Any obvious errors in this diagram for 3 SC?

[allmektig]

I think that's the finished schematic I want for my strat.
the phase turning swithes are on/off/on.
The series/parralell switch is a 4pDT on/on switch.
I know a 6PDT switch would have been better, but I don't have access to those.

The on/off switches are DPDT on/on.

The plan was to combine this:

With a standard Brian May wiring.

So, unless I've done something horribly wrong in the diagram, I think I'll get around to buying the parts and building it.

And I'll also draw up a prettier diagram when I'm sure it's right.

Any suggestions are welcome.

and yes, I know the series on/of switches have to be on for the neck and bridge pickup to work when in parralell mode, but to awoid that, I need a 6PDT switch, wich I don't know where to get.

[JohnH]

We have done this one before, so if you are interested in a design that has been built and tested, take a look at this thread:
guitarnuts2.proboards.com/index.cgi?board=wiring&action=display&thread=4641
However, I applaud your comitment to working it out for yourself!

cheers

John

[allmektig]

Ah.
Brilliant!
Thanks.


Edit:
I'm having a look at the final wiring diagram from that thread now, but I can't really say I understand how it work.
I know I can wire it up, but I like to understand HOW things work and why they work as they do.

And I'm having some problems understanding why you've wired the on-off switches the way you have done.
They seem quite different than the original Brian May wiring.

I'm horribly confused.


Edit number two:
Doesn't that schematic have the neck pickup hanging from hot when it's turned off?
I'm under the impression that that is bad (I have no idea why though.) and I wanted to awoid that.

[wolf]

I hope this doesn't confuse the matter further, but I recently drew a diagram for series / parallel Strat™ switching and I figured I'd throw a few phase switches onto it.

[allmektig]

Oh.
That one was actually a lot easier to follow.
Is that all DPDT on/on?
My least favorite switch I think is the DPDT on/on/on.
Those have me horribly confused.

[allmektig]

Wolf.
Would it be much of a bother for you to redo that diagram and remove the phase switches and the tone controls?
Would make it a lot easier for me to understand the series/parralall and on/off switching.

[wolf]

allmektig
It's funny you should ask that because I drew 2 diagrams for that circuit on my webpage. Anyway, here's the other diagram:

[allmektig]

Great!
Now I can figure that one out, then add additional components as I figure out how it all fits together.

[JohnH]

Well I think you have all you need now. My version and Wolfs are similar in principle, but probably a bit different at the level of exactly what lugs are used. It is different to the Brian May, but achieves the same results. On the thread I noted, you can find sound samples from the sucessful build, and Wolf has built from his as well. The idea behind them both is that, in parallel mode, the pickups get one end grounded and the hot end connected or not depending if they are switched on. In series mode, the three are put into a series chain end to end, then the unused ones bypassed by the switch.

My diagram there focusses only on wiring it up, taking into account the switch positions on a BM guitar, and with tat I can work out my best routes for connecting lugs. This type of diagram is a companion to a schematic, where it is focussed on following the signal flow, without relating to the actual installtion. I normally do both, and I have the schematic for almost this design on my ToneMonster2 thread. Wolfs diagram is in between, a clear diagram of connectivity, but switches located differently to the real guitar - Wolfs info is good!

John

[allmektig]

Ah
So the DPDT switches for on/off is used as two unconnected SPDT switches really...
One side is used for paralell mode, and the other for series mode.

In the normal brian may wiring, the pickup is compleltely removed from the circuit, but in this case, when in series mode, it's shorted out. Or bridged. Or whatever termoniolgy is used.
Is there some drawback to that?

in parralell mode, though, it works pretty much like a regular strat.
Grounds all conneted to ground, and hots either on or off.

It's starting to make sense now.

I'm sorry about all the quetsions. I just need to get a bit more clarity in how it works.


Edit: Fixed spelling

[newey]

allmektig-

So the DPDT switches for on/off is used as to unconnected SPDT switches really...
One side is used for paralell mode, and the other for series mode.

Now you're thinking like a guitarnut! Just because a DPDT has 2 poles doesn't mean they have to be connected together. Many Strat wiring designs you'll see around here make use of the 2nd pole on the 5-way by moving the V and T control connections over to the 1st pole, and then disconnecting the 2 poles, so that the second pole can be used for other purposes.

You've also latched onto the elements of modular design- those phase switches can be easily moved in or out of the diagram because each is a module, not dependent on interacting with other switches or components.

Stick around, we can use you . . . ;D ;D +1!

[JohnH]

In theory, the shunting of those series pickups makes some difference. In practice, its all completely fine, and this and the related design Tonemonster2 have been built several times. The test on my version was, with one pickup selected as on, and switching the others off, does changing from series to parallel make any difference? in the first case, the other pups are shunted and in the second they are not. I could detect no change at all in tone, or noise/hum - all was good, although in theory a tiny amount of string energy is taken by the shunted coils.

[wolf]

JohnH

Wolfs info is good

Thanks John, and (as you know), I needed some help from you with those diagrams.
And good explanation newey and it seems almektig now has a pretty good understanding of the circuit.

Edited to add:
Just thought I'd mention that I built that circuit about a week ago directly from the diagram and it does work.

[allmektig]

Brilliant.
I'll get around to ordering the parts then.

I'll stick with a master tone and master volume.
What values do you reccomend for the pots and cap in that case?

[wolf]

I'd say for the pots 250 K and the capacitor .02 mfd.
I'm just going by the standard parts usually used in a Stratocaster™.

[newey]

Pot and cap values are, within limits, a matter of taste, so wolf's answer is as good as any. But combining 2 SCs in series effectively makes them into a widely-spaced HB, and the 250K pots may make those settings a bit too dark, again, depending on one's tastes.

You could use 500K pots to brighten up the series settings; if this makes the SC and parallel settings too bright, backing off on the tone knob cures that.

Or, you could use one of each- a 250K and a 500k together give an effective resistance of about 330K, more or less splitting the difference.

[JohnH]

I have used 500k on the guitars that I have built with 3sc in series - it keeps the series sound clearer as newey says. But I believe that the BM guitars use 250k. I recommend log pots, with treble bleed circuits comprising 220k and 1nF cap in parallel between hot and centre volume pot lug, for consistent tone - again a matter of taste.

John

[allmektig]

Hm.
This design just shunts the pikcup, but the regular brian may wiring removes the pickup completely from the circuit.
What's the pros/cons with either solution?
Does anyone make a 6pDT miniswitch?

[ashcatlt]

In theory, the shunted coil is trying to do its job as a transducer (some would say generator), converting some of the kinetic energy of the string into electrical current. In fact, since it's trying to drive a 0Ω load, it should be trying to generate an infinite amount of current. As the late ChrisK was fond of pointing out, the Law of Conservation of Energy says that this current cannot come for free. It must take some of the kinetic energy "away from" the string. This should cause - at the very least - a decrease in sustain, and is also likely to affect the harmonic balance in one way or another.

In practice, the difference turns out to be fairly subtle, and almost impossible to quantify without a big elaborate test scenario.

When I have one of the pickups on my Strat in HB mode, and the others off, I've got 4 shunted coils, and I don't feel I'm missing anything. In fact, it raises another practical issue in that (for some reason I never have figured out) I was not able to get any of the pickups to go all the way off w/out shunting both coils. Disconnecting the hot output drastically reduced the volume, but did not kill the pickup. I'd imagine disconnecting the ground at the same time would, but was impossible with the switches I used.

I guess - as a matter of best practice - we try to avoid shunting coils when we can, but will take a shunted coil over a hanging hot every time. At least, I think that's the consensus around here...

Can't help you with the switch.