PORTABELLABZ

The 208 ToolBox and BOB expander FAQ


User

My ToolBox or BOB doesn't want to insert into the Easel card slot.
Some recent BEMI Music Easels seem to have a
card slot slightly shorter than standard and come with tapered program cards.
Sand gently the ToolBox's or BOB's male connector will ease insertion. Pay attention to sand equally both edges to keep the male and female contacts aligned.


Should I turn my Easel or 208 off before plugging or unplugging the ToolBox or BOB expander ?
Yes

Some features like the envelope looper or sequencer outs don't work.
Ensure the "control" switch next to the 208's edge connector is well in its central position ("both").

The envelope doesn't start looping when I switch the looper to self.
The envelope needs an initial pulse, like the pulser. If switched when off, it won't loop. Switch while on or trig it with a pulse.

External CV/gate signals don't work.

Ensure the 208 and external device grounds are well interconnected via a jack socket or the ground banana socket.
 

Can I use the BOB expander standalone ?
Yes

Can I connect the ToolBox horizontally to the BOB expander ?
Yes but you should support it from below.

Can I safely connect other gear to the 
208 via the ToolBox or BOB expander ?
Yes but check the max voltages the other gear accepts. The 208 can output voltages up to +/-15V.

Do the edge connectors need cleaning ? How can I clean them ?
If bad contacts occur, the edge connectors are probably dirty.
Rub the
ToolBox's or BOB expander's male connector on both faces with a cloth and Isopropyl Alcohol (IPA).
Fold a thin cloth wet with IPA onto the
male connector of a program card and gently plug it a few times into the 208's connector to clean the female contacts.

Is there a risk to damage the 208's edge connector using the ToolBox or BOB expander ?
The 208's female edge connector is solid and as long as it's not heavily forced it's ok. Hold the ToolBox or BOB expander with hand when plugging or unplugging  a patch cable relieves pressure on the edge connector.
I've been using similar patchable cards for years and it's still perfect on my own Easel.
No related issue was reported to my knowledge, being with the ToolBox or iProgram card or other.
If an accident occurs, it's easy to replace, no special DIY skills or tools are needed and I can supply with a direct drop-in replacement.




Builder

The kit came with 2 x 4.7F and 1 x 22F caps, but the PCB silkscreen says 1
x 4.7F and 2 x 22F.
My mistake in the BOM, sorry. It's fixed now.
If you have no 22F cap on hand, the 4.7F can be used in place of a 22F. The value is not critical.

I have another problem with my kit.
Please contact the seller (WeedywhizZ or SynthCube), the kits are beyond my control and I'm not able to help.

What is the large rectangle in the white silkscreen on the back with 3 arrows and 3 x 3 pads for ?
This is meant to host a LittleBits module and should be ignored otherwise, nothing else should be mounted there.

Can I purchase a kit or parts directly from you ?
No. Only PCBs sets or pre-built units are available from me.

What are the +15V, 0V, -15V pads for ?

These pads are directly connected to the power rails and meant to power extra circuit built on the perfboard.
Those should NOT be connected to anything else or shorted.

The envelope looper doesn't work.
Check you well placed the jumpers or bridges for the pot course as described in the build notes.

If the LED is always on, replace the 2N3904 next to the CD4093.

A builder reported that a CD4093BCN didn't work in this circuit and switch it to a CD4093BE fixed the problem.

A feature doesn't work.
Double check your build for a missing part, a bad solder joint, a solder bridge shorting 2 pads etc...
A possible cause is a short with 0V
(ground plane). Do a continuity test with 0V on the banana eyelet and edge connector pad. Most traces are banana eyelet > resistor > edge connector and easy to follow.
Contact me if a drawing of the signal trace is needed.

When the ToolBox is plugged in my Easel stops working.
There's likely a short between power rails and/or 0V (ground plane).
Remove the ICs from their socket and perform a continuity test between the +15V, 0V and -15V pads.
If there's a short, you can locate it by cutting the rail trace at different points and do a continuity test after each cut. You can repair the cuts afterwards by bridging with a cable.
 
I don't seem able to debug myself.
Depending on the quality of your build, I could accept to fix it at cost if it's shipped to me.
Contact me.