Triode as Voltage-Controled Dynamic Resistance in Compressor/Limiter

[TheeAldeen]

I tried the 6BA6 and it can be used. I think I could get 60 db or so of gain range out of a 6386, and maybe 35 or 40 out of a 6ba6. If I remember right the 6AS6 is another possibility. You can use either G1 or G3 for gain control. There is a TV tuber triode that worked good, but I can't remember the number and all my notes and stuff it packed away due to a recent move.

THANK-U tubelab.com u sir are my Daily-Hero! I ended up deciding to go the Opto-path & implement the LA-2A into my Tube Channel Strip.. but now .. reading this I can use the 6BA6 and build a Fairchild-ish Compressor... Correct?

 

[jechentau]

there is a nice toshiba photovoltaic optocouplerthat i know of (and have), the tlp3914, which would enable galvanically separated control of the bias voltage of a triode. up to -10V or so, with a 330K shunt/grid resistor. i'm not sure but it may be easily modulated fast enough for use in a compressor. it would make a unique compressor.

 

[TheeAldeen]

Stunned over this website -- just reading through it now -- might come in handy for me :") if anything it's d*mn interesting + loaded w/goodies :'D

http://www.tangible-technology.com/dynamics/comp_lim_ec_dh_pw2.html

 

[TheeAldeen]

there is a nice toshiba photovoltaic optocouplerthat i know of (and have), the tlp3914, which would enable galvanically separated control of the bias voltage of a triode. up to -10V or so, with a 330K shunt/grid resistor. i'm not sure but it may be easily modulated fast enough for use in a compressor. it would make a unique compressor.

.....please tell me more -- what you said though I did not understand 100% of it -- was & is VERY interesting. I am ALL about odd-ways to achieve something been done over + over the same way.

 

[jechentau]

this pic basically looks like how i meant it, except with a triode instead of the mosfet, the array the other way around for negative bias, a 300K shunt resistor across the array, and a analog control signal to the LED. the triode then is a controllable resistor.

 

[TheeAldeen]

jechentau, can u draw what is in your head up for me + repost it in the forum ASAP. I think we just answered the $64,000 question my friend 😉

 

[TheeAldeen]

...but still... The valve is just an addition to the "work"... For the LED + thee Array... Correct? Thus it would be no-different than using the T4B Photo-Cell *(as seen in the LA2A) in conjunction w/ a valve... Right? Ok, jechentau ...I need u to help me understand the difference of how this system would work compared to the Vari-mu system seen in the old vaccuum tube compressors + limiters.

Here is why -- I want to build a compressor + limiter using the 3-different systems for varying/controlling the resistance to create the effect we need..

So, the 3-different compression methods I am trying to learn + tackle are:

Optocell -- LA2A
Vari-mu
tube VCA..? *by modulating the grid/ screen/ or suppressor.

...I'm going to Start a New-Thread on Ideas we can come-up w/ to Modulate the ef86. This is what the thread will read:

I'm using it in my Mic Pre section of my Tube Channel Strip + I want to be able to Modulate + Control the ef86 in ANY way possible to affect the sound I will have available + at my disposal... I'm trying to get everything I can from this signal... Anything + Everything... If I can squeeze even one once of tonal-change from being able to use the extra electrodes of the Screen+Supressor... As ways to alter the signal.. please lay it on me guys + gals.. the ef86 will be used as in the REDD47 design + modulated/ altered by means of the extra electrodes of the pentode. *the extra electrodes of the ef86 are NOT connected to Cathode -- so they are perfect for modulating/ altering the signal as spoken by the Great Eric Barbour... A man I idolize by taking the "odd+unused" & manipulating & altering them & their signal for added effect..

Barbour is a man that has taken random odd-ball tubes & used them to build differing designs from guitar amps ("The *******-******") and has put out a VERY successful line of synthesizer modules under the name METASONIX. His work is what inspired me to think outside of thee box when it comes to the odd + unusual😉

All n' all, we have all the time in the world + I want to pick each & every one of your brains😉