DAC AD1862: Almost THT, I2S input, NOS, R-2R

[namghiwook]

I soldered the AD797 I/V PCBs.

I don't know that this Civ of AD797 I/V is optional like the Civ of miro's AD1862 DAC.

Can I solder a jumper wire instead of Riv of miro's AD1862 DAC for AD797 I/V?

 

[EUVL]

I have written many times.
When you're using the passive IV with AD797 gain stage,
You MUST remove Riv and Civ from the Miro PCB.

Patrick

 

[woodturner-fran]

@namghiwook - message sent.

 

[Vunce]

I soldered the AD797 I/V PCBs....

What is the reason for the glue/silicone substance?

 

[namghiwook]

I made the leads just like the pictures attached.
I glued the leads just for not-loosening and holding tight together

 

[namghiwook]

I have written many times.
When you're using the passive IV with AD797 gain stage,
You MUST remove Riv and Civ from the Miro PCB.

Patrick

@EUVL
Thank you!
Now I see.
Just removing Riv Civ and keeping the state opened.

 

[happylistening]

AD1862, I2SoverUSB v.III - not flipped, 20-Bit uf.l connectors

I2SoverUSB not flipped (pin-headers installed on the bottom side on I2SoverUSB) ... the heatsink and USB connector are on the TOP

Hi Miro,
Using "the not flipped PCB version" and the I2SoverUSB v.III powered-up itself. If only H3-9 to H3-16 connected btw both boards, no-touch on SJ1, SJ2 and SJ3, is it correct?
Thanks

 

[miro1360]

@happylistening "I2SoverUSB v.III powered-up itself" -- I assume you mean powered by a USB cable:
SJ1 - close
SJ2 - close
SJ3 - open
Jumper J4 on I2SoverUSB board - close

If you mean powering by itself as powering from an external power supply (not with USB cable from intergrated regulator on I2SoverUSB board), than as you typed: SJ1, SJ2 and SJ3 is open (no-touch), just the jumper on J4 and the respective power supply for I2SoverUSB board.

 

[happylistening]

Thank You for your shift reply
^______^

 

[Sorenm]

Quick question before starting on the shunts. What current draw do you see from the AD1862 and the shift registers? I found one post mentioning the 5v shift registers draw ~25ma and each ad1862 seems to consume ~15ma judging from the spec sheet.

Cheers -

 

[Sorenm]

required current as a rough estimate with a fine reserve, in the reality it is less:
+-200mA for analog (+12V/200mA, -12V/200mA)
+-100mA for digital (+5V/100mA, -5V/100mA)

I found these numbers in post #234. The seem a bit high but maybe a good start.

 

[Vunce]

Hi @Sorenm,

A while ago I checked the current draw of Miro's AD1862 DAC board loaded with OPA1611 and Burson discrete opamps.

With OPA1611 opamps installed:
+12V = 22mA
-12V = 30mA

Burson V6 Classic opamps:
+12V = 40mA
-12V = 48 mA

5v supply @idle/active signal:
+5V = 5mA/22mA
-5V = 3.3mA/3.3mA

 

[Sorenm]

Thank you @Vunce !!!

 

[danny92]

5v supply @idle/active signal:
+5V = 5mA/22mA
-5V = 3.3mA/3.3mA

The current draw is much higher in the +5V supply for an active signal and in the -5V supply it remains unchanged, any ideas why this happens?

 

[NIXIE62]

Shift registers?

 

[danny92]

They draw all that current, WOW, from the datasheet it seems much less.
At which frequency were the tests performed?

 

[Sorenm]

I got PCBs in hand and am looking to order parts. Has anyone identified upgrades for the caps on the DAC side of the board (ad1862)? I saw one person substituted the ceramic and polypropylene caps with SMDs.

Cheers, Soren

 

[Sorenm]

Particularly curious about the C1-C6 0.1uf ceramic caps and the C9/10/13/14/19/20/23/24 0.1uf PP caps.

 

[zoom777]

@Sorenm , you have 5 boards. Do two or three boards to try out and listen.., 😜🤣

 

[Brijac]

I got PCBs in hand and am looking to order parts. Has anyone identified upgrades for the caps on the DAC side of the board (ad1862)? I saw one person substituted the ceramic and polypropylene caps with SMDs.

Cheers, Soren

If you substitute, go for c0g (np0) ceramic, or go for rubycon MU capacitors. But as zoom said, make it first, then mod