I have one for sale, with the Level 2 modifications from Parts Connexion. Asking $2,20.00 plus shipping, from ZIP 18661. Details from dealer ad shown below:
Our mod was designed by Chris Johnson, the founder and former president of Sonic Frontiers.
The following details the Level-1 modification:
a) We add 1 DEXA Technologies “discrete” DUAL op amp module to the input buffer.
b) We upgrade 4signal path resistors with KIWAME 2-watt 1% Carbon Film resistors
c) We upgrade the power supply regulators with 2 DEXA Technologies “discrete series” regulators (+ & - 15V)
d) We replace the inexpensive AC connector with a FURUTECH Rhodium-plated AC inlet
e) 10 feet of WBT Solder is used throughout the mod
f) 4 hours labor are required to complete the mod
Sonic changes of our Level-1 mod:
Better low-level detail and 3D ambiance retrieval
Macro dynamics are improved It seems to play louder, with improved microdynamic contrasts
Midbass is improved to add weight to voices and make them sound more real
The midrange is a little more liquid than the stock machine's
Imaging is more defined, soundstage depth is enhanced
Bass extension and impact are improved with more weight and authority
The high frequencies are a little smoother
Prices
The Level-1 modification to your preamp is $750.00 + freight
New modified preamps are available for $2,595.00 + freight
One year warranty on mod work to your preamp.
New preamps have a 1 year Underwood warranty
We also have a Level-2 modification that is more comprehensive at $1,400.00 to your machine. New Level-2 modified preamps are $3,190.00+ freight.
The Level-2 takes all of the level-1 and adds:
1) Two additional DEXA Technologies “discrete” DUAL op amp modules. One for each output buffer.
2) 6 Mundorf AG-Series main Power Supply filter caps at 22,000uf 25V each