Two stage preamp with tone controls,variable input sensitivity and very low power draw.
http://www.redcircuits.com/Page69.htm
If anyone is interested i did a pcb layout
Tracks, red are jumper wire
Etch this
Have you built this circuit? If so, what's it sound like? Does it work well? Thanks for posting this circuit, it looks interesting and promising.
Hi Joe not as yet, however i have etched the boards and will test it out in a week or so. I am currently building a mobile amp and have got a few preamps to test out in it. I will keep the board posted with my progress.
Phil
Just to say as it stands this circuit will not work, there is an error in the layout.
I will update if anyone is interested, once i have the thing built. The second gain stage was not biased to the reference volatge, opps
how are you coming along on the build? I've finally decided to go and build an amp for my own... I plan on using an OPA549 I have lying around the house and have a pre-amp infront of it... this one looks good. It would be either this one or the tonemender in runoffgroove
To be honest i havent built this one as yet, got my handsfull with the own preamp design ( loads of help from Teemuk) and the english channel I have also finished. I did however find some errors on this design which i have now corrected if you want to try it by etching one. I should point out however that this and the tonebender only give a maximum of 10x gain so they might not provide enoguh boost for what you need.
And placement
Quote from: lefizz on October 11, 2007, 10:48:08 AM
I should point out however that this and the tonebender only give a maximum of 10x gain so they might not provide enoguh boost for what you need.
okay since you brought it up, what exactly does that mean? what sort of problems would I encounter? sorry your talking to a newbie :-[