freestompboxes.org

For now here are some guts and for few days schematic.

apollomusicservice wrote:For now here are some guts and for few days schematic.

count on me for pcb layout

Hi apollo,

This is the link to the datasheet of the 20 pins BBE custom chip: http://pdf1.alldatasheet.com/datasheet- ... 2153D.html

Hope the diagram in page 4 of that document helps you to trace this unit.

Cheers,
Jose

For drawing schematics I use Eagle Cad but I did not find library for NJM2153.
I will make my own simplified circuit for 2153 chip in dip 20-pin package.Tnx

apollomusicservice wrote:For drawing schematics I use Eagle Cad but I did not find library for NJM2153.
I will make my own simplified circuit for 2153 chip in dip 20-pin package.Tnx

remember baja or bbe sonic maximizer is part of this new pedal,i thing

This morning somebody left this schematic at my front door.

Does anybody know whats going on with the switches on the schematic??? the pre/post switch, -12dB switch and phase switch have some strange numbering. Then there is the switch coming off the XLR jack that has no label. Any help would be greatly appreciated. Thanks in advance.

Lani

Lani wrote:Does anybody know whats going on with the switches on the schematic??? the pre/post switch, -12dB switch and phase switch have some strange numbering. Then there is the switch coming off the XLR jack that has no label. Any help would be greatly appreciated. Thanks in advance.

Lani

Even though the switches have wrong pin group labeling, their purpose is pretty clear. It becomes even clearer after you review the user manual posted on BBE website.
No-named switch is a ground lift, others - pretty obvious.

I built the gain, and the freq/notch section. I did not add the treble and bass controls. But the output is so low, I have the amplifier almost turned all the way up to hear anything out of this thing.

Any thoughts on why this thing has no output?

It looks like it uses a bipolar power supply (+/- 12V ?). Other than that, doesn't appear be overly complicated.

Yes I used a bipolar power supply. But should this have at least a unity level output after the freq/notch section?

caspercody wrote:Yes I used a bipolar power supply. But should this have at least a unity level output after the freq/notch section?

Are the dual ganged pot (R7) connected as per schematic ?

Both sections acts as rheostat using only two wires each and must increase/decrease in value at the same time. Perhaps one of these sections is connected bacwards...

Cheers,
Jose

I tried just the gain stage by coming off of pin 7 of IC1B and there is barely any signal. Should I be getting a boosted signal at least from this stage?

And what signal level are in IC1A pin 1 ?

The gain feedback resistor R14 seems too small. And what’s with those weird values? Anyhow try 22k - that should give you some gain.