Varitone: Pull DOWN resistors=misnomer?

[David Schwab]

Does this happen to sound familiar?

Yeah, but what I didn't mention was I didn't just double his values and use those. I changed a few until I had something I liked.

I have a few circuits lost to time and memory... like a passive system that made a bridge pickup sound like a neck pickup. I lost the schematic years ago, and tried to reconstruct it from memory, but it was never exactly the same. It also had something to do with the exact pickup I was using, which I also no longer have. C'est la vie!

[David Schwab]

But does this shit sound any good?

I'm not a major fan of passive "tone control" madness. Most of it sounds crappy, and the perceived volume differences from one setting to the next are intolerable. Just because you CAN make a passive electric guitar or bass sound different doesn't mean that it's musically useful.

If you can't make pickups that sound good on an instrument that sounds good, no amount of capacitors and inductors and resistors will make it any better.

This is like attempting to build a great recording studio with nothing but SM-58 mics and a pile of equalizers rather than getting a good selection of mics first.

Rick, I'm all for "active" setups in instruments. But Varitones are kind of fun. They are more subtle than an active notch filter, and have a certain funkyness I like. I had an 8-string bass I made from a Fender P bass that was very clangy in the mids. Real harsh sounding. I eventually fixed that by making a new neck, but at the time I used a Varitone circuit to tame the mids and it sounded a lot nicer.

My favorite use though was in my '81 Les Paul Standard. On the last (lowest notch) setting it gave the guitar a glassy bright tone like a Tele. it used to freak people out!

But the real goofy thing is people spending $100 on one of those ToneStylers, which is just a rotary switch and a bunch of caps. And then they claim it boosts the mids, but don't mention it does that while removing the highs!

Having said all that, I don't have any Varitones in any of my instruments at the moment. But some people are fixated on passive is better, so I'm going to offer some passive tone circuits.

[David Schwab]

Or take ... (LSD) for instance...

Stay away from the purple KoolAid!

Isn't that called LSI and VLSI?

[rjb]

Isn't that called LSI and VLSI?

Now it is. I guess the folks who decide these things got tired of the cracks about purple Kool Aid.

Later,
Ralph "What was wrong with Cycles Per Second?" Barthine

[rjb]

...could you please post whatever further specs or info you may have on the Gibson nut-washer-and-bolt inductor?

In a different thread, David posted this:

The inductors in the Gibson Ripper were made from a 1/4 steel bolt and three steel washers, and would as a humbucker with two coils. I think it was 36 AWG wire.

(Note this is for a different circuit, not the Varitone.)

-rb

[rjb]

Que sound of scales falling from eyes.

Make that CUE sound of scales falling from eyes. I used to know how to spell, too. I swear I did.
-rb

[rjb]

I'm not a major fan of passive "tone control" madness. Most of it sounds crappy, and the perceived volume differences from one setting to the next are intolerable.

Now, I do admit to being a non-musician with a lead ear- but I thought this didn't sound half-bad:
YouTube - 12-way, variable cutoff, resonant peak, passive low-pass tone control (prototype).
It's just a rotary switch with a bunch of caps- no inductor. The guy who built it claims to be a touring musician, and says the signal level is consistant except for the 200 Hz position. And, oh yeah, it's in an SX PBass copy (didn't say if the pickups are stock).

Later,
-rb

[rjb]

Wrapping Up(?)

...just trying to avoid re-re-re-inventing the wheel....

Well, I can't say I achieved that particular goal, but I do thank you all for your kind assistance.

I've detected a pattern... every time I post a question here- no matter what the topic- someone eventually suggests I build a band-stop filter "Varitone".

So, here's my plan of action:
> Put the PBass back together with 2 tone caps and an ON-OFF-ON switch (no-load in the middle), just to have something working.
> Order a 12-position rotary switch, a bunch of caps, and 2 identical audio transformers.
> Try various caps [with and without choke(s)] outside the bass, with switch in OFF position and Volume on 10. (Experiment to include wiring the primary windings "end-to-end" for humbucking action).
> If I like the results, build "Arby's Amazing UltraTone™" with just caps or caps in series with choke in whatever positions I see fit; install in bass.

