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K&K Audio Rakk Dac


tkam

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I think this kit has been discussed here before. I have great interest in building one w/ the passive output (2V is more than enough for me) but as usual, no fracken time to do anything about that.

If you get one built Todd, I'd probably go w/ a sigma11 power supply rather than the RAKK PS kit. I'm a firm believer that when it comes to digital there's no such thing as too clean a power supply.

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I think this kit has been discussed here before. I have great interest in building one w/ the passive output (2V is more than enough for me) but as usual, no fracken time to do anything about that.

If you get one built Todd, I'd probably go w/ a sigma11 power supply rather than the RAKK PS kit. I'm a firm believer that when it comes to digital there's no such thing as too clean a power supply.

the question would be how well does the sigma11 perform with small current draw. has anyone seen any tests on this? I tried a couple of the circuits on my DAC that requires 6 power supplies and the sigma22 didn't sound quite right.

edit: heh, my psu looks very similar to the RAKK psu, but with a preregulator and a r-core transformer.

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I have no idea at what current output level amb performed his tests. You could post the question in the headwize thread if you're curious. I would expect it to perform well, but have no basis for saying that other than the man behind the design.

The RAKK PS looks pretty damn simple. The basic looks like not much more than a TREAD and the premium is pretty STEPS-ish looking.

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I have no idea at what current output level amb performed his tests. You could post the question in the headwize thread if you're curious. I would expect it to perform well, but have no basis for saying that other than the man behind the design.

The RAKK PS looks pretty damn simple. The basic looks like not much more than a TREAD and the premium is pretty STEPS-ish looking.

yeah, agreed. I don't know what the deal is... there are a particular digital build at diyaudio where people are using a simple LM7808 with Black Gates on each side, and I was skeptical and setup a jig to A/B and it sounded much better than a sigma11 supply to the 2 or 3 people that were over at my place comparing.

I don't really understand it myself, but felt unmotivated to really find out why.

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I'm using a Sigma22 clone on my I/V stage, which is a really small current draw, and haven't noticed any problems... not that I was looking for any. I just wanted a really clean supply, but amb's board was too big and I didn't need paired output devices.

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yeah, it's strange now that I have a number of digital projects you find a lot of stuff just by playing around. The above is one example, another is how much better EI and r-core transformers sound than toroids, _for digital_, and how much better oversized transformers sound. YMMV of course, but it's been a fun and eye-opening experience for me to just try things and not just grab the thing with the best "specs" out there and be satisfied.

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Where do you pick up EI and r-core traffos?

I'm currently rebuilding my Buffalo DAC with a Sigma22 for the IVY power supply and two sigma11's, one for digital and one for analog for the buffalo itself. Perhaps I should take a look into a different solution? Also, I'm using all Antek Inc. toroids...they're physically larger for same rating compared to Avel Lindbergs or Amvecos. Is that what you're referring to with the oversized traffo comment?

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yeah, agreed. I don't know what the deal is... there are a particular digital build at diyaudio where people are using a simple LM7808 with Black Gates on each side, and I was skeptical and setup a jig to A/B and it sounded much better than a sigma11 supply to the 2 or 3 people that were over at my place comparing.

I don't really understand it myself, but felt unmotivated to really find out why.

yeah, it's strange now that I have a number of digital projects you find a lot of stuff just by playing around. The above is one example, another is how much better EI and r-core transformers sound than toroids, _for digital_, and how much better oversized transformers sound. YMMV of course, but it's been a fun and eye-opening experience for me to just try things and not just grab the thing with the best "specs" out there and be satisfied.

Marc,

Interesting. Do you have a pointer to the diyaudio thread? And how big on transformer are you going here? 80VA? 300VA? Any preference for R-core over EI? And I assume you are grabbing R-core at v4tc? Or did you find an alternate supplier?

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Marc,

Interesting. Do you have a pointer to the diyaudio thread? And how big on transformer are you going here? 80VA? 300VA? Any preference for R-core over EI? And I assume you are grabbing R-core at v4tc? Or did you find an alternate supplier?

two sources are Kitamura Kiden and vt4c. The KKK [ :) ] transformers I've found NOS or pulls from Ebay or surplussupply.com. I've also contacted Custom Magnetics, Inc. but haven't really acted on anything yet. I really like the vt4c, but expect a 2-3 month wait on a custom job though. Their specs are also a bit liberal... I'd figure 80% current draw that they state and then subtract another 15% for safety margin.

I'm talking on the order of 100VA or so, for oversized.

For EI I've used various Hammond transformers...

Here's the thread:

diyAudio Forums - Finally, an affordable CD Transport: the Shigaclone story

I'll be upfront and say I'm somewhat a Peter Daniel fan-boy :) :)

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Thanks. I'd found the thread already (did a search then remembered the shigaclone). I'm not sure what I would do with a 7808 type supply, as I would need +/- 15V (7815 / 7915 I guess) and it might require too much thought :eek:

Hmmm, I may actually have a pair of the regs around.

I figured you were a PD fanboy... :prettyprincess:

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Thanks. I'd found the thread already (did a search then remembered the shigaclone). I'm not sure what I would do with a 7808 type supply, as I would need +/- 15V (7815 / 7915 I guess) and it might require too much thought :eek:

Hmmm, I may actually have a pair of the regs around.

I figured you were a PD fanboy... :prettyprincess:

swapping out the transformer is no biggey and if there is a model that vt4c / "whatever the ebay seller is that's the same guy" sells, then it's cheaper and faster :) I bet you can find a dual 18 VAC or something that will work and get it shipped for around $50 or less.

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  • 4 months later...
two sources are Kitamura Kiden and vt4c. The KKK [ :) ] transformers I've found NOS or pulls from Ebay or surplussupply.com. I've also contacted Custom Magnetics, Inc. but haven't really acted on anything yet. I really like the vt4c, but expect a 2-3 month wait on a custom job though. Their specs are also a bit liberal... I'd figure 80% current draw that they state and then subtract another 15% for safety margin.

I'm talking on the order of 100VA or so, for oversized.

For EI I've used various Hammond transformers...

Here's the thread:

diyAudio Forums - Finally, an affordable CD Transport: the Shigaclone story

I'll be upfront and say I'm somewhat a Peter Daniel fan-boy :) :)

Marc,

The transformer I need for the Aleph clone is 2 x 55-60V secondaries (and probably something to do a 5Vdc supply off of for input selector/volume control ala Dantimax or TwistedPear, etc.). I was looking at vt4c, but only see the custom 50VA and 100VA, of which I would probably want the 100VA one. They are somewhat unclear, as they have a statement

# Only available in large quanntity normally;

# Custom order available in 50 pieces or more;

but then provide pricing quantities of 1-3, etc. which would seem to indicate that I could order 1?

Regarding your last statement, I ran across this thread today which I found rather illuminating... particularly around the middle of it (p5 or so, p8 is interesting :palm:).

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Marc,

The transformer I need for the Aleph clone is 2 x 55-60V secondaries (and probably something to do a 5Vdc supply off of for input selector/volume control ala Dantimax or TwistedPear, etc.). I was looking at vt4c, but only see the custom 50VA and 100VA, of which I would probably want the 100VA one. They are somewhat unclear, as they have a statement

but then provide pricing quantities of 1-3, etc. which would seem to indicate that I could order 1?

Regarding your last statement, I ran across this thread today which I found rather illuminating... particularly around the middle of it (p5 or so, p8 is interesting :palm:).

Can you go larger? [url=http://www.diycable.com/main/product_info.php?cPath=140_141&products_id=596]DIYCable.com : Intro

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