DAC AD1862 and similiar NOS R2R DACs

DAC AD1862

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

Basic instructions for the cheapest AD1862 DAC:
1. DAC: version with the universal I2S input #1 (you can install some or all capacitors from the bottom and have more space for a discrete I/V #339)
2. I2S: cheapest USB-I2S source based on the PCM2706 from aliexpress
3. PSU: PSU 1 Eco #6025
4. another construction material (case, connectors, wires, switch, led, ...)

Main (and best) DACs in my threadAD1862, AD1865, PCM63, TDA1541A, TDA1540

AD1862 DAC (without common digital filter) 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 💣

What do you need for a working DAC?

  • basic: 
    • I2S device (USB-to-I2S when the audio source is computer USB (PCM2706 is cheapest, XMOS based is more expensive and maybe better), or SPDIF/Optical-to-I2S, or bluetooth-to-I2S, or SDcard-to-I2S, ...) - cheapest option: buy it ready-made
    • DAC
    • PSU (Power supply)
  • advanced:
    • everything from basic
    • custom I/V
    • headphones amplifier
    • reconstruction filter (probably useless for AD1862/5 or PCM63P)
    • inputs selector (the best is with relay switch)
    • ...

How to order PCB from any PCB service? #2602


# PCB for AD1862:
- version with the universal I2S input: 
#1, (#2180) (I2S GND pin 8 is disconnected, either use another I2S GND pin or bridge it with GND pin 7 from the bottom)
- version without I/V: #7031

- version PCB for stacked I2SoverUSB: #2546 - if the jlcpcb viewer is not working, enter dimensions manually: 111 x 75 mm; configuration for new I2SoverUSB board? #7297; newest I2SoverUSB: #7326

Some measurements: #3540#3862

# PCB for AD1865:
PCB for download: #1431 

#PCB for PCM63P:
PCB for download - #4167, updated PCB: #6563
do not install capacitors C43, C44

#PCB for TDA1541A:
PCB for DAC: #5356
PCB for PSU: #5358
PCB for DC Protection: #5697
do not install capacitors CF1, CF2

#PCB for TDA1540:
PCB for DAC: #6176
PCB for PSU: #6177
Tutorial for I2S to TDA1540 converter: I2S-TDA1540

#PCB for PCM58P:
PCB for download - #4639 + update #6244 ... Tested by: chi0001
do not install capacitors C43, C44

# PCB for PCM1702P:
PCB for download: #4101 (use only with 74HCT164D shift registers)
Note 1: It is hard to obtain a working and not damaged PCM1702 chip
Note 2: I2S GND pin 8 is disconnected, either use another I2S GND pin or bridge it with pin 7 from the bottom: #6861

# PCB for lesser known DACs, probably lower sound quality - are cheaper:
PCM56P, AD1860, AD1851, AD1861, AD1856, PCM61P ... one PCB#1477
Tested by: har297mllumtwitchie


PCB for PSU:
PSU 1 Eco: #6025
PSU 1: 78xx/79xx - Tested: #1460
PSU 2: LT1963A/LT3015 - Tested: #1461 + values correction2R2 resistors on power rails or #3854

Input source:

PCB for USB-I2S:
(Cheapest solution based on PCM2706 from aliexpress)
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: 
- 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: 

PCB for I2S to Simultaneous for TDA1541A: #5379 (not needed for TDA1541A DAC by miro1360 because it is integrated, but it allows you to add the NOS mod to your existing TDA1541A DAC or Player and bypass digital filter ... now you will have I2S input where you can connect almost any source, included USB or Bluetooth).

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 the 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
  • input I2S: standard I2S (64fs) ... there are many ready-made devices: USB-I2S (PCM2706, XMOS, ...), RPi-I2S, bluetooth-I2S ?, spdif-I2S (WM8804/5, DIR9001), optical-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 are not installed for normal operation ... 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 is not installed for normal operation ... if installed, it should be a C0G type ... or use polypropylene (PP) THT cap
  • C37, C38 (PP or C0G type) - is not installed for normal operation ... it was meant as a simple RC filter on the output (about 330kHz cut-off frequency), but do not install it
  • @Vunce suggested the great inspiration to install some capacitors from the bottom. You can achieve 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


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, AD797, THS4031? and much more are discussed in the thread (like SS3601).
AD797 mod from @Hidy: #2687 (can be used for any opamp, try it with yours)
Opa1656 (opa1655 without adapter)

PCB for I/V:
- OPA627 Discrete clone: PCB: #6427 (note: There is small error on the PCB - Vout GND pin is disconnected - please scratch the mask near the pin and solder disconnected pin with exposed GND)
- custom I/V by @Vunce: #7261#7343
- tube I/V by @grunf #3611#4802

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


TPA6120 Headphone Amplifier: #7040

Where to find the 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)
    - try order in digikey (during checkout fill the personal order form, maybe for repair purpose)
  • 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; 2022.07.31 - 63529; 2022.10.31 - 63443; 2023.02.01 - 63028; 2023.05.01 - 62618; 2023.09.13 - 62212 - price up $26.34)

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:
- bigger heatsink for I2SoverUSB: #7218
- BOM examples by @flak monkey #3192
- connectors by @Vunce #4022
- SD Card player by @woodturner-fran #4380
- OPA861 I/V output stage PCB by @Vunce (inspired by P. Rogic’s Aya II DAC)) #1417
- nice tube test by @woodturner-fran 
- tube I/V by @grunf #3611#4802
- 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 #2225 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)
- arduino OLED sampling frequency indicator from LRCK signal: #7388 #7389

- TPS7A regulators mod by @jimk04 #2073
- @Ripster connected I2SoverUSB over the raspberry usb (seems like any USB-I2S can be configured that way - it is better than raspberry directly) #1373
- @Ripster #3802

Other PCBs:
- AD1862 jlcpcb minimalistic version by @mallikreddyk: #6169

My CPLD converters (VHDL code) tutorials:
- I2S to TDA1540 CPLD converter
- I2S to TDA1541A CPLD converter
- I2S to D20400 CPLD converter
- I2S to PCM CPLD converter (all DACs like: PCM56, AD1851, AD1856, AD1865, PCM58, PCM61, AD1860, AD1864, AD1862, PCM63, PCM1702, PCM1704)

Thermionic Valve Analogue Stages for Digital Audio
PSU comparison Battle of power supply regulators with listening tests

PCM63P is built by:

TDA1540 is built by:

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

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