Jackson-Charvel JE-1500 Parametric preamp complete

rcustoms · Post by **rcustoms** » 14 Dec 2011, 04:16

round and round on my junk box ,i pick up this

: catalog brochure

rcustoms · Post by **rcustoms** » 14 Dec 2011, 04:21

more info

: jackson wiring info

rcustoms · Post by **rcustoms** » 14 Dec 2011, 04:26

enjoy with that

: layout

je1500.pdf: (894.04 KiB) Downloaded 726 times

rcustoms · Post by **rcustoms** » 14 Dec 2011, 04:36

datasheet

LF441.pdf: (445.45 KiB) Downloaded 311 times

andregarcia57 · Post by **andregarcia57** » 14 Dec 2011, 20:37

this project is similar to EMG PA2 Booster?

rcustoms · Post by **rcustoms** » 14 Dec 2011, 21:43

I think not because it has a parametric eq and you can play with a couples of variations ,see the article

gmulak · Post by **gmulak** » 09 Jan 2012, 20:10

rcustoms wrote:I think not because it has a parametric eq and you can play with a couples of variations ,see the article

Hello,
Well done rcustoms!

I could not find dual switch in electronic stores. I only got a stereo pot at the link below.

http://grupmarketim.com/urun.asp?katego ... runid=1486

Does it work??

And what is the 250p? Capasitor?

rcustoms · Post by **rcustoms** » 10 Jan 2012, 14:10

yeah mr askwho, its a stereo pot (many bass guitar use that pots with center tapped, for mix their mics)

gmulak · Post by **gmulak** » 10 Jan 2012, 19:33

Thank you all rcustoms and askwho69

..I 'll try it with two 50k pots first..
cheers..

Dirk_Hendrik · Post by **Dirk_Hendrik** » 10 Jan 2012, 21:04

Quickie since I don't like layouts without explanatory schems:

Dirk_Hendrik · Post by **Dirk_Hendrik** » 10 Jan 2012, 21:18

gmulak wrote:Thank you all rcustoms and askwho69 ..I 'll try it with two 50k pots first..
cheers..

No. You don't

. You're going to try the pot you posted here: http://grupmarketim.com/urun.asp?katego ... runid=1486 first and it will work for you. I do not see why it should be wrong as Askwho suggests.

For this application, or better, for a proper response, the pot needs to be stereo. Two mono pots will give a crappy control.
You want a linear pot curve. That's the "B" for most Japanese pots like Alphas. You do not want a log curve, the "A" unless you wire the pot for center frequency increase when dialing counterclockwise (the other way around). In the ideal case you use a "C" taper. That's reverse log.
This tonecontrol is rather similar to the parametric mid in the Ibanez ST9 supertube:
http://www.dirk-hendrik.com/temp/ibanez_st9.pdf

Dirk_Hendrik · Post by **Dirk_Hendrik** » 10 Jan 2012, 21:20

Rcustoms,
Are you sure that 1n cap is not a 10n cap? Would make far more sense.

gmulak · Post by **gmulak** » 10 Jan 2012, 22:06

Dirk_Hendrik wrote:
gmulak wrote:Thank you all rcustoms and askwho69 ..I 'll try it with two 50k pots first..
cheers..
No. You don't . You're going to try the pot you posted here: http://grupmarketim.com/urun.asp?katego ... runid=1486 first and it will work for you. I do not see why it should be wrong as Askwho suggests.

For this application, or better, for a proper response, the pot needs to be stereo. Two mono pots will give a crappy control.
You want a linear pot curve. That's the "B" for most Japanese pots like Alphas. You do not want a log curve, the "A" unless you wire the pot for center frequency increase when dialing counterclockwise (the other way around). In the ideal case you use a "C" taper. That's reverse log.
This tonecontrol is rather similar to the parametric mid in the Ibanez ST9 supertube:
http://www.dirk-hendrik.com/temp/ibanez_st9.pdf

So

Do I need a stereo dual 50k reverse log pot?

How can I find it?

Could you send me a link to purchase?

Dirk_Hendrik · Post by **Dirk_Hendrik** » 11 Jan 2012, 09:51

Ideally, yes. Otherwise use the linear you liked already.

I "always" make these combining the top of a dual log pot with the reverse log deck from a single pot.

rcustoms · Post by **rcustoms** » 11 Jan 2012, 18:24

Dirk_Hendrik wrote:Rcustoms,
Are you sure that 1n cap is not a 10n cap? Would make far more sense.

i re-check again and the label show(102j) means .001 uf,i copy the circuit exactly .
thanks anyway for the schematics

Dirk_Hendrik · Post by **Dirk_Hendrik** » 12 Jan 2012, 06:52

rcustoms wrote:
Dirk_Hendrik wrote:Rcustoms,
Are you sure that 1n cap is not a 10n cap? Would make far more sense.
i re-check again and the label show(102j) means .001 uf,i copy the circuit exactly .
thanks anyway for the schematics

Innawesting.

Thanks for the verification!

gmulak · Post by **gmulak** » 12 Jan 2012, 20:34

I couldnt find dual pot unfortunately

..Can I use two stereo pots wired together? What are my other chances?

Dirk_Hendrik · Post by **Dirk_Hendrik** » 12 Jan 2012, 21:03

What's your location? (Which country do you live in that is)
Might help to point you out to a supllier in your region. Otherwise they're being sold at, for instance, www.futurlec.com.

gmulak · Post by **gmulak** » 14 Jan 2012, 00:00

Finally, I prepared the preamp. I used LF442 instead of the original one..I don't know what it's gonna happen but I'm excited

I'm waiting the cargo including dual pots and LM4250 (my nightmare).. Thanks for the help guys..
Cheers..

Dirk_Hendrik · Post by **Dirk_Hendrik** » 15 Jan 2012, 15:57

askwho69 wrote:
gmulak wrote:Finally, I prepared the preamp. I used LF442 instead of the original one..I don't know what it's gonna happen but I'm excited I'm waiting the cargo including dual pots and LM4250 (my nightmare).. Thanks for the help guys..
Cheers..
I think lm4250 is single opamp.. you cant used it in this circuit.. or else make another layout that has 2 lm4250...

Why can't you use a single opamp in a circuit that uses... a single opamp?