Hiend2, You stated the attenuators will upset the input impedance? I assume you mean the input impedence going into my preamplifier, correct?
Cann anyone else comment about this? I'll ask too, Scott Endler about this.
Then you say Hiend, "Get the Alpha"? Get the Alpha what??? lol Mark |
Hi, Thanks for your responses.
When I recieved the Alpha, there were two JAN-Phillips 5751 tubes, and those I replaced with two Mullard CV-4004 (12AX7A Equivalent) Tubes.
I'm using top of the line Straightwire 75ohm Digital vetween the Transport, and DAC , and Straightwire Maestro 1M Cables between DAC and Pre-Amp.
Both Power Cords are stock CAL Cords.
I am using the Endler Attenuators at the lowest 4db cut, and the output seems smoother, not so hot, but I remember the Sigma II giving a little bit better Bass response versus the Alpha.
The rest of my system sounds fine with no complaints of bass response though my Analog set up, and R-R Tape Deck.
I would assume that yes, a EQ could be inserted just between the DAC, and Pre-Amp, but as other would most likely say, it's a band aid trying to fix something that shouldn't need fixing in this manner, and another CD Player (or DAC) would better solve the problem. Mark |
Hi Bob, Thank you for your response, and assurance that I didn' make a mistake about the Attenuators.
At the time, I hadn't thought of this, but I recall Cal Audio Labs used to ship the Alpha DAC from the factory with some resistors to alter-modify voltage output if needed, and these would be soldered in somewhere in the output within the unit.
As far as I can see, and understand, the Endler Attenuators gave me the same end result without the need of tearing into the unit, and soldering resistors, and also the advantage of variable output to whatever I desire with these 12 step Attenuators Robert Endler makes which I believe go from 4db to 48db cut.
I knew right away with this Alpha that the Alpha was much higher output versus my year's ago vought new Sigma II, as I can barely get my Mac MX-130's to 11, and it's blowing you our of the house, and makes you put your hands over your ears with such a shrill, len sound. Truthfully, I feel my Sigma II to be a better sounding unit, and this shouldn't be considering the higher original price of the Alpha.
I had perhaps considering buying, and inserting something like the Berhinger DEQ2496 between the DAC and Pre-Amp, and also as another option perhaps even trying the DEQ2496 elsewhere in the chain between Pre Amp-Amp?
Of course I have Bass+Treble Tone controls on the MX-130, and could perhaps just turn up the bass higher, and turn down the treble below flat a bit? Mark |
Hi again all,
No, I think the transport is fine, has always worked just fine. Sure, I'll agree, and won't debate there's probably 100's of transports out there that will easily best the CAL Delta I have.
Running a search through the archives on the CAL Alpha, and various Tubes, I did come across a post from Zinfan (Tom) who remarked that the Mullard CV-4004 Tube in his own CAL Alpha DAC was "un-involving", or something similar to this effect, and I believe I'm noticing perhaps the same thing, as these may be the exact same Tubes Tom was referring to. He, in fact "gave me free!" a set of the Mullard CV-4004 to try, and I'm betting that these are the exact same pair he tried, and didn't personally care for.
As others have mentioned in older threads about the Alpha, these particular Units seemed to be a bit more sensitive to Tube Rolling, and as Tom has found, the Sylvania 5751 3-Mica Black Plates were the very best choice he found.
I don't doubt him on this, but truthfully, it can start getting awful expensive with experimentation with Tubes, even these small signal Tubes, and I sure wish I could find a relatively inexpensive alternative to try, without blowing a virtual week's pay for a pair of tubes! :-)
I was honestly thinking of trying again, the el cheapo Sovtek 12AX7AWPS just for the heck of it, but in truth, I read some mixed comments about these, both good, and some not so good.
At least with the JAN-Phillips 5751's that were in it before, dynamics, involvement, and Bass seemed a bit better at the expense of highs that seemed to be a bit too glassy, and "screechy". Mark |
Hi Newbie, You mentioned brand, but not number of Tube?
I assume by "EH", you are referring to Electro-Harmonix, correct?
Is it the 12AX7 EH you refer to?
Of course too, there are a number of different model Sovtek in 12AX7 (3 I believe?) Was it the Sovtek 12AX7LPS you tried?
I've seen some new NOS Sylvania Gold Brand 5751WA 3 Mica BlackPlates w/Square Getter on the net somewhere, but asking price is $140ea, and I'm thinking that this is a bit out of line, regardless how nice they are! Thanks, Mark |
Hi all again,
I've come to this realization about the Cal Alpha (through the archives) and perhaps other equipment like this, that shares similar qualities.
Tube rolling is the key to suitable sound, but one sad fact, is that if one wants to put in a pair of NOS Sylvania 3-Mica BlackPlates with D-getter, be prepared to pull your pants down.
I just bought four c-9 version Shuguang-Sino 12AX7 tubes to try. In all honesty, they might be better than the crap shoot buying "supposed" NOS tubes from the online scalpers. Mark |
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. |
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. |
