Author Topic: Interesting clocks  (Read 26357 times)

Offline zenelectro

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Re: Interesting clocks
« Reply #20 on: July 22, 2016, 05:59:47 PM »
Quote
[/quoteMost all of the caps on clock board are film caps, no ceramics as they are microphonic.

   Hi Terry .  I am glad u made this comment as it is very important . I have been modding up my teradak clock (valab) for a while now .
      I have one by one replaced  the caps with the best ones I have ,and increased the  size of the filter caps to multiples of the originals .

     But one cap that made a bigger improvement  than all of the others was changing a 100pf ceramic in the onboard regulator in the clock . I assume it was there for stability .I chose a copper foil polystyrene  for its high frequency performance .
     The valab clock  is good value for price but if u want super high end then general purpose capacitors are not good enough .Its clear that the clocks are very sensitive to the  quality of the power supply fed to them .
      Here is a pic of the clock .The little yellow cap is a source of grain and glare .

  I have since  changed out some ceramics in the 94 mk2  power supplies withe similar results .
  My experience seems to support the view that ceramics have no place in audio circuits .
     

Unfortunately there will also be almost certainly ceramic cap(s) inside your oscillator can.

SMT Ceramic caps (mlcc) have the smallest form factor, lowest ESR ESL of any cap and so are used extensively in fast digital decoupling applications as they
are the most efficient at reducing digital noise and bounce.  But they are also piezoelectric.

So the question becomes what is more important - good PS decoupling or a non piezoelectric cap?

I actually had the last batch of zenclocks made with a loose can (not welded / soldered) so I could remove the main mlcc power supply cap for oscillator.

As far as ceramics and regulators go - be careful, your regulator might start oscillating with the wrong cap. You really need a cro for this stuff.


Good luck.

T
 

Offline ozmillsy

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Re: Interesting clocks
« Reply #21 on: July 22, 2016, 06:37:02 PM »
Nice work Terry,  still plan to get my Wadia to you.

Q:   If I like the treble turned down,  and you like the treble turned up.....  what does that say about our hearing?   ;-D

Offline brenden

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Re: Interesting clocks
« Reply #22 on: July 22, 2016, 08:05:20 PM »
Thanks for the advice Terry .I will keep an eye on  it .But for now the  improvement is way above the ceramic.
   I figured the polystyrene foil cap would be very low esr and esl   also ,but without the piezo effects.
     But whatever the reason ,i am getting much better sound quality ,so  I will monitor it for now
  Maybe I should  come down one day and pick your brains and get some measurement tips . :)

      If there are ceramics in the oscillator  can ,they can stay there  for now . I generally steer clear of surface mount parts if possible.  the best parts are almost always  much larger when it comes to capacitors .

     I would like to one day test these small copper foils against the ceramics to see how they compare with digital bounce and rf etc .
   
   
   

   

   

   

Offline zenelectro

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Re: Interesting clocks
« Reply #23 on: July 22, 2016, 09:12:54 PM »
Nice work Terry,  still plan to get my Wadia to you.

No worries Oz any time.

How about I do a mountain run and catch up with a few people. I haven't seen you for ages.




Offline zenelectro

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Re: Interesting clocks
« Reply #24 on: July 22, 2016, 09:44:33 PM »
Thanks for the advice Terry .I will keep an eye on  it .But for now the  improvement is way above the ceramic.
   I figured the polystyrene foil cap would be very low esr and esl   also ,but without the piezo effects.

Yes ! WRT ESR / ESL it's all about size....  ;) or lack of it to be precise. Physically large caps cant have low ESR / ESL.
So for digital bypass you are looking for physically small cap, or the largest uF in the smallest case. There are exceptions
such as Tantalum caps which have higher ESR do to chemistry. But even now there are Tantalum / organic hybrid caps called
Poscap which have very low ESR and are super tiny. I haven't tried them - they may be very good - don't know.
You should try some.

Quote

     But whatever the reason ,i am getting much better sound quality ,so  I will monitor it for now
  Maybe I should  come down one day and pick your brains and get some measurement tips . :)

      If there are ceramics in the oscillator  can ,they can stay there  for now . I generally steer clear of surface mount parts if possible.  the best parts are almost always  much larger when it comes to capacitors .


It depends - if its high speed and there are really fast edge rates like some of the logic these days, you have to be
careful with large caps.

Quote
     I would like to one day test these small copper foils against the ceramics to see how they compare with digital bounce and rf etc .
   

I think for digital and not audio, the rules change.

You have to be very careful and not fool yourself. I remember once comparing two clocks and one 'won' the comparison.
But the loser had longer wires. When wires were shortened they were almost identical. It was just ground bounce that
was causing difference in sound.

