Go Back   Home > Forums > >

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

DAC AD1862: Almost THT, I2S input, NOS, R-2R
DAC AD1862: Almost THT, I2S input, NOS, R-2R
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
Old 7th May 2020, 12:32 AM   #1
miro1360 is offline miro1360  Europe
diyAudio Member
 
Join Date: Mar 2010
Default DAC AD1862: Almost THT, I2S input, NOS, R-2R

Main DACs in this thread: AD1862, AD1865

Why?
AD1862 DAC is one of the best analog sounding DACs ever made:
- dynamics is perfect
- no digital fatigue for the ears
- just a pleasant analog sound
- nicer sound than PCM1704 on the same input, power supply and I/V
It was used in the most expensive premium players, whose production has been gradually replaced by economical delta-sigma devices.
This DAC easily beats many modern delta-sigma DACs from the expensive class, if not all of them

AD1862 has been built and tested by: (is anyone missing?)
chi0001, Vunce, pistollero, nano35 with update, Paddy Garcia + .2., happylistening, Ripster, galac - custom, Robin De Wolf, manniraj, RickRay, diyiggy, woodturner-fran, har297, kempraj, jimk04, Sligolad, mllum, ernesternest, Kuka, tubee, gaszto, meanie

AD1865 has been built and tested by:
Vunce


PCB for AD1862:
PCB version 1.0 - Tested: #81
PCB version 1.3 - Untested: #1278
PCB version 1.3 (pad) - Untested: #1323

PCB version 1.3 - Tested, prefer this: #1351; 2 different I/V opamp packages: DIL08 and SO08; BOM example; with uf.l: #2180

PCB for AD1865:
PCB for download - Tested: #1431

PCB for PSU:
PSU 1: 78xx/79xx - Tested: #1460, #jimk04 TPS7A mod
PSU 2: LT1963A/LT3015 - Tested: #1461 + values correction, 2R2 resistors on power rails

PCB for USB-I2S:
Based on PCM2706+WM8804 (better - low jitter) - Untested: #2111
Based on PCM2706 - Tested: #1694

PCB for SPDIF/Optical to I2S:
Based on WM8804 - Untested: #2139

PCB for USB/SPDIF/Optical to I2S:
Based on PCM2706, WM8804 (low jitter) - Untested: #2151; with uf.l connector: #2165


Lesser known DACs for testing, probably lower sound quality - are cheaper:
PCM56P, AD1860, AD1851, AD1861, AD1856, PCM61P ... one PCB: #1477
Tested: har297, mllum


Build notes for AD1862:
VA: +12V and -12V analog power supply, a filtered regulator MC7812/MC7912 is fine (from OnSemi) ... or LT1963A/LT3015, or another discussed in this thread
VD: +5V and -5V digital power supply; again a filtered MC7805/MC7905 is fine
- required current: #1391
- you can try other power supplies at any time, write your comparison in the thread; read the thread for hints from other members
I2S: can by DIY or bought a ready-made ... standard I2S ... there are many ready-made devices: USB-I2S (PCM2706, XMOS, ...), RPi-I2S, bluetooth-I2S, spdif-I2S (WM8804/5, DIR9001), toslink-I2S (WM8804/5, DIR9001), MCU-I2S, xyz-I2S ... I2S signal can be also sourced from your existing player (find out if there is the signal)
J1-J13: is 0R resistor, or a wire jumper for the PSU 1. Use 2R2 or 3R3 resistors for the PSU 2. Jumpers can be used as an alternative input for separate power supplies for each channel (no significant advantage with separate channels).
R8, R9: this resistor sets the output voltage from I/V (L-OUT, R-OUT), 1k4==1.4Vp, 2k4==2.4Vp, 2k7==2.7Vp (2.7Vp==5.4Vp-p)
C15, C16, C25, C26: the exact values must be maintained (ratio 1:10), a high quality electrolyte (Nichicon UFG or UKZ), (or a tantalum can be installed), again your preferred choice
R4, R5, R6, R7, TR1, TR2: install only if the MSB trim adjustment will be performed and you know how (not easy task), better let it empty
C31, C36: this is SMD, everyone can solder SMD 1206, it should be a C0G type ... or use polypropylene (PP) THT cap (alternatively it can be omitted)
C37, C38 (C0G type), but let it empty, don't populate it, it was meant as a simple RC filter on the output (about 330kHz cut-off frequency), but it is better without, my AD1862 is without this filter ... someone tried a passive Bass-Boost? #684
@Vunce suggested a great inspiration to install some capacitors from the bottom. It can open a space on the PCB for future experiments (custom I/V boards), or as a way to deal with bigger capacitor packages. Check his build for more details: #141, #339, #525

