AudioCircle

Industry Circles => Audio by Van Alstine => Topic started by: Hiphile on 11 Feb 2024, 10:27 pm

Title: Switchable op-amps in a phono stage
Post by: Hiphile on 11 Feb 2024, 10:27 pm
Hi, Recently I bought a DAC from Geshelli Labs with sockets in the board so you can switch op amps as you wish with really good sonic results. Pardon my ignorance but Can this approach be implemented in a phono stage?
Thanks!
Title: Re: Switchable op-amps in a phono stage
Post by: ceylon on 2 Mar 2024, 06:04 pm
in phono stages with switchable opamps it can. i recall a jolida opap phono stagea tube buffer that still gets mis-identified as a tube phono. it was incredibly popular to own and to upgrade parts, especially the opamps.

van alstine has an opamp phono amp, the vision Q+. its excellent. dunno if its modeular or the opamp is easily replaced.
Title: Re: Switchable op-amps in a phono stage
Post by: Tone Depth on 3 Mar 2024, 02:00 am
Not sure if they are still using socket-mounted op-amps, or if they switched to surface mounted op-amps. On the website, there is an oblique view of the interior of the phono preamp.
Title: Re: Switchable op-amps in a phono stage
Post by: Hiphile on 4 Mar 2024, 01:10 am
This is an exciting proposal, the improvement of sound quality when replacing op-amps in the Geshelli DAC is not subtle (Burson to Sparko 3602) akin of rolling vaccum tubes  :D Currently shopping around for a new pre with phono and the Fet Valve CF is high on my list. Having the versatility of switching op-amps in the phono section will be a closed deal for me.
Title: Re: Switchable op-amps in a phono stage
Post by: jandrews on 4 Mar 2024, 01:35 am
Just my guess, but I would think that AVA designed the unit with the best sounding op amps that they could work with.
The newest model has upgraded chips already.  I doubt there would be an improvement by swapping them out. 
Title: Re: Switchable op-amps in a phono stage
Post by: avahifi on 4 Mar 2024, 10:40 pm
Please leave the Vision Q+ opamps alone.  We did many hours listening to select the best ones for this application.  Also for best stability often associated passive parts need to changed too for optimum stability.

Vrank
Title: Re: Switchable op-amps in a phono stage
Post by: Hiphile on 5 Mar 2024, 09:10 pm
Got it! Thanks for the answer.  :D