Messages

I have a production board built up now (prototype didn't have the ghost option). I'll try it out and tell you what I think. It might be awesome, or awesomeful.

I think the key here is he states that it can cause loss if the cap itself is leaky. So, yes, I can see that being the case but not at the max volume because the cap is shorted at that point. Maybe a shorted, leaky cap can cause treble or bass loss, I don't know.

I've done a couple treble bleed caps on Strats...usually a small ceramic, but no parallel or series resistor. I can kind of take it or leave it.

I do use 22n for all my tone caps. It's the perfect range for my ears.

Thing is, increasing the gain of stage two might affect the tone control a bit, so I'm not sure that is the way to go.

Here's what I suggest. Socket both R5 and R8. First try a smaller value in R5 (say 5k1 or close to that) with R8 staying as 47k. This should increase the output some. If that doesn't work for you, leave R5 as 10k and increase R8 to a value between 68k-100k.

I think I will make a goal of doing something with it in the next two weeks. It could be a good resource for several things besides doing some artwork. It's a waste not to take advantage of it.

Maybe I will have something to show for it soon!

I still have it. Thing is, not long after I bought it I decided to switch to manufactured boards over hand-made ones. It hasn't really gotten any use although every week I think "yeah, I really need to get back to that". Probably the best use of it now would be to do some etched artwork on boxes since I very rarely do handmade boards anymore.

I have it set up with a Windows machine running Mach-3.

Yes, absolutely!

Yeah, that is very strange. Normal voltage drop would be pretty small. Could be the current draw of the circuit is proving to be too much for a 1/4W resistor? Not sure. I'll look into this and see if I can re-produce the result you have.

Alternatively, I can suggest using a 1n5817 there. If it is something I've bonked up, then my sincere apologies. There is maybe a larger issue in play about this kind of filtering that I'm not realizing.

Are you sure it is 100r? Go ahead and remove it and install a jumper in its place.

Yup, that looks good!

Something is wrong with the charge pump area then. You should be getting about 9v on pin8 of the charge pump and about 18v into the regulator and 15 out. That's where you need to focus.

You did wire the filter PCB to the 9v/G pads, not the 18v pads, correct?

Your voltage is low for some reason. What are your voltage reading going into the regulator? Is it 18v (approximately)?

Okay, that's what I suspected. That's exactly how it should be.

Looks good! You know, here's what would make it better; move R7 back a bit so it is between C1 and R5. This way, you get the signal limiting (if it's needed) without it throwing off the bias voltage delivered through R5. Other than that you are good to go.

For some more reference about the apparent mistake on the smallbear schem, take a look at both the DOD FX-90 and DM-2 schems for the MN3005. You'll see that the negative ground setup follows just as I described (although these are for 9v, not 15v).

http://www.freeinfosociety.com/electronics/schematics/audio/pictures/dodfx90.jpg
http://www.freeinfosociety.com/electronics/schemview.php?id=128

Well, that's pretty bizarre. With IC2 removed you should get clean signal at pin16. You are getting that, so good. But, you said removing both IC2 and IC3 you get no signal at pin16 of IC2. Frankly, I don't know how that is possible. removing IC3 should not effect the path of the clean signal in any way.

I'll have to think so more about this.

You can use 50k in a pinch. You could also use 20k, 22k. Maybe 10k, but I haven't tried it.

The down side of a 50k is it narrows the range a lot on dialing in the Bias and may prove more difficult to make minute adjustments (which can have a big effect on distortion levels). If you have trouble with the 50k, an you have an extra 47k resistor, you could tack the resistor on the bottom side of the board between pins 1 and 3 of the trimmer to half its value.