SD Card Memory FLAC/WAV 192/24 player - ESS crescendo II - AK4495 - DV20A

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I leave the DAC board at peace for now :) I ordered a new TCXO oscillator after identifying the 27mHz oscillator on the I/O board. It's one i used before and it has it's own powersupply.
I used coax cable from a wireless antenna to connect it to the board. Removing the old one was easy, just heat up the the whole oscillator.
Almost always a nice upgrade ! Even the LCD creen looks sharper(?) and the ghosting in the TFT got less.

CD player high stability clock buffer module low noise power (no TCXO included) | eBay
 

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Now i'm going to try to tune up the powersupply from the I/O board.
Too bad that there is no real information about the main chip, the ESS Crescendo 2.

The rectifier is made of Schottky SB850 diodes, The 3x1500uF elco's are Panasonic FL ?
I can only find them on ebay, old stock perhaps. Changed them for FM types.
First regulator is a heatsinked LM350 which provides the current of almost 1A.
After that the 5V output goes to 3 LM317's and to the front display.
At that junction is again one 1500uF FL cap, changed it for 2 1500uF FM types.

The only thing that i can do is change the LM350 for a TPS7A4701 reg, it should provide the needed current.
On of the 3 LM317's is heatsinked and get's an input of 3.5 V, the 5V main voltage is lowered using 2 diodes in serie. Is it helpful to use caps over the diodes to bring down the noise ?
 

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The series diodes works well to keep the noise down, it’s when you only have one that it could be an issue.

Project looks like a rewarding one!
I have a somewhat similar project that uses an ak4495 dac board, a “lossless turntable” SD card player, and a headphone amp all in one case. Am going through making improvements where possible much as you are.
 
Yes, i like this tuning very much and nice that you're working on someting similair.
Hopefully your I/O chip is an AK brand one.

ESS is hushhush about chipinfo, so i have to guess which regulator to change. The 2 LM317's have a output of 3,3V, the sinked one 1,475V. I think about changing that one.

The stock I2S cable is 15cm long and i'm gonna use shorter coax instead.
Still waiting for amps from China, it's free shipping but 3 weeks is al long time !

HIFI Fever OP03 Full Discrete Component Field Effect Input Dual Op Amp Module | eBay

MUSES02 dual op amp JRC new Japanese flagship high fidelity HIFI | eBay
 
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I don’t want to muddy up this thread with too many particular details regarding my Frankenstein apparatus, but will comment on common features or modifications that are shared.
As far as power supplies go, one that I wanted to use for the sd player portion was a lt3042 board from ebay that was pretty reasonable, mine never functioned and I haven’t gotten another. Others have had them work successfully, there’s both single and dual versions.

Dual Way LT3042 Linear Regulator Power Supply Board DC Converter Pre-amplifier | eBay

I did have good luck with larger VREF caps on my ak4495,
(2PCS) 4700UF 16V PANASONIC X-PRO ELECTROLYTIC CAPACITORS 16V4700UF AUDIO | eBay

I am interested in that discrete op amp you have coming, I am using one like this, is also get input. I tried a bipolar input Burson IV, from another setup, and it didn’t work well there.
OPM2401 MK2s DUAL Offset Adj AUDIOFEEL DISCRETE OP-AMP Some as a OPA2301 | eBay

I have had good results with using Nichicon LF, in a 47uf size around the various digital circuits, and clocks. Any larger size and the lower impedance will likely create a resonance.
Mounting them directly to the ends of the smd decoupling ceramic parts works to keep the inductance down in between the parts, lower the chance of a resonance.

Snubbers on the rectifier diodes helped too, was inexpensive, and there wasn’t much in the way on that portion of the board(s).
 
Looks like the LT3042 is the new king in town :)

Last mods i did make was to change the I2S flatcable into 7cm long coax.
Isolated the chassis from the powersupply ground.
I got rid of the TP regulator and use only 2 TPS7A4701 for AVDD /DVDD.
Now i'm just waiting impatiently for those opamps from China.
 

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I just received the Muses02, indeed a good sounding upgrade over the stock 8820 type.

Those are Hans his posts and yes they are for zeroing the offset, my DAc has only about 15mV output, so i'm not going to change that.

Funny that you asked about the clock upgrade, i've just finished a positive Ebay review to rate the product. It does what a good clock upgrade has to do : a more refined, stable sounding dac. Easy to implement.

Did it before with a cd chassis :)

p.s. i don't know if the seller likes my added pictures because i replaced almost all the stock caps.
 

