[]eep]

I already did on page 16 (top)
http://www.head-fi.org/t/512389/mini-dac-tda1543-x-4-nos/225#post_7312137

 

[wushuliu]

Quote:

 
 
It's not so much a 'muddying' of the sound... the rolled-off treble extension and a lack of definition in the lower bass doesn't suit me. To be honest I'd be very surprised if the grounding mods can help in this regard - every NOS DAC that I've heard has been very similar in this regard.
 
I can see how they would sound good with some music types, but at this stage it simply isn't resolving enough for me and my choice of music.
 
I will look into the grounding mods when time permits, and perhaps some of the resistor replacements as outlined earlier in the thread. I need to get some other audio projects out of the way first. 
 

 
Yes the Muse does have that characteristic. Yum

. I would still be using it but Floyd came out with the Immersion sets in hi-rez so I auditioned a bunch of budget dacs and chose the Dacport LX, which has turned out better than any dac I've had so far including the DAC19MK3 and CS4398 diy w/ output transformers, etc... so time to say goodbye to the Muse.
 
 

 

[Sapientiam]

Quote:

Sapientam, you'r not really helping with your secrecy. I keep looking at the photo's but I keep seeing things that make no sense to me. Why do you keep me guessing like this.
- I can see you made some crude cuts on the pcb but I can't see what you cut. The traces aren't visible.
- On the TDA you have some bare wires across pin 4 5 6 and 7. So what pins are shorted together?
- And where is the wire on C9 going to?
- What did you do near U03 (what was there anyway)?
- C8 and C9 are just removed, not shorted right?
- where is the wire on C6 going to? Why not simply short C6 and C7 with a blob of solder or a short wire. Or pin 6's and 8's straight to the outputs? No traces, no solder no muck.
Can't you make a drawing in the photo per mod (if needed a color per mod) to show what you did? Like I did on page 24...

I'm not hiding anything deliberately here, just have no wish to waste time explaining every detail if there's no interest. That's why I wait for questions and then deal with requests for further info as they arise.
 
Yep, I made some crude cuts - they're through the ground planes on both sides of the board. So its practically impossible to show where they go, the white solder mask hides the groundfill anyway. Wherever a yellow wire is going to, from the star earth, that component must be isolated from the groundfill first with cuts on both sides. For some of the components its necessary to remove them to get to the fill areas on the top side. The directions are simple - find out where the 0V of that component connects to the groundfill and make sufficient cuts to isolate it. Check this with a continuity meter and continue hacking until there's no beep.
 
On the TDAs - no pins are shorted together. But there are 3 SMT 0805 1k resistors (hard to see) one each to 0V on pins 6-8. They have their own dedicated ground wire now, as shown on this updated photo.
 

 
The wire on C9 its just a relic of a former mod which I was too lazy to remove. Its not doing anything. The function of R10,11  & 17 is now handled by the multiple 1k resistors previously mentioned.
 
On U03 there was a wrong component (5V reg) which I had to replace with an LM317 with output resistors giving 3.3V (not having a 3V3 reg to hand).
 
Yes C8 and C9 removed, not shorted.
 
Wire on C6 is just a short - can't recall why I used wires rather than solder - perhaps at some point I had a bigger cap fitted there which needed a flying lead.
 
What kind of drawing would you like? If you want me to show the exact location of ground plane cuts it ain't going to happen. But clarifications of unclear things I'm happy to provide.

 

[ETAHL]

Quote:

 
Yes the Muse does have that characteristic. Yum

. I would still be using it but Floyd came out with the Immersion sets in hi-rez so I auditioned a bunch of budget dacs and chose the Dacport LX, which has turned out better than any dac I've had so far including the DAC19MK3 and CS4398 diy w/ output transformers, etc... so time to say goodbye to the Muse.
 

I also been into other budget DACs.

Another gem is the AK4396 DAC. You can find them on eBay very inexpensive, as a board or fully assembled.
It is easy to listen to like the MUSE.  It has all the 'air' and none of the 'glare' of OS DACs.

 
With all the noise about the Schiit Bifrost with its bigger brother AK4399 chip, this DAC may just be the ticket for guys on a slim budget.

 

[wushuliu]

Quote:

I also been into other budget DACs.

Another gem is the AK4396 DAC. You can find them on eBay very inexpensive, as a board or fully assembled.
It is easy to listen to like the MUSE.  It has all the 'air' and none of the 'glare' of OS DACs.

 
With all the noise about the Schiit Bifrost with its bigger brother AK4399 chip, this DAC may just be the ticket for guys on a slim budget.

 
Yes, the Dacport uses the AK4396 and I love it!
 

 

[]eep]

I'm not accusing you of malice. Just laziness. I can tell from the pictures
Thanks for the clarification.

So, if I get it, you connect pins 6=left and 8 =right to ground via an invisible 1kOhm resitor. But where do R19 and R20 come in?

If I would connect all pins 6 together direct to output and short it to ground via a 1k resistor, that would do it? Or is 250 enough (since you use 4 R's in parallel).
Wouldn't it be easier just to clip the legs (4, 7) 6 and 8 and solder them to a seperate wire? That way I could bypass all PCB traces from the analog signal path. I could use some decent wire for that (and some simple wire for ground).
Oops nr 1: C15 etc should connect pin 5=V+ to ground so clipping the leg means I have to lift that one and connect it to the groundwire too.