I/V
Operational amplifier has a direct effect on the sound quality and is one of the key parameters of sound in any DAC. Get the opamp only from a trusted supplier, avoid fakes from china (post in the thread only results based on genuine opamps).
Alternatively any custom I/V can be connected (or a high quality audio transformer with ratio 1:10 .. 1:20, low input resistance).
Good genuine opamps, tested, which are not obsolete, in random order: LM6171, ADA4627, ADA4898-1, OPA828, AD797, AD711, OPA627 and much more are discussed in the thread.
PCB for I/V:
- OPA627 Clone - Untested: #2201


Where to find AD1862 chips?
a) AD1862, AD1865 is still available from eBay, aliexpress or other china stores. It comes as a genuine part, but could have been used before! (DAC chip is not easy to fake, they were often only remarked from a lower grade to a higher grade (N to N-J or N-K), sold out as a remaining stocks, or extracted from electronic waste, certainly not produced as a new chip). Read condition on the seller's ad: "Used" or "New".
When you buy such a chip, take a good look at whether it is new or shows signs of use:
- legs bent to round (not straight), very scratchy, corrosion, ...
- signs of abraded surface (remarked)
- remnants of old tin is the worst, because such a chip was extracted using heatgun and can be degraded
b) The last genuine seller of obsolete AD1862 & AD1865 chips is Rochester: Post #290 ... consider a group buy in your location due to a lower postage ... as a group supplier count with additional costs (customs duties, VAT, fee)
Group buys are taking place in the forum, read new posts and stay updated.
c) In old CD players: List ... find out if the chip is soldered or inserted into the socket and get the inserted one

Group buys:
Group Buys forum
by @Paddy Garcia from US, international shipping
by @Paddy Garcia from US 2
@Paddy Garcia is holding a few genuine chips for you, AD1862, AD1865
... or start own in your location


Other shortcuts:
- nice tube test by @woodturner-fran #1850
- big I/V review from @woodturner-fran #2079
- @Mark Johnson created a nice power supply from LM317/337 + de-noiser + CRC, see his thread: VRDN ... @RickRay tested it with this DAC: #1224
- dual to single opamp adapter from @Vunce: #1140
- 192kHz is nicely playable with XMOS #1272
- how to connect and configure new version of JLSounds I2SoverUSB v.III, read from post #617; note that the configuration and connection without shift registers is different: #538 and configuration pins are described in the manual (don't be confused at this point, without shift registers it is more for testing purposes, you can still use shift registers with JLSounds in standard I2S configuration) - #2225
- @Ripster connected jlsounds over the raspberry usb (seems like any USB-I2S can be configured that way) #1373


Share your experience with other members in this thread, it is helpful.
Attached Images
File Type: png Screen Shot 2020-07-20 at 12.38.39 PM.png (275.6 KB, 4764 views)
File Type: jpg Screen Shot 2020-07-20 at 12.39.02 PM.jpg (214.7 KB, 4964 views)
Attached Files
File Type: zip diyAudio_AD1862_DAC-rev1.1_2020-06-20_JLCPCB-Gerber.zip (625.7 KB, 193 views)

Last edited by miro1360; Yesterday at 10:43 PM. Reason: update
  Reply With Quote
Old 7th May 2020, 12:39 AM   #2
miro1360 is offline miro1360  Europe
diyAudio Member
 
