My Kubelik DAC Build

[Mike H]

Greetings chasps, and now the moment you've all been waiting for.

Sorry for the delay, been busy! Stuff and stuff. And, Kubelik DAC...

Which started with Ray P very kindly giving me a working Kubelik DAC board ...

After the pre-amp and some other stuff, I started working on installing it in a case – I had the case before I started looking at the project. I know Ray said don't worry about that to begin with, just get it working – crazy as it may seem, that was neither simple or convenient – lack of space put a restriction on having loosely connected modules trailing around; they'd probably end up on the floor and I didn't fancy that idea at all.

Anyroad – so it began with test fitting... (if this didn't work out, I had a bigger box).
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Kubelik in WA140 Xformer.jpg (117.21 KiB) Viewed 3442 times

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Rear panel done, with cut-out for the USB port on the JL board...
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Kubelik build-001.jpg (56.26 KiB) Viewed 3442 times

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Kubelik build-002.jpg (79.35 KiB) Viewed 3442 times

[Mike H]

Continues...
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Kubelik build-003.jpg (93.08 KiB) Viewed 3441 times

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Kubelik build-004.jpg (86.22 KiB) Viewed 3441 times

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Installation of a copper partition...
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Kubelik build-005.jpg (99 KiB) Viewed 3441 times

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Notes: as may have become apparent, the whole thing runs off one transformer winding (that is to say, 2 x 9 VAC in series. (The transformer is a Talema toroidal type 62071.) I couldn't see why it shouldn't, and one of my favourite sayings is, 'Only one way to find out' ... two LM317 regulator boards, one outputs 20V for the Kubelik board, and the other 5V for the JL board. (The front end of the JL board is powered by the PC. 'Cause, it can. I appreciate these arrangements may not agree with everyone )

Between the transformer and 20V reg board is a 10Ω resistor, the idea was to give the rectifier diodes an easier time, as they're 'only' 1N4002. Only the 20V reg board has the rectifier diodes. The other, 5V reg board is just piggy-backed in parallel, but the +V connection is via a 33Ω resistor. (I was a bit concerned about surge currents, as the reservoir caps are 10,000 µF each.)

The reg boards are so close to the bottom panel (height of caps headroom restriction), just two nuts worth, I put a piece of celluloid underneath as a precaution.

The transformer secondary has a fuse in series, because, I've got them. Tip: if you bend the solder tags of a PCB mounting 20mm fuseholder out sideways, they are very prone to snapping off (or these ones are) so the developing fractures had to be soldered up!

All corners of the mounting faces of the case panels have had the paint or powder coat (whichever it is) filed or emery-clothed off so that they all have electrical continuity, and form a fully screened enclosure.

[Mike H]

Continues...
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And then suddenly you turn around and it's fully wired up...
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Kubelik build-006.jpg (119.91 KiB) Viewed 3441 times

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I had read the JL literature several times and concluded (several times) that I don't actually have to do anything to the JL board (configure jumpers etc.), it should just work as is (I2S is default). The JL board is the I2SoverFIO version (Fully Isolated Outputs), V.III.

So it should work – JL driver was already installed on the PC, so let's plug it all together, turn it on and see if anything happens.

And lo, JL device doth appeareth in Windows settings, so we pushed the 'Test' button and 'Tinga-ling!' (left) 'Tinga-ling!' (right). Alrighty then! Fairy nuff.

[Mike H]

Continues...

So here, ack-shirley working ... lid not been put on yet...
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Kubelik build-007.jpg (96.33 KiB) Viewed 3441 times

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Kubelik build-008.jpg (150.35 KiB) Viewed 3441 times

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Kubelik build-009.jpg (76.4 KiB) Viewed 3441 times

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Yes it sounds very nice! Noticeably more airy sound, and seems a bit louder than the other so have to watch it with the old tinitus. But well worth doing.

Need to give it more listening.....

Next ... (?)




ENDS

[Ray P]

Excellent Mike, I'm glad you think it sounds nice.

[Tony Moore]

Excellent build Mike! Looking very nice.

[Mike H]

Still using it, been playing lots of different music and been hearing things I've not heard before - always a good sign ...

[vinylnvalves]

Interested as looking at replacing my Amanero board with the JLsounds board. Did you power the JLsounds board with its own 3.3/5v feeds or are you relying on the power from the USB? Cannot see any wires on the photos but they could be underneath.

[Ray P]

Interested as looking at replacing my Amanero board with the JLsounds board. Did you power the JLsounds board with its own 3.3/5v feeds or are you relying on the power from the USB? Cannot see any wires on the photos but they could be underneath.

Mike only used two of the three power supplies I sent him and I'm pretty sure he's powering the 'dirty' side of the JLSounds from USB power and the 'clean' side from a linear regulated supply.

[Mike H]

Yes. The 2 boards have a ground connection between them obviously, so there is only one +5V wire to the JL board (isolated side - red wire in pictures). I thought this was preferable to duplicating ground connections. Return current is only about 90 mA.