G9(and other mic/inst pre) mods

[WJS]

anyone have any favorite mods for the g9? or any other preamps?

This is the schematic I used for my last project(my drawing software desided to lose the triode symbol I had made, but i'm sure you can figure it out.

this is a very simplified version, as it only had to run a guitar signal.

has anyone else played with the g9? (i'm sure you have) what did you do with it?

 

[gyraf]

I've done quite a few modifications to the G9 - after all, the DIY-version is based on the rev#16 or so of the commercial model :razz:

What sort of modification are you looking for? To acheive what? Or are you just looking for a modificitation for the mod's own sake?

Jakob E.

 

[clintrubber]

If you just need to mod :wink: :
add a HiZ buffer before the inputTX, (wasn't it the Jensen AS004.pdf that would be suited ?).
It could be interesting to compare the sound of the post-inpTX DI-input vs a DI/HiZ-input including the inputTX.

Regards,

Peter

 

[gyraf]

..yes - tried that, but the added section wasn't nearly as universally useable as the post-transformer input I ended up with..

 

[clintrubber]

ThanksJakob for catching this one - my suggestion based on..., well, there's no G9 around here - and you've actually tried it, so that's way more useful info.

Just curious, what kind of issues did you run into ?

I must add I haven't build the Jensen-circuit 'as is'; among others I replaced R9 with a current source (coming from a negative voltage).
And powered it from a 'normal supply' (didn't use P48), but that's less relevant for now.

http://www.jensentransformers.com/as/as004.pdf

Regards,

Peter

 

[WJS]

I was just thinking the could be a place to bounce ideas/results of changes

although rev 16 gives the impresion that its been done.

 

[gyraf]

Yep, ideas about changes would obviously be interesting to discuss, but you need to be specific about what and why you want changed..

Jakob E.

 

[WJS]

I dont have anything i want changed, i just wanted to know if there were any popular changes. i'm brining the pre i made to its first real session in the next few weeks so i might have some ideas of things i want then but i'm rather happy with what i've gotten. (even if it is only half of the real thing)