Varitone with Allparts 6 position, 4 pole switch

[javacody]

Here is the switch I have:



I'm thinking that I wouldn't have to stick to the standard varitone schem here. With this switch, I can eliminate 4 of the 5 10 MOhm resistors by tying 5 of my positions together on one pole and running those through a 10 MOhm resistor and running that into one of the other poles, I can then run the 5 caps out from that poles 6 positions. Does that make sense?

Now I have 2 poles left on this switch. I could run a push-pull pot to switch to these other two poles, but what would I do with them? I read that I could somehow make a mid boost rather than cut with a varitone, but how? And can someone explain in simple terms how a varitone works? Also, in the Gibson Blueshawk schem, Gibson lists a 7.2 Henry inductor, how would this sound different from using a 1.5 Henry Inductor as in other varitone schems?

[MR COFFEE]

The 10M resistors are to avoid popping noise, using the other pole defeats the purpose. No cigar.

The inductor and capacitor sizes control the frequency of each position. Changing either changes the tone range effect at each position. Changing the inductor alone (same caps) by 5 times would change the frequency range affected by each position dramatically. Decide what you want it to sound like, or better yet, buy an inductor in the general range and tweek the caps to YOUR liking.

Have fun

[javacody]

OK, so no go on the second pole.

The original Varitone was used with buckers and on the blueshawk, its used on P90 type pickups that aren't wound as hot as standard p90's (they are about 6K) and also instead of screws for pole pieces, it has alnico magnet pole pieces (like on a strat). I'm thinking that the blues90 pickups used in the blueshawk would be less midheavy than a bucker or standard p90. However, I'm using standard type p90's. I'm hoping that the original 1.5 Henry inductor will get me a good sound. What do you think?

[MR COFFEE]

Well, you are setting out for unexplored territory, dude, and expect to do a fair amount of tweaking.

The varitone is a resonant beast using an inductor and cap network, and the source impedance is the impedance of the pickup, which is variable over frequency, and has it's own resonances with the capacitance in the windings themselves as well as the capacitance of your guitar cord.

My guess for what would get you into Varitone territory is an inductor between 2 and 6 henries, but I don't know the impedance and self-resonant characteristics of the Blueshawk pu or the old-style P-90. I have the data for the old Gibson humbucker, measured, not spec, around here but it won't help much without comparison data.
I would guess it needs to be closer to the Blueshawk design than the Humbucker.

:idea: Maybe someone else here or over at the pickup makers forum at Ampage could give you some data on those. :?:

Ampage pickup makers  folks have been very helpful to me in the past.

High value inductors are hard to come by - send me a message if you decide you want to fool around with this and 5H looks like it's worth a try - I have a few miniature 5 Henry inductors in my parts bins around here somewhere that might fit the bill for your guitar. :idea:

[Ge_Whiz]

Yep, the Varitone uses a capacitor and an inductor to make a simple, passive bandpass filter. However, like an inductor wah, the sound depends critically on the quality of the inductor, and, in my experience, most high-value 'choke' inductors don't cut it. I struggled for ages trying to build my own and finally gave up because the effect was just too subtle. Eventually, I just used one half of a six-position two-pole switch to switch five different capacitor values from 1nF to 22nF across the output jack, and it sounded MUCH better.

[MR COFFEE]

GeeWhiz,

Please explain to folks what you mean by your remarks about unsuitable 'choke' inductors...

I suspect you are bringing up a valid point, but that you have never really understood what went wrong in your attempt at a Varitone, and your reply doesn't really say anything useful except, may I paraphrase,

"Stay away from the Varitone circuit (if you don't know what you are doing)".

My guess is your bad experience with trying to put a Varitone circuit in your guitar has to do with:

a) The Varitone circuit isn't all that useful for the sounds you are after in the first place (I have actually had people come to me wanting a Varitone put in their guitar that had never played a guitar with one in it before, because, "Well..., BB King has one in his guitar"  :shock:  Jeez people. LOTS of things sound good in magazines  :oops:  :cry:  :lol:

or

b) You misapplied  the Gibson circuit by using it cut-and-paste style with pickups whose impedance curve wasn't suited to the circuit (like hot-rodded humbuckers - whose impedance curve is way different from the Gibson standard humbucker design with alnico magnets, or single coils)

and/or

c) You tried to build one from a Gibson schematic without regard for the inherent dc resistance of the inductor, because it isn't spec'ed on the schematic.

The only pertinent aspects of the inductor used in a Varitone are inductance, resistance, hum pickup (Q at audio frequencies shouldn't have much to do with anything other than dc resistance in a properly designed inductor), and core hysteresis. IMHO.

