Maybe a wrong pot ? It's easy also to mistake with a resistor marking with all that different values , but I assume you already checked the soldered resistors !
I just fried an expensive usb to I2S board because of a faulty chip on a ready made reg board that certainly fried as well ! So the faulty reg chip is not an idea to give up ! Unfortunately it is hard to source those two LT regs on Mouser or Farnell... as many parts those days due to sillicon supply-chain crisis !
What are the purpose of the // serie diode resistor on this design ? Faulty diode ?
Btw I find odd in the design the last 0,1 uF of the second smoothing main cap as it is shared for all the regs and the capacitance value is lower than each individual pre reg cap (100 uF)... Would it not be better to avoid them and let the 100 uF//0,1 uF before each reg to do the job ? I don't like the idea of a little shared common cap that answer to several different voltage needs. I'm not sure also it is needed for the stability of those regs here but it was maybe a design reflex pf the past when one added 0,1 uF everywhere for stability with the older To220 regs ?
I just fried an expensive usb to I2S board because of a faulty chip on a ready made reg board that certainly fried as well ! So the faulty reg chip is not an idea to give up ! Unfortunately it is hard to source those two LT regs on Mouser or Farnell... as many parts those days due to sillicon supply-chain crisis !
What are the purpose of the // serie diode resistor on this design ? Faulty diode ?
Btw I find odd in the design the last 0,1 uF of the second smoothing main cap as it is shared for all the regs and the capacitance value is lower than each individual pre reg cap (100 uF)... Would it not be better to avoid them and let the 100 uF//0,1 uF before each reg to do the job ? I don't like the idea of a little shared common cap that answer to several different voltage needs. I'm not sure also it is needed for the stability of those regs here but it was maybe a design reflex pf the past when one added 0,1 uF everywhere for stability with the older To220 regs ?
Last edited:
Further to my multi spdif input query I have just taken delivery of this from Aliexpress. Cost me £13 GBP . It has an HC153 'thing' to do the 4 in 1 out. Takes 5vdc.
I wonder if I can adapt some of them to coax inputs.. there are 100R on the 4 inputs so maybe change to 75R for coax.
Untested apart from it powers up ans cycles through the inputs correctly. Comes with a remote and does appear quite nicely made and even in a metal case....no plastic!
I wonder if I can adapt some of them to coax inputs.. there are 100R on the 4 inputs so maybe change to 75R for coax.
Untested apart from it powers up ans cycles through the inputs correctly. Comes with a remote and does appear quite nicely made and even in a metal case....no plastic!
Attachments
Working Mouser cart
Hi,
I just received my boards from OshPark (an effort to support US business) and I am ready to get building. Does anyone have a recently working Mouser or Digikey cart? I'm not lazy, just have been filling BOM's for other projects and the joy has gone from looking for alternates for every 3rd item.
The boards were ordered with 2oz copper and so came as half thickness .6mm boards. With a small amount of effort they could be sharpened to a dangerous level. For anyone else that goes with Osh I would stick to the 1oz copper and be prepared to wait and pay far more than you are used to for production. ~$50 and three weeks plus.
OJG
Pricing for 3 boards
Hi,
I just received my boards from OshPark (an effort to support US business) and I am ready to get building. Does anyone have a recently working Mouser or Digikey cart? I'm not lazy, just have been filling BOM's for other projects and the joy has gone from looking for alternates for every 3rd item.
The boards were ordered with 2oz copper and so came as half thickness .6mm boards. With a small amount of effort they could be sharpened to a dangerous level. For anyone else that goes with Osh I would stick to the 1oz copper and be prepared to wait and pay far more than you are used to for production. ~$50 and three weeks plus.
OJG
Pricing for 3 boards
Attachments
Last edited:
22r in i2s lines
Indeed thin boards.! Nice in ENIG. I applaud your loyalty in keeping it on your home turf but $50 is a bit spendy for me. Well done though.
I have started on the Miro SPDIF board and got the 8804 soldered on last night. Scary but went well when I got the correct tip and technique.!
I proceed with stuffing the R and when I came to the 22R realised I had none. Then I got reading into series resistance in the I2S lines. Seems they are better going near to the point of transmission than at the other end. I already have the 22R on the DAC board so should I omit the 22R on the spdif board.? Or stuff those and jumper the ones on the DAC? I assume we don't want both sets.!
TIA
Indeed thin boards.! Nice in ENIG. I applaud your loyalty in keeping it on your home turf but $50 is a bit spendy for me. Well done though.
I have started on the Miro SPDIF board and got the 8804 soldered on last night. Scary but went well when I got the correct tip and technique.!
I proceed with stuffing the R and when I came to the 22R realised I had none. Then I got reading into series resistance in the I2S lines. Seems they are better going near to the point of transmission than at the other end. I already have the 22R on the DAC board so should I omit the 22R on the spdif board.? Or stuff those and jumper the ones on the DAC? I assume we don't want both sets.!
