[Hendrik]

hi,
 
it seems that my DIR9001 is dead, yesterday remove it and replace it now led's s working
but still no signal, and he is getting really HOT
 
need to know the voltage modification R1 now 510 ohm add 4K serial or parallel?

 

[Sapientiam]

You might have one of the units where they fitted a 5V regulator by mistake instead of 3.3V - this is the one that powers the DIR9001. Double check its output voltage - seems the most likely cause of a fried DIR.
 

 

[Hendrik]

I will check this so 7805 instead of LM317... I have an black PCB

 

[Hendrik]

Is there a way to make the power supply adjustible that way you can adjust the voltage you need
For the dir9001 that must be 3.3 volt instead of the 5 volt

 

[Sapientiam]

LM317 is an adjustable regulator - you set its voltage with the ratio of two resistors at the output.

 

[Hendrik]

Quote:

LM317 is an adjustable regulator - you set its voltage with the ratio of two resistors at the output.

better to make it adjustible by using a pot, but anyone knows how

 

[curiousmuffin]

Put the pot between adjust and ground. Range youll have to figure out according to the resistor value between adjust and output. Normally its 240ohm which means youll want 1k ohm pot or higher if you want to raise the v to 8. also bypass the pot with 10uf tantal

 

[lordearl]

Is anyone able to show on a picture which resistors are the iv resistors on the muse? I need to reduce the gain but don't know which two resistors to de-solder.

 

[Sapientiam]

Can't be bothered to post another pic up but on mine its R10 and R11 which are the I/V ones.

 

[lordearl]

Ok thanks - what value would cut the output in half?

 

[lordearl]

Quote:

The 47k resistors sit in between the output caps on the board layout. I'll short them out then.
 
Glad the rolloff will be a function of the preamp load, that makes things easier and cheaper.  

 
[size=medium]A word of warning  - the 47k resistors on the output cap side are there for a load setting purpose.[/size]
 
[size=medium]I removed and shorted the 10uF caps at the output because my preamp has 0.47uF film caps at the input.[/size]
[size=medium]But you can’t remove and short the 47k resistors, otherwise you short the signal outputs.[/size]
 
[size=medium]You can remove the 47k resistors, but don’t short them.  Doesn’t seem to have changed the sound signature at all.[/size]

 

[Sapientiam]

I've long since removed mine so can't remember the original values for R10,11 but the silkscreen says 680ohm. Your safest bet is to halve the values you have, that'll halve the output. Quickest route to that is solder another resistor of the same value in parallel with the existing ones.
 

 

[xxxfbsxxx]

hi everyone, i just bought the muse tda x4 and the 15V adaptor which came with it is terrible, generated a lot of hissing noise, so i changed to a better 9v@1.3amp adaptor. So do i need to change any resistor value or its fine to use the 9V adaptor? and can you please point me some hints for modification this little dac
thanks for reading and sorry for my poor English
 

 

[drbluenewmexico]

hey JEEP!  Are you still doing NOS153 x4 NOS chips mods??  i love the way mine sounds stock with a high current 12 volt external battery attached.
what else would you do to significantly improve the sound and what would be the approx cost?  thanks, drblue

 

[]eep]

Sorry, lost sight of this thread because I didn't see anything new much. But I still do mod these.
I'm just not sharing exactly what I do because It took me a lot of time and money to get it to this level. You can send me a PM though.