gang of elk
Well-known member
mini, as in 2 x 2 x 1.. not as in lbs/kg. :green:
modules are from a collins 212E-1 console, circa '57-'63. the 2 preamps are 356A-1's and the limiter is a 356E-1 vari-mu.
the preamps have 40db of gain and 28db of feedback so i rigged a switch to raise R in the feedback loop and boost gain to 65db or so. with no feedback it's a very colorful amp. in the 'low' / 40db position, the preamps are flat and sound robust and articulate, quiet as a mouse.
there's also a switch to send each preamp signal to its direct output or to the limiter. the signals can be blended into the limiter's input.
the limiter has a 600 ohm T on it's input and a pot for variable threshold. the output is followed by a fixed 20db pad then another 600 ohm T for final level control. it's all very usable considering these modules were designed to operate at such high levels.
i lucked out and found these matched tubes (and a new 6386 for $30!) from nice ham radio guy.
total of (4) 600 ohm mallory T's (thanks NewYorkDave!) help keep levels under control.
homebuilt PSU made w hammond 369ax, original collins choke from 26U, and dual cap from angela. it's putting out 302Vdc under load, just right!
thanks to everyone here at the lab and especially to NewYorkDave for all his contributions to the subject of passive mixing.
modules are from a collins 212E-1 console, circa '57-'63. the 2 preamps are 356A-1's and the limiter is a 356E-1 vari-mu.
![collins4.jpg](https://proxy.imagearchive.com/7ef/7ef305ed1d4ae55fd75b022b9327b607.jpg)
the preamps have 40db of gain and 28db of feedback so i rigged a switch to raise R in the feedback loop and boost gain to 65db or so. with no feedback it's a very colorful amp. in the 'low' / 40db position, the preamps are flat and sound robust and articulate, quiet as a mouse.
there's also a switch to send each preamp signal to its direct output or to the limiter. the signals can be blended into the limiter's input.
![collins2.jpg](https://proxy.imagearchive.com/ff8/ff8434494e2e2bb0459ea54525218f50.jpg)
the limiter has a 600 ohm T on it's input and a pot for variable threshold. the output is followed by a fixed 20db pad then another 600 ohm T for final level control. it's all very usable considering these modules were designed to operate at such high levels.
![collins3.jpg](https://proxy.imagearchive.com/193/1936e3e77cd9fe5c0542238d057a5ebe.jpg)
i lucked out and found these matched tubes (and a new 6386 for $30!) from nice ham radio guy.
![collins6.jpg](https://proxy.imagearchive.com/f78/f786f79b78177718c92e57bcb99de57b.jpg)
total of (4) 600 ohm mallory T's (thanks NewYorkDave!) help keep levels under control.
![collins5.jpg](https://proxy.imagearchive.com/33d/33d836168b564fce5f3a6b1cf1c79144.jpg)
homebuilt PSU made w hammond 369ax, original collins choke from 26U, and dual cap from angela. it's putting out 302Vdc under load, just right!
![collins7.jpg](https://proxy.imagearchive.com/6f7/6f7f7e0a7fe64843e2b89efca54e6bdc.jpg)
thanks to everyone here at the lab and especially to NewYorkDave for all his contributions to the subject of passive mixing.