Multi-capacitor tone control

[tonebrulee]

Originally Posted by scotch

Yup, love having different cap options! I went with an outboard passive solution- 10 combinations with an inductor 'choke' available on a push/pull tone pot!

Cool - what does the choke do?

[arginator]

Hey guys, thanks for all the info! I just finished this mod and it works great.

[SGD Lutherie]

Originally Posted by tonebrulee

Cool - what does the choke do?

The choke turns it into a notch filter, which cuts out a band of frequencies instead of just rolling off the high end.

Real Varitones have a choke and are midrange notch filters.

[tonebrulee]

Originally Posted by SGD Lutherie

The choke turns it into a notch filter, which cuts out a band of frequencies instead of just rolling off the high end.

Real Varitones have a choke and are midrange notch filters.

Ahh, OK - that's interesting. So the eq change is something more along the lines of a scoop, where the width and center of the scoop is determined by the cap value?

I ended up changing the middle cap value in my setup from .022mF to .01mF so that the three values are .047mF, .01mF and .0047mF. It's an old-school P-bass setup with LaBella flats and foam under the bell and I found that the .01mF value results in a more usable tone difference from the .047mF than the .022mF did. Without the foam though, or with round-wounds, I'd have stuck with the .022mF.

[khutch]

Nice idea, just a few random thoughts. You could use a standard DPDT center off switch by putting the small value cap across the center terminals. When you do that the switching pattern is not the increasing from one end to the other that you get with the more expensive switch but you can learn it. The small value cap i also appears in parallel with the other two when you use them so you either adjust their values down to get what you want (parallel capacitors add in value) or live with the larger resulting values for the two "outside" switch positions. Tone control capacitor values are not exceedingly sensitive so higher values won't matter all that much in many cases. For example, if you want 0.0047, 0.010, 0.047 you could use two 0.0047 caps and a 0.047 to get 0.0094, 0.0047, 0.0517 in the three positions. I wrote them in that order because with a center off DPDT the small value will be obtained in the center off position.

If you want really small capacitors try getting some ceramic chip caps. You could solder them between the pins on the switches and they will take up no extra space at all. They are so small in fact that you likely will have to solder one end to the switch pin and use a small bridge wire to connect to the other pin -- unless you shop around for very large ones they will be too short to bridge the distance between pins!

Chip caps may be denoted in uF but since they are often used in RF circuits they may also be denoted in nF. The conversion is simple 0.001 uF = 1 nF, 0.047 uF = 47 nF, etc. In other words divide the nF value by 1000 to get the uF value you are familiar with. Chip caps are harder to find but they can easily be ordered from places like DigiKey. Shipping costs can be a killer but once you decide what values you like you could have one person place a mass order and distribute them to everyone else. Chip caps can also easily be stacke on top of each other to get non-standard values and still take up virtually no space.

Ken

[SGD Lutherie]

Originally Posted by tonebrulee

Ahh, OK - that's interesting. So the eq change is something more along the lines of a scoop, where the width and center of the scoop is determined by the cap value?

Yes, and also the value of the inductor coil (choke).

[sixway]

Subscribing so I can find this again!

[MarkA]

Originally Posted by sixway

Subscribing so I can find this again!

Ditto. Considering something like this to add flexibility to my P-bass.

[tonebrulee]

Gotta say, I'm still extremely happy with this setup. In particular, the .0047 with the tone rolled all the way back is just a great, woody tone, if that's something you like. That said, I'm really into the classic P-bass-with-flats woody sound, so I can't really speak to how useful the setup would be for folks into more aggressive tones.

[Angel LaHash]

Im just reading all the posts and link and got a lot ot catch up on this,

The way i did it .. From the TONE to the Middle leg of a SPDT (On-Off-On) switch [ Can get these dam to real small if you like to take up less space {Ultra Mini SPDT (on-off-on)} ]
one side 25nF and the other side 11nF, the other sides of the caps going to earth.
Also in from the TONE Control a Cap 22nF going to earth.

This makes a 22nF when in the OFF (Central Position)
47nF(22nF plus the 25nF in Paralle)
33nF(22nF plus the 11nF in paralle)
Giving you a (on-Off-on) (47nF, 22nF, 33nF)
i picked them from what you seem to find in guitars, but they can be changed

[Angel LaHash]

Originally Posted by tonebrulee

Gotta say, I'm still extremely happy with this setup. In particular, the .0047 with the tone rolled all the way back is just a great, woody tone, if that's something you like. That said, I'm really into the classic P-bass-with-flats woody sound, so I can't really speak to how useful the setup would be for folks into more aggressive tones.

Ive been trying to catch up and reading this and the links all day. you got to play around with different values of caps and types.

So may i ask how you rated the tones you got out, ie what was your 3 Cap Totals Ratings you went for, as i would like to put it in my own. But i did a different switching.

Like the other guy the 2P2T (on-on-on) was new to me, only new of the (on-on) and the (on-off-on) so am confused as the cross over bit..

Ive got a P-Bass as well just got to fix it up as its NAKED when i brought it all wires hanging out and had a 100nF Cap on it. I would like to make a Mix of J/P Bass one time, but i want to get it up and running first.

[tonebrulee]

Hi Angel - with my setup there is no interaction between the 3 caps, which are .047, .01 and .0047 which give the broadest range of usable variations to my ear. I started with .022 in the middle, but switched it to .01 to get a more even (sonic) spread between the different caps - i.e. .022 sounded too much like .047. See my earlier posts for sound samples and details on the tone. Good luck!

