Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Digital Line Level DACs, Digital Crossovers, Equalizers, etc.

China ES9018PRO ES9028PRO 9038PRO mods&upgrades
China ES9018PRO ES9028PRO 9038PRO mods&upgrades
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 17th April 2019, 01:36 AM   #171
Terry Demol is offline Terry Demol  Australia
diyAudio Member
 
Terry Demol's Avatar
 
Join Date: Apr 2002
Location: *
Quote:
Originally Posted by KCHANG View Post
Your description of the effect of adding the relatively large (in terms of capacitance) film caps to bypass the power rails fits what I experienced very well. In the last few months, I have tried adding various combinations of large PP film caps to the power rails of my 9038Pro board. "Lush" and "smooth" were two adjectives that came to mind when I listened to the DAC board with the added film capacitors.

Ultimately, however, I have decided to remove all the film caps, and even the 0.1uF X7R bypassing caps I also added, from the board. The reason is that I am not convinced that "lushness" or "smoothness" corresponds to better sound quality. For instance, I don't think I've ever heard a female or male voice in real life that is "lush," "smooth," "warm," or "rounded"in the way presented by the DAC with large bypass film caps.
At the end of the day, it's a guess anyway as to what the recorded voice was supposed to sound like. Voices in recordings are almost always 'tweaked' to suite the material, mix or purely just to make, for example a lean sounding voice a bit warmer.

A good example of this is Bradley Cooper's voice in 'A Star is Born' compared to his actual voice in, say an interview. They sound very different.

T
  Reply With Quote
Old 17th April 2019, 05:47 PM   #172
KCHANG is offline KCHANG  United States
diyAudio Member
 
Join Date: May 2004
Location: San Jose, CA, USA
Quote:
Originally Posted by Terry Demol View Post
At the end of the day, it's a guess anyway as to what the recorded voice was supposed to sound like.
Hi Terry,

Thanks for the comments. The "guessing" part is what makes this audio hobby so frustrating. No knowing exactly how the original events sound like and what happened in the recording processes makes all the efforts and attempts to tweak a system to make it sound "real" or "good" a wild goose chase.
  Reply With Quote
Old 17th April 2019, 07:01 PM   #173
Markw4 is offline Markw4  United States
diyAudio Member
 
Join Date: Jul 2016
Location: California
Quote:
Originally Posted by KCHANG View Post
Not knowing exactly how the original events sound like and what happened in the recording processes makes all the efforts and attempts to tweak a system to make it sound "real" or "good" a wild goose chase.
That may be an overstatement of the issue. What original events sounded like may not matter as far as digital reproduction goes. If digital playback sounds very close to what original master tapes sound like when played back on the original machines used to do the mastering, that should be enough to evaluate A/D and D/A overall accuracy.

If one went further by mixing and matching A/Ds and D/As perhaps we could do some statistical analysis to tease out effects of A/Ds vs D/As.

Obviously, it would be expensive and complicated, but at least one audiophile has done the first part of it already, along with some of the second part. Mostly likely some mastering engineers have done their own comparisons too.

Doing all that at very low cost would probably not be possible. We can at least take home some lessons for what usually seems to get closest to the source in terms of accuracy of reproduction. For dacs, it typically means some combination a very good measured performance, and very detailed yet musical sound quality.

The way to approach that particular combination of things that tend to be associated with accurate reproduction in a diy setting is probably to mostly stick with tried and true basics. Clean design with careful attention to things like power supplies and regulators (perhaps a several regulators dedicated to different loads), low jitter clocking, RF, grounding, low distortion output stages with proper filtering and possibly balanced interconnects, etc.

In particular, starting with a cheap dac and swapping in some easy to change parts is not likely to get one very far in most cases, whether or not particular changes hurt or help accuracy of reproduction (perhaps some of both is common). One big problem with trying to do it is because many low cost dacs are not mod-able enough so as to make it possible to fix all the things that are wrong, which is usually almost everything. Why everything? Because low cost dacs or other audio components are built to a price point and if well designed they should be pretty well optimized for their market sector by the designer(s) to be close to equally compromised everywhere, in a balanced and carefully considered way. Chances of a really good designer making stupid mistakes and building a great dac, but with only a few easily changed bad parts should be very low. Wouldn't be a very good designer in that case.

Last edited by Markw4; 17th April 2019 at 07:07 PM.
  Reply With Quote
Old 17th April 2019, 07:27 PM   #174
eziitis is offline eziitis
diyAudio Member
 
Join Date: Aug 2016
Quote:
Originally Posted by Markw4 View Post
.... many low cost dacs are not mod-able enough so as to make it possible to fix all the things that are wrong, which is usually almost everything.....
thanks for pointing out this. now it is pretty much clear.

is
  Reply With Quote
Old 4th May 2019, 01:39 AM   #175
mateusfig is offline mateusfig  Brazil
diyAudio Member
 
Join Date: Jan 2011
Default transformer connection

Am I doing the right connections from transformer to ES9028PRO board? The board itself don't have input voltages tags. There is not docs about this board, I could not locate one. I bought this transformer in ebay and it is the right one for this board.