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Glad the muse parts worked out, the auction sites can be a little hit and miss.
The reason I asked about the clock board was because I had a similar board that made no difference in the sound of a dac I was working on. The usb receiver that it was supplying, died just a few days afterwards, so I abandoned the clock board the next time around...

Funny about the cap replacements; what do they expect when thy make decent stuff and then put the rot-gut caps on there?
 
The Muses02 is better than the 8820, but the discrete opamp beats them both. I'm almost satisfied with the sound performance.
The music can still be a bit too bright, i've changed some of the filtercaps into polystyrene caps and replaced the neighbouring smd resistors to Dale-Vishay rn55d.

Those resistors are hard to find in Europe if you want hem for a fair price, here's one :)
40x Dale Resistor (RN60C/RN60D) 1% Customerized Values | eBay

Bought 2 Amtrans AMCH capacitors for the filter to see if that helps.
Amtrans AMCH | Hifi Collective

I use ETI rca connectors but these are very expensive, i found a "copycat"on Ebay that looks really well. Should have known that earlier.

Star Line Tellurium Copper RCA Plugs connectors 2 Pair 4pcs interconnect cable | eBay

Yes, fake IC's, resistors, caps, etc. Some oriental Manufacturers use everything from everywhere. But it's a sport to locate and replace those parts.
The clock board seller didn't place my pictures ;)
 

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At first i thought that this dac would be a funny sidekick for my TP dac, which is filled with shunt regulators. Slowly that idea changed, i now like this Chinese dac to be almost as good as the other one. I installed a Salas Reflektor-d mini for DVDD /AVDD at 3.3V, what a huge positive difference over the other low-drop regulators. Good !:worship:
I 'm trying to squeeze one more in this tiny chassis.

Other things i changed : removed the brass 8 pin holder for the opamp, on the motherboard and the discrete opamp. Removed all smd resistors for leaded Dale/Vishay rn55 and all filter caps are now Amtrans AMCH type.

Adjusted the output gain :
Finally Weiliang released ak4495+ak4118 dac today.
 

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Nice setup, thanks for the picture.
I have likely smoked the 4118 chip while attempting a clock swap on my card player board, it was easier to replace the board than try and repair it for now.
The replacement board has a better clock or something that is allowing it to remain in signal lock more than the first board. It sounds much better too. A simple cap swap has cleared up a nasty sound, and all is good.

If you removed your discrete op amp, what are you now using for an I/V filter?

If you can fit it in, a ferrite, X-cap on the incoming a/c makes difference too, when you are to the level that you are.
 
I wasn't very clear in my writing, i removed both 8pin sockets, the one on the motherboard and the one underneath the dicrete opamp. Soldered the opamp directly onto the main board. You mean the AK4118 controller chip ? On which thread are you active, so i can see your DAC.

thanks, Erik.
 
Hi again, I did put a picture somewhere, but here is the entire setup, dac is off in the corner with the three filter capacitors...
Someday when I want a more involved repair project, and I have the hot air tools, then I may try something. Just glad it’s working again.
 

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So how do you like the discrete op amp that is now soldered in?
Was there a noticeable difference after the solder connections?

I’ve never soldered an op amp for two reasons, either the ic type I never could decided if it sounded great, or the discrete types were so large that I didn’t want to risk damage after hard mounting. Have wondered if it would sound better however...
 
Hmm, i changed too many things at once, so i don't know what the influence might be.
It's just soldering gives the best connection and brass (8 pin socket) does sound harsh.

Tomorrow i ill find out where to use the second Reflektor reg, split up the supply for AVDD/DVDD into 2 Reflektors, or just use one there and the other one for VREF/VDD.
1 Reflektor sounds much better on AVDD/DVDD than 2 TPS7A4701 reg's. FINALE :)
 
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I did always wonder what the rationale was in the akm suggested circuit that had both avdd and dvdd together, and how the high numbers they attained don’t necessarily translate entirely to the way it sounds.

That must sound pretty good there I can imagine.

Have you tried any film/foil capacitors in the dac output filter(around the op amp)?

My favorites are the Wima MKP2, or the EMZ or Seimens KS polystyrene, in pf values.
 
I’m not familiar with that Panasonic capacitor, is it a metalised type do you know?

I’ve had good results with Nichicon LF for digital supplies, however they can interact badly with tiny ceramic decoupling caps if they are too close together. Also to limit the size of the Nichicon to 47uf helps to keep the esr a bit higher than the larger sizes.
 
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