This is what I use for phase rotation for my audio. Old School Broadcasting Tech.

[Onelasttime]

Don't want anyone left behind. I have used this for years. They used to be sold on ebay but not now. It is actual much cheaper now that it is not on ebay. When my old home made one I built in middle school on bread board died I found this. I do not do hifi I went the opposite route long ago. I use this plus tube mic amp and parametric eq and compression. Obviously this is for base operation I use this before compression. A very average compressor seems as if it is world class compressor. Just like adding a tiny amount of delay and reverb not enough that you can tell but enough to liven up your voice on AM especialy if you are in a dead room. If anyone can tell you have added delay or reverb you have missed the bus! LOL

It is not all about hifi! Cheers!

For mobile I use other methods. Just thought I would share!

Audio All Pass Filter, Phase Rotator Module Board, MD-A110, Audiowind A-110

Audio All Pass Filter, Phase Rotator Module Board, MD-A110, Audiowind A-110

czh-labs.com

I know this is this can be done in software today but this works.

 

[G-Golly Wally]

I once put a BIG RADIO SOUND ECHO BOARD in a cobra 29, it seemed more reverb than echo. At that time I could get accurate radio checks and several locals liked just the slightest echo and the slightest reverb. So that's what I went with, and always got compliments on the sound of that radio.

 

[dave457]

 

[TM86]

I once put a BIG RADIO SOUND ECHO BOARD in a cobra 29, it seemed more reverb than echo. At that time I could get accurate radio checks and several locals liked just the slightest echo and the slightest reverb. So that's what I went with, and always got compliments on the sound of that radio.

I wired up a cheap Radio Shack reverb for use with a CB mic back in the 80's. I got... comments about it.

 

[Enterprise312ok]

I put an old lt2 or lt1 echo board in a washington, great reverb I used it with a workman silver salute electret desk mic and the audio was broadcast quality. I received many compliments am and sideband.

 

[Onelasttime]

Most echo boards have delay and reverb. You usually had to turn the echo on to get the delay function and reverb to work. The trick was to just barley turn the echo on and add in just enough delay and reverb to warm the voice but not enough that people could tell you had the effects working.

Just like when you would use reverb in the 1970's and 1980's on your stereo you did not want your music to sound weird you wanted to add warmth to the sound not make Garth Brooks or Michael Jackson sound like a robot or like they are singing into a soup can! LOL

 

[Onelasttime]

View attachment 62401

Kool! That was what I was trying to duplicate in middle school was the Kahn Research Laboratories Symmetra.....