[penguin69]

A​bsolutely fab - thanks as ever, b0bb. I'll get these ordered tomorrow.
 
I miss my RPi's somewhat. My software skills exceed my electronic skills (not difficult), so I had great fun with the Pi: I remember creating a scrolling LCD music track display, which was quite cool so long as you were able to ignore all the wires hanging off the GPIO!

 

[abartels]

http://twistedpearaudio.com/digital/cronus.aspx

 

HI again b0bb,

I found the Accutek adaptors, but the company don't appear to have an online store - did you source yours from them by e-mail?

The Twisted Pear Audio site shows no sign of xo adaptors (unless I'm missing something).

http://twistedpearaudio.com/landing.aspx​

Sorry to be a pain. I thought it might be somewhat easier to source these items. Are there so few DIY'ers out there?

On a separate note, do you have a preferred front end for your LKS? I used a Raspberry Pi with MPD for about 3 years, running the USB out into a cheap PCM2704 converter and then optical into my old DAC (another older EE Minimax). I loved the fact it could play lossless with just 2% CPU usage, and I could leave it running for months without crashing. I recently switched to a Mac Mini for ease of use with Tidal, and so the connectivity is now via USB. For some reason I miss Toslink; I always found it sounded great despite the reported jitter issues with Toslink tranceivers. 

Contact Accutek directly, the boards are made to order, takes about 2 weeks.

The part is 4 Pin SOJ Crystal to 4 Pin(14 Pin Full Size) 300 MIL DIP AK14D300-XTAL-04SOJ



Twisted Pear's adapter is the Rhea, scroll down towards the end of the page
http://twistedpearaudio.com/digital/cronus.aspx

I use the Logitech Music server (LMS) and Squeezelite combo.
Squeezelite is run on the Raspberry Pi2 (Picoreplayer)  and  Odroid C1+ (Max2Play)

Rpi2s on the left  Odroid C1+ on the right, Odroid has the benefit on not sharing the USB with the ethernet, sound quality especially imaging is considerably better

Hi b0bb,

Not using I2S-out anymore? All connected with USB?

Btw, did you order your Pulsar 100mHz directly from Italy? Can you share the pricelevel of those?


Regards,
Alex

 

[b0bb]

Hi b0bb,

Not using I2S-out anymore? All connected with USB?

Btw, did you order your Pulsar 100mHz directly from Italy? Can you share the pricelevel of those?


Regards,
Alex

I use I2S for my Soekris R2R dac, these 3 are for my USB DACs (LKS, Schitt Yggdrasil and Esoteric D500/Breeze USB)

The LKS I2S input lacks the noise filtering, its USB is galvanically isolated and much nicer.

The Pulsar came directly from Italy, there were no discounts, about 400USD shipped.

 

[abartels]

Hi b0bb,

Not using I2S-out anymore? All connected with USB?

Btw, did you order your Pulsar 100mHz directly from Italy? Can you share the pricelevel of those?


Regards,
Alex

I use I2S for my Soekris R2R dac, these 3 are for my USB DACs (LKS, Schitt Yggdrasil and Esoteric D500/Breeze USB)

The LKS I2S input lacks the noise filtering, its USB is galvanically isolated and much nicer.

The Pulsar came directly from Italy, there were no discounts, about 400USD shipped.

What kind of Noise filtering, related to I2S, are you talking about?
Pulsar's are great, suppose you received them taxfree, those are about €450 in Europe Need two pieces for my FIFO set, maybe a (very) nice Xmas present to myself

 

[penguin69]

  The 14pin socket can be soldered using a conventional iron, post a picture of the area of the XO where the white wire is soldered in to be absolutely sure.
You will need an adaptor for the SMT crystals like the CCHD950. Twisted pear make them.
 
The one in the pictures below is made by Accutek Micro.

 

 
 
...
 
Pulsar is the top of the line XO for the LKS and the price is correct, Crystek 950 is a sane starting point.

 
Hi,
 
My Crystek 950 delivery has arrived - just waiting on the adapter board deliveries now.
 
I notice that the Crystek XO has no pins. I'm a little worred that, because of the lack of pins, it may be a little harder to solder the XO to the Twisted Pear adapter board, and as a ham-fisted neophyte I could easily cook the XO. Any tips here? Solder at as low a temperature as possible, with minimum contact time, perhaps.
 
A second challenge is that one of the 4 gold-coloured 'washers' on the LKS board has come away after I de-soldered the cable modification (see picture below of the cable before removal). I assume it is ok to solder instead to the inner raised contact to its left? This makes life a little harder when it comes to using the 14 pin reusable adapter, but I figure it's a price worth paying as I don't fancy my chances of getting the washer repair correct.
 
Or maybe I can attempt the repair, and if the DAC returns silence (i.e. XO not working), then I should try soldering to the raised contact ...
 
As an aside, I have left the lower cable in situ for the time being, I am guessing it is just drawing power for the XO modification board in the bottom right of the pic.
 

