DAC AD1862

Almost THT, I2S input, NOS, R-2R


Main DACs in my threadAD1862, AD1865

Why?

AD1862 DAC is one of the best analog sounding DACs ever made:
- dynamics is perfect
- zero 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 (D-S) devices with different filters. Sadly the economical D-S crap is trying to convincing regular customers: The more money you spend the better it sounds 🙈
This DAC easily beats many modern delta-sigma DACs from the expensive class, if not all of them 💣

AD1862 is tested by: (is anyone missing?)

AD1865 is tested by:
Vuncerehanabid + updategaszto - customchi0001

What do you need for a working DAC?

  • basic: 
    • I2S device (USB/I2S when the audio source is computer USB (PCM2706 is cheapest, XMOS based is more expensive), or SPDIF/Optical/I2S, or bluetooth/I2S, or SDcard/I2S, ...)
    • DAC
    • PSU (Power supply)
  • advanced:
    • everything from basic
    • custom I/V
    • headphones amplifier
    • reconstruction filter
    • inputs selector
    • ...
  • what about easyDAC (all-in-one AD1862 SMD DAC)?  


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:  #1351 (popular); 2 different I/V opamp packages: DIL08 and SO08; BOM example;
- version with I2S uf.l: #2180
PCB for stacked I2SoverUSB (with PCM uf.l):
- flipped #2545 (untested);
- not-flipped #2546 (tested) - if jlcpcb viewer is not working, enter dimensions manually: 111 x 75 mm
PCB version 2.1 Stop-Clock #3969 (untested)

Some measurements: #3540#3862


How to order PCB from any PCB service? #2602

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

PCB for PSU:
PSU 1: 78xx/79xx - Tested: #1460
PSU 2: LT1963A/LT3015 - Tested: #1461 + values correction2R2 resistors on power rails or #3854

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 - Tested: #2249, correction: DATA and LRCK is swapped #2450, don't use GP1FAV50RK0F as optical input (it is 5V) use alternative for 3.3V (@jimk04 used TORX147)

PCB for USB/SPDIF/Optical to I2S:
Based on PCM2706, WM8804 (low jitter) - Untested: #2247;
version with uf.l connector: 
#2248;
- correction: DATA and LRCK is swapped 
#2450, don't use GP1FAV50RK0F as optical input (it is 5V) use alternative for 3.3V (@jimk04 used TORX147)

PCB for I2S Inputs Selector:
- Tested: #2526 (button needs correction on this PCB - #3210)
- pcb with the button correction - Untested: 
#2909

PCB for lesser known DACs, probably lower sound quality - are cheaper:
PCM56P, AD1860, AD1851, AD1861, AD1856, PCM61P ... one PCB#1477
Tested by: har297mllum


Build notes for AD1862 DAC:

  • 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: 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 (like SD card to 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), best if you 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) - don't populate it, it was meant as a simple RC filter on the output (about 330kHz cut-off frequency)
  • @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, OPA627, THS4031? and much more are discussed in the thread.
AD797 mod from @Hidy: #2687 (can be used for any opamp, try it with yours).

PCB for I/V:
- OPA627 Clone - Untested: #2201


PCB for Post-Filter:
- Sallen-Key Filter - Tested: #2738


Where to find AD1862 chips?

  • AD1862, AD1865 from eBay, aliexpress or other china stores. (mostly used) (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).

  • 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)
  • In old CD players: List ... find out if the chip is soldered or inserted into the socket and get the inserted one
Group buys are taking place in the forum, read new posts and stay updated.
(Rochester stock count: 2021.11.30 - 64083 - $23.15; 2021.12.31 - 63957; 2022.01.31 - 63915; 2022.02.28 - 63884; 2022.05.31 - 63630)

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:
- BOM examples by @flak monkey #3192
- OPA861 I/V output stage PCB by @Vunce (inspired by P. Rogic’s Aya II DAC)) #1417
- nice tube test by @woodturner-fran 
#1850
- tube I/V by @grunf #3611
- 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 and @Decek: #2762
- 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 the post #617; note that the configuration and connection without shift registers is different: #538 #2521 and configuration pins are described in the manual (don't be confused at this point, without shift registers is I2SoverUSB feature, you can still use shift registers with I2SoverUSB in standard I2S configuration) - #2225
- TPS7A regulators mod by @jimk04 #2073
- @Ripster connected I2SoverUSB over the raspberry usb (seems like any USB-I2S can be configured that way) #1373
- @Ripster #3802


Share your experience with other members in the thread, it is helpful.

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