Help me fix this old Maxon treble booster

manson · April 07, 2009, 09:38:08 AM

This is the Maxon MB-30 treble booster, but it doesn't work. Several wires are loose or missing. The orange wire was connected to the lower middle lug of the switch. And the battery connector is missing completely, and I don't know where it should go. Heck I don't even know what the input or ouput is

Can you help me fix this little thing? I'd like to hear what it sounds like

Look here for more pictures:
http://s113.photobucket.com/albums/n236/hoppekee/Maxon/

foxfire · April 07, 2009, 10:20:30 AM

it looks like it is just a LPB/screaming bird. looking at this picture, the orange wire soldered to the middle lug of the switch is your output tip and the lug to the left of it is your input tip. the bottom right lug is you 9vdc and ground is the black wire.

~arph · April 07, 2009, 10:33:36 AM

Input, I guess the little hole next to the lower left cap..
Output, Little hole to next to the top right cap.

Gnd is the black wire.
Pwr seems to be connected to the lonely switch pad below the letter ax.

manson · April 07, 2009, 11:07:41 AM

Ah yes it looks a lot like this one:

Only the 430k / 43k are 470k / 47k here. The white dial must be the volume pot, it's a 50k-B. Oh and the transistor is a 2SC828. I'll try to wire it up, thanks!

~arph · April 07, 2009, 11:27:25 AM

I might have switched the input & output.

foxfire · April 07, 2009, 12:05:14 PM

Quote from: ~arph on April 07, 2009, 11:27:25 AM
I might have switched the input & output.

the output is actually the middle lug of the pot which has a trace running to the switch...

manson · April 07, 2009, 02:04:18 PM

It's working! And it boosts treble allright.. it's a pretty useless effect haha. I might change the in/out caps to see if it'll sound more like a lpb-1

theehman · April 07, 2009, 02:07:31 PM

Quote from: manson on April 07, 2009, 02:04:18 PM
It's working! And it boosts treble allright.. it's a pretty useless effect haha. I might change the in/out caps to see if it'll sound more like a lpb-1

For an LPB-1, change the caps to .1uf. Put some bigger caps in for a Mole.

foxfire · April 07, 2009, 02:57:19 PM

Quote from: theehman on April 07, 2009, 02:07:31 PM
Quote from: manson on April 07, 2009, 02:04:18 PM
It's working! And it boosts treble allright.. it's a pretty useless effect haha. I might change the in/out caps to see if it'll sound more like a lpb-1

For an LPB-1, change the caps to .1uf. Put some bigger caps in for a Mole.

and then put another LPB or 2 behind it...

~arph · April 07, 2009, 03:03:51 PM

Why not keep it original and build two lpb's?

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Help me fix this old Maxon treble booster