 

[penguin69]

And, looking at the traces in the diagram above and in relation to the Crystek datasheet, it seems to me that:
 
- Top Right contact is the XO OUT, running to the resistors above and then to what I assume is Pin 24 (XI) on each ES9018.
- Bottom Right contact is GND.
- Top Left contact is 3.3v supply.
- Bottom Left contact not used?
 
(sorry if my terminology is rubbish.)

 

[b0bb]

What kind of Noise filtering, related to I2S, are you talking about?
Pulsar's are great, suppose you received them taxfree, those are about €450 in Europe

Need two pieces for my FIFO set, maybe a (very) nice Xmas present to myself

 
Ceramic feedthru caps on the I2S lines, this limits the rise-time of the pulses reducing RF noise. CF3-CF8 on the example diagram.
 

 
 
You can just buy one Pulsar first and see if you like it, suggest the clock for the 44.1kHz stream as it is more common.

 

[b0bb]

 
And, looking at the traces in the diagram above and in relation to the Crystek datasheet, it seems to me that:
 
- Top Right contact is the XO OUT, running to the resistors above and then to what I assume is Pin 24 (XI) on each ES9018.
- Bottom Right contact is GND.
- Top Left contact is 3.3v supply.
- Bottom Left contact not used?
 
(sorry if my terminology is rubbish.)

That looks right.

 

[b0bb]

   
Hi,
 
My Crystek 950 delivery has arrived - just waiting on the adapter board deliveries now.
 
I notice that the Crystek XO has no pins. I'm a little worred that, because of the lack of pins, it may be a little harder to solder the XO to the Twisted Pear adapter board, and as a ham-fisted neophyte I could easily cook the XO. Any tips here? Solder at as low a temperature as possible, with minimum contact time, perhaps.
 
A second challenge is that one of the 4 gold-coloured 'washers' on the LKS board has come away after I de-soldered the cable modification (see picture below of the cable before removal). I assume it is ok to solder instead to the inner raised contact to its left? This makes life a little harder when it comes to using the 14 pin reusable adapter, but I figure it's a price worth paying as I don't fancy my chances of getting the washer repair correct.
 
Or maybe I can attempt the repair, and if the DAC returns silence (i.e. XO not working), then I should try soldering to the raised contact ...
 
As an aside, I have left the lower cable in situ for the time being, I am guessing it is just drawing power for the XO modification board in the bottom right of the pic.
 

 
Leave the cable in place.
 
The washer (proper name pcb land) can be easily fixed, repair kits are available, example below is about 33USD.
http://www.all-spec.com/Catalog/Soldering-Rework/PCB-Board-Assembly-and-Repair/Circuit-Board-Assembly-Repair-Kits/CP090100AS-10123#

 
To avoid future overheating problems preheat the board first and use a fine tip iron.
Low cost hot-air wands is the tool of choice.
http://yihua-soldering.com/product-3-3-4-hot-air-rework-station.html/158746
 

 
Use the same method for the XO, tape down the XO to the adapter and warm it up, use heat resistant tape like kapton (the transparent golden tape around my Pulsar XO)
 
Apply rosin flux to both the XO and adaptor PCB lands, the  soldering operation should only take 1-2 seconds if the XO and board is adequately warmed up.
I use an air temp setting of 120-125 degC.
 
NOTE: The wand must always be constantly moving across the work piece to avoid hotspots.
 
MG chemicals makes a good Rosin flux pen
http://www.all-spec.com/Catalog/Soldering-Rework/Soldering-Chemicals/Flux-Pens/835P-1695?gclid=CLn13JL-g88CFQVbfgodtLYCeA

 

[abartels]

 

What kind of Noise filtering, related to I2S, are you talking about?
Pulsar's are great, suppose you received them taxfree, those are about €450 in Europe

Need two pieces for my FIFO set, maybe a (very) nice Xmas present to myself

 
Ceramic feedthru caps on the I2S lines, this limits the rise-time of the pulses reducing RF noise. CF3-CF8 on the example diagram.
 

 
 
You can just buy one Pulsar first and see if you like it, suggest the clock for the 44.1kHz stream as it is more common.

 
Thanks for clarification b0bb, not sure if my dac pcb uses these murata emi rfi smd filters, it's probably wise to inspect, and if not in-designed, trying to modify circuitry with them.
 
The pulsar's aren't available right now in the frequencies I need, btw, I still can use 45.1584 mHz and  49.152 mHz tcxo's instead of 22.5792 mHz and 24.576 mHz inspite of the table showed in AK4495SEQ datasheet!
This is very strange.... I tested sample frequencies up to 768 kHz and they all work flawlessly. Strange they mention this in their white papers

 

[penguin69]

   
Leave the cable in place.
 
