x0xi0 IO & Overdrive - Install & Troubleshooting

[kroutshev]

Allright Brian, i'll post you sample tonight !!
Thanks for OP275's !
Overdrive sound higher than distortion !
Have a good day !

[kroutshev]

Just coming back from my studio !! I begin to understand how work distortion and overdrive ... Very impressive !!
In sample http://dl.free.fr/v0cGbhJQv you will hear, in the beginning stock sound, after distortion, then overdrive and finish by stock sound !!
Thanks again Brian, your mod's get higher and massive x0x sound ...
Tomorrow i will test inputs and ouputs ... and after i'll wait full kit
All the Best Brian.

[bcbox]

thanks for uploading that sample, sound great!
The inputs & outputs are easier to test because they are simple circuits and they are independant of each other.

[knarleybass]

I love my x0xb0x and the i/0 mod is a must...
if not for any other reason is that there is an on/off switch. Seriously the overdrive sounds great!

[lazlokovacs]

Ahh! I'm going crazy !!
I just installed the IO kit, started her up and it worked fine but I got like ~11V on Accent Sweep Out, but THEN! a crocodile clip falls and lands on IC305. I'm pretty sure it short circuited it. Anyway, so nothing works so I change to a new LM317T, nothing works so I keep on changeing components, but nothing. I think I need some hint here because I'm going insane! I've looked for other short circuits but haven't found any...

The strange thing is that I get ~10V over the AC jack when she is turned off then just ~3.2V when it's turned on!?

I've changed:
C328
IC305

D40, 41, 42, 43
C3
C4
C5

AC jack
all wires going to the PSU area

[lazlokovacs]

Anybody?

[lazlokovacs]

Ok, so I changed some other components (IC303 & C322) and nothing, then I pulled the ICs, on the IO PCB, from their sockets and voila! She starts up and works! Just gotta get me some new ICs and everything is hopefully ok!

[prochi]

hi everyone

i just installed a xoxIO and i am finding that my overdrive isnt clipping. I get the xoxbox signal through at the same volume when overdrive is on but the diodes dont seem to be doing much. I replaced the diodes and no result. I checked the signal going through diodes on my scope and i see a large positive dc offset and the xoxbox signal.
The resistance measurements are consistant with the build notes. The tone pot works, and the amount pot doesnt seem to do anything. The amount pot works for distortion however.

I read in this thread that someone had a dud pot, has this happened to anyone else?
If i were to install a pot to test the if the pot is at fault where should i hook it up?

[prochi]

i am really stumped, pin 2 of IC301 looks exactly the same as pin 1 on my scope
the measurement of resistance between pin 1 and pin 2 slowly rises in resistance from 10k up when i turn the overdrive amount pot
i thought this slow rise could have been a bad cap so i took out the 47pf but it still does the same thing

im really stumped
would really enjoy some peeps to pick their brains with me

[bcbox]

there may be a short somewhere in the feedback loop of IC301A.
I would check VR301 first.

refer to the datasheet of the pot for pin designations:
http://www.mouser.com/catalog/specsheets/TW-700148.pdf

the distortion circuit using the first gang of the pot, pins 1, 2 & 3 (the ones without the circles around them in the datasheet).
First check that pins 1 & 2 are not shorted with solder.
If this is ok then lift one leg of R303 and test the resistance between pins 1 & 2 of VR301. The resistance should vary between 0 and ~1M ohms as you rotate the pot.

If everything is still ok you can rule out the pot as the problem.

[Luka]

(prochi)
VR301 pins 1+2 (without circles) measures 0<>1M, pins 1+2(with circles) measures 0<>100k with r303 pulled out

[prochi]

yes so as i stated in that last post (by Luka.. sorry i forgot my login deets but ill keep using this login to make things clear)

im not getting 1M on the pot with r303 removed. i tinkered with someother parts of the circuit and still am no-where. i checked the pcb with my magnifying glass and cant see any shorts around the overdrive (though i must admit it is pretty tough looking around as the board is so tight so hopefully ive not missed any, but i have all the circuit's components mapped so i thought i gave it a good look over)

i sort of understand this circuit so i am lost as to why im not getting any love with it. shouldnt the signal be overdriven by the diodes and the pot short circuits the affect of the diodes out. is this correct?
if i remove the pot the effect will be on at full power

i had a look at removing the pot last night and it looked like a PITA. Any tips?

[kroutshev]

Each time that i mount these trimpots i don't remember which one is tm301 and tm302 ! Could you help me please !
trimpot P 101 is ?
trimpot P 203 is ?
Thanks.

[bcbox]

TM301 = 20k
TM302 = 100 ohms

[Altitude]

Ok,
Just installed mine and have a couple of questions:

A) Nothing works No sound, VCO tests fine, the box worked fine before installing everything

1: R62 is pictured in step 14, but the 1st part of the manual says to remove it? Same thing with C17, there are only instructions to connect the - yet the + is shown connected as well..
2: Slide switch instructions say that the wires will be connected later but there is no further mention of it in the install manual..

*edit

ok, looking at the schems, it looks like pin t needs to go to the vco out (r62) correct me if i am wrong since again this is not in the build manual
i just realized that the slide switch is for a second vco so it is not used on just the i\o (confirm?)