Sold: Promitheus Audio DAC w/ Audio-gd opampsI am the original owner. Used in a smoke, pet and child free house.
Selling this, probably the last piece, of a complete Promitheus Audio 2
channel tube system as I finish transitioning to a higher-end AV pre/pro
and all class D amplification for both music and home theater ...and
then calling it good.
* Link to the original webpage:
http://www.promitheusaudio.com/dac.htm* The DAC allows up to 24/96Khz input.
* Selectable DAC output of 1 volt, 2 volt or 4 volt via jumper pins on the PCB
(Please see the green circled area in the 'close-up open top' photo).
* RCA or USB input via selector switch
* Pure silver RCA input and outputs
* No on/off power switch. Uses a 1A slow blow fuse.
* The DAC's power transformer (oversized M6 low loss audio grade core),
output transformers and digital pulse transformer are all custom wound
in-house by Promitheus Audio.
* Unit dimensions: 12" W x 9" L x 3.5" H
Uses a proprietary Promitheus Audio digital pulse transformer that seperates and isolates
the DAC's digital ground from the digital input's ground. The pulse transformer utilizes a
true 75-Ohm winding on a 2mils nickel lamination. So the transport/CDP sees a true 75-Ohm
connection.
Uses a CS8414 digital reciever, that goes into an asynchronous relocking module of 100Mhz,
from there it goes into the TDA1545A DAC. The DAC is run in non-oversampling mode. The
OpAmp used is 2 pieces of NOS NE5534 by Phillips. The OpAmp is in a turn pin socket, this
allows for swapping in/out other (compatible) single OpAmp pairs (13.6 volts is supplied to the
OpAmps). The power supply uses a master regulator that feeds into local regulators individually
feeding the ICs. So each digital IC is totally isolated from other digital ICs. The OPAmp segement
has it's own local discrete regulator. This keeps the noise isolated between the left & right OpAmps.
The unit has one output (RCA) that is coupled to an output transformer. The output transformer
isolates the DAC's ground from the rest of the componnets in the external audio chain (preamp,
intergrated/power amp). The output transformer also provides impedance matching between the
DAC and the preamp or intergrated/power amp.
* When this DAC was designed, Nicholas Chua made the PCB such that it was quick and easy
to 'roll' different opamps into the DAC. I purchased two Audio-gd discrete single OPAs
(OPA-Sun models) and two standard length 100MM 'BrownDog style' extensions. Please see the
(almost) last 3 photos below. I did NOT solder the Audio-gd opamps' ground wires to anything
...they were sercurely twisted and then taped into place around the -Neg ground of one of the
output transformers. The original Phillips NOS NE5534 opamps have since been replaced into the
unit and all is exactly as it was and perfectly operational (Please see photos #'s 5 & 6 below). One
of the nice things about these Audio-gd opamps is that the opamp's + & - rails are already bypassed
to each other and to ground at the factory using Evox MMK capacitors. So how does the DAC
sound with the Audio-gd opamps ...the person who buys this DAC should, without question,
roll the Audio-gd opamps back into the DAC. They better the Phillips NE5534 chips hands down.
It takes the DAC from sounding Ok, to sounding really good.
* The saved webpage from Audio-gd:
http://billthecat.webs.com/AudioGd_SunOpAmp.htmlThe price is
Sold $175.00 USD plus the actual shipping charges,
insurance and signature confirmation of delivery fee. Payment may be made by
USPS money order or PayPal (plus PayPal fees, if 'gift' not used). Personal Checks
are accepted, but item will not ship until the check clears at the bank. I will ship
via USPS or FedEx only. ...local pick-up option is open to discussion. Please use
the information and links below to give an accurate estimate of the total costs.
Ships in the original packaging, plus all seams and edges have been reenforced with
generous amounts of clear packaging tape. The parcel is damn near water-proof.
Parcel ships from zipcode: 43082
Parcel weight: 11 lbs. 15.80 oz.
Parcel dimensions: 16.25" x 14.25" x 8.5"
FedExUSPSIf you would like to purchase or have questions, please send me a PM.
For feedback on me as a seller / buyer ...please do a search using the
terms 'For Sale', 'FS' and 'Sold' with the username 'Oscillate' on all the
AudioCircle Trading Post subforums.
...Thanks for looking
