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.

New DAC based on AK4497EQ
New DAC based on AK4497EQ
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 22nd December 2016, 01:17 AM   #21
wengtech is offline wengtech
diyAudio Member
 
Join Date: Feb 2012
Quote:
Originally Posted by ChuckT View Post
I have a Jensen jt11p with the ak4495, it sound pretty darn good.
One thing about transformers is that a lot of them ring (I have measured a few with a scope). For Jensen jt11p I use their recommended snubber 13k + 620pf across the secondary and the measurement looks good, you might want to check the snubber value for your your Jensen.
Quote:
Originally Posted by clay-speakers View Post
Hi Chuck,
Thanks for that info. I will fire up the scope & see how a square wave looks.
The transformers I am using are Jensen JT-11-FLCF. 1:1 standard 600/600 ohm output transformers. My board has no output stage so the transformers were just a quick lash up to have a listen. Currently no snubber or loading on the secondary but I have to admit it sounds pretty good as is.
i just wondering why using transformer with AKM dac output?
as i know AK4490/95/97 are voltage output which doesn't need IV converter.
the only need for the outputs are low pass filter to match the internal frequency response.
so AK4490/95/97 need LPF, is that output transformer act as LPF?
  Reply With Quote
Old 22nd December 2016, 10:50 AM   #22
Dimdim is offline Dimdim  Greece
diyAudio Member
 
Join Date: Sep 2008
Location: Athens
New DAC based on AK4497EQ
I finally received my test boards and built one to make sure that I had a proper handle on things. Everything seems to be working fine.

I wrote a piece of Arduino code to control pretty much every parameter of the chip that relates to sound quality for my single chip board. I've put it up on my blog.
It accepts commands through the serial port to change the various options. Here is its menu:

New DAC based on AK4497EQ-serial_port_menu_v1-33-png

Next up is building a second unit so I can try dual mono operation.

What concerns me is the output stage. I've looked at the dual mono reference design for the 4497 part but I haven't gone as far as comparing the 4490's output characteristics with the 4497's so as to determine whether the 4497's reference design could be applicable to the 4490s.

I also don't like the 100uF capacitors in the signal path, before the summing of the signals. I would like to have full DC coupling if possible.

I'm a noob at analog electronics so any suggestions would be appreciated.

I'm OK with using op-amps but I would prefer something more "interesting", of the class-a discrete flavour. Balanced output would be preferable.
Attached Images
File Type: png Serial_Port_Menu_v1.33.png (36.5 KB, 1799 views)
__________________
http://www.dimdim.gr
  Reply With Quote
Old 26th December 2016, 09:24 PM   #23
clay-speakers is offline clay-speakers  Australia
diyAudio Member
 
Join Date: Aug 2006
Location: Gold Coast, Australia
wengtech - the AK4497 outputs a diferental signal also with dc (2.5v)
The transformer is just a very simple way to remove the dc & also obtain a single ended output (rca) if required. Depending on the transformer there may also be some hf filtering.

Dimdim - thanks for all the good info & link to your site. Well done!

Hey a couple of questions.
1. Has anyone experimented with "heavy load mode"?
It seems to be related to the analogue output stage so maybe it increases the bias on the output opamps. It may effect the output impedance??
Bottom line does it change the sound quality?

2. The digital core on the AK4497 (1.8v) can optionally be supplied by a internal regulator or fed with an external supply - I'm currently using the internal reg but just wondered if anyone has compared the two?
  Reply With Quote
Old 29th January 2017, 12:28 AM   #24
ggetzoff is offline ggetzoff  United States
diyAudio Member
 
ggetzoff's Avatar
 
Join Date: Nov 2004
Location: Southwest
New DAC based on AK4497EQ
Quote:
Originally Posted by Dimdim View Post
I finally received my test boards and built one to make sure that I had a proper handle on things. Everything seems to be working fine.

I wrote a piece of Arduino code to control pretty much every parameter of the chip that relates to sound quality for my single chip board. I've put it up on my blog.
It accepts commands through the serial port to change the various options. Here is its menu:

New DAC based on AK4497EQ-serial_port_menu_v1-33-png

Next up is building a second unit so I can try dual mono operation.

What concerns me is the output stage. I've looked at the dual mono reference design for the 4497 part but I haven't gone as far as comparing the 4490's output characteristics with the 4497's so as to determine whether the 4497's reference design could be applicable to the 4490s.

I also don't like the 100uF capacitors in the signal path, before the summing of the signals. I would like to have full DC coupling if possible.

I'm a noob at analog electronics so any suggestions would be appreciated.

I'm OK with using op-amps but I would prefer something more "interesting", of the class-a discrete flavour. Balanced output would be preferable.
Want something interesting, use these: Home - Sparkos Labs.com
__________________
Airline Pilot-If it's not Boeing I'm not going.
Aleph J, DCB1, VHEX + USSA-5, BA-3 Pre, DCG3,USSPA
  Reply With Quote
Old 12th January 2018, 03:59 PM   #25
ArturoKiwi is offline ArturoKiwi
diyAudio Member
 
Join Date: Sep 2013
Hi to everyone... I know that this chip is no more a news, but I would like to try to build a dual chip dac with the ak4497eq.

Could someone suggest me some "kit" o where I could found some tutorial?

Best regards and music to all
Arturo
  Reply With Quote
Old 15th January 2018, 08:32 AM   #26
grg31 is offline grg31  France
diyAudio Member
 
Join Date: Nov 2014
Quote:
Originally Posted by ArturoKiwi View Post
Hi to everyone... I know that this chip is no more a news, but I would like to try to build a dual chip dac with the ak4497eq.

Could someone suggest me some "kit" o where I could found some tutorial?

Best regards and music to all
Arturo


AK4497EQ DAC Dual-chip Decode support DOP DSD 384K & Led Screen & Remote Control | eBay

Thé CI ak4497eq 21$ piece

https://www.arrow.com/fr-fr/products...es-corporation
  Reply With Quote
Old 16th January 2018, 07:19 PM   #27
ArturoKiwi is offline ArturoKiwi
diyAudio Member
 
Join Date: Sep 2013
Sorry for my ignorance, but the chips are difficult to solder on the board?
I need specific equipment?

Arturo
  Reply With Quote

Reply


New DAC based on AK4497EQHide 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
FS - Quanghao latest DAC-END24 AD1865 tube based DAC rol Swap Meet 1 7th March 2015 09:36 AM
Opinion on/Moding Suggestions for DAC-24192-ABR (Korean Sabre 9023 based) DAC matijaudio Digital Line Level 11 22nd January 2015 06:25 AM
My tda1543 based dac (as if there where not enough of them around ;o) hifi Digital Source 21 31st July 2012 03:25 AM
USB based DAC project bluetech Digital Line Level 49 15th July 2009 02:03 PM
Another PCM1730 based DAC JensRasmussen Digital Source 18 11th August 2006 07:41 PM


New To Site? Need Help?

All times are GMT. The time now is 01:56 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki