between the SMPS + and - and the Mainboard + and - and leaving the SMPS board as is. I tried to remove the main board, but I cannot remove XLR connector release lever at the back (I dont have the specific tools that does that). And what I did was I just remove the rear IEC socket and let the wire go thru there. Not too bad.

[zoltan]

21 minutes ago, Kritpoon said:

 

 I tried to remove the main board, but I cannot remove XLR connector release lever at the back (I dont have the specific tools that does that). 

 

1

You don't need specific tools really. Watch this video. (The beginning is rather annoying but after that it shows you how to do it.)

 

[SwissBear]

A few things worth remembering at this stage IMHO:

• this is an interesting source of inspiration about these transformations: https://www.head-fi.org/threads/the-diyrs-cookbook.781268/page-73#post-13459530
• Mutec has not been very encouraging about these modifications. Anyhow, from here and there, we could grab the following information:
  • it is mandatory not to exceed 6V (extreme max is 6.2V). Unless, the circuits of the MC-3+ USB which are not protected, could be damaged
  • it is better to unsolder the SPSU as, if remaining, the second stage of the SPSU could be activated by the power supplied to the Mutec, and cause interference.
  • if not able to completely unmount the main board, some users have successfully unsoldered the SMPS by heating the four feet of the board, one at a time, and gently separating each foot from the main board by applying a gentle lever effect. This is how I personally did for my second unit, the first one having been operated by a skilled friend of mine who had done things 'properly'...

Hope this helps...

[ismewor]

I would love to add an LPS to my MC3+ but I'm a little skeptic, I just got a reply from their US Distributor, they said once you modded the warranty doesn't apply. I'm having a hard time to pull this one off.

[r11bordo]

Nobody has tested the 5V PSU Allo.com at 12$ ?

[zoltan]

1 hour ago, SwissBear said:

 

• it is mandatory not to exceed 6V (extreme max is 6.2V). Unless, the circuits of the MC-3+ USB which are not protected, could be damaged

 

One reason that holds me back from doing the mod is that this voltage thing has not been fully clarified. I remember reading that several people tested and the actual voltage from the original SMPS is 6.2-6.3V. It works with 5V but is it optimal?? 

I'm planning to supply it with 7V and internally (before reaching the board itself) burn off 1V as heat. I have a technician around who said that such a component can be installed together with a small heatsink in the space that is available after removing the SMPS. 

The SOtM SMS-200 apparently works better (SQ) at 12V than lower voltages. Might be the same for the Mutec unit.

I wish somebody compared 5V vs. 6.2V using the same LPS. 

[mecani]

Hello, someone has experience in network dcs connected to a mutec mc3 usb, ref 10 as master clock?

[skatbelt]

On 11/2/2017 at 4:18 PM, Kritpoon said:

 

Thank you SwissBear, the improvements are really nice and I wish I should have done it long time ago... For the energizing unit of LPS-1, recently there has been much discussion on other threads about the supply energizing units (The Meanwell SMPS) leaking the high frequency leakage current into the LPS-1. This can be taken care of by shunting the negative output of the Meanwell to ground and the procedure and part costs are really cheap. I might try that first to see what kind of improvements I get. Per your recommendations of another LPS powering the LPS-1, with this approach I think its the same concept since LPS has no leakage current at high frequencies. Thank you for your advice

 

Question: do you know if the negative DC output of the SMPS in the Mutec MC-3+ USB is already connected to the ground pin of the AC input? If not, this alone could be an improvement based on the @JohnSwenson advice! Of course, one should be willing to violate warranty terms.

[Kritpoon]

On 11/13/2017 at 3:48 AM, skatbelt said:

 

Question: do you know if the negative DC output of the SMPS in the Mutec MC-3+ USB is already connected to the ground pin of the AC input? If not, this alone could be an improvement based on the @JohnSwenson advice! Of course, one should be willing to violate warranty terms.

 I dont know if the negative DC output of MC-3+ USB is connected to the GND pin of the AC. Perhaps @julian.david can clarify?

