*SOLD* - Audio Research SP9 Mk II preamp w/GNSC Reference Mods

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mdconnelly

ARC SP9 MkII preamp with the Reference mods by Steve Huntley at Great Northern Sound Company. On top of an already great preamp, the GNSC reference mods create dramatic improvements across the board including enhancement to the already excellent phono section which has performed extremely well with my  MC cartridge.

The Great Northern Sound mods were done in 2001.   Before I had the mods done, I had been listening to an ARC LS25 ($5k+) and had been thinking of getting out of vinyl.   Instead I went the way of GNSC (that was my first but certainly not last foray into mods) and it turned out to be a great decision.

I think the modded SP9 ended up sounding every bit as good as the LS25 *plus* it has a great phono section.

$1600 to AC members.  The GNSC Ref mods were $1825.  An unmodded SP9 has a current book value about $1k, so this is a very nice deal.

See Audiogon ad: http://cgi.audiogon.com/cgi-bin/cl.pl?preatube&1187453031&item

Thanks!
Mike
« Last Edit: 19 Aug 2007, 06:43 pm by mdconnelly »

lonewolfny42

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Mike...... :birthday:


For your birthday I'm giving you a "bump".... :lol:


The SP9 MK II with the GNSC Reference Mods happens to be very good preamp. I've had an SP9 MK II here since 1986....matched it with a Krell amp....sounds nice. With Great Northern mods...even nicer !!!
And....comes with a built in phono stage which works very well when you need to spin a few lp's. And....don't forget were talking Audio Research ....well built...quality stuff. 8)

Good luck with the sale..... and have a great day...:thumb:

mdconnelly

Thanks, Chris, for the bday bump!

Summer is a tough time to move equipment... my month ran out on A'gon so I'm posting the ad here (and AN and AA).   Price now firm at $1550.    Here's info about the GNSC mods (you can find lots of posts about Great Northern Sound on A'Gon and AA or check out www.greatnorthernsound.com).

This is an Audio Research SP-9 MkII preamp with Reference mods by Steve Huntley at Great Northern Sound Company.  On top of an already great preamp, the GNSC reference mods create dramatic improvements across the board including enhancement to the already excellent phono section which has performed extremely well with my low output MC cartridge.

As stated in the GNSC Reference level update documentation....

The reference level modification package for the SP-9 is an all-encompassing upgrade designed to maximize the musical performance of this great unit while maintaining or exceeding the component tolerances and overall reliability of the original ARC design.

The sonic improvement is significant in virtually every way. There is blacker background; much lower noise, improved speed and dynamic capability, deeper bass extension and weight, a more natural presentation, greatly improved clarity and resolution, much more open top-end, and simply a more involving experience listening to music through it.

Specifically, the modification includes:

-- The installation of high-speed (fast recovery) rectifiers in the power supply.
-- The main filter capacitor is replace and the supply is "beefed up" significantly. Appropriate bypasses are added.
-- The tube filament supply filtering is improved, bypasses are added.
-- All signal coupling capacitors are upgraded.
-- Regulator lines are noise reduced with a very unique technique.
-- The chassis is fully damped to reduce vibration and resonance.
-- An IEC connector is installed in place of the stock power cord.
-- Critical signal resistors are upgraded.
-- Internal wiring is upgraded.
-- The volume control is replaced with a very high quality 24 position stepped attenuator.


The unit performs flawlessly.  An unmodded SP9 has a current book value about $1k.  The GNSC mods were an additional $1825.    Will sell for $1550 + shipping and paypal.  Check my Audiogon feedback here: http://cgi.audiogon.com/cgi-bin/fb.pl?user=Mdconnelly

Additional pair of 6922 tubes included.   Click here for photos

Whitese

Can the phono do the high gain ones? like 2.5 mV?

thanks

jack


mdconnelly

Can the phono do the high gain ones? like 2.5 mV?

Not a problem... I originally had been using a Benz Micro high output 2.5 mv Glider and it sounded great.   The only thing I did when I switched to a .4 mv ZYX MC cartridge was add a 200 ohm caddock resister to drop the impedance of the phono section from 47k ohms down to 200 ohm which seemed to help the MC cartridge a bit in body.   That resister can be easily removed if needed.
« Last Edit: 23 Jul 2007, 01:17 pm by mdconnelly »

mdconnelly

Bump.   Need to sell soon.  Steal at $1500.

Thanks!

mdconnelly

Sold!