Cal Audio Alpha 24/96 upgrade?

If you haven't tried swapping tubes in this unit, i would go that route before spending the money on the 24 / 96 upgrade. Then again, i know others that have done the upgrade and found it WAY better than any tube swap. It's all personal taste and system based. I've got 3 different CAL dac's and they all have different sonic signatures.

If you are hell bent on doing the upgrade, you should probably do it relatively soon. I don't know how much longer CAL will be doing these mods, but i don't see it continuing that far into the future. Sean
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I "somewhat" agree with Camadeco as you might have summed up from my first post. Bargain hunters ( most everybody on this site ) see the 16 bit Alpha's for sale at reasonable prices and have a hard time spending the greater amount of cash for the 24 bit. As such, it may be harder to move them at a price that takes into account the cost of the upgrade.

In terms of tubes, there are literally dozens and dozens out there. What tubes work best in your system is going to be up to personal taste and the tonal balance / amount of detail that your after. My suggestion is to "start cheap" and work your way up. It is quite possible that you can find something that you like for low bucks and it MAY end your search. Then again, there are those folks that are "never satisfied"... : )

There was a similar thread to this one a few weeks back. I think that Kevin Deal at Upscale Audio said that the Mullard's were what he sold the most of for this piece. Then again, i think that people have read that others were using them and tried that as a starting point since they already knew that they would be decent. Kind of a "monkee see, monkee do" type of events. No offense to anyone on that statement, as i too was a "monkee" : )

You might want to try looking at www.partsexpress.com to see what they have. These are new tubes and they are an electronics supplier. For the price of one "big name" set of tubes, you can literally purchase a wide variety and see what works best for you. For your convenience and for those that may be interested, i've included some part numbers below:

072 - 410 Sovtek 12AX7WA / 7025 LOW NOISE $5.25 EACH

072 - 420 Sovtek 12AX7WB / 7025 HIGH GAIN $5.90 EACH

072 - 662 Philips 12AX7WA $10.80 EACH

072 - 680 G.E. 5751 $11.50 EACH

I somehow posted early and didn't finish the job. Is this what they call "premature....." ??? : )

Even if you ended up buying a pair of each tube listed above, it would set you back a whopping $75 including shipping. This would give you 5 sets of tubes to compare (4 new pairs and the originals). As such, $75 would not even cover ONE pair from a "tube specialist".

While these tubes may not be on the "hot list" of "tubeheads", they would give you a good idea as to the different sounds and levels of performance that are possible with some simple tube swapping. Keep in mind that there are literally WAY more options open to you. I simply suggested Parts Express and these specific tubes as a matter of pricing, availability, selection, convenience and listed those that i know will work in your specific piece of gear.

Here's a link to the previous discussion on this subject: http://audiogo1.iserver.net/cgi-bin/forum5.pl?ddgtl&989021343&read

Hope this helps and widens your options. Sean
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One other thing. If you use your DAC on a regular basis, i would simply leave it on all the time. I've done this and never had any problems whatsoever. Life expectancy of a low level tube like this is VERY long compared to what you get out of a power tube. Not only does this negate warm up time, the internal temperature of the DAC remains consistent, making its' operation more stable. Besides that, the high volume of in-rush current DEFINETLY shortens the lifespan of ANY component. The only time that i would worry about leaving it on would be if i lived in a "black-out" zone or the area was prone to very heavy electrical storms. Sean
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