freestompboxes.org

Hi there!

I'm currently into researching for a good overdrive for bass and I have been seriously amazed by Microtubes B3K and B7K. I would be very interested in studying the schematics, but I couldn't find them anywhere the internet. Does anyone have any informations about them? I know the creator used to be an active member of this forum and the other one, and maybe he still is, in which case I would be very grateful if he would share his circuits with us.

On the other hand, I'm pretty new here and I'm not sure if it's okay to request a schematic from a member's product. I mean no harm and I don't want to be rude, so if my request is wrong please tell me.

Thanks.

The original design is over at DIYSB's. Try searching for CMOS distortions. It was a while back so you'll have to do some digging.

Great. I'm also very interested in the B3K. Here's the link to the thread at DIYSB:

https://www.diystompboxes.com/smfforum/ ... ic=69335.0

From viewing the video demos, I'm pretty sure the blend-circuit is a constant power blender a là R.G.'s "blending for fun".

Thanks guys. I already knew the original Microtubes 2K and I learned a lot from this thread. It seems to be more guitar oriented though, so I would have liked to see the fine tuning of the bass models. I will have a look at this "constant power blend" concept by the way, thanks for the tip.

Please?

Yeah I saw that picture but it doesn't really help much; to actually trace the circuit we'd need the backside of the PCB as well. Additionally, there seems to be some kind of daughterboard underneath that board that controls the two switches on the pedal, so we'd need front and back of that too.

Looks like both switches are in the main board...
I think there's a previous thread about this pedal... too loose to search, sorry

Actually now that you mention it I think you're right. Odd, there's a YT video out there that's a time-lapse of this pedal being built and there's clearly a secondary board going on there.

Never mind about that, I guess... but some values and a shot of the board's underside would be awesome

The underside of the board has little tracings. I just traced a 'vintage' Microtubes and that one looks a lot like this one!!

Do you happen to have a schematic?

Ehrm...
Where did this thread go from "open up" to "trace"?
And who is the "we" you're referring to?

Seems a classic case of "how about you buy one, trace it and share your results here".

It didn't. That's exactly it - I was willing to try and trace it myself if someone had a picture of the board (i.e. someone that owns one that would be so kind as to open it up). Bernarddur mentioned he had traced the VMT and that would be a great step forward in getting this one done. By "we" I mean the community of this site - all of us can benefit from having a circuit traced. Also, there are certainly people here with more tracing experience that could help crack this one that are welcome to help. Never did I ask anyone to "buy one, trace it and share their results here".

Indeed you did not ask anyone.

I meant to suggest YOU are the one doing that buying, just as many have done before you.

Ah Yeah I'd really love to have one, I might just have to save up... lol

lose the "might" and you're on the right track in finding new (but usually very temporarary ) friends

The best I can see and possibly presume from that picture is the obvious parts.

There is no sub pcb under the main board, but the two jacks are mounted on there own little separate pcb's.
The bypass is done using the relay and quite likely a uC which could be pic or atmel.
There is an IC at the top which the markings I see look like CD40xx so this might be a hex inverter for the fuzz/dist.

From that picture that's the best I can do.

Yep that's about as far as I got as well

So apparently somebody took the time to trace this one out?

I don't have any cd4049ube to test this out, so could anyone else give it a shot?

kroaton wrote:So apparently somebody took the time to trace this one out?

I don't have any cd4049ube to test this out, so could anyone else give it a shot?

That's not the same pedal. its a for a 2k not b3k