2-channel passive mixer-independent volume control for each pickup

[Alec_t]

The question is, if I put the output of this micropre 2 at minimum at the input of my fishman preamp should it work?

I don't see why not.
Does the Fishman already have a volume control that you use during a gig? If so, that would be the master volume control.

The fishman is calculated to receive a voltage from the piezo of μV, but putting this buffer to a minimum would be too high for Fishman?

I doubt it. From what I read, guitar piezo pickups can put out several mV.

 

[bluebb]

I don't see why not.
Does the Fishman already have a volume control that you use during a gig? If so, that would be the master volume control.

I doubt it. From what I read, guitar piezo pickups can put out several mV.

yes,the fishman's volume control would be the master volume,the master volume in the diagram i put in the answer #57 would be the gain,and the i have two volume pots for each pickup.
This would be the best solution for me,but there are the answers #58 and #59.
:-(

 

[Alec_t]

If I were using that MicroPre unit then, rather than use the post #57 circuit, I'd revert to the post #22 circuit but, now that we know the preamp output impedance is 3.5k, with R1 and R2 omitted and with the blend lin pot value increased to 25k to give a wider blend range.

 

[bluebb]

If I were using that MicroPre unit then, rather than use the post #57 circuit, I'd revert to the post #22 circuit but, now that we know the preamp output impedance is 3.5k, with R1 and R2 omitted and with the blend lin pot value increased to 25k to give a wider blend range.

you mean the figure 5 from this:

https://www.schattendesign.com/PDF/MicroPre.pdf

but without the "Tone" pot and the capacitor.(i have to EQ on the Fishman):


But schatten says 500k for blend pot,and 500k for volume pot,why?check it:

https://reverb.com/item/4129280-sch...r-micro-pre-2-piezo-buffer-preamp-two-channel

This schatten's values are to go directly in the P.A. and you told me the values into another preamp?
Thx

 

[Alec_t]

you mean the figure 5 from this:
https://www.schattendesign.com/PDF/MicroPre.pdf

No. That uses a dual-gang log pot for balance (blend).
You can go the Schatten route if you want. In post #63 I was saying how I'd do it.
Those are high prices in the link.

 

[bluebb]

No. That uses a dual-gang log pot for balance (blend).
You can go the Schatten route if you want. In post #63 I was saying how I'd do it.
Those are high prices in the link.

Ok, you're telling me that using,"1 dual-gang log pot of 500k and 1 log pot of 500k" or "1 lin pot of 25k and 1 log pot of 50k" will give "about" the same result??

I didn't know that is possible having a blend/balance with a normal pot (not dual).
The dual gang offers more connection possibilities,but in this case is un-needed,right?

 

[Alec_t]

Ok, you're telling me that using,"1 dual-gang log pot of 500k and 1 log pot of 500k" or "1 lin pot of 25k and 1 log pot of 50k" will give "about" the same result??

No, I'm not. I think both options would work, but there are differences. A 500k logarithmic balance pot would provide a greater range of adjustment, but that will only be important if you want a big imbalance between the two pickups, e.g if one is magnetic and the other is piezo. Not being a guitarist, I don't know how much adjustment you are likely to want.
That higher resistance, plus having two pots rather than one, makes the setup more prone to interference pickup.

 

[bluebb]

No, I'm not. I think both options would work, but there are differences. A 500k logarithmic balance pot would provide a greater range of adjustment, but that will only be important if you want a big imbalance between the two pickups, e.g if one is magnetic and the other is piezo. Not being a guitarist, I don't know how much adjustment you are likely to want.
That higher resistance, plus having two pots rather than one, makes the setup more prone to interference pickup.

yes,i bought a little alluminium box(3x3.5x8.5cm),and I will put all in the box,all will be good shielded,the cables also i bought are braided shielded.
This because i will put 3 pots,master volume,and volume for each pickup,i think this is the best solution,the pickups are with different outputs voltage and it's better with 1 pot for each.
The bridge plate piezo "K&K pure mini":


which is three piezos in series has i think double voltage than the undersaddle piezo "Fishman matrix":

Thanks!

 

[bluebb]

Add 1: Having your images upright would save us a lot of neck bending.
Add 2: You connected the pickup to the center tap ot the potentiometes and the end of the potentiometers to the amplifier. Swap these connections as show:

please check this article,this the reason i connected the input to the centre lug:

https://www.stewmac.com/How-To/Onli...ing/Understanding_Guitar_Wiring_I-4000_4.html

Thanks

 

[Harald Kapp]

See my reply in your other thread.