build flat pickups

[surdopickups]

preparation plates harmonic steel
bonded magnets
bonding the second plate,
insulation inside the coil with tape type scotck
winding made of 42 awg terminals soldered to the cable
welding of the plates to a greater structural strength
filling the interior coil with epoxy resin
turns to brown steel sheet with wine vinegar

[surdopickups]

turns to brown steel sheet with wine vinegar "passivazione" "passivation"

[Jason Rodgers]

What number of turns do you get with the wire? There is not much space for the wire in there!

[David King]

Jason, These are a low impedance design. Mr Surdo mentioned that in his previous thread. Depending on what he is plugging these into it's probably between 150 and 600 ohms total. I'm curious to know myself as I love this design.

[big_teee]

It looks like it is a lot thinner than it needs to be for most apps.
He May want to also make a medium thin/thick model.
A little thicker and some 44spn, and you would be in medium Impedance biz!

[Jason Rodgers]

Yeah, I get that these are pretty low impedance, like the Flatpups, but these seem to have even less space for wire. With that sort of aperture, I'd want to turn them by hand. And THEN welding the corners?!

[surdopickups]

What number of turns do you get with the wire? There is not much space for the wire in there!

Hello everyone
Use 42 AWG wire polysol
I made pickups wound up to 1500 turnss with no problems and there was still room for further rounds
the resistance that I got
approximately

1100 turn 1 Khom
1500 turn 1.3 Khom

no problem for the welding of steel sheets - use the technique of brazing
no problem abutment for the winding in such a confined space, even with manual winding.
However, particular devices or techniques must be adopted for the construction of the pickups.
The main problems encountered are due:
* to the steel plates that are very flexible,
to the power of the magnets, then special precautions during bonding.
difficulty in isolating the interior space with electrical tape to prevent short-circuit winding on the plates,

how I solved these problems, excuse me if I keep a little secret

forgive me for my english

[surdopickups]

1100 turn = +/- 1 kohm
1500 turn= +/- 1.3 kohm

awg 42 polysol

[surdopickups]

neodimio

before moving on to other measures
I'm going to build pickups with neodymium magnets N45 grade higher than those who have used up to now N35
to see the difference

http://surdopickups.blogspot.it/

[surdopickups]

It looks like it is a lot thinner than it needs to be for most apps.
He May want to also make a medium thin/thick model.
A little thicker and some 44spn, and you would be in medium Impedance biz!

1 kohm 1100 turn
1.3 khom 1500 turn

I think we may already be in the average impedance

[surdopickups]

https://www.youtube.com/watch?featur...&v=FPWHI-NMD3A

[charrich56]

Are you going directly into a microphone input on a mixer with these?

Just curious from the numbers you gave, because you might be able to better match the microphone input with a different winding.

Take care,

Charlie

[bbsailor]

before moving on to other measures
I'm going to build pickups with neodymium magnets N45 grade higher than those who have used up to now N35
to see the difference

Surdo Pickups

Here is one more thing to try. Most XLR mic inputs have a real input impedance of between 1,500 ohms to 2,400 ohms. This value is deisgned to put a minimal load on microphones normally rated at 150 ohms to 300 ohms real impedance. If the impedance of your pickup is near the real input impedance of the mic mixer input, you would loose about half your signal voltage. Try using about 1/4 to 1/3 the number of turns. You could even use a little thicker wire like AWG 40 or AWG 38 with about 300 to 400 turns. Also, try using a two conductor balanced line with a shield (common low Z mic cable). Wire the two pickup leads to XLR pins 2 and 3 with the shield soldered to the metal plates acting as the top and bottom of the bobbin attached to XLR pin 1. This should make a low noise pickup which can use a little higher gain on the mic amplifier stage to make up for the lower output of less windings and the loading of your 1K ohm to 1.5K ohm pickups being loaded by the mic input impedance.

You may even hear a little better high frequency response with this setup.

You presented a nice creative way to make a lower Z acoustic guitar pickup.

Joseph Rogowski

[surdopickups]

Here is one more thing to try. Most XLR mic inputs have a real input impedance of between 1,500 ohms to 2,400 ohms. This value is deisgned to put a minimal load on microphones normally rated at 150 ohms to 300 ohms real impedance. If the impedance of your pickup is near the real input impedance of the mic mixer input, you would loose about half your signal voltage. Try using about 1/4 to 1/3 the number of turns. You could even use a little thicker wire like AWG 40 or AWG 38 with about 300 to 400 turns. Also, try using a two conductor balanced line with a shield (common low Z mic cable). Wire the two pickup leads to XLR pins 2 and 3 with the shield soldered to the metal plates acting as the top and bottom of the bobbin attached to XLR pin 1. This should make a low noise pickup which can use a little higher gain on the mic amplifier stage to make up for the lower output of less windings and the loading of your 1K ohm to 1.5K ohm pickups being loaded by the mic input impedance.

You may even hear a little better high frequency response with this setup.

You presented a nice creative way to make a lower Z acoustic guitar pickup.

Joseph Rogowski

thanks for the valuable information
no doubt will try to build some pickups as you suggest, to be honest I was already thinking this solution, but I thought it was an unwelcome solution for guitarists who prefer to go with the cable jack directly into amplifier to take advantage of equipment already in their possession .

[surdopickups]

Are you going directly into a microphone input on a mixer with these?

Just curious from the numbers you gave, because you might be able to better match the microphone input with a different winding.

Take care,

Charlie

thanks
I think I'll try following your advice
so far I would go directly to the guitar amp (no mixer)
do you think is wrong?