Gain Tubes vs Output Tubes - Aesthetix Calypso

So, do you still have your Aesthetix Calypso, and if so, what was your final tube configuration? .....thanks, Chris

I've been using a Calypso for a little over a year now. With the original tubes, the preamp sounded too thin and solid state like. I did some tube rolling with the 12ax7's, smooth plate telefunkens and 1950's mullard long plates 12ax7 (both came from Andy @ Vintage Tube Services). I found the mullard tubes to be smoother and richer sound, more to my liking. My associated amp is a Theta Dreadnaught, with a tube amp the telefunkens might have been my tube of choice.

I also tried different tubes for the output tubes. 6922 white shield amperex and 6dj8 orange globe a frame amperex tubes. I wound up using the 6dj8's but there is not a lot of difference in the sound between the two.

In my experience, the gain tube changes the sound substantially more than the output tube with the Calypso. But like everything, all of the associated equipment imparts some sonic signature on the sound. I just like the richer sound more harmonic sound that a tube preamp brings to the system.

Ok, I purchased a pair of Amperex 12ax7's from Andy at Vintage Tube Services and like the sound of them compared to the stock tubes that came with my Aesthetix Calypso. I found the stock tubes to offer a bit more lower end response (deeper or perhaps just louder bass) but at the expense of a noisier background (not as black is the only way I can describe it). The Amperex 12ax7 offers tighter bass and a bit more air and transparency.
In combination with the Amperex 12ax7, I've have a few 6dj8's and 6922's to play around with (Siemens CCa's, Mullard 6922's, Amperex PQ White label 6922's, Amperex Orange Globe 6dj8's (Holland) and Phillips SQ 6922's.
I've read Joe's tube lore and don't necessarily agree with his findings regarding the 6dj8/6922 tubes. I'm sure his findings are valid with HIS particular equipment though. I previously owned the Copland CVA 306 (which uses 6922 tubes) and found that what sounded good on that preamp doesn't necessarily apply with my Aesthetix Calypso.

With that said, the best combination that I heard was the combining the Amperex 12ax7 with the Amperex 6dj8 Orange Globe Holland tubes. This combination really was a step above everything else I tried. The other 6922 variations sounded just slightly brighter and perhaps more etched. The Orange Globe 6dj8 on my Copland preamp made the sound buttery warm, but in the Aesthetix, it was the best I've heard (esp the midrange on female vocals, a bit more recessed, but so seductive with no hint of any grain whatsoever!). If there was any area that I'd like to see improved upon, it would be in the area of upper-end micro detail (without etch).

My question to all Aesthetix Calypso users would be: Is there an alternative to the Amperex Orange Globe 6dj8 that provides the upper end extension and detail AND produces the midrange magic of that tube? I have not tried any of the other variations of the Amperex 6dj8 such as the bugle boy white label or the Orange globe A frame dimple getter versions and would like to hear from those owners that may have tried these other variations.

It's truly amazing how the tube can change the character of my preamp to such a large degree. I've heard my Aesthetix Calypso sound extremely harsh and bright....and I've also experienced close to sonic nirvana. It's hard to believe it's the same piece of equipment.

Any input would be appreciated!

calgarian

As Jim White states in his reply to this review:

"As you wrote, the Calypso is a simple circuit. It basically consists of input switching, volume control, gain stage (12AX7), output stage (6922). Therefore, anything that happens in the 12AX7 goes directly to the power amp and will be heard.

Thank you again for your wonderful review, I enjoyed reading it."

Best regards,

Jim White
Aesthetix

It would seem that the 12AX7 has the most bearing on the sound. Make sure the 12AX7's you use a very quite, or as Mr. White says, you will hear them.

John

I changed my gain tubes first, and the output tubes later.
I'd have to say go for the gain stage first...