Booster for bass question

[cordovaplata]

I recently discovered a very simple opamp booster, but it is designed for guitar. i know that I need to do a couple mods to make it work for bass. Any ideas?

http://guitarwiring.blogspot.com/2010/09/guitar-preamp-buffer-booster-easy-to.html

[Hallmar]

I'm not exactly a pro on this but i think that changing the output cap should let more bass through.


Don't remember if lowering the value should get you more bass response or increasing the value.

You should check it out.

[jimilee]

I'm not exactly a pro on this but i think that changing the output cap should let more bass through.


Don't remember if lowering the value should get you more bass response or increasing the value.

You should check it out.

increase

[Gus]

A 5532 and 1meg input resistor is questionable.  Also what did they do with the other opamp in the dual package unused pins?

here is a current post http://www.diystompboxes.com/smfforum/index.php?topic=102931.0

Myself and other have posted about opamp gain stages in the past.  

Active or passive bass?

What input resistance do you want?  This has an effect with passive basses and the cable capacitance.  Also helps pick an opamp.  Sometimes selecting a lower input resistance could be better.

What input high pass frequency do you want?

What fixed gain or variable gain range do you want?

What power supply voltage?

What will the output be driving?

Knowing the above you can look in a textbook or search the web for how to "design" one.

Here is something I posted before.  This is with a single coil sim you would change the pickup inductance and resistance and the tone and volume parts for the bass used




You could also build an inverting opamp gain stage

[cordovaplata]

Thanks for the reply. I want this booster to work with both passive and active bass, my priority is the active bass. I want a flat response, no coloring (if possible) y want to drive a distortion stomp or using it at the final stage to boost the overall volume.  I always use a bass amp. I never use a mixer

[Gus]

Why do you want a booster with an active bass?  You should have more than enough output from an active bass and a bass amp.  How much signal level can the input of the bass amp accept?

I don't understand the use of a flat boost with a bass.  

The graph I posted shows the interaction of a passive guitar and cable with the 1 meg input resistance.  The higher frequency bump is the interaction.  The booster has a flat response, everything to the left of input on the screenshot is a simple sim of a guitar and cable.  

With a 9VDC power you will most likely clip an opamp  based boost even set to low gain after a distortion.

Also if you boost bass you might want to cut more of the lows to keep it from getting "muddy" you might even want to cut some highs.

[artifus]

dear poor deluded gus - cos i want the best you big silly. simple, no? don't be confusing the issue with your science and facts and other such inconvenient truths. i just want to sound awesome. a pedal will do that for me, right?

*nevermind - just put it in a funky looking enclosure and give it a cool sounding name and i'll buy it anyway*

[cordovaplata]

Gus, I got your point and youre right. maybe i was trying to use this as a "solo-er" kind of pedal. but due to the nature of an active bass.... y can just use a pot shunting the signal to ground to attenuate the signal so it's almost the same... maybe i just wanted to build something :p thx for your replies.

[deadastronaut]

if you just want to build something for bass..

bass preamp?...

http://www.diystompboxes.com/smfforum/index.php?topic=101898.msg907034#msg907034

[Gus]

Thinking about this some more it makes sense about using a gain stage after some distortions and as a lead boost.

You might want an opamp booster that is adjustable down to a minimum gain of 1  and then up the max gain you want.


 

[cordovaplata]

yay! that could work! now i'm planning to build a DIY iRig stop... internally a iRig stomp has buffer or booster