CAL Alpha and an Equalizer

Hi again all,
I'd like to conclude this post, and end it with some very nice news, that all is well in CAL Alpha-Land!

As was later suspected, and through the help of all you kind helpful folks here, and especially Tom (Zinfan) the CAL Alpha has been known to be a bit more sensitive to Tube Choices than it's less expensive sister, the Sigma-Sigma II DAC.

Yesterday, I recieved 4 new 12AX7A-c9 Shuguang Tubes from an Ebay seller (for $24.00 plus shipping) and after installing them this afternoon, and doing a test listen, my CAL Alpha has never sounded so durn good!!!!

I won't doubt other's findings about Vintage NOS Tubes Like Sylvania 3-Mica BlackPlates, etc being grand, but I honestly cannot see substantial gains being made, as this Unit of mine seems to lack absolutely nothing at the moment. I'm sure after a bit of breakin, they'll even sound a bit better!

I am surprised at the nice build quality of these Chinese Tubes, posessing 3-Mica Spacers, and BlackPlates to boot (Appear to be a round-halo getter)

I hope this post to this thread helps other CAL Alpha owners to find a nice Tube, in which one won't have to run the gamut of NOS Vintage Tubes, and spend a veritable week's paycheck to get enjoyment. I've found these Tubes to offer quiet operation, solid authorative Bass, smooth, crystal clear mids, and superb, soild highs, without being Tizzy, or harsh, andgreat dynamics.

I'm very glad that A-Gon is here for us all, and wish to thank all again who've responded to me here, and in the past. Mark D.

hi markd51:

i have a cal alpha and have tried a variety of tubes and have found the dac insensitive to tube changes.

just for the record, have you found any tube which rolls off the treble and shifts the balance to the lower mid range ?

the chinese tubes you mention, i assume are current production easy to find.

i am surprised you like the tubes. i have yet to hear anyone speak well of chinese 12ax7 tubes.

Mr T, There are a number of folks on the AA tube forum that have posted positive comments about these tubes. Haven't heard them myself, and I don't know what about them differentiates them from the croud. Nor have I heard anyone describe them as rugged, but the good new is they are cheap.

Hello MrTennis, and Newbie,
To speak of my own personal findings with my own (Bought new in 1997) Sigma II, and my bought used from A-Gon Alpha DAC, I have noticed quite substantial changes in the sound, and here's my own personal experiences with both Units:

With my Sigma II, when I first got it, I had noted the stock Chinese Tube in it, it sounded very darn good, and then thought I was going to make sonic improvements to the sound, changing out the one 12AX7A, and trying out the then touted Sovteks. In this Unit, every Sovtek I tried, which was every model available 6 years ago including the 12AX7LPS sounded dull, lackluster, and the detail, clarity, and slam that the Sigma II DAC once had was gone slightly. I threw the stock el cheapo Chinese Tube back in, and in fact that tube still sits in that DAC 7 years later with no problems.

Now onto the Alpha I acquired: When I got it, it came with two Phillips-Jan 5751 Tubes, and the sound was extremely brittle, screechy, bright, and essentially unlistenable in this Alpha in my particular system.

A very kind A-Goner by the name of "Zinfan" (Tom) seen my earlier cries for help some months back, came to my aid, and rushed me out both a Copy of the Alpha Owner's Manual, and a pair of virtually New-NOS Mullard CV4004 Tubes to try in the DAC, as he noted a bit of rolled off highs with this particular Tube in his Alpha.

Well, I noted the same, and again, thought of this particular Tube as being lakcluster, and seemed to restrain the Alpha of its true capabilities.

I was right, when I had just gotten these Shuguang, 12AX7, and these are the latest C9 version, which have BlackPlates, Triple Mica Spacers, and a round Halo Getter. Very nicely made Tube IMO, and I'm of the thinking that this Tubes is an improvement over older Shuguang 12AX7's. Just like the three bears, this tube seemed to be "Just Right" (for me anyway, and my particular McIntosh-JBL Based System, 2-2105's MX-130, four L-65's)

I cannot speak for the Shuguang 12AX7Ac9 version longevity, but generally it's been found pretty much that both the Alpha, and Sigma II DAC's are very "easy" on Tubes. In other applications perhaps, this may not be the case for the Shuguang, so I cannot honestly say either way.

It is pretty much a well knows fact the the '50's Sylvania 5751 BlackPlate Triple Mica with D-Getter to be one of the top vintage "12AX7 type" Tubes in these Units as far as sonics are concerned, but I've also heard that this particular Tube has a relatively short life. Perhaps installed in either the Alpha, or Sigma II, this wouldn't be an issue. Biggest problem is, thier rarity, and thier very high desireability, and cost. I seen a pair of these NOS Sylvanias being sold online last week by a dealer for $140 ea!

IMO, this is just too much no matter how nice they are.
Of the two Mullard CV4004 I have which I had noted rolled off the highs-mids a bit, I really cannot sell these, as they were in essence truthfully "borrowed" to me by Tom, and if I didn't care for them, I was to send them back to him. I in fact just wrote him a letter yesterday asking if he would like them back, as they are rightfully his. Mark D.