Tube Reamer drive control

[shooter_mi]

I've got the Tube Reamer build from Run off Groove on the breadboard and everything seems to be working right, but that the drive control doesn't offer much breadth of sound. Basically it kicks things up a notch at about 1/4 turn and then remains the same throughout the rest of the rotation. I haven't substituted any parts. Is this a normal limitation of the Tube Reamer? What can I do to try an get some more articulation out of that pot?

[B Tremblay]

Are you using a linear or audio/log taper pot for the Drive control?

[shooter_mi]

Good question. Audio taper, per the schem. I tried a linear, and the range was even more limited.

[Baktown]

I'm reviving this thread as I have the same problem as Shooter_Mi, and I didn't find any resolution to the problem.

Besides the drive control not making any noticeable difference in the sound, it's also a little muddy sounding.  Should I change the input cap to a lower value to clean it up a bit?

Thanks dudes!

Axl Bundy

[km-r]

i guess its a limitation..
the only drive setting ive used is the min and max...

btw, i used red leds instead of Si diodes, sounded awesome IMO!

maybe try a higher value pot?

[Baktown]

I'm going to plead newbie ignorance here.  How does increasing the pot size affect the drive?

Thanks!

Axl

[km-r]

gain is:
[resistance across the output of the op amp to the inverting input] <-- the gain pot
divided by the
[resistance from the inverting input to ground or Vb]
plus one...

thats the simplified math there...
so increasing the gain pot will increase the gain of the op amp section...

[MartyMart]

Try a reverse log pot - smallbear has them, this will smooth out the gain range
works well on a number of OD circuits.
MM

[shooter_mi]

I tried a reverse log on mine, and it did smooth out the range, but in the end I used the reverse log pot in an MXR microamp and kept a regular audio taper in the tube reamer. For the record, I think the the tube reamer is a very cool circuit, and it sounds great. As far as the limitation of the drive control, I think commercial effects may have made me accustomed to a range of dial-twisting that is simply unnecessary. I'm used to this tube reamer control now, and I think the pedal is a great overdrive, period.