2 Tonebender MKII issues / questions

[fuzzy645]

So I have my 1st attempt at a Tonebender MKII working in a breadboard, and overall it sounds really good using OC76 tranny's.  Before I move forward with a permanent build, there I have a few kinks I want to work out, and hoping some have recommendations.

Problem 1:  have noticed the attack knob doesn't seem to have a huge swing.  Since i have never played an original MKII I have no idea how what the sonic range of this 1K attack pot is supposed to provide. Don't get me wrong, there is swing, but it goes from thick to thicker.  I would have expected a wider tonal range.  I'm sure the attack interplays with the 8.2K Q3 collector resistor.  I do have a 10K trimpot hooked up for this resistors in series with a 3.3K fixed resistor so the range of trimpot goes from 3.3K to 13.3K, and it seems to sound best in the middle, which ironically is at approx. 8.2K.

Problem 2 is that I'm getting some noise.  One factor which helped a bit is making sure to use a 100K pot for the Q2 collector resistor. I have seen both 47K and 100K for this resistor in various schematics so I tried both.  The tone is about the same, but 47K is louder and with more noise, but I still get some noise with the 100K although its better.  Is there a spot I can use some kind of extra filter cap to help with this noise perhaps?  Any other ideas?

Thanks in advance.

[LucifersTrip]

Problem 1:  have noticed the attack knob doesn't seem to have a huge swing.  Since i have never played an original MKII I have no idea how what the sonic range of this 1K attack pot is supposed to provide.

there's a bunch of demos on youtube...here's one:

http://www.youtube.com/watch?v=Immtik9JqSs

I'm sure the attack interplays with the 8.2K Q3 collector resistor.  I do have a 10K trimpot hooked up for this resistors in series with a 3.3K fixed resistor so the range of trimpot goes from 3.3K to 13.3K

Problem 2 is that I'm getting some noise.  One factor which helped a bit is making sure to use a 100K pot for the Q2 collector resistor.

most MkII  freaks recommend tuning the bias with a trim/pot on Q2C, not Q3...so you don't need to choose 47K or 100K...put a 100K trim/pot there and pick your best

[Arcane Analog]

Problem 2 is that I'm getting some noise.  One factor which helped a bit is making sure to use a 100K pot for the Q2 collector resistor. I have seen both 47K and 100K for this resistor in various schematics so I tried both.  The tone is about the same, but 47K is louder and with more noise, but I still get some noise with the 100K although its better.  Is there a spot I can use some kind of extra filter cap to help with this noise perhaps?  Any other ideas?

Thanks in advance.

You might want to try different transistors if you have yet to do so. You could simply have a noisy device. Try a bunch out.

[fuzzy645]

Thanks guys!

I did listen to the video and my breadboard model sounds a lot like it. I noticed that when his attack knob is fully CCW it still sounds quite fuzzy.