I'll explain quickly :
Helping a friend whose modified Tele has only an EMG active bridge pickup (humbucker).
Says he misses a single coil at neck.
He never uses the tone knob. Doesn't plan to use both pickups at the same time.
At first we thought of adding an independent volume knob for the single, though it's not comfortable in use. + big difference in levels & impedance for latter pedals etc.
So we had the idea to boost the single coil to roughly match the active pickup's level, and take benefit of the already present 9V battery. I was thinking of using Escobedo's Duende circuit for its small size.
Question : would the 25k of the EMG be efficient at the output of the Duende circuit ? So I can use only 1 output vol. ?
I can't find any info on the Duende's output impedance (and can't deduce it myself for noobness).
Thx for your help.
Helping a friend whose modified Tele has only an EMG active bridge pickup (humbucker).
Says he misses a single coil at neck.
He never uses the tone knob. Doesn't plan to use both pickups at the same time.
At first we thought of adding an independent volume knob for the single, though it's not comfortable in use. + big difference in levels & impedance for latter pedals etc.
So we had the idea to boost the single coil to roughly match the active pickup's level, and take benefit of the already present 9V battery. I was thinking of using Escobedo's Duende circuit for its small size.
Question : would the 25k of the EMG be efficient at the output of the Duende circuit ? So I can use only 1 output vol. ?
I can't find any info on the Duende's output impedance (and can't deduce it myself for noobness).
Thx for your help.
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That EMG is kind of expensive eh? Not any people on diyaudio responding to this. I think that is because this is really NOT an audio topic. Stompbox forums would be better or just go ask Dan Armstrong.
Anyway since I have built several stompboxes and mini preamps as well as currently looking into a rewire for one of my own guitars I think I can answer your question. As you probably know most guitars use 250K pots even with passive pickups. I am not sure why but it is likely due to better quality comes with the 250K pot.
Yes you can use the 25K pot. That is plenty to shut it down and have good attenuation control. At full volume the pot is not actually engaged it is bypassed which is where it will be almost all the time anyway.
The Duende circuit is a very simple 9VDC supply preamp circuit as well as the EMG. There are two versions of the Duende circuit and one utilizes a 25K pot for volume control while the other has a preset volume attenuation using a 5.1K resistor rather than a pot. The fixed resistor version is for an instant boost 1 or instant boost 2 with a stomp switch. The other version with the 25K pot is so the volume can be preset and driven higher or lower as well as stomp switch boost 1 and boost 2.
You can also use the original Tele pots too.
A better option for a single coil neck pickup (seeing how you already have the 9V battery) would be a Sustainiac pickup which is actually a pickup and transducer all in one coil with a preamp designed for the guitar cavity. I have one on my Jackson and it is something every guitarist should have if they are into making mods on their guitar. You can sustain any note until the battery runs out. Any kind of feedback you want you got it. It can feedback really high harmonics and squeals if you chose to do that and you can hold them as long as you want. The coil is also a driver like a speaker where the coil is is used to make the strings keep vibrating at whatever note your playing.
Anyway since I have built several stompboxes and mini preamps as well as currently looking into a rewire for one of my own guitars I think I can answer your question. As you probably know most guitars use 250K pots even with passive pickups. I am not sure why but it is likely due to better quality comes with the 250K pot.
Yes you can use the 25K pot. That is plenty to shut it down and have good attenuation control. At full volume the pot is not actually engaged it is bypassed which is where it will be almost all the time anyway.
The Duende circuit is a very simple 9VDC supply preamp circuit as well as the EMG. There are two versions of the Duende circuit and one utilizes a 25K pot for volume control while the other has a preset volume attenuation using a 5.1K resistor rather than a pot. The fixed resistor version is for an instant boost 1 or instant boost 2 with a stomp switch. The other version with the 25K pot is so the volume can be preset and driven higher or lower as well as stomp switch boost 1 and boost 2.
You can also use the original Tele pots too.
A better option for a single coil neck pickup (seeing how you already have the 9V battery) would be a Sustainiac pickup which is actually a pickup and transducer all in one coil with a preamp designed for the guitar cavity. I have one on my Jackson and it is something every guitarist should have if they are into making mods on their guitar. You can sustain any note until the battery runs out. Any kind of feedback you want you got it. It can feedback really high harmonics and squeals if you chose to do that and you can hold them as long as you want. The coil is also a driver like a speaker where the coil is is used to make the strings keep vibrating at whatever note your playing.
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I meant to say the Duende uses the 25K pot for gain control and it is a trim pot to find your sweet spot. It also controls output power. It also appears there are several versions one with with 3 boost settings. There are many similar circuits out there based around the JFET and the amount of boost typically is not very much but I don't think you will need a lot. It depends on what passive pickup is used. Typically the neck pickup puts out more power and thicker sound anyway due to more movement of the strings in the neck area relative to the bridge area.
Are you still here? 🙂
Please post your EMG equipped Tele circuit for a proper answer.
Also the Duende schematic you will use.
Both , as Kurt mentioned, have many variants, not sure which ones you have/use.
What does this mean?
Is EMG 25k internal impedance?
Is current volume pot 25k?
Are you still using Tele original 250k Log/Audio Volume pot?
Is the tone control still present?
Which values?
Hello and yes, still here.
I'll post it once we find a pleasant solution.
The 25k : i was refering to the RMG volume pot. Hé completely removed the original circuit so no more 250k.
The tone's still present yes, though i don't know its value right now as it's not my guitar.
The duende circuit would be this one http://1.bp.blogspot.com/-qJnkA79h5...E/s1600/Escobedo-Duende-JFET-JHS-MiniBomb.png
For its very small footprint...
I'll post it once we find a pleasant solution.
The 25k : i was refering to the RMG volume pot. Hé completely removed the original circuit so no more 250k.
The tone's still present yes, though i don't know its value right now as it's not my guitar.
The duende circuit would be this one http://1.bp.blogspot.com/-qJnkA79h5...E/s1600/Escobedo-Duende-JFET-JHS-MiniBomb.png
For its very small footprint...