[bassbenj]

Originally Posted by tonebrulee

Hi Angel - with my setup there is no interaction between the 3 caps, which are .047, .01 and .0047 which give the broadest range of usable variations to my ear. I started with .022 in the middle, but switched it to .01 to get a more even (sonic) spread between the different caps - i.e. .022 sounded too much like .047. See my earlier posts for sound samples and details on the tone. Good luck!

This is pretty much what I found too. Only my setup is a bit different. For one thing the smallest cap in mine is NO cap. The reason is that this makes the instrument as bright as it goes. Even when tone is at max value there is still a small amount of cap loading. I use a DPDT center off switch. One cap is .047 and the other, like you is .012 or maybe .015 (something I had...anything around this value seems good)

The deal with my setup is not only the bright as it goes setting, but also the switch lets you go between maximum bright (center off) and some other setting on one or the other cap where you've dialed in a tone on the pot. So you can switch while playing from max bright to some dialed-in tone WITHOUT fooling around with the tone pot. I find this a big plus over trying to max the pot for bright and then trying to re-dial-in the tone again. This way it's just a switch flip!

[Angel LaHash]

Ok so say, i have 100nF 47-22nF and a 15-10nF

as the Bass has a 100nF in it (104k) what i was shocked at
i can give it a 100nF 47nF and a 10nF on a Toggle

or i got a Rotar Switch 2P4T and i could add a one with no Cap then.
what would be 100nF 47nF 10nF and maybe 5nF
ill have to look what switching i can get, ive got a 1P12T one on order from China

Dont know what this will do on a Bass, but on a Strat they have a "Sweet Tone" 1MOhms with a 10/12nF and 270KOhms with a 3n3/3n9F..it hooks on the line from say the tone control to each side of the resister and then on to a switch, that clicks between caps.. Its good for stopping any switching clicking sounds coming up

[SurferJoe46]

I still wonder at the word: TONE in relation to any adjustments on a bass at all.

I concede: boomy and less boomy, or perhaps metallic-sounding and less-metallic-sounding, maybe even 'clarified and less-clarified - but 'tone' kinda leaves me wondering if it isn't somewhat a vague and less than honest appraisal of the voice/output/sound of a bass and it's adjustable parameters.

[tonebrulee]

Originally Posted by bassbenj

the smallest cap in mine is NO cap. The reason is that this makes the instrument as bright as it goes.

The one thing I'd say about the small .0047 cap is it produces an extraordinary woody tone (see my earlier post) when the cap is dialed all the way in. With your 2-cap setup, I'd probably drop the .01 in favor of the .0047.

Originally Posted by bassbenj

So you can switch while playing from max bright to some dialed-in tone WITHOUT fooling around with the tone pot.

Nice!

[Angel LaHash]

ToneBrulee

Kind of my hero (living) at the moment with these caps.
Ive just got a 1P12T switch Rotary, and woundering what the best 12 options would be
Ive got a P-Bass (naked as i had to repair it) it has a 100nF (0.1) Cap in it at the moment so would like to keep that (Jim Haxley) so after that I am open to what to put on each leg of the switch, i do own some 47nF (0.047) 33nF 22nF 10nF 3n3F 3n9F 1nF all Green Sweetie design but have some of the BOX type Caps in different values..i do own SMD ones too but i have no clue how i would get them to soilder from one bit to another

1) 100nF 2) 47nF 3) ?22nF 4) 4n7F
Maybe i dont need a big 12 way switch then again i couldnt get any thing between 5Way
Might try and use it all say 100nF and then 1/2 it bring it roughly in line with some of the caps you suggested to use
1)100nF 2)50nF 3)25nF
4)13nF 5)6nF 6)3nF
7)2nF 8)780pF 9)390pF
10)190pF 11)97pF 12)47pF

[kurosawa]

I had an old Bill Lawrence choke, took it out, forgot how to wire it (he sent a diagram with it but I don't know where it went), NBD 'cause I kept the tone dimed anyway. Bought a newer BL that's supposed to sub for the cap. I'll put it in this frankenbass I'm working up. Maybe I'll actually use it. We'll see.

[ricobasso]

I love all this enthusiasm. Don't forget to always use the same guitar lead for any comparisons. Different leads have different capacitance.

With the guitar Volume control at max and the Tone at minimum resistance, any guitar lead capacitance is directly in parallel with your tone control capacitor. If your guitar cord has a capacitance of 1000pF, don't expect to hear any difference when switching between a 47pF and a 100pF! Both will be swamped by the cord.

[bumperbass]

I love it, too (the enthusiasm, that is). Never have I used the tone control. Mine's always on 10, with a 500K pot. Maybe it's me, but I figure a tone control is -- 10 = normal, less than 10 = take clarity away.
I understand wanting to get an authentic old school rolled off tone, though. IMO, a tone control isn't the way to do it. I am not bashing you guys. I always use EQ settings to get my tone. Please enlighten me, but if you use flatwounds on a P-bass, how come you can't get an authentic Jamerson tone from an EQ, or maybe a variable mid-scoop control (called a contour control on some new heads).
I used to use the parametric EQ on an old Peavey Mark IV I had (and still have). You could dial in exactly where you wanted the scoop and how much of a scoop or boost you desired. Sorry to say, this circuit isn't in most new amps. Maybe it's because it's too much to mess with nowadays.
Like I said, I read all the posts and enjoyed them, because I'm a tinkerer, too, but to all of you guys that use tone controls, please enlighten me. Maybe I'm missing something.