Join Date: Mar 2010
PCB details
Attached Images
File Type: jpg image001.jpg (502.7 KB, 5565 views)
File Type: jpg image002.jpg (509.3 KB, 5416 views)
File Type: jpg image003.jpg (570.5 KB, 5287 views)
File Type: jpg image004.jpg (293.4 KB, 666 views)
File Type: jpg image005.jpg (446.7 KB, 646 views)
File Type: jpg image006.jpg (455.2 KB, 620 views)
File Type: jpg image007.jpg (524.1 KB, 542 views)
File Type: jpg image008.jpg (241.7 KB, 475 views)
  Reply With Quote
Old 7th May 2020, 12:55 AM   #3
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...
Have you listened to it without the 4n7s on the outputs of the OPA627s? I'm curious how they affect the SQ.
__________________
I know everything you know about this times 1000 - Amir @ ASR
  Reply With Quote
Old 7th May 2020, 04:12 AM   #4
miro1360 is offline miro1360  Europe
diyAudio Member
 
Join Date: Mar 2010
C37, C38 can be omitted, it is just a simple RC filter on the output (about 330kHz cut-off frequency), my AD1862 is without RC filter
if such a filter is not here after DAC, it will be present at any amplifier input (if not manually removed)
the sound is affected by the capacitor type, it is least affected by the type of PP and C0G (SMD) (they have the lowest THD of all capacitor types)

Last edited by miro1360; 7th May 2020 at 04:17 AM.
  Reply With Quote
Old 7th May 2020, 04:30 AM   #5
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...
I wasn't thinking about distortion caused by cap type (I assumed NP0). Rather loading on the opamp output at higher frequencies. Filters at the input of amps generally have higher valued Rs than 100ohm before shunt caps. And have lower values of caps (1n would be about the highest I've seen).
__________________
I know everything you know about this times 1000 - Amir @ ASR
  Reply With Quote
Old 7th May 2020, 04:48 AM   #6
miro1360 is offline miro1360  Europe
diyAudio Member
 
Join Date: Mar 2010
right, it has to be omitted, or the value with resistor can be changed easily for any combination
  Reply With Quote
Old 7th May 2020, 10:09 AM   #7
dewdrop is offline dewdrop  Singapore
diyAudio Member
 
Join Date: Mar 2004
Subscribed!
  Reply With Quote
Old 7th May 2020, 10:59 AM   #8
juancho is online now juancho  United Kingdom
diyAudio Member
 
Join Date: Apr 2005
Location: London, England
Subscribed. But why not a nice tube output stage for this DAC instead of opamps?
David
  Reply With Quote
Old 7th May 2020, 02:31 PM   #9
miro1360 is offline miro1360  Europe
diyAudio Member
 
Join Date: Mar 2010
there are many different tupe output stages, that's why I left the basic opamp with the possibility of Iout for any tube stage ... likewise, power supplies are not on the PCB because everyone prefers something different ... it is only a purely basic solution of the DAC module with endless expansion possibilities
  Reply With Quote
Old 7th May 2020, 03:18 PM   #10
juancho is online now juancho  United Kingdom
diyAudio Member
 
Join Date: Apr 2005
Location: London, England
Quote:
Originally Posted by miro1360 View Post
there are many different tupe output stages, that's why I left the basic opamp with the possibility of Iout for any tube stage ... likewise, power supplies are not on the PCB because everyone prefers something different ... it is only a purely basic solution of the DAC module with endless expansion possibilities
Fair enough! And thanks for the great work DAC AD1862: Almost THT, I2S input, NOS, R-2R
  Reply With Quote

Reply


DAC AD1862: Almost THT, I2S input, NOS, R-2RHide this!Advertise here!
Thread Tools

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
I2S to AD1862 batteryman Digital Line Level 24 30th November 2018 08:01 AM
FS: AD1862 R2R NOS DAC from diyinhk + miro1360 Swap Meet 2 1st November 2018 07:25 PM
AD1862 balanced Dac batteryman Digital Line Level 0 9th September 2018 02:24 PM
?? on using the AD1862 - jitter and LE input B Cullingford Digital Source 9 28th September 2005 06:08 PM


New To Site? Need Help?

All times are GMT. The time now is 09:32 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Copyright ©1999-2021 diyAudio
Wiki