Stereo Tele project

[sumgai]

newey,

I was about to reply earlier today when I got "called away", if you get my drift.....

The above circuit will work, but in point of fact, the Bridge leads are reversed. You show the hot going to the Ring connection, and the more-or-less ground going to the tip. Not a real big deal, but when a plug is inserted into the stereo jack, the signal between the two pickups will be out-of-phase when the switch reads "Normal", and in phase when the switch reads OoP.

Of course, this isn't happening inside the guitar, it happens outside, at the grill cloth from your speakers. I mention it only because you may note sonic anomalies, thanks to this tiny gotcha.

HTH



sumgai

[sumgai]

newey,

Mar 5, 2010 22:36:10 GMT -5 newey said:

I also added a "truth table" for the stereo mode. This discloses that, with both plugs inserted and the switch set to Pos 1 (Bridge only), I'll get the bridge pup through channel B only, channel A will be dead.

Is there a way around this? Can I get the bridge pup through both channels at that position? (I think this should be doable, but I haven't figured it out yet- I can't just jumper over to the switch, or it won't be stereo.)

I can't see anyway to do it, given your current parts list. Now if that stereo jack had another switch section, isolated from all signals and ground, then ya, we could make it happen.

Short of that, since you're getting essentially the same sound in 3 of the 4 positions anyway, it's not likely that you'll be rotating the rotary very often anyways, when in Stereo mode, am I right? Now if you were plugging and unplugging the Stereo jack in the middle of a song, I'd agree that it might be nice to not have one channel drop out, should you be in position 1, but......

Keep in mind that an acoustic OoP sound is subtly different from in-phase. You may end up never bothering with the rotary switch, once you go stereo.


BTW, you inverted the "tip" on your stereo jack - the way it looks now, as a plug is inserted, the switch will never open.....

HTH




sumgai

[newey]

BTW, you inverted the "tip" on your stereo jack - the way it looks now, as a plug is inserted, the switch will never open.....

Yeah, I was looking at the symbol for that jack backwards, thinking the longer contact represented the tip. Real world, shouldn't be a problem as the jack switching is obvious to the naked eye- switched leads go to the other half of the diagram, unswitched leads go to the bridge pup.

You're probably right about the stereo mode not needing use of the switch anyway, so I'll leave it "as is".

[JohnH]

Im glad you are getting back into this one newey. Gotta keep that stereo Oop if possible! Its one of the new interesting features to try in stereo.

On the issue of only sending bridge to one channel (B) only in stereo mode, I could see a way to send it to both if you abandoned the oop, and also gave up on trying to keep the two grounds seperate. In that case, you would have a common ground, one switch pole for each pickup hot. The third pole would be used to join the two outputs together. This could happen in 3 out of 4 positions, so in stereo mode, you would have Bridge to both outputs, B+N to both outputs, B&N to seperate outputs, and N to both. Not bad, and it would be OK going into a stereo amp, or with careful common grounding of two amps.

But I think it is better as you are heading. An optional extra switch, if you still wanted to get the common signals going to two amps, would be a push/pull that shunts the two grounds together and similarly the two hots. Could be added later. I think there is some merit in having two amps running, and still being able to try both the common mono or stereo mix of pups

cheers

John

[newey]

Yeah, I'm going with this plan, I think it's the most workable. I'm going to have to do some careful fitment of components into the Tele cavity anyway, so adding more switches, etc. may not be an option anyway.

The dual gang pot for the tone control is a full-sized pot, and the rotary switch will also take quite a bit of room once it's wired. I will use the dime-sized volume pots to save some room, but it's still going to be tight getting three pots and a rotary switch in there.

I'm to the point of needing to fabricate the control plate for the 4 holes I'll need- which need to be evenly spaced or it won't look right. I should have bought a couple of those blank control plates, since I'm probably destined to screw at least one of these up.

I'm going to mock the plate up using a piece of cardboard to ensure fitment, then the cardboard can serve as a template for drilling.

[newey]

As I noted in the build thread, in the Gallery, I'm thinking of a modified scheme, moving the OOP off of the rotary switch to a p/p pot, and adding a series setting at position 3 on the rotary.

Has this got the goods?

[sumgai]

newey,

It works, but don't ship it just yet.....

Everything is in order except for the Stereo jack's Ring and Tip connections. Look more closely, and you'll see that when a plug is inserted, the Bridge's hot lead will be going to the Ring, which in turn will be interpreted as the ground side of the cable's signal. Obviously, the Bridge's ground connection (signal return) will be heading out on the Tip.

Now in the normal scheme of things, this won't hurt when the plug is not inserted, IOW when you're in Mono mode. And technically speaking, it won't hurt in Stereo mode either, because the jacks are isolated. However, aurally, meaning what you hear coming out of the speaker cloths/grills, the labeling of your Pickup Phase switch will be backwards from what you'd expect. If you select "in phase" while in Mono mode, the two pups will indeed be in phase. Unfortunately, they'll be out of phase in Stereo mode.

The fix is easy - just take the two connections to the Ring switch, and swap them for the two connections on the Tip switch. Be sure to keep the relative positions the same, so that the signal actually goes out the jack, and not the selected combo from the rotary switch!

BTW, you're still showing that Stereo jack in slightly "impossible" mode.... inserting a plug should break the connection, whereas you show it as making the connection even more strongly (as if that were possible ). Not to mention, since I've got a handful of nits here that need to be picked, you don't "insert a jack", you insert a plug into a jack. Or do they do things "a bit differently" in Ohio?

HTH


sumgai

[newey]

Yeah, the jack problem was pointed out earlier, and I meant to fix it in this version but forgot to do so. I'll clean that up, I was just looking at the diagram bass ackwards.

Not to mention, since I've got a handful of nits here that need to be picked, you don't "insert a jack", you insert a plug into a jack. Or do they do things "a bit differently" in Ohio?

No, here in Ohio, the plugs pretty much mate with the jacks the same as everywhere else. But only after the third date. ;D