Thanks again, folks
-rb

[David Schwab]

(Note this is for a different circuit, not the Varitone.)

Not entirely true. It's one selection from a Varitone with an added potentiometer. The Gibson EB-2 had a similar single frequency choke circuit with a push button. I had an EB-2D and found the "baritone" setting useless, so I replaced the push button with a rotary switch and 5 caps.

[rjb]

Not entirely true.

Didn't mean to give out false information. I thought I read (but may be misremembering) that the Varitone used chokes in a can and the Ripper used the "humbucker on a bolt". I don't know if the different configurations have the same inductance- that's the distinction I had in mind (but neglected to state) when I said the bolt version was "for another circuit".

It's one selection from a Varitone....

Oy, semantics... what is a Varitone, if it doesn't *vary* the tone? What's the difference between "one selection from a Varitone" and a textbook band stop filter? OK, I'm being silly.

But talking about textbooks (how's that for a transition?), here's some info for anyone wanting to "roll his own" inductor (old pros, please talk quietly amongst yourselves).

Inductance is:

• Proportional to number of turns squared
• Proportional to cross-sectional area
• Inversely proportional to core length
• Proportional to core permeability

Stated as a formula:
L = (N² x µ x A) / ℓ

For:
L = Inductance (H)
N = # turns
µ = core permeability (H/m)
A = cross-sectional area (m²)
ℓ = Core length (m)

But how do you find out the permeability of a bolt from the hardware store? I have no idea.
Well, that's my contribution for the day.

Later,
-rb

[David Schwab]

Oy, semantics... what is a Varitone, if it doesn't *vary* the tone? What's the difference between "one selection from a Varitone" and a textbook band stop filter? OK, I'm being silly.

It's a notch filter. One of them has more frequencies to choose from, the other has variable depth. But they are both a choke and a cap.

You have to look at it from a guitar control point of view. The "tone" control cuts treble, and the other is a midrange control. Both the Ripper and the L6-S had them. The EB-2 also had its own version.

How they made the inductor is irrelevant, it's still an inductor. The inductor on a bolt thing was a Bill Lawrence design. He probably wasn't concerned with the exact specs as long as it worked. He made other inductors as well, with the L and Q filters. Don't know if he still makes them.

[rjb]

The EB-2 also had its own version.

I think my brain is even fuzzier than normal today. What was the switch supposed to do? It looks to me like a high pass filter vs. a notch filter with Fcutoff or Fres = 290Hz. So it either cleans out all the lows, or it takes out the ~200Hz mud and leaves the bottom? Did it work?

How they made the inductor is irrelevant, it's still an inductor.

I bet you'd feel differently if you worked for the inductor company!

And I'd guess an unshielded inductor vs. a shielded inductor vs. a humbucking inductor might make a difference in how well your loop antenna picks up [EDIT]COUSIN Brucey (not Uncle Brucey).[/EDIT]

So much for "wrapping up",
-rb

[Rick Turner]

Throw a little chunk of gallena in there for some real performance...

[David Schwab]

I think my brain is even fuzzier than normal today. What was the switch supposed to do? It looks to me like a high pass filter vs. a notch filter with Fcutoff or Fres = 290Hz. So it either cleans out all the lows, or it takes out the ~200Hz mud and leaves the bottom? Did it work?

It was the "baritone" switch. It removed all the low end. I guess in the other position there was that mid cut. I only remember the switch making the bass sound very thin.

I bet you'd feel differently if you worked for the inductor company!

Yeah, guitars aren't that fussy.

And I'd guess an unshielded inductor vs. a shielded inductor vs. a humbucking inductor might make a difference in how well your loop antenna picks up Uncle Brucey.

I'm old enough to remember Cousin Brucey...

[rjb]

I'm old enough to remember Cousin Brucey...

We all are. He still has a show on Sirius XM satellite radio. Problem is, I can't pick it up on my Varitone- even with the gallena crystal.

OK, I'm calling it- this thread is officially dead.


Thanks again, everyone,
-rb