August 1, 2009

DIY Kable Kooker Rev.B

This is an old post of ours in the blog we previously contributed to.

The outside, nothing has been changed.

Many thanks to GCK and a few others whom pointed out some missing elements in my home brew Kable Kooker. Chief amongst those is the variable frequency sine sweep function, which unfortunately, came to a point where a DIYer like me has to call it a day. After all, certain things are just beyond my grasp and abilities.

The inside, note the white 5W rated loading resistors.

I went to the Audio Dharma website, where there's plenty of information on how the real thing worked. It than dawned on me that I had made two mistakes in my earlier attempt. The mistake was that I had used the standard XLR/RCA cable spec impedance to load the cables as it cooks. As per explained clearly by Alan Krafton on the Audio Dharma website, I should 've used a power amp's load to cook the XLR/RCA interconnects instead. A quick consult on my Pass Aleph 0 manual indicates the amp's load to be 25k ohms for XLR and 10k ohms for RCA. Further consultation with my senior DIYer sifu tells me that some tube power amps can present loads as much as 47k ohms for XLR and 20k ohms for RCA interconnects. Just to be sure, I used the bigger values for a more effective cook.

Another view of all the loading resistors for XLR, RCA and speaker cable cooking. The top 2 resistors for XLR loading value 47k ohms @ 5W.

As my previous load resistors for the XLR and RCA are rated 2W, I've found them to run moderately warm when cable cooking. To increase reliability and lifespan, I used 5W rated resistors this time. Similarly, my home brew kable kooker also measured up to 1.86 amperes when cooking speaker cables, against the original measuring 1.88 amperes. That means I was right on the $$$ where speaker cable cooking is concern.

The RCA(at bottom) load resistor value 20k ohms @5W.

Just to try, for my self, I re-cooked my AQ Sky and Colorado XLR interconnects again, and found the results of the cooked cable much more sonically satisfying at shorten cooking time. To get the same level of results, I used to have to cook about 96 hours, or 4 days. Now I can do so with the same great results in 24 hours!

Now that's what I mean efficient cooking!

Once again, thanks for sharing your "desirable thoughts" with me. I've learnt so much from your kind responses. 11 January '09

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