Fodera, Sadowsky, aguilar, and other bass preamps

Stompboxes circuits published in magazines, books or on DIY electronics websites.
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bajaman
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Post by bajaman »

Here is the photoview of the SMD board :wink:
Baja three band active bass preamp SMD 051112 .bmp
Baja three band active bass preamp SMD 051112 .bmp (676.28 KiB) Viewed 3210 times
300dpi

and a black and white view without the silkscreen legend
Baja three band active bass preamp SMD mono051112 .bmp
Baja three band active bass preamp SMD mono051112 .bmp (113.67 KiB) Viewed 3210 times
600dpi
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bajaman
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Post by bajaman »

I have the gerber files for the silkscreen and the copper (*.GBR) but the forum will not allow me to upload them :( :scratch:
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Post by roseblood11 »

You could change the file extension to .TXT
Or use dropbox...

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Post by bajaman »

tried .txt ,.jpg, .bmp etc - none worked :(
email me if you need it :wink:
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Post by darmstat »

This is my first attemp at using the Express SCH software to make a schematic for the Vente. Thanks for all the work Bajaman. Did you use 8 KHZ OR 12 KHZ for the treble frequency for the Fender 3 band eq?

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Post by bajaman »

Did you use 8 KHZ OR 12 KHZ for the treble frequency for the Fender 3 band eq?
ALL the info you need is in the schematic and the graphs :wink:

By the way - your schematic with OPA2134 op amp has many mistakes and WILL NOT work as drawn.
ALSO - OPA2134 draws much higher current than the low current TL062 or it's National Semiconductor equivalent the LF422 :secret:
The American Deluxe Fender Jazz Bass circuit is also powered by 18 volt NOT 9 volt which can easily overload (not in a nice way :wink: ) when extreme settings are used on the tone controls.

Who the hell is Vente anyway :?:

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Post by darmstat »

You are right...I made a mistake with the first op-amp. The 1k should go to pin 3 of the op-amp. I will fix it, again my first time using new software....lol

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Post by darmstat »

Here is the revised Bena(Vente) 3 band eq.

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Post by bajaman »

still some mistakes :wink:
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Post by darmstat »

Ok...What may thoses mistakes be? Please.

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Post by bajaman »

pin 4 of the first op amp should be connected to the junction of the 10k resistors and the +9v supply should be connected to pin 8 and pin 4 should be connected to ground :wink:
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Post by deltafred »

darmstat wrote:Ok...What may thoses mistakes be? Please.
The reference (half supply) voltage divider is wrong, the resistors are correct, the caps aren't. You don't want a cap across the top reistor, it sould go across both resistors.
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Post by bajaman »

The reference (half supply) voltage divider is wrong, the resistors are correct, the caps aren't. You don't want a cap across the top resistor, it should go across both resistors.
agreed, but in practice it makes very little difference in this case - only 47n in series with 47u which is 1000 times the size. In reality when running from a battery source the 47n is totally uneccessary and so is the diode unless you insist on connecting the battery the wrong way around :roll:
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Post by bajaman »

For all those who do not want SMD board layout, I shall be designing a through hole component board layout in the next few days for my BAJA three band bass preamp :wink:
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Post by darmstat »

That would be great Bajaman....through hole component board layout . I have revised my Benavente. Practice makes perfect.... :D

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Post by bajaman »

still NOT correct darmstat :roll:
see my post (4 back in this thread :wink: )
between the junction of the 10k resistors etc :secret:
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Post by darmstat »

Ok...I see it. wow...I really never make this many mistakes... :|

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Post by darmstat »

Ok...I hope i got it this time.

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Post by bajaman »

almost there - just connect pin 8 of the op amp to +9v and pin4 to ground and it will work properly :thumbsup
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Post by darmstat »

It is very sad Bajaman. I have built 2 of these and from a handwritten schematic. I try to use the software to make one schematic and it takes 4 tries. I should have just uploaded the handwritten one, but i wanted it to look nice.... :D Thanks for the help and believe me the preamp does work... :applause:

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