TECHNICAL WORK.
  
  
 
Accumulated rotary switches and attenuators.
  
  
Daven.
  
Peerless E-204-D, possibly the best repeating coil transformer. Used to encode the MS loop in the mastering console.
  
Four channels of mic preamplifiers based on the Jensen 990. Two channels with Jensen transformers in-out. Two with Traid HS-66 input, direct out.
Hamptone HVTP2 two channel tube mic pre. Built from Scott Hampton's kit. Nickel-core transformers in-out, regulated B+ and filament supply, excellent shielding. 12AY7 gain stage with 12AU7 totem pole output. Upgraded with Alps blue pots, Axon and Orange Drop caps.
  
Refurbished Altec 1566a mic pre—beefed up power supply, selenium rectifier replaced with FRED's, signal caps changed to Orange Drops and Vitamin Q, improved grounding, cable shielding.
A two channel tube mic pre I designed and built into a completely gutted Dynakit PAS-2 case. B+ is still rectified by a 12X4, the filament supply uses fast recovery diodes. Signal path: Beyerdynamic input transformer, 12AT7 common cathode gain stages, and paralled 12AU7 cathode follwer output (unbalanced transformerless). Not ideal for driving 600ohm loads, but fine for most modern equipment with bridging inputs. Largely wired point to point, external 48V supply.
   
Jensen Twin Servo mic preamps using cards made by Steve Hogan. Classic circuit using JE-16 input transformers with phantom power and relay-switched polarity reverse. External Avel-Lindberg toroidal power transformer. Both Jensen transformer balanced and direct impedance balanced (using Jensen output isolators) outputs are available for differenet sound as well as isolated splits. Custom duo equalizer/mic pre. The EQ's are built around Spectra Sonics 500 RLC modules, each with channel gain pots. To the right are two transformer-coupled (Beyer) IC mic preamps using Burr Brown OPA627BP and DRV134's with 20db pad and phantom switches. 12-position stepped attenuator with 1% metal film resistors provides precise gain setting. Point to point wired, star ground.
One of seven modules in the Altec 9062A passive graphic EQ. Each module contains two inductors and capacitors for the bridged-T network.
  

   
The pcb traces are gold plated, and the stepped (±8db in 1db steps) switch wiper is bifurcated. Accuracy is calibrated within ±0.5db. Electrodyne 253-A, built by Langevin, same as the Altec 9060 "microphone equalizer." This is a trimmed down version of the Langevin 251, with fixed 7k peak/10k shelving cut and 100hz shelving boost cut.
  
Spectra Sonics 500 module LCR networks, designed to work in the feedback loop of the 110 40db line amp cards. Currently used in a custom Organized Sound gain section.
  

   
Neumann PEV eq. Passive eq section with input, interstage and output transformers. Discrete balanced make-up gain. Two channels each of Spectra Sonics 101 (with Triad HS-56 input xfmr) and Altec 9475A (Shallco T-attenuators on the output).
The Acoutilog CM-3 console on the bench. When I purchased the mixer, it came in variously unfinished parts, all wraped in New York Times from 1983, when it was put aside.
 
   
Refurbished TV-3C/U tube tester.
 
My old bench.