The washer (proper name pcb land) can be easily fixed, repair kits are available, example below is about 33USD.
http://www.all-spec.com/Catalog/Soldering-Rework/PCB-Board-Assembly-and-Repair/Circuit-Board-Assembly-Repair-Kits/CP090100AS-10123#
 
 
To avoid future overheating problems preheat the board first and use a fine tip iron.
Low cost hot-air wands is the tool of choice.
http://yihua-soldering.com/product-3-3-4-hot-air-rework-station.html/158746
 

 
Use the same method for the XO, tape down the XO to the adapter and warm it up, use heat resistant tape like kapton (the transparent golden tape around my Pulsar XO)
 
Apply rosin flux to both the XO and adaptor PCB lands, the  soldering operation should only take 1-2 seconds if the XO and board is adequately warmed up.
I use an air temp setting of 120-125 degC.
 
NOTE: The wand must always be constantly moving across the work piece to avoid hotspots.
 
MG chemicals makes a good Rosin flux pen
http://www.all-spec.com/Catalog/Soldering-Rework/Soldering-Chemicals/Flux-Pens/835P-1695?gclid=CLn13JL-g88CFQVbfgodtLYCeA
 

 
Many thanks as ever, b0bb.
 
As it happens, I already ordered an air-wand very similar to the one above, it arrived a couple of days ago. The instruction manual is appalling but the tool itself looks good and is mostly intuitive.
 
I will order the Rosin flux pen.
 
I got impatient and connected the Crystek XO to the LKS using some bread-board jumper leads (sub-optimal of course, but I wanted to get started). The LKS Audio DAC is now listenable, even in this configuration. Previously, I could not listen to the DAC at all without becoming irritated with the seemingly brittle, jittery sound.
 
Tomorrow I may try taking the regulated voltage supply from that small aftermarket board I showed in the picture rather than the PCB rail, to see if there is any difference. If this helps, then for the final configuration I will consider connecting 2 of the XO pins, OUT and GND, directly to the board (via the TwistedPear adapter) but take the voltage supply from the aftermarket regulator board.
 
If this all goes to plan and I don't screw anything up, then I will be interested to try out some other XO's. The Pulsar is the end game, assuming that it is within my capabilities to use it.
 
For the record, I bought 2 Crystek 950's, just in case I fry or irretrievably damage one of them!
 
I'm actually a little bit surprised that the Crystek works with the jumper leads, given they are about 3 inches long.

 

[b0bb]

   
I'm actually a little bit surprised that the Crystek works with the jumper leads, given they are about 3 inches long.

That is OK during the process of bring-up, to get the max performance (lowest jitter etc) it needs to be as close to the DAC as possible.
 
You have an radio transmitting antenna there, the XO operating at 100MHz is just below the top of the FM radio band (108MHz), keep an eye on the radio interference.

 

[penguin69]

No updates from me so far as I am still waiting on parts to arrive. Once the Twisted Pear adapter board arrives I will install the new clock properly.
 
On a clock-related note, is there a preferred DPLL setting of the nine on offer? I currently have AUTO as the setting. FWIW, I listen mostly to Tidal and my own 44.1 redbook rips (.wav).

 

[b0bb]

  On a clock-related note, is there a preferred DPLL setting of the nine on offer? I currently have AUTO as the setting. FWIW, I listen mostly to Tidal and my own 44.1 redbook rips (.wav).

On material with 44.1kHz sampling any setting can be used, start with the lowest setting compare it to AUTO, you might like the sound, which has a fuller body in the midrange at the expense of the spatial presentation, that is to say a little more fuzzy with loss of image placement on the downside by a much sweeter midrange on the upside.
 
If you have DSD or high sampled PCM material of 192kHz and above, the AUTO setting is best, the sound drops out at the lower settings

 

[penguin69]

  On material with 44.1kHz sampling any setting can be used, start with the lowest setting compare it to AUTO, you might like the sound, which has a fuller body in the midrange at the expense of the spatial presentation, that is to say a little more fuzzy with loss of image placement on the downside by a much sweeter midrange on the upside.
 
If you have DSD or high sampled PCM material of 192kHz and above, the AUTO setting is best, the sound drops out at the lower settings

Thanks b0bb, I'll try that out. I listen almost exclusively to 44.1khz material.
 
I'm still waiting on the Twisted Pear adaptor board to arrive so that I can get rid of my RFI aerials (jump leads).
 
I got bored today with the inactivity so I re-wired the Crystek 950 XO to take its feed from the aftermarket regulator board. The sound is still good, arguably it is a little larger and more airy than it was - although any change is subtler than the step change of swapping out the 575 XO (which incidentally seems to work ok on the EE Supreme).
 
I've ordered the Ticha 994 op amps for the I/V section, let's hope that they don't take as long as the Twisted Pear board is taking.
 
Once everything I have ordered is in place, I will work backwards through the thread and see what I should next focus on. My soldering/desoldering is getting better, aided by a decent magnifying glass and a reasonbly good quality temperature controlled iron with a fine tip.