livo wrote:Thanks aot. So what your saying is that even after this mod, it still sounds like a fuzz.
I posted another explorative question about the BITMO 2BO mod here.
http://www.freestompboxes.org/viewtopic.php?f=11&t=3113&start=40 It explains my impression of the pedal out of the box and it's problem plus what Behringer did and said about it.
According to the OP of that thread, the BITMO 2BO mod is apparently 2 resistors and 2 caps (added in, swapped out, other removals or connections???? I don't know. Even though repeatedly asked he failed to expand or clarify anything. Then the thread was hijacked to cover the VT999). Supposedly this mod makes the Gain / Drive pot more widely variable or controllable. So rather than having all the adjustment available compressed between 0 and 1, you get a more expanded adjustment or finer control. This would be a big improvement in my opinion.
Some other reading I have done simply says that swapping out the tube to a good one is all that it takes. I haven't tried this yet.
Then there is the mod that you've done, (minus the Opamp swap) but you say it is still just fuzzy.
I'm wondering if it is worth pursuing or not and just doing what your suggesting is ditching the guts of it and using the box shell.
Hi,
Here's a copy and paste of what I sent to others about the Bitmo mod over the years.
"I'll tell you the values and where the components go here - if you want to post it later it's all yours.
Parts list:
100k resistor (was supplied with a tan carbon comp)
460 OHM resistor (blue - metal comp [I think])
1200pF capacitor (metalized polyester type)
.0047uf capacitor (not sure of this one - it was aqua-coloured and axial type - was marked with the number 472.)
You have to unscrew the tube board to do the job - but that's all. Looking at the tube board from the solder side there are the 9 pins - 1-9 going clockwise from the gap at the bottom of the board. The .0047uf cap goes between pin 1 and pin 7 of the the tube on the tube board. The 460 OHM resistor is connected to pin 7 and also the negative lead of the electrolytic capacitor (on the other side of the board). You should see the electrolytic cap's 2 solder connections just slightly above pins 6 and 7.
On the drive knob you just connect the 1200pF cap and the 100k resistor in parallel and solder them to the two outer pins of the pot - the instructions advise turning the knob all the way down before soldering.
Remount the tube board and that's it. You should notice when you plug it in that it has only a fraction of the gain it used to. I found the lower gain 12AU7 was no longer enough to get adequate output from the pedal so I dropped in a Sovtek 12AX7A - which was the highest gain tube I had laying around. The original Chinese tube seemed to not sound quite as good to my ears."
Hope this helps, I sold the pedal recently so no longer have it as a reference."