Build thread for ES9023 + JG Buffer boards (betatest)

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Jump to Latest
C

curryman

Member
Joined 2010
Paid Member
milosz said:
I'm building a USB-input / Curryman DAC into a Beta 22 headphone amp, just for fun.

I am now come to the part of the build where I want to lash up the DAC stuff, see if I can get it to work. I have an Amanero USB=> I2S board and one of the Curryman DAC boards from MiniDSP. I have spent the evening reading about isolating the USB side from the DAC side, which implies an isolator between the Amanero board and the Curryman DAC on the I2S lines.

Many agree that IN THEORY isolation here is a good thing, but the only measurements I've been able to find are ambiguous as to the value of this isolation. ( https://hifiduino.wordpress.com/2012/04/01/experiments-with-nve-il715-isolator/)

In addition, I can't find a simple little I2S isolator board out there for sale... I'm too old and feeble to try hand- SMD soldering some tiny little chip into some kind of homebrew perfboard, so really I NEED something to buy...

OR - just do without isolation.

Anyone have any experience using the I2S outputs from the Amanero board directly into the Curryman DAC? Daniel... your thoughts would be welcome.

I read through this whole thread and found some people using the ACKO LABS isolator / clock board which isn't available any more, but no real answer to the question "do you need an isolator between Amanero USB and I2S of Curryman DAC" etc....
Click to expand...

Hello Milosz,

quite difficult to give a general answer :eek:

As you already mentioned theoretically it is a good thing to isolate however as per the datasheet of those isolators you will probably end up with increased jitter. On the other hand the ESS DACs are quite good at suppressing incomming jitter (ASRC). Problem is that AFAIK in the DIY comunity no one is really able to precicely measure and analyze jitter and it's influence on the audio signal. As a consequence its all hear say and subjective impressions. It will probably also strongly depend on the source and the ground noise it is emitting.

I am using the curryman DAC connected to the Amanero through an isolator (TI ISO7640) using the one of the free boards from DIYinHK. Friends of mine are using this combination without isolator which works fine too. I did not perform comprehensive comparisons of this same setup with and without isolator so I can't give you a definite recommendation, sorry. My personal feeling is that if you need to isolate (read, you know that you have a ground noise problem) and want to have lowest possible jitter then you should go with a FIFO. OTOH it's a 40$ DAC ;)

kind regards, Daniel
 
M

milosz

Member
Joined 2006
Many thanks!

Yeah I am unlikely to be able to solder the parts to that board from HK. I'll skip the isolator.

There are USB isolators available for about $15. They limit the speed of transfer - not sure if it's limited to the 1.5 Mbps of USB 1.0 or if it goes to the 12 Mbps of USB 1.1, but for sure I've never seen one that does USB 2.0 (480 Mbps.) Whatever spped is possible through them, they are fast enough for Red Book 44.1/16, I know that is true because I have used one of these isolators to eliminate a ground loop, and it worked fine on 44.1 / 16 .
 
S

svadim79

Member
Joined 2016
Hello, I know the discussion is very old but I want to show you my interpretation of curryman dac:


Input I2S from POPCORN HOUR TRASFORMER
Philips BC capacitors (9x4700uF)
Panasonic FC, Sanyo Oscon and Nichicon FW audio dedicated electrolytic capacitors
3xLT1963AEQ (Linear Technology's ultra-low ripple LDO power regulator IC) HiFi Power Supply ±13.2V, 5V Output
1A Low noise toroidal transformer
2x10MH Common mode inductors 25A max EMI high frequency large current power filter
(the internal circuit of the two-stage filtering, the effect of filtering out noise is better)

Sound is good but not so good :-( my SONY SCD-XB940 is the best.

e011dabe3ac5.jpg


6cbec2dfc9ef.jpg


e4fa26bebadf.jpg


0fcf37409b3d.jpg


50f9395e2e5b.jpg


I think about little upgrade: nichicon or elna capacitors for analog and maybe sanyo oscon in digital... any opinions?
 
Last edited:
S

svadim79

Member
Joined 2016
doctormord said:
I miss the point where the whole enclosure is connected to earth for safety.

What do you mean by "good but not so good"? Does it hum, is it distorted? The EMI want help in the enclosures for the, in my opinion, way to long cable connections. Rolling caps won't change the situation at all.
Click to expand...


In Lithuania not all flats and houses have ground contact on ac 220v socket, I don't need connect case on ground. Dac sound is very clean and powerfull but my sony have more air and details...
 
C

curryman

Member
Joined 2010
Paid Member
Nice build :)



I am wondering if I2S is the ideal interface in this case. How long is your interconnect cable between the cases? Also grounding may seriously influence the signal transmission.

And I second the recommendation (necessity) to connect the enclosure to protective earth, even if some houses do not provide protective earth.


best regards, Daniel
 
S

svadim79

Member
Joined 2016
I2s wire is 30cm
Аs if I did not want to say this, but a simple board from the audiophonics for 15 euros + switching power supply unit plays just like your curryman dac with a EMI filter + toroidal transformer + LDO stabilizer.
Compared sound on a serious set of AVM
I tried as spdif AK4118 and DIR9001, I like dir more…
I want cry that so much money, work and time is spent in nowhere…
 
C

coolnose

Member
Joined 2009
V+/Gd/V- wiring mistake...

Dear all,

I recently rewired my Dacs when redoing the enclosure and of course I accidently inverted my PSU Ground with the V- and hooked it up...

After realising my stake I switched the supplies but the DACS remain silent...

Any suggestions to start troubleshooting those ? I understand I might have fried the Jfets as they are using the symmetric supply...

Thanks in advance,

Max
 
C

curryman

Member
Joined 2010
Paid Member
Hi Max,


I still have some fully assembled curryman DACs (last stock from miniDSP) here, so contact me if you don't want to fiddle with the JFETs.



I also might have some BF862, but probably not the other JFETs (need to check).


Good advice to check the ES9023 output first.


BR, Daniel
 
C

coolnose

Member
Joined 2009
Daniel,

thanks for your kind offer, I don't mind "playing" with it a little while, but certainly not too much... so I'll get in touch with through PM.

Is there a link to final schematics/parts placement for the DAC/PCB ?

Are the output pins situated between the DAC-chip and the close to output coils the direct DAC out ?

Danke,

Max

EDIT: Found the schematics in the "other", i.e. commercial thread, outputs right close to C41/C51 are indeed the direct out from the DAC OPA, will check later today what it says...
 
Last edited:
E

enjoybiking

Member
Joined 2011
maybe the Micrel regulator took a hit too, cut off the buffer connections, see if you have the DC V's yet... I have all that stuff in a tub somewhere. Parts. 100+ Es9023 chips, lots of regulators, like 700+. and the FETS probably too. I would have to dig but I think I have it all.



jFETS are going end of lifed very often these days. I was buying them 100+ at a time so should have.



If I can find you the parts it would save you some grief. Daniel's offer for new boards is also pretty handy for you.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Top Bottom