Ultra II Selector Switch?

[tintin]

I'm just receiving a LP Ultra II. Any recommendations for a selector switch with option of blending nanomag and humbucker outputs?

 

Thanks

[carverman]

I'm just receiving a LP Ultra II. Any recommendations for a selector switch with option of blending nanomag and humbucker outputs?

 

Thanks

 

Your guitar should already have a 9V battery for the nanomag, so the output of

the nanomag may be infact buffered low impedance via a 25K? pot volume pot.

 

There is (probably )no schematic drawing yet for this model, so unless Epiphone

customer service can provide you with one..assume that the two outputs are

not compatible to combine on a mini-toggle switch.

 

I had a little experience with blending humbuckers with a LR Baggs piezo TOM

bridge..and those two had to be blended through an LR Baggs CtrlX preamp

(available from Stew-Mac). The Ctrlx does have a full blend (pan pot) but it

requires space inside the cavity so I don't think your Utra II can accomodate

the circuit board in any case, (which runs off a 9volt battery, BTW).

 

I think your best option is to hold off until you find a schematic for this guitar

(if they will eventually release one that is) OR feed both outputs into a external

preamp (like a LR Baggs CtrlX preamp which has input buffering and a blend control)

and keep your guitar unmodified.

[tintin]

Thanks. Ya. 9 volt. Can blend with controls on the front of the guitar for now. On one of the videos, they show use of a Whirlwind selector switch.

[carverman]

Thanks. Ya. 9 volt. Can blend with controls on the front of the guitar for now. On one of the videos' date=' they show use of a Whirlwind selector switch.[/quote']

 

That's an external box with A/B selection or Both. It runs off another 9v battery

(or 9v power adapter), and they claim it has optical switching to avoid pops and clicks.

 

That being the case, it probably has some sort of buffer amp inside that takes two separate

inputs so that the inputs are not electrically run into each other, which could cause some

strange problems if the impedance values between the humbuckers and the low impedance

(probably buffered output ) are paralleled and not matched within reason.

 

 

New technology always seens to create new situations with signals.

As soon as we add something different from the standard 2 humbucker/2 volumes/2 tones,

we have to be concious of what can happen when signals of different levels and

difference output impedance values dump together ( ie:combine).

 

I would suspect that the low impedance nanomag output would suck down the signal

from the selected high impedance humbuckers..so that's why they provide separate outputs.

 

Otherwise they could have combined both signal sources inside the guitar and just had one

output jack.

[tintin]

Actually, I think one of the jacks will output a combined signal from any or all of the pick ups including the Nanomag. The separate jack will output solely from the Nanomag.

[carverman]

Actually' date=' I think one of the jacks will output a combined signal from any or all of the pick ups including the Nanomag. The separate jack will output solely from the Nanomag.[/quote']

 

So it must have some sort of 9V preamp on board. Is the nanomag an active

p_up?

 

I wouldn't be surprised if they keep this one as proprietary and good luck getting

any sort of schematic drawing for it. Even if somehow, one was found, it probably

would show a "potted circuit"..that's as good as the old "pat pending" they used

to discourage the competition..which would probably be "over there".

[51xt33]

I remember reading somewhere that the impedance of the humbuckers are reduced to match the nanomag. The HBs plug into the board and from there go to the jack. On the board is where the impedances are more than likely matched up. I thought about removing my HBs from the board and connect them straight to a mono jack where the current stereo jack is, but was worried about how the output would be ie: the HBs or the nanomag having a much stronger signal than the other making it difficult to match up the volume levels. I'm not a rookie at these things, but definetly no where near the knowledge levels of many others on the forum. I figure I'll let someone else experiment on this.

[carverman]

I remember reading somewhere that the impedance of the humbuckers are reduced to match the nanomag. The HBs plug into the board and from there go to the jack. On the board is where the impedances are more than likely matched up. I thought about removing my HBs from the board and connect them straight to a mono jack where the current stereo jack is' date=' but was worried about how the output would be ie: the HBs or the nanomag having a much stronger signal than the other making it difficult to match up the volume levels. I'm not a rookie at these things, but definetly no where near the knowledge levels of many others on the forum. I figure I'll let someone else experiment on this. [/quote']

 

 

That would make sense..otherwise, you are going to have a hard time matching volume

levels on a 8k ohm to 13k ohm p_up (dc resistance) going to a 500k (or even 250K pot)

anytime you add signals with difference impedances, you will get a reduction in amplitude.

 

It's a delicate balancing thing...there has to be a circuit board with an buffer amplifier that converts

the higher impedance of the p_ups to (more or less) match the output of the nanomag (fb p_up)

and then the active circuit output is at a more common impedance that can be switched normally

through switches going out to the jack.

 

I would think that the 3 way is still just a normal wired circuit with both p_ups feeding the 3-way

and the output of the 3 way going to ONE input of the circuit board , while the nanomag going to the other input

of the circuit board. This way they are both isolated ,(hence the separate nanomag output jack),

until they are buffered and impedance matched.

I'm pretty sure if it's got some Gibson innovation in it....it will stay proprietary for a while longer.