TIA
Hi,
Super exciting project!
I replaced my Delta-Sigma Dac with R2R Dac (Denafrips Ares II) about year ago. I am supper happy with this Dac. However, having a diy DAC is something that is very hard to resist...
Is there any open group buy for AD1862 chips or anyone can sell two chips (the original ones)?
Thanks!
Super exciting project!
I replaced my Delta-Sigma Dac with R2R Dac (Denafrips Ares II) about year ago. I am supper happy with this Dac. However, having a diy DAC is something that is very hard to resist...
Is there any open group buy for AD1862 chips or anyone can sell two chips (the original ones)?
Thanks!
Hi @Decek, welcome in this thread 
@Paddy Garcia is very helpful with original chips from genuine seller:
New, unused AD1862N and AD1865N-J DAC chips
Going DIY is not easy, but it's fun associated with creation and in this case with magic result
@Paddy Garcia is very helpful with original chips from genuine seller:
New, unused AD1862N and AD1865N-J DAC chips
Going DIY is not easy, but it's fun associated with creation and in this case with magic result
Some work on my 2nd dac build and also the wm8804 spdif input board.
Using some different components than the 1st dac build. We will hear if there is any difference. Using SMR bypasses and 'oscons' on the digital lines. The spdif board is using a pair of Chinese lt3042 boards that I wasn't using and they are supplied via ferrite beads. Polymer hybrids on the output of the regs
More to follow as I progress.
Using some different components than the 1st dac build. We will hear if there is any difference. Using SMR bypasses and 'oscons' on the digital lines. The spdif board is using a pair of Chinese lt3042 boards that I wasn't using and they are supplied via ferrite beads. Polymer hybrids on the output of the regs
More to follow as I progress.
Attachments
@dewdrop Hi Ed, there is not adequate replacement 
Hopefully they'll stock it soon, the pandemic ...
You can consider the PSU1 with #jimk04 mod: https://www.diyaudio.com/forums/dig...862-tht-i2s-input-nos-2r-208.html#post6677715
Or stay simple with 78/79xx regulators for a while. I can't say anything bad about it
Hopefully they'll stock it soon, the pandemic ...You can consider the PSU1 with #jimk04 mod: https://www.diyaudio.com/forums/dig...862-tht-i2s-input-nos-2r-208.html#post6677715
Or stay simple with 78/79xx regulators for a while. I can't say anything bad about it
@dewdrop Hi Ed, there is not adequate replacement
You can consider the PSU1 with #jimk04 mod: https://www.diyaudio.com/forums/dig...862-tht-i2s-input-nos-2r-208.html#post6677715
Or stay simple with 78/79xx regulators for a while. I can't say anything bad about it
Thanks miro. I will just throw in the order and see if they can fulfill before Christmas;-)
@miro1360 as mentioned in my last posts I had enough time last week having 5 days off to populate few more PCBs for PSU.
Finally found out the reasons for erratic behavior of one LT1963 which at startup would show voltage of around 5 volts (give or take) but would drop afterwards to around 2 volts (give or take). PCB in the middle with SMD IN5822 is the one. Other two populated PCBs did not have the same problem they had their own share of minor issues but nothing major like this one. Took me a while but finally found out that one of the via for R2 (adjust to ground was damaged) so fixed that by soldering directly at R1 and ground on the bottom side of the PCB and it has fixed the problem.
So now I have three working PCBs with rest of the two (out of 5) are being populated, not that I would ever need so many DAC board but I can repurpose this PSU for other projects like my version of Turntable Pre Amps like Bugle 2 and Emerald and a few others.
if someone wants to omit the potentiometer and the other resistor ideal R2 value should be around 1050 ohms for LT1963.
@dewdrop you might want to give Aliexpress a try although they are selling both LT1963 and LT3015 in lots of 5 pieces that'd be around $40 odd.
But if you want to go for alternates LM317/337 in SOT223 packing could easily be on the same PCB without much alteration.
Finally found out the reasons for erratic behavior of one LT1963 which at startup would show voltage of around 5 volts (give or take) but would drop afterwards to around 2 volts (give or take). PCB in the middle with SMD IN5822 is the one. Other two populated PCBs did not have the same problem they had their own share of minor issues but nothing major like this one. Took me a while but finally found out that one of the via for R2 (adjust to ground was damaged) so fixed that by soldering directly at R1 and ground on the bottom side of the PCB and it has fixed the problem.
So now I have three working PCBs with rest of the two (out of 5) are being populated, not that I would ever need so many DAC board but I can repurpose this PSU for other projects like my version of Turntable Pre Amps like Bugle 2 and Emerald and a few others.
if someone wants to omit the potentiometer and the other resistor ideal R2 value should be around 1050 ohms for LT1963.
@dewdrop you might want to give Aliexpress a try although they are selling both LT1963 and LT3015 in lots of 5 pieces that'd be around $40 odd.
