Review: Aesthetix Callisto Signature and the KT-66 Tube preamp
I have done the KT66 tube substitute for years, I posted this five years ago at Audiogon. http://audiogo1.iserver.net/cgi-bin/forum5.pl?aamps&980918116&read&keyw&zzaesthetix I still have the special tool that will punch the power supply chassis so the KT66 will clear. |
42659: Just to ad a bit to what Jafox is saying; I was not kidding (alright a little) about the Genelex KT-66's being part of my portfolio....... I have seen these tubes selling for $600-$700 per pair in some places. If you have a dual power supply like Albert (John I'm not sure about your setup) that would ad up VERY quickly. It would be impossible for a manufacturer to do something like this........ Like Jafox say's; you have to be able to stock replacement parts (in this case spare tubes). Albert, I wonder if you could talk a little more about the sonic differences in the 6922 valves you have tried?. The only rolling I have done in this regard is with the Mullard gold pins. Someday I want to purchase an IO. Do the same tube replacements have a similar effect in that unit(incrementally speaking)? |
Yes your correct Cmo that the KT66's can be expensive and could not be done for production units but what surprised me is that Jim White never experimented with his own unit to see how these tubes would sound with his own system even after some people including Mr. Albert porter reported back with very positive results from changing the tubes. If I was a designer I would like to satisfy my own curiosity and know for my self how these tubes improved the sound of my preamp. Other improvements like upgrading the female rca’s jacks to pure copper Vampire’s (the stock cardas sound very poor in comparison) and changing the male IEC in the power supply to the much better sounding Furutech are not that expensive and made a very nice improvement on my Jadis JPS 2 preamp. Johnny |
Cmo, The Mullard (dimple plate) gold pin is what I run in my Aesthetix Callisto. In the Aesthetix Io, the 6922 of choice is the old diamond bottom Telefunken 6DJ8. Oddly enough, the Telefunken does not sound as good in the Callisto nor does the Mullard sound as good in the Io. Although the same 6922 tube is supplied from Aesthetix, they perform different jobs in the two units. In the Callisto the 6922 is paired with either 5692's or 12AX7's depending on input or output side. In the Io it's in the output and not directly paired with another tube (as near as I can tell from the circuit). So as usual, the answer is not always tube "X" is best, depends on where it goes. I don't know if the link I provided in my earlier post opens where you can read all the comments. I had problems clicking on other posts from within my link and got a server error. If that did not make it, I can copy and post it here. I discussed at length the differences between Siemens, Amperex, Mullard and others. |
