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CAL Alpha DAC - Cool Tubes?

This is a two part question. First, I recently purchased a CAL Alpha DAC with the 24/96 upgrade. I have found that I prefer the sound of a tube DAC and I am enjoying it very much. However, I've noticed that it is completely enclosed with no holes for ventilation and cooling. This is obviously by design, but I wonder if this is good for the tubes and internal components in general. I know that there are quite a few current and former owners out there and would welcome your comments. Second, I would appreciate any recommendations on tubes, tweaks, and such. I am currently running Mullards.

Thanks!

John
stereomaniac

Showing 2 responses by fpeel

fpeel
455 posts
 
Some owners believe the Alpha sounds better with the cover off. One unit listed on AudioGon in the past even had louvers stamped into it! The cover stays on mine so as to protect the internal components from dust. As for NOS tubes, Mullards (best bang for the buck) and Amperex Bugle Boys (best all around) have been my favorites thus far, especially the latter. '60's vintage Sylvanias were OK, too. If cost is a concern the Sovtek 12AX7LPS is a surprisingly good tube, especially given the cost. Very good extension on the top, but without the sterile sound of the rest of the Sovtek family. BTW, my Alpha does not have the 24/96 upgrade.
fpeel
455 posts
 
You did ask originally ask about tweaks, didn't you? My Alpha sits on BDR cones and Those Things which cleans the sound up a bit. The top end gets a little fuzzy when they're removed. The original PC was replaced with a Synergistic Master Coupler. This added more "meat" to the sound; I believe the appropriate audiophile phrase is "it sounds more palpable". The Alpha is connected to a Delta transport with an Illuminati D-60 digital cable. Of the various digital cables tried it suited the system best. I've also tried mass loading, inner tubes, various wooden shelves, etc., but none of these seemed to add anything desireable.
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