ideas for my design? Onboard Guitar&Bass Preamp

[sir_modulus]

I've searched a long time ago for some good somewhat complex (controllable) DIY onboard EQ (mainly for bass here...but hell, a guitar EQ would be nice). To me, here's what I want out of the preamps I'm going to *design* (you all know I'm just gonna be hackin' some other designs to bits and slappin them together):

Guitar:
-Fet Based Buffer at the very front of the preamp
-Active tone control section (normal tone control put between two opamps)
-10 dB or so gainboost on the output
Holes Needed:
1 = Tone, pull for gainboost

Bass:
-Fet Based Buffer at the very front of the preamp
-Active 3 band EQ with mid shift on mid knob
-Buffered Booster output (10dB at max)
1 = Bass/Treb (stacked pots)
2 = Mid/Midshift
3 = Volume, pull for boost

What do you guys think? Anything you'd like to see in there?

Cheers,

Nish

[sir_modulus]

bump 

[Roobin]

Have a look at this for 3 band eq:

Caps/resistors might need changing for bass.

[markusw]

Don't know about guitar but for bass I would like to have the following controls:

Bass and treb (concentric pots like you suggested but separate pots would be OK for me)

Mid + parametric mids on concentric pots, the parametric mids with a gyrator or maybe preferable with a state variable filter (oops would need a dual pot + a single pot concentric)

pu blend pot (maybe after two separate buffers, one for each pu)

volume

(Ideally all pots pcb mounted)

The tone control on the Bart NTMB already is very fine IMHO. Doesn't have parametric mids though.

Don't know if separate buffers for each pu would be an advantage. Although I have them in my current on board preamp I don't know if the sound is better than with just one buffer.

Actually I wanted to mod the NTMB for parametric mids but I couldn't find any concentric pots that fit into my bass (needed a thread of at least 10 mm).  

Regards,

Markus

[Dragonfly]

you might check Albert Kreuzer's page for some ideas...he has a couple fet based preamps on his site....

[sir_modulus]

I like all of these ideas so far!

I was actually planning on using the EQ from the Albert Kreuzer Preamp, and just adding a mid shift pot instead of changing the caps.

Any other ideas/suggestions?

Cheers,

Nish

[sir_modulus]

I've talked to a couple of bassists, and am currently working on drawing up the schematic (have it on rough paper right now).

Here's the layout as I see it now:



The Jumper on the preamp board selects between using a selector switch or using a blend knob. Any other suggestions or ideas?

Cheers,

Nish