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DIY Stompboxes => Building your own stompbox => Topic started by: trocker767 on October 28, 2006, 01:19:21 AM

Title: BSIABII Problems
Post by: trocker767 on October 28, 2006, 01:19:21 AM
Hi there,

I just finished building a new effect pedal for myself, the Brown Sound In A Box 2 from GeneralGuitarGadgets. http://www.generalguitargadgets.com/index.php?option=content&task=view&id=150&Itemid=178 (http://www.generalguitargadgets.com/index.php?option=content&task=view&id=150&Itemid=178)
I used NTE457's instead of 2N5457's and NTE458's instead of J201's.
I checked all the transistor voltages and everything looks fine.
The Problem is that the effect is so quite, I have to turn my crappy Fender Frontman Amp's volume all the way up to hear it, and it's still super quite.
I'm sure i haven't burnt out any of the transistors, and i have no clue how to fix it.

Any suggestions?
Title: Re: BSIABII Problems
Post by: ward on October 28, 2006, 04:29:49 AM
Have you downloaded datasheets of the transistors to check they're compatible ?
Are you aware that NTE458 does not have the same pinout as J201 ?

Title: Re: BSIABII Problems
Post by: trocker767 on October 28, 2006, 04:39:52 AM
Really? The J201 doesn't have the same pinout as the NTE458?
Then i've been lied to harsh.
Is there an NTE replacement for the J201?
Title: Re: BSIABII Problems
Post by: ward on October 28, 2006, 05:51:23 AM
You could download the datasheets from the fets you're substituting and the ones you have.
I only had a quick look for the J201 vs NTE458, and I could be wrong.  Don't believe me, check for yourself !!
I did not check for the 2N5457 you're substituting, definitly check those too.

Are you working on the GGG pcb ?
Have you socketed the transistors ?
The NTE 458 will probably work, IMHO I'm certainly no expert. 
It is a N-channel J-fet general purpose just like the J201.
But the pinout must be right, you could bend the legs to try it out if you've socketed the transistors that is easily done.

Title: Re: BSIABII Problems
Post by: trocker767 on October 28, 2006, 01:45:07 PM
I'm downloading the datasheets right now to double check,
But there is distortion, just very very quite.
And yes, i am using the GGG pcb.
Title: Re: BSIABII Problems
Post by: trocker767 on October 29, 2006, 02:58:45 AM
bump
Title: Re: BSIABII Problems
Post by: ward on October 29, 2006, 06:37:20 AM
pinout NTE458 = gate in the middle
pinout J201 = source in the middle
you need to deal with this first,

Get the pins in their place, be very carefull when bending pins out of place, you can easily damage or have 'em shorted out.

Then come back and report what happens.
Title: Re: BSIABII Problems
Post by: trocker767 on October 29, 2006, 11:53:41 PM
hey, now i most likely have to buy new transistors, or is there a chance i could just save em and switch the pins?
Title: Re: BSIABII Problems
Post by: tungngruv on October 30, 2006, 01:09:11 AM
Hey trocker767, I have some extra trannies. Send me a pm w/ your mailing address and I'll mail em to you. The BSIAB2 kills.
Title: Re: BSIABII Problems
Post by: trocker767 on October 30, 2006, 01:23:04 AM
It's ok, i can get them really easy from my supplier.
Thanks anyways  ;D
Title: Re: BSIABII Problems
Post by: MartyMart on October 30, 2006, 07:01:47 AM
Strip the plastic jacket off a small piece of wire and slip this over one of the
legs of your fet, ( middle leg )  so when you switch G&S they are insulated from each other.
works a treat !

MM.
Title: Re: BSIABII Problems
Post by: trocker767 on October 30, 2006, 05:56:43 PM
Thanks MartyMart!
Thats a killer idea.