Reader Bill W recently sent us a few interesting ancient DIY audio projects that we had not seen before. Today’s post is from RADIO-ELECTRONIC ENGINEERING and was written by one Ed C. Miller.
DOWNLOAD THE COMPLETE ARTICLE:Constant Output Broadcast Amplifier
The article details the operation and construction of the above-illustrated broadcast-remote mixer/amp, which includes a limiter. While the overall unit is probably not something you’d want to ‘F’ with, the limiter component could be added to a DIY tube mic preamp (perhaps with a true-bypass switch). One caveat: as the article warns, there are apparently ‘thumping’ artifacts inherent to this circuit, which was acceptable in its intended operation since it was designed for voice-frequency.
Anyhow, might be a fun project for a rainy day – build a pair of these into box with cheap 1:1 input transformers and simple line output stages? Crush some room mics? Anyone?
7 replies on “A Simple One-Tube Compressor Circuit c.1953”
would this work at the front end of guitar amp?
Hi. It’s possible, but it would be ill advised. I would recommend putting at least one voltage-gain stage ahead of it, and an interstate volume control as well. c.
So, what makes this different than a simple single stage tube amp? Is it the configuration of the capacitors that cause the compression?
I am not sure exactly how it works but it sounds awful and i don’t recommend that anyone build it, total waste of time.
hey…i know it’s an old thread but could you tell my your experience more why is it awful? Mine sounding pretty awesome…cheers!
I found this thread a few months ago, I find very easy to give a try, did you use 6SL7? what voltage did you apply?
Is strange 470K for plate, did you try lower resistance? I will like a clean sound.
Hi, what type of transformers do you recommend for mic input and line output? I have no experience with this type of circuit. What voltage did you apply? Thanks a lot!