PORTABELLABZ

The 208 ToolBox and BOB expander FAQ


User


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

Why are some features like the envelope looper not working ?
Ensure the "control" switch next to the 208's edge connector is well in its central position ("both").

Why does the envelope not 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. You want to switch while on or trig it with a pulse.

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.

Why are external CV/gate signals not working ?
Ensure the 208 and external device grounds are well interconnected via a jack socket or the ground banana socket.

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, why ?
My mistake in the BOM, sorry.
If you have no 22F cap on hand, the 4.7F can be used in place of a 22F. The value is not critical.

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, what's wrong ?
Check you well placed the jumpers or bridges for the pot course as described in the build notes.




When the ToolBox is plugged in my Easel stops working, what happens ?
There's likely a short between a power rail and 0V (ground plane).
Remove the ICs from their socket and perform a continuity test between the +15V, 0V and -15V pads.
I found a short between +15V and 0V at the exact same place on 2 "batch 4" PCBs : the "MO hi - 120k" resistor eyelet  next to the +15V print. This short seems to occur only when the resistor is soldered in place. Maybe other PCBs have the same etching problem ? Others I built were all ok.
Cut the eyelet's trace and connect the resistor's leg to +15V pad.



If the short is elsewhere, you want to 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.

A feature doesn't work, what's wrong ?
Doublecheck your build for a bad solder joint or a solder bridge shorting 2 pads.
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.

I don't seem able to debug myself, what can I do ?
You can send me your ToolBox or BOB and I'll fix it.
Contact me.