What value do you use from pin 7=Vref to ground? 330?



Plz explain in laymans terms, I'm not trained in electronics. I'm not stupid but sometimes you electronicsbuffs cut too many corners for me.

 

[applepancakes]

c14-17, r11/r10/r11 (removed c9 +r8/r9) are all directly soldered to the ground of the rca jack.

 

[Sapientiam]

Quote:

I'm not accusing you of malice. Just laziness. I can tell from the pictures

Thanks for the clarification.
So, if I get it, you connect pins 6=left and 8 =right to ground via an invisible 1kOhm resitor. But where do R19 and R20 come in?
If I would connect all pins 6 together direct to output and short it to ground via a 1k resistor, that would do it? Or is 250 enough (since you use 4 R's in parallel).
Wouldn't it be easier just to clip the legs (4, 7) 6 and 8 and solder them to a seperate wire? That way I could bypass all PCB traces from the analog signal path. I could use some decent wire for that (and some simple wire for ground).
Oops nr 1: C15 etc should connect pin 5=V+ to ground so clipping the leg means I have to lift that one and connect it to the groundwire too.
What value do you use from pin 7=Vref to ground? 330?
Plz explain in laymans terms, I'm not trained in electronics. I'm not stupid but sometimes you electronicsbuffs cut too many corners for me.

On laziness, I plead guilty as charged. Though one man's laziness is another's path of least resistance 

 
Thanks for pointing out R19,20 - I had up to now ignored them. They are I believe originally on the far side of the output caps, so they're now between analog outs and (dirty ground plane) 0V. They're 100k, so not particularly significant but they do compromise the grounding a very small amount (in ratio 400:1). So I'll remove them now you've mentioned them.
 
Yeah but all pin 6 are already connected together on the PCB. 250R is what I've got yep. Can't see the point of bypassing perfectly serviceable PCB traces, but that's the laziness in me. I don't think a PCB wire (trace) is inherently worse than one of my yellow ones. Its ground planes I bypass simply because they're shared amongst other components, not because PCB tracks are somehow bad. Pin7 to 0V is also 250R (4 1ks in parallel).
 
Feel free to continue to pester me until you've got it sussed. I agree us electronic bods tend to sometimes (often?) be frustratingly terse. We assume a lot of knowledge in others which we don't realise is not common. So we do need non-electronics types like you to point this out.

 

[]eep]

So, I've just finished the mods for a new mini DAC. I'm listening to it now. I'll post foto's later. It's a bit late for that now (3.40 AM).

I've only done the caps removal and short, Vdac down to 7V, blue led and on/off switch. So nothing to grounding yet. But this is allready quite pleasing.

 

[Wood]

Help Please
 
 
After changing the four 0.1uf chip caps on this dac my friend tell me he only gets lots of hiss and tiny music signal. He changed the chips for new ones thinking that he might have damaged the TDA1543 chips, but it made no difference.
 
Also he found that changing the foobar volume control makes no difference to the volume of the hiss and music signal he is getting. The result is the same with coax or Opt.
 
Anyone got any idea what might be at fault here??

 

[Sapientiam]

Check that the TDA1543s still have the correct power supply voltage - between pins 4 and 5.

 

[]eep]

$#@$ :mad: I think I damaged the LM317 bij accidentally connecting R01 and R02. While I finally had it working...
I was loosely holding another resistor over R01 to lower the voltage some more to hear if it made any difference. And then I slipped. Fortunately I was measuring the V over pin 4 and 5 and saw the V+ rise to 12V! I switched it off immediately. So no further harm done.

Why would I do such a thing? Well, I noticed piano I was listening to was over-modulating and I was trying to prevent that. But changing V+ to the chips made no difference whatsoever.

Now I connected 4 batteries to pin 4-5 (<6v) and that works like a charm... Hmmm. :rolleyes:


@ Wood: i had the same when i had disconnected pin 4 from Gnd. Also, if you remove R10 and R11 you have almost no output. You need a R of 200-100Ohm between output and Gnd.

 

[ardilla]

I have some problems too with "thick" piano sound on my (unmodded) Muse also. I can you the track if interested. 

 

[]eep]

Well, I may be on a wild goose chase. Since I hear the same on my Musiland Monitor 02US (PCM1793+opamp). But it's not like it should be. The recording is very good I think (François Chaplin playing Chopin Nocturnes in 24/88.2). Piano and sopranos are always the ultimate test.

I decided not to moap and make the best of it. I ordered some new LM317's (with heatsink $2 2pc) and some AAAx4 battery holders. They are side by side so they should just fit over the TDA's and battery power is always cleaner. If 5V will do its not even a bad idea to load it with rechargeable batteries. Al in one little smart box.

 

[Waluch]

Hello everyone,  I am using MUSE DAC for a few months. I made some mods, which greatly upgraded sound of this little DAC.

First of all, with my friends help we use 2x small blue  Philips capacitor for bypass + polish Unitra Telpods in parrell

Now DAC sounds more open, spacious, it has a lots of micro dynamics, very musical overall, much much better than original.

Of course I ordered new power supply (9V) ( luxury version ) from Toroidy.pl to my little DAC , and aluminium  chassis, in spare time I will put DAC in this new chassis.

Thanks everyone for this topic. Without it I will not find so nice sounding DAC.