IMG_0789.JPG

IMG_0787.JPG

My top doubt is about the 15v wires (2 blue and 2 yellow). There are 3 bolts connections (I suppose they are for the 15v)

Last edited by mateusfig; 4th May 2019 at 01:44 AM.
  Reply With Quote
Old 4th May 2019, 01:59 AM   #176
phase is offline phase  United States
diyAudio Member
 
Join Date: Oct 2004
It “looks” correct, however, you will need to verify with an ohm meter which two of the yellow and blue leads are indeed the center or 0V.
The ohms reading should of course be similar between the two yellow/yellow, and the blue/blue. The ohms reading between the two center leads will of course be a lower reading than the other remaining pair.
I hope I explained that so that it makes sense anyways.
  Reply With Quote
Old 4th May 2019, 04:18 PM   #177
mateusfig is offline mateusfig  Brazil
diyAudio Member
 
Join Date: Jan 2011
Quote:
Originally Posted by phase View Post
It “looks” correct, however, you will need to verify with an ohm meter which two of the yellow and blue leads are indeed the center or 0V.
The ohms reading should of course be similar between the two yellow/yellow, and the blue/blue. The ohms reading between the two center leads will of course be a lower reading than the other remaining pair.
I hope I explained that so that it makes sense anyways.
Thank you so much. I understood and I will do it
  Reply With Quote
Old 5th May 2019, 02:21 PM   #178
KCHANG is offline KCHANG  United States
diyAudio Member
 
Join Date: May 2004
Location: San Jose, CA, USA
Quote:
Originally Posted by mateusfig View Post
Am I doing the right connections from transformer to ES9028PRO board? The board itself don't have input voltages tags. There is not docs about this board, I could not locate one. I bought this transformer in ebay and it is the right one for this board.
...
My top doubt is about the 15v wires (2 blue and 2 yellow). There are 3 bolts connections (I suppose they are for the 15v)
I have exactly the same transformer from China, also ordered off eBay. The two 15Vac secondaries are wound separately, and if you measure the resistance between the a blue wire and a yellow wire, it should be very high -- > tens of mega-ohms (out of range on my Fluke multimeter). The resistance between the blue wires or between the yellow wires should be around several ohms.

To figure out how to connect the transformer 15Vac secondaries to the board, first you arbitrarily combine (simple twisting is fine for this test) the end of a yellow wire with the end of a blue wire to form the "central" or ground connection. This is done with the transformer not connected to the board and before the primary is connected to the AC outlet. The remaining blue and yellow wires and the "central" have to be kept apart securely to prevent shorting. I taped the wires on my workbench so that they could not move. Then you apply AC to the primary and measure the voltage across the remaining yellow and blue "non-central" wires. If the voltage is around 30Vac or higher (mine measured ~37Vac), this "central" configuration is fine, and you can connect the wires to the board accordingly. If the voltage across the remaining yellow and blue wires is close to 0, however, just switch out one yellow wire (or blue wire) with the other yellow wire (or blue wire) for the central, then the two secondaries will be connected properly.

Since you have already connected the 15Vac secondaries to the board, you can just measure the voltage between the screws of the two non-central terminals on the connector. If the voltage is 30Vac or more, then your connection is fine.

Hope this helps.

Last edited by KCHANG; 5th May 2019 at 02:34 PM.
  Reply With Quote
Old 6th May 2019, 05:14 PM   #179
mateusfig is offline mateusfig  Brazil
diyAudio Member
 
Join Date: Jan 2011
Quote:
Originally Posted by KCHANG View Post
I have exactly the same transformer from China, also ordered off eBay. The two 15Vac secondaries are wound separately, and if you measure the resistance between the a blue wire and a yellow wire, it should be very high -- > tens of mega-ohms (out of range on my Fluke multimeter). The resistance between the blue wires or between the yellow wires should be around several ohms.

To figure out how to connect the transformer 15Vac secondaries to the board, first you arbitrarily combine (simple twisting is fine for this test) the end of a yellow wire with the end of a blue wire to form the "central" or ground connection. This is done with the transformer not connected to the board and before the primary is connected to the AC outlet. The remaining blue and yellow wires and the "central" have to be kept apart securely to prevent shorting. I taped the wires on my workbench so that they could not move. Then you apply AC to the primary and measure the voltage across the remaining yellow and blue "non-central" wires. If the voltage is around 30Vac or higher (mine measured ~37Vac), this "central" configuration is fine, and you can connect the wires to the board accordingly. If the voltage across the remaining yellow and blue wires is close to 0, however, just switch out one yellow wire (or blue wire) with the other yellow wire (or blue wire) for the central, then the two secondaries will be connected properly.

Since you have already connected the 15Vac secondaries to the board, you can just measure the voltage between the screws of the two non-central terminals on the connector. If the voltage is 30Vac or more, then your connection is fine.

Hope this helps.
I had already used the technic pointed by @phase. I will use your tip next time. Thanks you anyway!
  Reply With Quote

Reply


China ES9018PRO ES9028PRO 9038PRO mods&upgradesHide 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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Dynaco - ST 400 PC-29 mods/upgrades jsmd Solid State 3 7th May 2015 06:09 PM
ESP P3A Mods/Upgrades blap0220 Solid State 77 24th October 2014 11:40 AM
Denon DCD-820 mods upgrades tomst Digital Source 10 4th October 2014 12:18 PM
Onix/Melody SP3 Upgrades and Mods rhing Tubes / Valves 7 18th December 2010 11:32 PM
Threshold Mods or Upgrades msb64 Solid State 13 26th April 2010 02:15 AM


New To Site? Need Help?

All times are GMT. The time now is 12:11 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki