Madbean MOAR

[MAO]

Update 03/16/2016: the smaller 19 x 11 layout down below has been verified

Overdrive - ideas from Timmy and Rat

MOAR info here

[Hozy31]

Built this but getting no sound. Been through the usual culprits and all seems fine and dandy.
Voltages for LM1458 from 8.35v supply are:
1 4.43
2 4.77
3 3.99
4 0
5 3.66
6 4.04
7 4.06
8 8.02

Also the cut on the bottom row on the cuts and jumpers page should be one more hole to the right.

Any help appreciated.

[MAO]

It looks like the layout matches the schematic, I'll build mine tonight and compare notes.

Thanks for the heads up on the cut, I updated the layout above.

I've since changed the layout a bit to reduce by 1 column, but I'll leave the original above in case someone else has started to build it.

Here is the smaller layout - verified 03/16/2016 

 

[MAO]

I'd like to say the "smaller" layout is verified. Sounds great with a 9v battery, but I am getting a thumping when using an adapter.  

I temporarily paralleled the 47u and 10u each with a 100u cap which didn't help. I also swapped out the 1N5817 for a 33R, no change with the thumping. And also tried another LM1458.

I'll have to get back to it tomorrow night, but it sounds really nice with the battery. I used all 1N914s and a LM1458.

Hard to tell much difference between the 2 clip positions with my little practice amp, but both switch settings sound good. The tone control is decent and there is plenty of volume. I didn't have a 500k log pot so I'm temporarily using a 500k linear for the gain pot, which I wouldn't recommend.  

Hozy31, I'll post my voltages once I get rid of the thumping. Do you have an audio probe?

[MAO]

Smaller layout (19 x 11) verified, turns out the adapter was the cause of the thumping.

I also borrowed a 500k log pot from another build and now the feel and range of the gain pot is as it should be. Goes from clean to a nice overdriven crunch.

My voltages with a 9.3v supply (I still have a 33R resistor in place of the 1N5817)

1. 4.80
2. 4.81
3. 3.99
4. 0
5. 4.76
6. 4.81
7. 4.92
8. 9.16

As for the adapter, it's one a bought from BLMS a year or so ago.  It was fluctuating from 9.21 to 9.25 with no load. It used to be a steady 9.41 IIRC. I took it apart and didn't see or smell anything burnt, I added a 9.1 zener internally across the output wire pads. Now the thing puts out a steady 9.3 volts, how with a 9.1 zener across the output is beyond me, but it's working for now and quiet again.  

[traktop]

Would be great to hear some clips, but not gonna ask for that.
Could you explain a little what you did?
Best regards, Gilberto.

[MAO]

Hey Gilberto,

Sorry, not sure what you are asking.

"Could you explain a little what you did?"

Are you referring to the problem I had with the AC adapter?

[Hozy31]

Bigger layout is also verified. Turns out Bitsbox sent me 1 ohm resistors rather than 1M. Glad I noticed.

[MAO]

Cool.

I like this one, I've been trying out a bunch of smaller circuits to use with a headphone amp.

Think I'm going to go with the MOAR.

[verr76]

Ifdo you think its possible to add the bass control that the Timmy has, on which of the two RC lines do you recommend to do it?

[nocentelli]

verr76 wrote

Ifdo you think its possible to add the bass control that the Timmy has, on which of the two RC lines do you recommend to do it?

I love the Timmy, and I would definitely try adding a bass pot to allow you to tailor the low end separately for more or less wool and fuzz at different levels of gain. The timmy is the only pedal out of >dozen I have on my board that stays on all of the time.


If I was going to mod the Moar layout posted, I would replace the 100n with a smaller cap as a "minium bass" cap (which is 39n in the timmy but 33n or 47n are more common values and would probably do) and replace the 10n with a larger cap of 100n up to 1 or 2u, remove the 6k8 fixed resistor and replace it with a 50k pot. If you've already built it, the pot needs to be wired to the two points that the resistor took, using lug 1 and (2+3) for a Timmy-style bass cut, or (1+2) and 3 for a bass "boost" which I prefer. If you haven't build it, I'd just add an extra column to the left and there would be two convenient spots above gain 1 and below gain 3 to connect the bass pot.


You should either experiment on the breadboard to find what values you like for the cap sizes and the 4k7 value on the minimum bass settings and raise resistance/lower capacitance for less bass at minium, or use a simulator to get same response in terms of maximum bass boost/cut as either the timmy or the moar.