[john925]

Does anyone know if MC3+USB supports UAC2.0?  I would like to connect usb out from NAS to MC3+USB, or a usb out from Roon Ready device, which supports UAC2.0.  

 

Thanks,

John

 

[zoltan]

I would like to put a capacitor at the entry point of DC  (while converting to linear power supply). 

I have good quality Auricaps around like these https://www.soundlabsgroup.com.au/p/AU-0U47-400-10/0.47uF+400V+Auricap

 Should I connect the red or the black lead to the + terminal? 

 

[Miko]

Has anyone tried a Bybee Rail yet? I just picked up another MC3USB off eBay this morning.. I think I’ll send that to my mod guy to install them and see if they can lower the noise floor as well as they did in my DAC. I included the measurements from Busman Audio as he did the mods on my A/D/A

[yoghurtlidlicker]

I got problems with my new Mutec USB.
It doesn't work under Windows 10 but works fine with my Macbook.
USB connection goes ON/OFF over and over again.
Tried WASAPI and ASIO.
Tried 2 different USB cables (both "printer" quality though).
No luck.
Not enough power from the USB port, maybe?!

cheers!

[Miko]

it works with win 10 as that's what i'm using. with Jriver 23

 

[Miko]

my chain of three MC3's!!!!

[One and a half]

9 hours ago, yoghurtlidlicker said:

I got problems with my new Mutec USB.
It doesn't work under Windows 10 but works fine with my Macbook.
USB connection goes ON/OFF over and over again.
Tried WASAPI and ASIO.
Tried 2 different USB cables (both "printer" quality though).
No luck.
Not enough power from the USB port, maybe?!

cheers!

Oh!

Try a USB3 port on its own, or a USB2 powered hub.

[yoghurtlidlicker]

7 hours ago, One and a half said:

Oh!

Try a USB3 port on its own, or a USB2 powered hub.

thanks.

It looks like an issue with USB 3.0 controller... so sad. 
I don't have any USB 2.0 ports!
I will try USB 2.0 hub.



 

[mitch751]

is there a way to using A+ / HQ player / Roon to oversampling to MC3+USB ?

[One and a half]

3 hours ago, mitch751 said:

is there a way to using A+ / HQ player / Roon to oversampling to MC3+USB ?

I know the first two players can upsample to the MC-3+USB maximum capability, but OSX is limted to DSD128 over DoP. Other than that, feel free. I didn't like upsampling on the software players with the MC-3+USB, didn't sound all that good long term. So left the files to play as is.

[zoltan]

3 minutes ago, One and a half said:

I know the first two players can upsample to the MC-3+USB maximum capability, but OSX is limted to DSD128 over DoP. Other than that, feel free. I didn't like upsampling on the software players with the MC-3+USB, didn't sound all that good long term. So left the files to play as is.

I think it largely depends on what DAC follows the MC-3+USB. My DAC sounds best if it is fed with 192kHz signals, so I upsample redbook CDs in HQPlayer. I guess experimentation is advisable. 

[One and a half]

1 minute ago, zoltan said:

I think it largely depends on what DAC follows the MC-3+USB. My DAC sounds best if it is fed with 192kHz signals, so I upsample redbook CDs in HQPlayer. I guess experimentation is advisable. 

One advantage of upsampling is the DAC doesn't change to the different sampling rates, some people think the relay click is bad, but it's normal to do so. Yeah, I guess the DAC depends, mainly on what algorithm is in use to upsample internally or not. If you had a dead simple DAC, software changes makes sense to implement, DACs like the PSAudio Directstream undergo extraordinary upsampling schemes, it's best then, to leave the signal unaffected.

[Miko]

My Tascam does 192/24 so I upsample everything with Jriver. Works out awesome.

[mourip]

1 hour ago, Miko said:

My Tascam does 192/24 so I upsample everything with Jriver. Works out awesome.

 

I do this also with JRiver using SOX to upsample to 24/192, M3USB to re-sample, and on to my Yggy DAC.

[Miko]

I never tried SOX.. how does that work vs just upsampling from the menu?