BTW - Is there an abbreviation for "In-my-puffed-up, I-know-what-the-hell-I'm-talking-about-opinion"? Just for future reference  :lol:

I'm betting that what you mean by 'choke' inductor is a BIG inductor meant to carry large amounts of current in a power supply application, rather than a tiny one like Gibson uses, intended for use in a low-audio-signal-level application. You bought an improper inductor, tried to put it in the Gibson circuit, and then got frustrated when it sounded bad and gave up, eventually going for a multi-position, put-a-variety-of-caps-across-the-pickup-coil tone switch. Right?

If the inductor is the right value, is about the same size as the Gibson inductor (tiny), if it has tiny nickel or nickel-steel laminations thinner than paper (or an iron-powder toroid core), and if has wire the size of pickup wire, it'll be usable and work fine. It's that simple.

Ahhhh, well, ... maybe that's not that simple, huh?  :wink:

Tiny low-level-audio-inductors aren't in any of the parts-jobber catalogs I get. They are a specialty item.

The Varitone is a simple circuit to implement if you understand the variables involved, and are willing to use it as designed, or use your ears to design one suited to your pickups. You could even eliminate that position NOBODY uses and put something else in there (PRS 'Sweet switch', anyone?)

[javacody]

I'll take one of those 5H inductors off of your hands. How much do you want and will you take PayPal?

I have a Radio Shack miniature audio transformer, how many Henries is that?

[MR COFFEE]

Javacody,

I want to be sure you realize that the 5 Henry inductor I was offering (if it would help you out) is NOT the value in the standard Humbucker Varitone.

Have you found out about the characteristics of the pickups you plan to use it with, and are you going for the standard Varitone sounds? Have you played a guitar with a Varitone, and is this the sound you are after? Or are you just wanting to experiment? :?:

I don't want to sell you something you can't use. The inductors I have are - unfortunately - not as cheap as they are small: $12.85 a piece. Probably a mile of 44 guage wire on it, and the core is a tiny nickel-steel gapped E-I looking-style (actually they are 'F' style if you know what that is) and should ideally IMHO be put in a shielded enclosure (i.e., thin steel box) mounted inside the control cavity to avoid any and all hum pickup. The inductor is meant for PCB mounting and has two tab/pins on the core bracket and two full-length PC leads 1" long.

Email me and we can discuss what you're after and whether this might get you into the territory you are shooting for.    And yeah, I have a Paypal account if this is what you need.

I don't know about standard pc mount Radio Slack\Mouzzer\Taco Tokyo transformers. They tend to be cheap, and usually use fairly thick, plain vanilla laminations and thus cost less than $5. The inductance of such units in my experience is usually much lower - maybe 500 mh tops, and the copper resistance is lower as well. The gapping is usually minimal (overlapping E-I laminations), so the core is the primary contributor to the inductance of the windings. They are designed for higher signal levels where hysteresis doesn't mean much and the distortion is not a consideration (since they are intended for use in lo-fi gear anyway). Higher quality microphone transformers have higher inductance and very thin, low-hysteresis (some even have pure nickel) laminations, but they are pricey and not designed for use as an inductor, but if you've got one laying around and you can borrow an LCR meter to measure it, that could be a possibility.

Hope this helps.

[Ge_Whiz]

GeeWhiz,

Please explain to folks what you mean by your remarks about unsuitable 'choke' inductors...

Well, um, In-my-puffed-up, I-know-what-the-hell-I'm-talking-about-opinion, the answers to your points are no, no, and er, no. I do know about inductors and the varitone circuit, tried several, and didn't get results comparable to the real thing, almost certainly due to the inductor Q.

Thanks for trying to put me right, though.

[MR COFFEE]

Hi Ge_Whiz,

:oops:
I didn't mean to suggest your post was "In-my-puffed-up, I-know-what-the-hell-I'm-talking-about-opinion". That was just my sense of humor about MYSELF and my own post using "IMHO", because when it comes to some things, well, I'm really NOT feeling or being very humble about the opinion I'm expressing, and I was thinking my OWN post sounded a bit like I was posting using MY "puffed-up, I-know-what-the-hell-I'm-talking-about-opinion" attitude, and I was thinking I should own that.  :lol: Just laughing at ME! Emoticons don't always convey meaning very well for those of us with a somewhat twisted sense of humor. <feigned sob>

Since you really like the Varitone sound, you might retry your inductor and just put a resistor in series with it to make up for (I am presuming) the lower dc resistance relative to the Gibson one.  :idea:

IF your inductor isn't a power supply type (has a low hysteresis core designed for low level audio), it should work just like the Gibson version if you are driving it with suitable pickups. The Varitone inductor is wound with very thin wire and uses a tiny core made with very thin stacked laminations of nickel-steel. The Q isn't all that high because of the resistance of the fine wire. Too high a Q tends to make the "V" of the bandstop filters too narrow, which isn't all that pleasing to the ear. A series resistor will lower the Q and widen the notch.

