SOLD Prototype 2 preamp with granite enclosure.
Quantity in Basket:
Shipping Weight: 40.00 pounds
This unit is SOLD.
This is the second generation 770 preamp prototype.
an aluminum chassis and comes with the 1/2" thick
acrylic-granite enclosure. Granite Audio's MSRP list
price on the granite alone is $1,000.00 . This
prototype is an experimenter's dream. The chassis has
lots of room to add to, or change the existing circuit.
The chassis is set up for six 12AX7 tubes, one 6X4
tube, two VR tubes, and one octal rectifier tube. The
chassis comes with the power transformer already
installed. It also has ALPS BLACK BEAUTY volume and
balance controls. These were discontinued years ago and
are very rare now. Current market value is around $85.00
each, and this prototype has 3 of them.
The selector switch, tape monitor
switch, and power switch are all solid silver contacts
and rated for 50,000 cycles without degradation of the
The RCA input & output jacks are pure OFC copper with
direct hard gold plating. They sell for $25.00 per pair,
and this prototype has 9 pairs.
The chassis wiring is
Mil-Spec aircraft Teflon silver wire and retails for
$10.00 per foot. So, this chassis is loaded with the
best audiophile quality parts that you can buy. The
OEM value of the parts alone are worth the asking price.
This prototype has 5 inputs, tape monitor loop, MM
phono input, and weighs 31 pounds with the granite.
Dimensions: 18.75" x 13.5" x 6.5" high.
There is no top or bottom for the chassis and no
knobs. There is an incomplete schematic available with
this unit as it is a prototype and will differ
somewhat from the schematic. This unit is sold AS-IS.
You will need some advanced DIY skills to examine this
prototype before plugging it in and turning it on.
This preamp is in working condition if you add tubes.
It is priced without tubes, but I can supply tubes if you
There are many photo links below showing the top,
bottom, front, back, and insides of this amp. Please
use the links to see all the super quality parts that
come with this prototype.
Bottom of chassis
Top of chassis.
Front with granite.
Back with granite.