build flat pickups

[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

hello Joseph
believe that the XLR connection type as you described before works well?
when I proposed such a solution, a sound engineer told me that it was not a viable or feasible.
serves as a transformer microphone attached to pickups
what do you think
thanks

[Mike Sulzer]

Of course it will work fine. You will get very flat frequency response, maybe or maybe not what you want, but there are multiple methods for adjusting the ff. This method is extremely quiet in regards to electrical noise.

hello Joseph
believe that the XLR connection type as you described before works well?
when I proposed such a solution, a sound engineer told me that it was not a viable or feasible.
serves as a transformer microphone attached to pickups
what do you think
thanks

[surdopickups]

Of course it will work fine. You will get very flat frequency response, maybe or maybe not what you want, but there are multiple methods for adjusting the ff. This method is extremely quiet in regards to electrical noise.

build a pickup with this technique,
However, even now the pickups is extremely quiet, a little background noise.
thanks

[David King]

The results you get with the present pickup will depend to some extent on the cable's self capacitance and the input impedance of the amp you are plugging into. Going to a low impedance, balanced XLR will allow you to get consistent, quiet results over 30M cable runs if needed.

[bbsailor]

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?

If you want to go directly into a high impedance (1 Meg ohm, typical) guitar amp all you need is one mic matching transformer with an XLR input and a .25 inch male plug on the amp end. This type is available in many music stores and is similar to a Shure A95U matching transformer. This transformer has about a 1 to 12 turns ratio when going into the low impedance XLR side. Try this with about a maximum of 300 ohms to match the transformer input impedance. For a little more control of your sound, try going into an XLR low impedance mic mixer and then plug the output of the mixer into the guitar amp. This way you can obtain some extra equilization from the tone controls on the mic mixer.

One thing you will notice is that since your design keeps the coil and magnets near the same distance as the guitar top, about .5 inches, the string balance is better than it would be if the strings were closer to the strings as in a electric guitar pickup with staggered magnet heights to match the fingerboard curve. Acoustic strings have another challenge as only their core is ferrous metal. Typically the wound string core thickness is about one half the outside diameter of the wound string. The B string tends to be the loud string and requires some creative ways to obtain a balance. This is typically more of a problem when the magnet and coil is closer to the strings.

Joseph Rogowski

[surdopickups]

If you want to go directly into a high impedance (1 Meg ohm, typical) guitar amp all you need is one mic matching transformer with an XLR input and a .25 inch male plug on the amp end. This type is available in many music stores and is similar to a Shure A95U matching transformer. This transformer has about a 1 to 12 turns ratio when going into the low impedance XLR side. Try this with about a maximum of 300 ohms to match the transformer input impedance. For a little more control of your sound, try going into an XLR low impedance mic mixer and then plug the output of the mixer into the guitar amp. This way you can obtain some extra equilization from the tone controls on the mic mixer.

One thing you will notice is that since your design keeps the coil and magnets near the same distance as the guitar top, about .5 inches, the string balance is better than it would be if the strings were closer to the strings as in a electric guitar pickup with staggered magnet heights to match the fingerboard curve. Acoustic strings have another challenge as only their core is ferrous metal. Typically the wound string core thickness is about one half the outside diameter of the wound string. The B string tends to be the loud string and requires some creative ways to obtain a balance. This is typically more of a problem when the magnet and coil is closer to the strings.

Joseph Rogowski

I share your thoughts

I had also thought about building a pickups with the magnets facing the ropes EBGD graduation magnetic higher than the magnet that sees the strings BE
believe that it is valid as an idea

grazie Jaseph

[David King]

I would try mixing grades of magnetic materials to even out string volumes N35 under the outer strings and N42 or N52 in the center.

[surdopickups]

I would try mixing grades of magnetic materials to even out string volumes N35 under the outer strings and N42 or N52 in the center.

Ok thanks,
you're a Great
Mr David

[surdopickups]

https://www.youtube.com/watch?v=mN-bvwlrYOk