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.

AliExpress AD1865 R2R DAC
AliExpress AD1865 R2R DAC
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 19th October 2018, 07:09 AM   #91
wushuliu is offline wushuliu  United States
diyAudio Member
 
wushuliu's Avatar
 
Join Date: May 2008
Location: Pacific NW
Quote:
Originally Posted by PJN View Post
My AD1865 board arrived today. It looks very well made, same maker as the "little giant" 1387 board. Seems to have some quality parts if they are real. I can plunk it into the test box I have the TDA 1387 board in to give it a listen, but I need to get some connectors for the board first, I ran out in my parts bin. I'm out on vacation next week so I'll post back with my impressions when I get back.
Have a good vacation.
  Reply With Quote
Old 19th October 2018, 12:55 PM   #92
Hugh Jazz is offline Hugh Jazz  Taiwan
diyAudio Member
 
Hugh Jazz's Avatar
 
Join Date: Oct 2018
Quote:
Originally Posted by jean-paul View Post
Those 2 caps seem to be a key selling point:

7. It adopts the early Hongbao lime skin electrodeless coupling capacitor which has been discontinued for many years. The charm is very good, delicate and rich in music. There is no general sense of particle coupling in the electroless coupling, and it is very rare to couple the sound.

Well, the caps don't sound too bad with their bypasses. I removed them and they test okay. Value measures as 20uF (marked 22u) with 0.3 ESR and 1.8% voltage loss. Rather than replace them, I shorted the holes, fed a little DC into the buffer op amp, and trimmed the DC output to zero. No cap sounds better :-)
  Reply With Quote
Old 19th October 2018, 01:06 PM   #93
Hugh Jazz is offline Hugh Jazz  Taiwan
diyAudio Member
 
Hugh Jazz's Avatar
 
Join Date: Oct 2018
Quote:
Originally Posted by PJN View Post
My AD1865 board arrived today. It looks very well made, same maker as the "little giant" 1387 board. Seems to have some quality parts if they are real. I can plunk it into the test box I have the TDA 1387 board in to give it a listen, but I need to get some connectors for the board first, I ran out in my parts bin. I'm out on vacation next week so I'll post back with my impressions when I get back.

I 'm also looking forward to your impressions! :-)
  Reply With Quote
Old 19th October 2018, 05:55 PM   #94
stellarelephant is offline stellarelephant  United States
diyAudio Member
 
stellarelephant's Avatar
 
Join Date: Jan 2017
Location: Western NC
Quote:
Originally Posted by matt_garman View Post
Random, possibly silly, thought: what if the NOS rolloff is actually what makes NOS appealing to (some) people? And if that is true, could that be approximated by creating a filter that deliberately starts rolling off the high frequencies around 16khz like NOS, but applied to sigma delta DACs (I.e. the exact opposite of what abraxalito's droop correction filter does)? Only suggesting this for curiosity's sake...
I have heard only three implementations of TDA1387, one of which is the filterless Pi hat you designed, Matt, and then Richard's first LingDAC 1.1 (which I believe uses the same filter being discussed) and lastly the Audiophonics board, which has a less precise NOS droop filter that can be seen here.

They all sound good to me, but I actually DO prefer the NOS rolloff for headphone listening, where I find it prevents fatigue. Over speakers, I think both correction filters sound more realistic than none. Of course there are other differences in the implementations to consider, but I have at least A/B'd LingDAC with and without the filter engaged, and found this to be true. Somebody with very bright speakers may disagree.
  Reply With Quote
Old 24th October 2018, 06:37 AM   #95
abraxalito is offline abraxalito  United Kingdom
diyAudio Member
 
abraxalito's Avatar
 
Join Date: Sep 2007
Location: Hangzhou - Marco Polo's 'most beautiful city'. 700yrs is a long time though...
Send a message via Yahoo to abraxalito
Quote:
Originally Posted by abraxalito View Post
Initial listening results are promising...
I really enjoyed the sound from the balanced AD8067 I/V followed by AD8065 3rd order filtering. It made music more exciting. But only at first, after a few days it gave me a slight sense of unease. My gf wasn't particularly impressed she said the HF wasn't as clean as from lingDAC (her hearing goes up higher than mine). I figured the difference might well be in the steepness of the filtering - lingDAC uses a much steeper filter than the single-stage MFB circuit I've posted up here.

So I decided to build an active version of lingDAC's steeper filter, using 12 * AD8065s (4 channels, 3 opamps per channel). This took rather longer than I imagined because I couldn't get it to stop being a 50MHz oscillator. Perhaps no surprise when using 100MHz+ opamps on prototyping board, no groundplane. In the end I managed to tame it with a little bit of help from some ferrite beads.

