Coupling caps in DAC output - diyAudio
Go Back   Home > Forums > Source & Line > Digital Source

Digital Source Digital Players and Recorders: CD , SACD , Tape, Memory Card, etc.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 6th July 2005, 03:08 PM   #1
diyAudio Member
 
Sunsun22's Avatar
 
Join Date: Jul 2004
Location: Hong Kong
Default Coupling caps in DAC output

I just received my Dack 2.0 DAC and it sounds sweet and smooth after a few days of burning in. Yet, I am not too sure on its bass because it doesn't have the punch that my Assemblage ver 2.7 is delivering (after changing all the caps to Panasonic FC and the output opamp to OPA627BP).

I saw the Dack 2.0 has two output caps in parallel. One 3.3uF Auricap with the red lead pointing to the output RCA socket and one 0.1uF Sonicaps with the -ve to the output RCA socket. My questions: -

1. Does it mean that it is adopting the Black Gate E-Cap nonpolar concept - with two caps with oppositing poles in parallel? What are the pros for this arrangement? Or is it a manufacturing fault?

2. I've tried to parallel another Jansen Copper Tube 0.1uF to the output caps and the bass immediately becomes more punchy. What would it be IF I disconnect the Sonicaps 0.1uF and change it to Jansen? I don't want to do it immediately to void my warranty.

3. If I want more punch, should I replace the sonicap or auricap with original value or change the value of caps?

Thanks

Sunny
  Reply With Quote
Old 6th July 2005, 03:26 PM   #2
diyAudio Member
 
Peter Daniel's Avatar
 
Join Date: Jul 2002
Location: Toronto, Canada
Send a message via AIM to Peter Daniel
Here's ho Parts Connexion explains the paralleling of different caps (types/values):

5a. All critical caps changed to the best Film and Electrolytic types....(2) Rel-Cap TEFLON TFTExotica
bypasses (2) for the new (2) AuriCap metallized polypropylene coupling caps +
"paralleled" BLACK GATE FK-Series coupling caps (2), replacing the cheapest quality generic
electrolytic caps in the stock unit. This double-bypassed coupling cap hybrid gives us the best of
all worlds - bass and dynamics provided by a "quality" high value electrolytic; the tonal purity of a
world-class film cap; and the speed, delicacy and high frequency sparkle achieved by adding a
Teflon bypass cap!


Personally, I prefer a single, good cap and my current choice goes to V-Caps: http://v-cap.com/tefloncapacitors.html
__________________
www.audiosector.com
“Do something really well. See how much time it takes. It might be a product, a work of art, who knows? Then give it away cheaply, just because you feel that it should not cost so much, even if it took a lot of time and expensive materials to make it.” - JC
  Reply With Quote
Old 6th July 2005, 08:29 PM   #3
diyAudio Member
 
Join Date: Jun 2005
Location: Los Angeles
Peter would know better than I, and his suggestion is corroborated by empirical audio's recommended MOD to:

"Chris VenHaus' Teflon V-caps really add ultimate clarity to the high frequencies that is missing when using only the Multicap Polystyrenes or the V-cap oil caps."

Also, Ack's own "Hi Rez Option" entails adding:

"Super-fast, low-dissipation Teflon output coupling capacitors are added to enhance texture and speed in the high frequencies. Requires 250hr break-in period."

I'm not certain whether Ack uses VH Audio's teflon caps, though. Probably not since the hi rez upgrade is $85 and empircal's teflon V-Cap mod is $175.
__________________
Cheers ~ Mike
  Reply With Quote
Old 7th July 2005, 12:03 AM   #4
diyAudio Member
 
Join Date: Dec 2003
Location: Sydney
My suggestion when it comes to coupling is to compare V-Caps with Black Gate 4.7uF / 50V C type at one tenth of the price. I have tried V-Cap (oil) 4.7uF and was very disappointed with harsh unnatural sound. Paralleling with smaller values should be avoided as well. I played with this a lot and to me, single coupling capacitor always sounded better - definition, more space - better 2 and 3D.

Regards,
Extreme_Boky
  Reply With Quote
Old 7th July 2005, 01:04 AM   #5
diyAudio Member
 
Peter Daniel's Avatar
 
Join Date: Jul 2002
Location: Toronto, Canada
Send a message via AIM to Peter Daniel
I actually switched from BG N 4.7 to teflon V-Cap.

Although I regard BG N as one of the best coupling caps ( I prefer them over Hovlands MIT RTX and Jensens), V-Caps TFTF are better (however, they cost 100 x more )

A single cap is indeed better and I never use them in parallel even for PS bypassing.
__________________
www.audiosector.com
“Do something really well. See how much time it takes. It might be a product, a work of art, who knows? Then give it away cheaply, just because you feel that it should not cost so much, even if it took a lot of time and expensive materials to make it.” - JC
  Reply With Quote
Old 7th July 2005, 01:20 AM   #6
diyAudio Member
 
Sunsun22's Avatar
 
Join Date: Jul 2004
Location: Hong Kong
Thank you for all the inputs. The new DAC is not yet burn in therefore I'll give it more time. Changing to V-Cap would be the last option because firstly it is not available in Hong Kong and secondly, it is very $$$$$.

The bass is still disappointing up to this morning but the fact is I can only turn on the DAC for 4 to 5 hours in a day because of the battery. 5 days x 5 hours = 25 hours would still be very green for a new DAC. I'll try to make an AC supply with + - 12V this weekend and hope it will mature earlier.

If eventually the bass is still disappointing and I decided to use only one coupling cap, should I go for a higher uF or lower uF?

Sunny
  Reply With Quote
Old 7th July 2005, 02:03 AM   #7
diyAudio Member
 
Peter Daniel's Avatar
 
Join Date: Jul 2002
Location: Toronto, Canada
Send a message via AIM to Peter Daniel
Usually higher uF produces bigger bass.

You should be able to charge the batteries while the DAC is powered, if it's not possible, I recommend modyfying it. I have my DACs always on for best performance, otherwise it may take up to an hour to reach optimum performance.

Since BG N caps are expensive, you might try them for coupling (4.7u or 10uF) . Up till recently that was my preferred choice. I connect the longer pin to the RCAs.
__________________
www.audiosector.com
“Do something really well. See how much time it takes. It might be a product, a work of art, who knows? Then give it away cheaply, just because you feel that it should not cost so much, even if it took a lot of time and expensive materials to make it.” - JC
  Reply With Quote
Old 7th July 2005, 07:20 AM   #8
Werner is offline Werner  Europe
diyAudio Member
 
Join Date: Jan 2002
Location: Belgium
What's your DAC driving? 3.3uF is not a lot for output coupling. If it sees a 10k load then the -3dB point is at 5Hz, with audible effects up to 50Hz or so.
  Reply With Quote
Old 7th July 2005, 02:15 PM   #9
diyAudio Member
 
Sunsun22's Avatar
 
Join Date: Jul 2004
Location: Hong Kong
There is a resistor 425K (I presume, the color rings are yellow, red, green, organge, brown) connecting the ground after the two caps (at RCA side).
  Reply With Quote
Old 7th July 2005, 02:33 PM   #10
Werner is offline Werner  Europe
diyAudio Member
 
Join Date: Jan 2002
Location: Belgium
At the amplifier or preamplifier input, of course ...
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Ono/ Xono Output coupling Caps Barry1 Pass Labs 40 9th July 2014 12:52 AM
Output coupling caps in Arcam Alpha 5 CDP filholder Digital Source 6 23rd June 2005 01:28 PM
coupling caps el capitan83 Tubes / Valves 10 17th December 2004 04:25 PM
switchable output coupling caps in pre? RichJones Solid State 1 26th September 2003 03:44 AM
output coupling caps, yes or no? catrafter Digital Source 1 8th May 2003 01:34 AM


New To Site? Need Help?

All times are GMT. The time now is 06:52 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2