201-202 Series board, Board has had all capacitor updates, +7dB gain, Input impedance set at 20? but can be adjusted, Lower gain version for high output moving coil, Condition: 9.
Black Pebble finish, small cosmetic flaws, above volume scratched very minor, right of "bass" discoloration, all lettering intact, very good condition, Condition #9
Black with white lettering, black anodized, all lettering intact *except (L-R) "L" slightly rubbed and discoloration of black surface, this face panel can use previous screws standard to regular face, very good, still shows nicely, Condition #9+
Black with white lettering, black anodized, all lettering intact, very slight discoloration of surface below lower right side screw hole, looks very nice, excellent condition, Condition #9
Black with white lettering, black anodized, all lettering intact, very light, small scratch below center screw very light about 2" long, this face can use previous screws standard to regular face, very good condition, shows well, Condition #9-
Email us at sales@audioproz.com or call (617) 926-8020 for more information about ADA modifications and repairs.
Apt Holman Rack Mount Face Panel
# 62875
Rack holes show some scratches and lower right hand corner slightly bent/distorted, grey smooth finish, lettering all intact and distinct, some paint scratch on top edge and bottom edges (19" wide x 3. 5" tall) Used Good Condition, comes with no hardware, reuse standard Apt face screws to install. Condition #8
Special kit of black, anodized knobs with a shiny finish. 4 small, 2 large. Unique, custom set for prototype audiophile version. For in house use, requires special fit onto shafts. Very sexy! Like new! Condition 9+
Rack mount version, green and black color. No handles included with this piece, but some may be available here. Good #7 condition with three or four long scuff marks in middle, but acceptable for someone who needs a rack face.
10k ohms X 2, detented control, #279Y10Kx2, 6 legs, 5/16" shaft length, 10 available, new, condition #9 (the listed price is for 2 controls)
FYI: These are fine detent (click) controls. They may be more accurate than the program channel balance you are sending through them, actually. To improve "scaling" of the control, a 2. 2k to 4. 7k resistor could be put in front (series) with the control. This would probably allow that at the average listening level, the position of the control would be about halfway up.
But this level of audio really also depends on what signal preamp levels come before, and what amplifier gain or input impedance you have after the control. Such matters of level are usually more inaccurate here than with the control itself. In a Japanese preamp like a Nikko Beta 1 (uses same part), control tracking accuracy is within . 5 db channel to channel balance. But passive control designs often are inaccurate, subject to matters as mentioned above.
It seems ironic, but passive circuit audiophile designs actually are not as accurate or as quiet as the op amp buffer IC pre and post the control. These controls can be wired in as a true gain control also (not a simple level control) and now frequency bandwidth, impedance matching problems, etc are all solved. But a passive control is OK as long as you are not trying to output a tube preamp to a tube in amp whereby the impedance and signal load matching is now usually a mismatch. It can be a problem to get everything right. Here is a case where probably you must "pre load" the control with a 50k series resistor! Tube preamps by design need to see this minimum requirement "load," FYI.
(2) Handle available, Matte nickle finish on Aluminum handle, Screws included (need to be cut to proper length for face panel with bolt cutters) 3" center-center, used, good condition Condition #9 Price is for the pair
Spare or substitute parts may be available. Email Us at sales@audioproz.com and include a picture and/or the number on the unit. We make excellent spare part selections.
APT HOLMAN PREAMP
# 61713
Power switch, complete with mounting harness, button, leads, used, salvaged from unit, fully in tact, great condition, works well, condition # 9
Pebble Black Finish, various available. One (1) in #9 Condition- $68. Six (6) more available in various conditions, all good with no major damage, approximate #8+ condition -$46.
Control,non detente (click) , Version with slightly longer shaft 1/8" inch higher but easily can wire jumped into board($6). Same type of central lab look and feel, connect ranging for bass & treble, original control detente ($12). 9 condition, salvage test 01.