So it goes.   :) :)








Offline brenden

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Re: Interesting clocks
« Reply #25 on: July 22, 2016, 10:33:36 PM »
I guess that brings me to another observation with digtal circuits that surprises me .I find that the substitutiion of a mylar capacitor  with a higher quality  foil capacitor in a digital  circuit gives me the same subjective  benefits as substitution in an audio circuit .what can cause this ?
       Its very clear ,to the point I have replaced nearly all of the cheap mylar caps with ultra high grade caps in my decoder/filter board and also around the tda1541a  these respond very well th high grade caps .
       Burn in is also the same ,a pain in the butt ,for digital .Does dielectric absorption cause some kind of jitter .or other noise .

Offline ozmillsy

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Re: Interesting clocks
« Reply #26 on: July 24, 2016, 04:08:17 PM »
No worries Oz any time.

How about I do a mountain run and catch up with a few people. I haven't seen you for ages.

Sure mate.   Give me a little notice, and we'll tee it up.
Q:   If I like the treble turned down,  and you like the treble turned up.....  what does that say about our hearing?   ;-D

Offline zenelectro

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Re: Interesting clocks
« Reply #27 on: July 24, 2016, 04:33:29 PM »
I guess that brings me to another observation with digtal circuits that surprises me .I find that the substitutiion of a mylar capacitor  with a higher quality  foil capacitor in a digital  circuit gives me the same subjective  benefits as substitution in an audio circuit .what can cause this ?
       Its very clear ,to the point I have replaced nearly all of the cheap mylar caps with ultra high grade caps in my decoder/filter board and also around the tda1541a  these respond very well th high grade caps .
       Burn in is also the same ,a pain in the butt ,for digital .Does dielectric absorption cause some kind of jitter .or other noise .

It depends where it is and what it does. If you are referring to 14 off bit decoupling caps on 1541, they are in audio path and low loss types are a benefit.

The 1541 actually runs fairly slow in comparison to modern cmos logic so is forgiving Wrt poor layout compared to say modern USB to I2S converter.

WRT decoder / filter board, I think they are a bit of a mess anyway. I couldn't see any way to make them work really well and I think all the various tweaks
are just choosing various flavors of the damage they do. That's why I did the reclocker board to take them largely out of equation.

I'm sure the re clocker board will also respond to various tweaks but I'd rather start from a solid foundation that is a better place.

T   

Offline brenden

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Re: Interesting clocks
« Reply #28 on: July 26, 2016, 02:24:32 AM »
 Hi Terry .The digital caps i was referring to are in  the decoder board .
  I agree the decoder  board  in the 94 is s bit of a mess as are the grounds, and the  way they  attached the dac board was sub optimal  .
       The reduction in distortion  by replacing the mylar caps on the decoder board  was easily as much as replacing a cheap cap in an audio circuit .
  In fact ,it really surprised me .This isnt about flavours .My sole aim is to reduce typical  distortions in every possible area  of the circuits by using  the very best engineered and lowest distortion parts available.
   I have found that mylar caps  anywhere  in the circuit will stop a piece of equipment from reaching its true potential
    With your cautions noted about ceramic caps in some sensitive circuits,my experience   in replacing them  so far has been overwhelmingly positive . The valab clocks are cheap ,so if there was a problem its easily replacable.
   I suppose you could say i am trying areas that many dont consider to be worthwhile ,and I know some would say its digital and it cant make a difference ,but i say "lets just try it to see what happens ".Thats part of the fun .The  discovery.

Offline rawl99

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Re: Interesting clocks
« Reply #29 on: August 13, 2016, 08:25:12 AM »
Hi Terry .The digital caps i was referring to are in  the decoder board .
  I agree the decoder  board  in the 94 is s bit of a mess as are the grounds, and the  way they  attached the dac board was sub optimal  .
       The reduction in distortion  by replacing the mylar caps on the decoder board  was easily as much as replacing a cheap cap in an audio circuit .
  In fact ,it really surprised me .This isnt about flavours .My sole aim is to reduce typical  distortions in every possible area  of the circuits by using  the very best engineered and lowest distortion parts available.
   I have found that mylar caps  anywhere  in the circuit will stop a piece of equipment from reaching its true potential
    With your cautions noted about ceramic caps in some sensitive circuits,my experience   in replacing them  so far has been overwhelmingly positive . The valab clocks are cheap ,so if there was a problem its easily replacable.
   I suppose you could say i am trying areas that many dont consider to be worthwhile ,and I know some would say its digital and it cant make a difference ,but i say "lets just try it to see what happens ".Thats part of the fun .The  discovery.

