Any suggested improvements for this shematic? And how close must values be?

[rockgardenlove]

Alright, so I was thinking of building this.  Do you guys have any suggested improvements you think I could do?

And how bad is it to use say a 3k resistor instead of a 3.3k...or a 1.5nf instead of a 1nf?

Thanks.

[Joecool85]

I would say those values shouldn't be a problem.  If you build this, definetly post in here about it.  This is the preamp I'm thinking about building for my lm3886 this summer.  Oh, and if you want, feel free to post it at http://ssguitar.thatraymond.com also!

[rockgardenlove]

I'll post on it for sure.  Thanks for the reply!

(Btw, thats a really cool forum you have there.  I don't post much cause I'm a n00b, but I check up and soak up the info...so I won't appear too stupid later :p )

[Joecool85]

That's cool.  And thanks for the compliment on the forum.  It will be even cooler once we get to our new server and also once we get more members, although, we did just hit 20 members today!  Not bad for the first week!

[rockgardenlove]

A new server already!?  It's only been one week!


Anyone else have any comments before I order?

I was also thinking, couldn't I install a little switch to send the signal to the ground instead of the op amp to cut out a certain frequency? 

[Rob Strand]

The 3k to 3k3 won't be an issue.
The 1n5 to 1n probably not an issue either - really needs simulating.

For improvements, the input if that circuit is unsuitable for direction connect to a guitar, it loads the pickup.  You need a buffer in the input - search the archives, I'm sure there's a few examples of buffers specifically for this EQ.   When in put into another circuit and driven by an opamp there's no problem with loading.

[rockgardenlove]

http://www.diystompboxes.com/smfforum/index.php?topic=41657.0
Would something like that be right?  I think it deals with the same EQ too.

[Joecool85]

A new server already!?  It's only been one week!


Anyone else have any comments before I order?

I was also thinking, couldn't I install a little switch to send the signal to the ground instead of the op amp to cut out a certain frequency? 

Yeah, well its down a lot since its the university's test bed.  But it was free.  A buddy of mine has some webspace with 1and1 and we are going to swap it over to that, along with buying a real domain name (ssguitar.com)

[Joecool85]

http://www.diystompboxes.com/smfforum/index.php?topic=41657.0
Would something like that be right?  I think it deals with the same EQ too.

It deals with a similar circuit.  However, I never made the EQ, just the buffer.  I did play around with it quite a bit though, and I didn't notice any difference between using it and not using it really.  I tried putting it in front of my lm3886, tried putting it before and after pedals.  It didn't work so well putting it before the pedal, I don't remember what it did, but I remember I hated it lol.

[rockgardenlove]

Hmm ok, so any other suggestions?

[rockgardenlove]

Anyone have a good buffer that would work with this?

[Connoisseur of Distortion]

you could just put in a unity gain non-inverting opamp stage.

take your ordinary, run of the mill opamp. run the signal through a capacitor into the non-inverting input on your opamp. Then, tie your inverting input pin to your output pin, and connect your output to the input of your circuit. simple!

this also means that you avoid the annoying single opamp situation. I just hate having them around...

[rockgardenlove]

I was planning on using that from GGG...does that look suitable too?