Would you mind sharing what positions of the Varitone you like, and what you use them for?  :?:

I've met MORE people who want a Varitone installed in their guitar because BB King or some guitar hero of theirs has one, and they have never played a guitar with one on it.  :shock: Then they are surprised when I tell them that BB King never even turns the thing on - he just wants to have the 'Cadilac' of guitars with all the 'luxury - deluxe' features, and he just sets his pickup switch in the middle so both pickups are on and wails. Often their interest in installing a Varitone  REALLY fades when they actually play through one  :lol: The Varitone circuit isn't for everybody, and they aren't cheap, either, especially for something you may rarely use.

I HAVE met a few people who really like the way the Varitone sounds, but they are usually Jazz cats. That your bag? Or have you found some other uses for it musically? What positions? :?:

[Eric H]

Then they are surprised when I tell them that BB King never even turns the thing on - he just wants to have the 'Cadilac' of guitars with all the 'luxury - deluxe' features, and he just sets his pickup switch in the middle so both pickups are on and wails.

He used to use it  --definitely not often though. I definitely remember him crankin' that thing in 1970.
Don't ask me what positions, though ;-}

[lovekraft0]

Has anybody had any luck using those subminiature telecom transformer primaries for Varitone inductors, a la Dan Torres? I had a chart some where that listed the approximate inductance ratings for some of  the Mouser/Hi-Q transformers - maybe I need to dig that out.

[Ge_Whiz]

Sorry Mr Coffee, my humour too.

Well, the varitone on my old Aria Pro II TS-600 works great - I tend to use it on one off brightest setting for some rhythm work, and one off dullest for blues lead. Of course, I don't know how that compares with the Gibson circuit, 'cos I never got that one to work. I'm perfectly happy with my capacitor-only circuit, which works fine on both my Burns Marquee (single coils) and Hofner Colorama (P90s), so I've no need to pursue further the 'true' varitone. That was the point of my original post - I think most people would be perfectly happy with a simpler low-pass tone switch.

[MR COFFEE]

Ge_Whiz said:

That was the point of my original post - I think most people would be perfectly happy with a simpler low-pass tone switch.

I pretty much agree with you on that, unless they are heavy into that 'big box' Jazz sound. It just isn't all that useful for Rock 'n Rollers, Blues, and Country pickers.

Perhaps it has a yet unexplored application in Heavy Metal...


Sorry, that was sick...:lol:

For the keep-batteries-away-from-my-guitar crowd, I have heard some interesting uses of tone circuits other than a rotary switch with a bank of different tone capacitors though. The TBX circuit was a start, and using rotary switches instead of a tone pot in general gives a lot more useful variation in tone if set up properly, usually without befuddling the guitarist, even the non-techie ones.

Of course, there is something to be said for the eliminate-almost-all-controls-so-you-can't-f**k-up-your-sound approach like EVH, too, but I expect most folks around here know how to work their gear and can figure things like that out. Prolly like more than one tone out of their guitars, too.  :wink:

[Eric H]

For the keep-batteries-away-from-my-guitar crowd, I have heard some interesting uses of tone circuits other than a rotary switch with a bank of different tone capacitors though. The TBX circuit was a start, and using rotary switches instead of a tone pot in general gives a lot more useful variation in tone if set up properly, usually without befuddling the guitarist, even the non-techie ones.

http://users.abac.com/ehensel/stompbox/guitars/epi-63.htm
Take a look at my '63 Epi-Professional. Along with the amp-controls was a series of 5 slider switches controlling various capacitors (in typical Gibson fashion it was prominently named the Frequenbobulator, or something) No matter what combination I selected it sounded no different than rolling the master tone knob off. The previous owner also had added a home-made vari-tone (since the guitar needed another hole) which was poor in function as well.

I ripped it all out years ago and kept it simple:
http://users.abac.com/ehensel/stompbox/guitars/guitars2.htm

-Eric

[MR COFFEE]

Yup,

You can take it to the bank... back in the 70's, especially, the major (manufacturing) players put 'didn't-do-sh*t" controls on guitars trying to attract the "Cadillac crowd", with varying degrees of sucess. :cry:  :lol:

Those of us in the "after market" crowd generally still largely cater to providing custom electronic modification services to those individuals, who, unfortunately for them, have "more money than sense" (or ears),  :cry: , ALONG with those few artists who actually HAVE an enhanced sense of what constitutes, IN FACT, truly exceptional, and uniquely artistic, TONE.  

Welcome to the 21st Century...

[javacody]

Mr coffee, thanks for your advice. I will wait on a varitone until I have time to try out a Little Lucille. In the meantime, I think I will use this switch as a "vintage cable sim" and throw it in a box with some other simple "toys", like the black ice and "THE POT".