ampage Tube Amps / Music Electronics	For current discussions, please visit Music Electronics Forum.

ampage archive

Vintage threads from the first ten years

Insanity Box (for Aron)

:

11/6/1999 2:11 AM

Insanity Box (for Aron)

Aron,
I'm not gonna kid around, The Insanity Box is a good
pedal, Really nice on bright, single note riffage.
however, I think it lacks girth and fatness. Changing the
LP cap in the tone section didn't do it for me.
For power chord work, I liked the following coupling cap
changes- (your opinion please)
Op amp output- .1 to 10uf
after diodes- .1/6.8k to 1.0/6.8k
between CMOS- add 10k/.1
before tone- .1 to 1.0
also added 100pf to input (Big AM radio in my area)
Please try this and let me know what you think. note, this is not one of those "I like what I like, and you like what
you like" deals. I like it already, but try the "girth" .
respectfully, Ed Rembold

11/6/1999 4:36 AM

Ed, did you build it already??? Wow, if so, then you are the first comfirmed build!

Aha! I took a look at your changes, yes, that would add bass. Here's the thing, mine has plenty of bass alright and "thickness". I'm wondering... could the brand of CD4049 have something to do with it? Frank Clarke tells me that he doesn't get much bass loss or frequency loss from his 4049 chips, but I sure do. In fact, the more stages I have, the more the frequency response degrades, both upper and lower frequencies.

I am going to build another one soon and try your changes.

When I did the "mod" for too much bass, man it was overblown and was too big.

Ed, what type of CD4049 are you using? What op amp?

Thanks for the feedback!

Aron

11/6/1999 10:53 PM
Hammy	Aron, In your schematic you say you used CD4049AE. From what I read, you're supposed to use the unbuffered ones with UB in the part number. Perhaps you just omitted for simplicity, or maybe it has something to do with the lack of bass response?

11/7/1999 2:20 AM
Jack	I believe that the "A" version of some cmos chips, including the 4049, are unbuffered. To be positive, use the CD4049UBE. JACK

11/7/1999 6:16 AM
Aron	Yes, it's unbuffered. It works fine, but yeah, the freq response thing is interesting. I think if you use it in the right way and put a "bass recovery system" (yeah right), it could be good. Aron

11/8/1999 1:39 PM

"Buffered" means that instead of a single CMOS inverter, each gate uses 3 CMOS inverters. This gives a better performance for digital (the transfer curve has a shraper transition from '0' to '1') but it's not good for analog where you want a "soft" transition. In other words you have three times more dBs of open loop gain with the buffered chips, and that does not sound good and makes it hard to bias them into linear operation.

The "AE" series is unbuffered. The "B" series is buffered. The "UB" series is unbuffered, but "guaranteed to meet buffered performance" (for digital). This means the UB series uses single CMOS inverters for each gate, but these inverters have much more gain than the AE series.

I strongly suggest using a CD4049AE, if you can find it.

11/8/1999 2:11 PM
Jack	Or if you really want to get basic, you could alter the design to use the CD4007, which contains 6 mosfets (3 of n-mos and 3 of p-mos). I'm probably in the minority here, but I have never cared much for the sound of mosfets. -JACK

Page 1 of 7