Brenden,
Your experiences appear to consistently mirror ours so keep up the great work Sir.
Anybody that says 'it's digital so it can't/won't make a difference' imo has just drunk the marketing cool-ade and should
either experiment with modifications to some nice sounding gear or stick with the uber-high-spec commercial designs and
leave us delusional fools to tinker away into oblivion and insanity.  I am pretty certain that the designers of higher
quality digital gear do not work with the 'it can't make a difference' pov when they are designing so it boggles my
mind why quite a few of the consumers and the ' knowledgeable' engineering types adopt this dogmatic viewpoint. 
My very simple question is: " if it can't make a difference how in the heck do companies like dcs etc sell a $20k "master oscillator"
 type of device. Either it makes a diff or it doesn't.

Thank the lord that One of the most talented digital guys I know ( T) does not operate with this mindset.
The unbelievers could optionally go and collect stamps.

Apparently under blind test conditions the outcomes change radically.  That is not my personal experience
and I am pretty sure it is not Marios either.  We all know that SteveG is of pretty much the same viewpoint.
I have done more blind tests than I care to demonstrate my ability to pick the differences, and now I am quite happy to
trust what I am hearing.  Much more time efficient.
  I can most very easily "prove" that " it's digital so it can't make a difference" is right, or wrong, depending upon
my choice  of equipment upon which to demonstrate said claim.  I am sure you know exactly what I am saying.
Cheers
C

Offline brenden

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Re: Interesting clocks
« Reply #30 on: August 14, 2016, 12:59:15 AM »
Thanks for the feedback Rawl . Its much appreciated.
      I take an unconventional  approach to my modifying .I look  to every single component in the CD  player or amp as a distortion generator Then  I search for a superior lower distortion  replacement. In most cases thats not too  hard .Back in the 90s I was using clocks hooked up to batteries etc ,stuff that I never heard of anyone   else  doing .All the local guys thought I was nuts. It soon became clear that everything makes a difference .I experiment a lot with caps ,wire ,resistors ,circuit improvements and diodes etc.I know what works ,through thousands of experiments .Not  having   any formal electronic  engineering  training has been a hinderance in some ways ,but a blessing  in others . I may not have tried many things that are suppose to make no difference.I have been at odds with posters on  some other forums  who cant open theiir minds to trying superior  parts that can  dramatically reduce distortion in audio gear .

     Capacitors  appear to be the weakest link  musically so i have centred most of my study around different construction and materials and how they affect the sound quality.  over the past few years I have been accumulating hard to find  caps to rebuild my gear  and now have an enviable parts box full of  the best parts ever produced . 
        No audiophile  type people have heard my system  since I  started up after a hiatus .It sounded horrible at the beginning ,,but after a couple of hundred changes its been  transformed .
         I now have a system I am proud of . Full of warmth dynamics ,timbral beauty ,separation ,ease  ,density,detail .and still more to go . After divorce I will be moving to a mates place  in October so not sure how  my audio  aspirations will pan out in the near future .All my audio gear goes with me  :)  Happy days .
       

Offline gamve

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Re: Interesting clocks
« Reply #31 on: August 14, 2016, 09:15:59 AM »
Auido - Divorce.  :-\ Audio - Divorce.  :-\ Audio - Divorce.  :-\
Audio wins every time  ;D

Offline brenden

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Re: Interesting clocks
« Reply #32 on: August 14, 2016, 04:08:03 PM »
Yep .
           You can switch the audio off when u are tired .
    My ex partner didnt have an off switch . Hopefully  I  can find some more time to catch up  with  some  of  you  in the future.

Offline zenelectro

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Re: Interesting clocks
« Reply #33 on: August 25, 2016, 11:35:05 PM »
Yep .
           You can switch the audio off when u are tired .
    My ex partner didnt have an off switch . Hopefully  I  can find some more time to catch up  with  some  of  you  in the future.

And when you ave found the perfect cap please start making them - haha.

PS - sorry about your split I hope things work out for future.

cheers

Terry




Offline brenden

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Re: Interesting clocks
« Reply #34 on: August 27, 2016, 10:56:33 PM »
Thanks Terry , I am looking positively to the future so its not all bad .
   I still  have music.
  I think film capacitors have come of age in recent years .

  As for the perfect cap ,closest thing imo  is the Duelund and the Jupiter . Not sure if these will be improved  apon  in any meaningful way .in the near future .

   I use duelund for coupling and jupiter for bypassing .. both give fantastic results .
 
   There is a gap  in availability   of  high end caps in the pf range  which is a shame but I was lucky enough to source
  what i need  from  new  old stock .