Franks Pultec/Classi PEQ gain
« on: February 11, 2017, 06:21:54 AM »
I just finished building a solid state Pultec style EQ. Upon testing it through Waves Q Clone, I found that, when set flat, the EQ curve (or line, I guess) sits at -24dB. That's really low, right?  According to Don Audio's instructions, lowering the resistance of the 10dB resistor (R5: behind the Output on the Gain Stage) will raise the gain. No dice. Can anyone offer help? Seems like these haven't been talked about much since 2013. Cheers!


Pusch3l

Re: Franks Pultec/Classi PEQ gain
« Reply #1 on: February 11, 2017, 01:06:48 PM »
You could replace R5 with a trimmer. I dont remember which Resistance the R5 has because my PEQ gainstage is buried in a box.
Solder the wiper (middle leg) from the trimmer to an outer leg and solder both outer legs onto the pcb.

Re: Franks Pultec/Classi PEQ gain
« Reply #2 on: February 11, 2017, 03:00:19 PM »
I have a ton of pots. How could I figure out the value?

Pusch3l

Re: Franks Pultec/Classi PEQ gain
« Reply #3 on: February 11, 2017, 03:45:55 PM »
There are two ways.. look at the BOM. I dont have it at hand sorry...
Or
Write down the color code and visit http://www.dieelektronikerseite.de/Tools/Widerstandsrechner.htm

I know its not elegant, but it will do the job ;)

And for example it is a 10K resistor take a 15K or 20K trimmer, solder the legs as mentioned above and pre-trim to 10K with a DMM. Then replace R5 with trimmer and check if the gain is the same as before. Then you can start trimming to decrease gain.
After that you could start hooking up your sowters.

Re: Franks Pultec/Classi PEQ gain
« Reply #4 on: February 11, 2017, 10:05:57 PM »
I owe you a drink!

pstcho

Re: Franks Pultec/Classi PEQ gain
« Reply #5 on: October 01, 2020, 12:36:23 PM »
Hello everyone

anybody has the BON for the gain stage?

thanks