But if you want to go for alternates LM317/337 in SOT223 packing could easily be on the same PCB without much alteration.
Attachments
Thanks Rehanabid, I am a bit skeptical buying components from Aliexpress as there are fake or quality rejects being sold.
Not too sure when we can get a dud. I will have to wait for Mouser to restock.
Ed
@rehanabid Very interesting story about your DIY
Nice how you fitted the regulator in SMD package
I'm looking forward to what you say about the sound result
Thanks.
Electronics has been a hobby for years and years now, the joys of living in a developing country are multiple and one of them related to my hobby is a choice between reliable parts (read shipping cost and customs despite the fact there is no custom for any product having a declared value of up to $99 DHL/Fedex/UPS etc etc charge handling fee/customs three times shipping cost around $120) and slightly risk parts at reasonable prices from aliexpress/bangood/ebay.
Purchased LT1963/LT3015 from aliexpress and they are available in TO263 packing, for PCB1 and 2 middle one and top one I adjusted the legs to put the regulators vertically which was cumbersome and left little space to change parts (resistors) if needed so for PCB 3 bottom one decided to solder as SMD just had to carefully turn pin 2 and 4 at 90 degrees in relation to the casing with a nose plier. Thus pin 1,3,5 are soldered as surface mount while pin 2 and 4 are through hole.
Anyways, perhaps that's is why many of us still go for DIY way.
I did run come comparative tests (listening only) between different DACs and turntable and OPAMPs for DAC so here goes some of my test.
1) Inter DAC
My old Marantz CD-7 died on me couple of years ago due to its mechanical so I modified it a bit and made it a DAC by putting in an Amanero with upgraded crystals (chrsytek I think) and a circuit based upon 74HCT164 PDIP type. As you might know it has original TDA1541 chip inside.
Second DAC to be tested was Chord Dave.
Third was a chinese known as XMOS X7 from FX Audio it has AK4490EQ as DAC and OPA2604 as OPAMP whihc I had replaced with OPA627 purchased from TI.
Source was FLACs
Taylor Swift (Fearless) purchased from 7digital as 24 bit, Lata Mangeshkar FLAC (an indian legendary singer, personally made from vinyl through AT-LP-120USB), Nazia/Zohaib Hassan FLAC (Pakistani queen and king of POP, personally made from Vinyl), an OPERA FLAC based around Beethoven personally made from Vinyl.
and Fourth DAC was obviously AD1865.
Firstly while Chord is a premium DAC and did cost me serious money so its performance as expected was much better.
XMOS X7 being of chinese origin well its not really too low in performance except for some loss in the low frequency and mid frequencies area.
The real competition was between AD1865 and TDA1541 and frankly I did not find much difference between both of the DACs.
In fact AD1865-NK in my opinion performed better for music and vocals.
Low frequency worked pretty good on both AD1865 and TDA1541 for all the FLACs. for mid frequencies/vocals particularly those of "swift" and "Lata" AD1865 definitely had an edge. For higher frequencies I would (may be I am bit biased) AD1865 performed slightly better. Frankly I couldn't find too much of a difference there.
I did not experience any audible distortion or jitters.
BTW amplifier in all cases was Onkyo 817RX "highly modified by me" with OPAMPs, capacitors, etc. Speakers were "Eminent Technology LFT 8 VIII Hybrid Linear Field Transducer Loudspeaker"
2) Inter OPAMPs with AD1865DAC
OPA627-PDIP
OPA2604-PDIP
AD743-PDIP
AD8610B-MSOP8
I ran out of OPA627 TO99 couple of years back so I only have the PDIP type.
I have omitted the 47Pf capacitor in all the boards for obvious reasons. Supply to all OPAMPs was around 4.98 volts on each rail.
RCAs are gold plated high end, RCA cables are DIY high end type RCA plugs are gold plated while cable did cost me like $15 per foot purchased from Japan personally.
worst offender was AD8610B although its performance in overall audio range was almost at PAR with OPA627 "almost" but after like a minute and a half tends to start producing strange noise in addition to music, which after few tries and re reading the data sheet may be due to less than required voltage. +/-4.97-98 vs +/-5.0 (minimum), additionally the SOIC to PDIP PCB did not have option for soldering 0.1u capacitors, so may be I will have to change the voltages and jury-rig some decoupling capacitors then have a go at it again.
OPA2604/AD743 are good sounding ones both miss out on low end and high end as compared to OPA627. AD743 though was better than OPA2604.
Next on the menu are OPA134, AD8610 and LME49720-TO99 with changed voltages. Since the source was clean and tested I did not experience any visible distortion or jitters.
Laptop for playing music is an old Qosmio X70 with 32 gigs RAM, GTX770M, 2 SSD of 1TB each and VLC.
I did run these test on AD1865NK vs Vinyl as well but results may be later some time since for all the mentioned FLACs I have vinyls as well.
May be will fire up oscilloscope next time to do some additional tests.
