tube wah by rg at geofex

[Headbuttking2]

I have a question about simulating this...

I know at the end of the article that the simulation may lie to you...

But when I simulated this...at the output it was just a high pass filter and its gain changes with the change of the pot.
The frequency never changed..

Since I didnt have any power mosfets to use in Microsim....I used a 12AX7 and fiddled with the cathode resistor..

Can the problem be the 220R resistor? I just put it in as 220 Ohm..

Am I doing something wrong that the frequency does not change?

[R.G.]

My sim showed a stock wah response. I'll go re-do it and post a pic.

[R.G.]

Yep, it gives a high Q lowpass filter response in the low audio range.

See http://www.geofex.com/FX_Images/Tube_Wah_Sim.gif

There may be something not quite set up correctly in your sim.

More importantly, others (not just me!) have built it and it works as a wah.

[Headbuttking2]

What are you using to simulate this?

I checked over the circuit 100x and it is exact to the specs.....but something must be off because with an input of
300 mV, I am getting an output of voltage that is around .02 fV, which makes no sense.

Either way, I plan on building this.

[analogmike]

>> Sprague Atoms, Orange Drops
When I see things gleaned out of tube guitar amps being applied to effects, I get this itchy feeling that my wallet is under attack.

Orange drops sound lousy anyway, there are much better caps available.   

[R.G.]

I checked over the circuit 100x and it is exact to the specs.....but something must be off because with an input of
300 mV, I am getting an output of voltage that is around .02 fV, which makes no sense.

I'll occasionally have a problem like that. When I do, I sometimes find that I neglected to put a DC power source on the circuit, or hook it up to ground, stuff like that.

Orange drops sound lousy anyway, there are much better caps available.

?

How's that on a tube based wah?? Que?

[sta63bmx]

been through the Mojo Thread yet, youngSta?

I missed this link the first time around.    What I hate is walking into a store and hearing these terms come from someone who wouldn't know a carbon comp resistor from a kick in the head.  Well, maybe they would.

Some day when I have time, I want to take two identical TS-808 clones, build one with a VINTAGE JRC4558, all carbon comp resistors, and poly film caps, and then build the other one with a TI 4558, metal films, and all ceramic caps where possible, and put them side by side in ONE BIG BOX with a button to toggle them.  I'll set the controls the same where the person can't see 'em and then let them toggle back and forth and play and see what they like better.  First off, if they weren't toggling it, I bet a lot of people might not hear the difference.  But if they COULD toggle it, I would be really surprised if even 75% of people consistently said "Oh yeah, huge difference, this one is WAY better!" and it was the "vintage" style one.

I mean, we all know that guitar electronics are a great place for The Emperor's New Pedals thinking to run free, since the subject of tone is subjective.  I like discussion on the subject, but some people just have this doofus attitude and they're totally convinced that "Yeah, it has to be a blah blah made in blah blah like blee blee used on BWAAAA BWAAA or else the BLEEE BLEEEE won't sound like the MEEEEEUUUUUUWER on the hoinky."  Or something like that.  Once you add in the fact that vintage guitar stuff is worth money, it just excites the already unstable system and BS-larity ensues.

My only caveat about the Blind Tubescreamer Taste Test is that anybody who insisted long and loud that you had to have the blah in the blee for the MEEUWER and then failed the test would be forced to wear an I LOVE CERAMIC CAPS shirt for a whole day.  Most people wouldn't care, but I bet that might drive some people to commit suicide, surrounded by their collections of unplayed Gibsons complete with all hang tags.

Goodbye Cruel World:

I learned today that I can't really tell the difference between an early 80's JRC4558 and a new TI reissue, and I can barely hear the difference between ceramic caps and poly film caps.  The agony reaches the bottom of my soul and I no longer wish to live.  Please bury all of my Gibsons with me and wrap them in plastic so they don't ever decay.  And please preserve my completely stock, near-mint 1982 L-82 Corvette and finish restoring the factory overspray under the hood so it's all concourse perfect. 

Sincerely,

Throckmorton D. Billingsworth, III

I'm not saying poly caps DON'T sound better, I'm just saying that I only use them because everyone else does at 1uF and under down to mica cap range.  But I can't say that I KNOW they sound better, cause I've never AB'ed two pedals built both ways.

[Headbuttking2]

What are you using to simulate?

[Headbuttking2]

Well I figured what is killing my voltage when simulating...

Its the 1 Meg resistor at the input to the first 12Ax7 Grid (brings it down to nano volts)....
I understand that this is needed, but should this be happening during simulation?

[TELEFUNKON]

reply #15!

[Connoisseur of Distortion]

that's hilarious. who made that decision? i thought metric conversions were well thought out, and universal? 

[Paul Marossy]

After I am done moving next weekend, I'm building this one. I think I've got an idea for a slick way to build this project. 

[Headbuttking2]

I have been using M....if thats the problem, thats BS. 


Thanks though, ahaha