COUNTERPOINT HYBRID PHONO STAGE UPGRADE


This is my first post, but I am well acquainted with this forum. I have recently imported a SA 5000 from a member and I am very impressed with the build quality, and performance of the line stage. It is a vast improvement over my modified SA 3. I have both service and owner's manuals, and the documentation is equally impressive, and worth the asking price.
I intend to do some of the Alta Vista upgrades, and would like to remove the JFET and inductor from the cathode circuit of the phono 1st gain stage as a starting point, and replace with a resistor, using the low gain common-cathode triode option for MM cartridge only.
I have no philosophical objection to hybrid circuitry, and I guess that Mike Elliot would have used the ARC SP11/15 as a reference for his own designs. Tube purists may have scoffed at the hybrid ARC products, but the people who make a living out of reviewing them, raved about it.
However, the Alta Vista upgrades for the SA 5000 and SA 9 involves removing the SS buffers and cathode JFETs, and associated circuitry. Any assistance in providing feedback and guidance on tackling these mods would be greatly appreciated.
Thanks in advance.


ozdiyer

You might have more luck over at the DIY Audio website.  The only person that really did any mods to these was Mike. The cached info for the preamp on his website is here if you don't have it:


https://web.archive.org/web/20140623010209/http://www.altavistaaudio.com/SA-5000.html

Good luck.


Thanks guys, I have all the Alta Vista upgrades stuff and will try swapping the JFET with a cathode resistor . 

No circuit diagrams were provided when I upgraded and Elliot did not make a set of specs/diagrams available  for upgrades  when he closed down the site. 
You need to get those jfets out of there . the Sowter 8055  used in my unit gives a gain of 10 times & sounds great. You can change the loading resistors to get different loading values tailored to your needs. I had it done.  You need to go higher than 47k ?
You really should mod that unit . You will not believe how much different and better it sounds. 
I do have the name and address of Eliiot*s  last technician who worked on my unit. No phone or email info as all my contact was with Michael.  He probably has instruction/ schematics . Don*t know if he could/would help you ..
i also wanted to ask what tubes you are using. Getting some new tubes can make a big difference.