I've been listening for a couple of days now and while it still sounds slightly forward, its definitely more subdued. To my ears the HF is silky-smooth even on the most demanding material.
__________________
I know you think you understand what you thought I said but I'm not sure you realize that what you heard is not what I meant - Alan Greenspan
  Reply With Quote
Old 28th October 2018, 03:17 PM   #96
Hugh Jazz is offline Hugh Jazz  Taiwan
diyAudio Member
 
Hugh Jazz's Avatar
 
Join Date: Oct 2018
I changed my mind and ordered the AD1865 from Taobao a few days ago.

It arrived this afternoon and I hooked it up. It took an hour to settle in and then sounded very good - better than the other DAC from the same seller. It had similar "Ch" "K" but was more natural on "S" "Sh" and "th" female vocals. I left if to burn in... and during one of the periodic checks, I found the left channel had stopped working and the buffer op amp was extremely hot.
I will have to return it I guess. :-(
__________________
Cheers! "not all measured performance behavior explains or correlates with listening tests by audio experts" (Texas Instruments, 2003, p.12)
  Reply With Quote
Old 28th October 2018, 03:35 PM   #97
canvas is offline canvas  Taiwan
diyAudio Member
 
Join Date: Nov 2003
Location: Taiwan
Quote:
Originally Posted by Hugh Jazz View Post
I found the left channel had stopped working and the buffer op amp was extremely hot.
I will have to return it I guess. :-(
It will take a long time to reach the seller by China post (the 'China' side), unless you can ship it with SF Express. I'd just replace the faulty op amp. I'm assuming it's NE5534?

Poting
  Reply With Quote
Old 28th October 2018, 04:19 PM   #98
Hugh Jazz is offline Hugh Jazz  Taiwan
diyAudio Member
 
Hugh Jazz's Avatar
 
Join Date: Oct 2018
Hi,


I don't think it is the buffer op amp (OP42 - out of production). I let it cool and then switched on again - it works - and in fact it is the I/V op amp that heats up first. The AD1865 also gets quite warm. BTW, if anyone is curious, the logic gate in between the AK receiver and the AD DAC is 74HC7266A and I think the branding is the Fairchild "F".

It will be hassle to return and I will lose money but I'm not going to waste time fixing badly made gear from China. So, SF Express it is - thanks ;-) I wasn't that impressed with the other DAC from this seller, although that could be the nature of the IC itself with it's rather large amount of ultrasonic noise... and that's still a work in progress...it's good enough and quite satisfying to listen to but not dynamic or finely detailed or any of that. I have no experience with TDA1387 other than this one though so maybe it can be better. Keep trying...

Besides all that, for the money, I can get a decent ES9018k2m, which I prefer $ for $ to these NOS dacs. Still, I will try to find a better AD186x DAC because I really want to see what a good R2R DAC can do.
__________________
Cheers! "not all measured performance behavior explains or correlates with listening tests by audio experts" (Texas Instruments, 2003, p.12)

Last edited by Hugh Jazz; 28th October 2018 at 04:44 PM.
  Reply With Quote
Old 28th October 2018, 06:08 PM   #99
stellarelephant is offline stellarelephant  United States
diyAudio Member
 
stellarelephant's Avatar
 
Join Date: Jan 2017
Location: Western NC
Bummer! This DAC looked promising, and the eBay seller's item description makes it seem like the sound would be quite nice, in spite of the funny translation. Too bad you got a defective board. What are the coupling caps used? And, could this DAC be modded to bypass SPDIF input, and instead accept I2S signal direct to the chip, like what Matt has considered doing with the Little Giant board?
  Reply With Quote
Old 29th October 2018, 12:39 AM   #100
Hugh Jazz is offline Hugh Jazz  Taiwan
diyAudio Member
 
Hugh Jazz's Avatar
 
Join Date: Oct 2018
Quote:
Originally Posted by stellarelephant View Post
Bummer! This DAC looked promising, and the eBay seller's item description makes it seem like the sound would be quite nice, in spite of the funny translation. Too bad you got a defective board. What are the coupling caps used? And, could this DAC be modded to bypass SPDIF input, and instead accept I2S signal direct to the chip, like what Matt has considered doing with the Little Giant board?
Coupling caps are marked Rubycon but electros get faked a lot in China so I wouldn't place any faith in what the skin says. The same ones on the other DAC tested okay though.

Yes, it can be hacked although it's not one of the easiest I've seen for this. It's really a question of how good your skills are.
__________________
Cheers! "not all measured performance behavior explains or correlates with listening tests by audio experts" (Texas Instruments, 2003, p.12)
  Reply With Quote

Reply


AliExpress AD1865 R2R DACHide 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
mono tpa3116 red aliexpress basreflex Class D 6 5th March 2017 06:56 PM
Transistor tester from Aliexpress ashok Equipment & Tools 8 30th May 2016 10:09 AM
Aliexpress EddieT The Lounge 9 26th November 2015 06:18 PM
about the Aurum Cantus G1 from aliexpress juanito Multi-Way 0 13th July 2013 06:28 PM
aliexpress class d amp telefunken Class D 9 26th October 2010 02:01 PM


New To Site? Need Help?

All times are GMT. The time now is 09:42 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki