EMG Active Pickup Circuit?

[rasta_maleek]

hi baja, could you repost the proyect info please?

[bajaman]

what exactly do you need reposted rasta

[rasta_maleek]

sorry!
Now I have all the info. I thinks that the link was death for a little time, because of the host change of the FSB forum.
I did all the work.
I go to post some guts and video comparation, of the EMG HZ-7 modded and my Ozzy signed epiphone LP Zakk Wylde(he singned this guitar to me in the Monster Of Rock here in spain,he played in Zaragoza), with Seymour Duncan Blackouts Mick Thomson signature.
I did the circuit with breadboard.
Guts.

the Guitar.



the circuits.



the installation
first i tried two 4250´s IC´s, later i installed for the neck pickup a NE5534, but i decided to reinstall two LM4250.







And some videos.


active comparation



passive pick ups(record with the iphone)



active pickups(record with the iphone)




Thanks so much for all the great info about this preamp, i revive this sh#t of pickups(EMGHZ-7) that sounded very very bad. Now i think that the sound is much better than before. Some people tell me that now the schecter sounds better than the epiphone.

[quaternotetriplet]

did anyone tried these preamp on single coils?

[quaternotetriplet]

^ have you tried shielding it?

[EddieTavares]

did anyone tried these preamp on single coils?

Yes, you can but without hum canceling but if you want just gain up or enhance/smooth any audio frequency it's OK, however, to have hum canceling you should try it with staked coil pickup as Dimarzio HS or VV family.

I tried a variation of that circuit, It's hard to find a LM4250 in Brazil, so I made it with more common IC like TL071 and 61.

[EddieTavares]

C8 is to smooth the brightness a bit what is not needed if you use the LM4250, the gain is controlled changing the values of R3, R4, R7 and R8.

[EddieTavares]

Ed can i ask what pot value are you using? is it really advisable 25k value?

You can use anyone with good results with no changes in your guitar pots but the smaller pot values are better, I use 22k log and it sounds very good!

[kmensik]

You need a 4 wire humbucker. If you have only one shielded wire comming from the pickup, you need to change that to 4 wires + shield, connect each half of the humbucker with a pair of wires.

[andregarcia57]

Here is the guitar with the active humbuckers fitted.
members/bajaman/Baja/Active%20preamp%20 ... uckers.JPG
cheers
bajaman

I will use this circuit in my Seymour Duncan JB pickup.
it is changed to make because the coils are different from EMG?
I use pot 250k?
grateful.

[CHEEZOR]

i dont get what you mean kmensik ... maybe a diagram can help me a lot thanks for the reply

What kmensik is saying is that the wire that is attached to the pickup needs to have 4 conductors inside it. Here is a picture of what he was saying:
http://www.artemispickups.com/images/up ... p-Wire.jpg

The wire on the top is a 4 conductor wire and the the one on the bottom is a 2 conductor wire. If you have a 2 conductor wire then you will need to change it to a 4 conductor wire. If you need to do this, then here is a page that should help:

http://www.diyguitarmods.com/rewire-hum ... ctions.php

[andregarcia57]

Here is the guitar with the active humbuckers fitted.
members/bajaman/Baja/Active%20preamp%20 ... uckers.JPG
cheers
bajaman

I will use this circuit in my Seymour Duncan JB pickup.
it is changed to make because the coils are different from EMG?
I use pot 250k?
grateful.

[andregarcia57]

I tested yesterday in the trial of the band preamp
seymour duncan JB pickup used.

I thought is very strong, how can I calm the preamp a little?

[EddieTavares]

If you are trying my circuit you can smooth the gain reducing R7 and R8 or/and increasing R3 and R4 but probably you are using the original EMG81 so I suggest you add an input resistor about 33k to the non inverting input and reduce the feed back resistor about 68k.

It sounds very nervous because the EMG81 is something like a paf with active circuit that boosts its signal and the JB has much more output than a paf.

[andregarcia57]

If you are trying my circuit you can smooth the gain reducing R7 and R8 or/and increasing R3 and R4 but probably you are using the original EMG81 so I suggest you add an input resistor about 33k to the non inverting input and reduce the feed back resistor about 68k.

It sounds very nervous because the EMG81 is something like a paf with active circuit that boosts its signal and the JB has much more output than a paf.

let me see if I understood. I should put a 33k resistor on the positive input of the pickup?
take a look below.
grateful

[EddieTavares]

Wow, this is not exactly the EMG81 circuit but is based in, it has the 33k resistor after the 22n cap what I said. I think you must try decrease both 330k resistors to something less than 150k and the 150k resistor next to the opamp to 68k, I think you must try it in the protoboard I never tried that circuit because I never found the LM4250 that has less bright than the TL0xx series and probably less volume to make the battery last more.

[slammer88]

hello all. members/bajaman/Baja/Active%20preamp%20 ... verlay.png

I've recently made this circuit to boost my Evo-7, and it worked very well However, i had to use a LM741 because i couldnt find any LM4250 on the local stores. My guitar is a Ibanez RG7321, with a DiMarzio Evo-7 on Bridge position. Now i've got some questions..

1- In default EMG pickup systems, because of interally shielded system, there isn't any humming sound even if the player doesnt touch the strings. I'm having this issue, what can i do to solve it?

2- Shall i connect the Battery's - lead to 3rd lug of the guitars female jack, in order to prevent battery drain or shall i only disconnect the cable?

3- Can i use this circuit for my bass guitar as well? It has only one pup in bridge, which is https://cgi.ebay.com/ws/eBayISAPI.dll?V ... AQ:US:1123, and there's only one volume knob. How shall i connect this one into this circuiT?

[deltafred]

....

I've recently made this circuit to boost my Evo-7, and it worked very well However, i had to use a LM741 because i couldnt find any LM4250 on the local stores. My guitar is a Ibanez RG7321, with a DiMarzio Evo-7 on Bridge position. Now i've got some questions..

1- In default EMG pickup systems, because of interally shielded system, there isn't any humming sound even if the player doesnt touch the strings. I'm having this issue, what can i do to solve it?

2- Shall i connect the Battery's - lead to 3rd lug of the guitars female jack, in order to prevent battery drain or shall i only disconnect the cable?

3- Can i use this circuit for my bass guitar as well? It has only one pup in bridge, which is https://cgi.ebay.com/ws/eBayISAPI.dll?V ... AQ:US:1123, and there's only one volume knob. How shall i connect this one into this circuiT?

1. Check that your bridge, control plate, pot backs, and any other metalwork is grounded first, that should cure most of the hum. Next you can shield the cavity but TBH I have found that good grounding cures most hum problems unless they are single coil related.

2. For a 741 I would definitely use a stereo jack socket to switch the battery off when not in use, and remember to unplug the guitar lead (something I forget to do all too frequently).

3. No reason not to use it for bass pickups, but for your MM style pickup I would recommend this https://www.freestompboxes.org/viewtopic.php?f=13&t=431.

[slammer88]

....

I've recently made this circuit to boost my Evo-7, and it worked very well However, i had to use a LM741 because i couldnt find any LM4250 on the local stores. My guitar is a Ibanez RG7321, with a DiMarzio Evo-7 on Bridge position. Now i've got some questions..

1- In default EMG pickup systems, because of interally shielded system, there isn't any humming sound even if the player doesnt touch the strings. I'm having this issue, what can i do to solve it?

2- Shall i connect the Battery's - lead to 3rd lug of the guitars female jack, in order to prevent battery drain or shall i only disconnect the cable?

3- Can i use this circuit for my bass guitar as well? It has only one pup in bridge, which is https://cgi.ebay.com/ws/eBayISAPI.dll?V ... AQ:US:1123, and there's only one volume knob. How shall i connect this one into this circuiT?

1. Check that your bridge, control plate, pot backs, and any other metalwork is grounded first, that should cure most of the hum. Next you can shield the cavity but TBH I have found that good grounding cures most hum problems unless they are single coil related.

2. For a 741 I would definitely use a stereo jack socket to switch the battery off when not in use, and remember to unplug the guitar lead (something I forget to do all too frequently).

3. No reason not to use it for bass pickups, but for your MM style pickup I would recommend this https://www.freestompboxes.org/viewtopic.php?f=13&t=431.

Here you can clearly hear the hum, which i'm trying to say You can easily notice, that i'm holding my hand on strings and/or bridge and then raise it. Is such humming sound normal or not?

[deltafred]

that i'm holding my hand on strings and/or bridge and then raise it. Is such humming sound normal or not?

If you touch the strings and the hum stops it is often the bridge earth/ground wire that is no longer in good electrical contact with the bridge.

Measure the resistance between the bridge and the jack socket body. it should be less than a few ohms. The nearer to zero ohms the better.