Tonemender HUGE Booster?

[mydementia]

Hi guys.
I just boxed up my perfed Tonemender (ROG) and immediately liked it.  I used a TL072 opamp and don't get much, if any, hum.  My one mistake (caused NO output when I fired it up the first time  ) was using 1M pots for all the 500k pots...  I ran 1M resistors across the pots being used as variable resistors but left the Treble pot open.  I thought about it at work today, and before spending any more troubleshooting time, I put a 1M resistor across both sides of the pot and it fired up just fine.  Whew!!

So...does anyone else's Tonemender have GOBS of boost?  I'm finding 'unity' right around 7:00 (6:00 is my 'zero'). 

Also...where's the best place in the chain for this type of EQ?  I put it at the end of my chain and ran a bunch of boxes into it - all took on the flavor of the Tonemender...it even 'crisped' up my TS808 clone.

Thanks for looking.  This site is awesome.
Mike 

[JimRayden]

So...does anyone else's Tonemender have GOBS of boost?  I'm finding 'unity' right around 7:00 (6:00 is my 'zero'). 

So it goes quickly to full boost and remains constant for the rest of the turn? Sounds like a taper issue. Perhaps you used a B-taper as the vol pot? Or maybe the 1M resistors are goofying around with the taper...

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Jimbo

[B Tremblay]

Mine has unity at around 10:00, but that's somewhat dependent on the tonestack settings.  I concur with Jim; incorrect taper of the Level pot could be responsible.

[mydementia]

Hmmm.... I always use linear pots for volume (and most everything else) - makes more sense to me (half way is HALF WAY!!!!). 
I don't know if a 'little above unity' is 'max gain' - as I recall, it just keeps boosting until I run out of rotation. 

Does it really matter which taper I use?  I actually didn't notice (until you guys pointed it out) that I was supposed to use audio pots for everything but treble (still getting the hand of building from schematics...the GGG project files spoiled me!!) ...I assume this would just make the interaction different...except on the treble and volume pots where you use both sides... interesting.

Ya think I should try it again with the right taper pots?  Maybe I'll check this build with my Condor to see if it will be a good clean booster/tone shaper...

Thanks for your responses.
Mike

[JimRayden]

Hmmm.... I always use linear pots for volume (and most everything else) - makes more sense to me (half way is HALF WAY!!!!). 

That's the spirit!

Too bad your ears don't agree (unless you've been through an accident of some kind that messed with your hearing dynamics). The audio taper is modelled by human's ear, which is not by any means linear. That is to protect your hearing system by attentuating the higher volumes. Your ears "amplify" quite well when you're listening to quiet music. But when you turn it up, the amplification factor of your ear goes down to prevent the amplified audio signal from hurting anything in you. Human ears are helluva great biological compressors.

So, if you follow a linear pot through its sweep, your ears amplify quite well at first but as it gets louder, you just don't sense the difference too well anymore. The brain just doesn't understand the linearity of your pot because there is the DAMN HARD-WIRED COMPRESSOR IN THE WAY!



Audio taper is there to save the day. It compensates the compressing effect and you'll sense the pot's rotation as linear. The slope goes gently at first and towards the end, it increases quite quickly.

Make sure to read this too: http://www.geofex.com/Article_Folders/potsecrets/potscret.htm

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Jimbo