Wonder Drive

[barmalej]

Hi, i soldered the circuit, checked all the components and did not find an error (i hope). But the output signal is completely not distorted. It is simply amplified if i turn the volume knob to maximum, tho other knobs do not change anything serious.
Has anyone already built this scheme? Can someone share the voltages on the amplifier and transistors?
Thanks for any help.
p.s. English is not my mother tongue, please excuse any errors on my part.

IC1:
1: 4,5
2: 4,5
3: 4,5
4: 0
5: 4,5
6: 4,5
7: 4,5
8: 9

Q1
C: 9
B: 4
E: 3,6

Q1
C: 9
B: 4
E: 3,6

 

[music6000]

Did you assemble the pots in the enclosure & test the circuit to get these results?

 

[barmalej]

I connected the circuit as in the photo (9v) and measured the values(not in bypass-mode), all potentiometers are approximately in the middle. Led light on.

 

[music6000]

The reason I ask is that the Tight & Bite pots need dust covers or Insulating so they do not touch the PCB.
Can you test for Continuity between Pot legs and Pot pads.

 

[barmalej]

The pots are ok(bent to the side), this is not visible in the photo, but they do not touch the board.

 

[Robert]

One thing to keep in mind, this is basically a Tubescreamer with no clipping diodes. It's not a high gain pedal on it's own.

Another guy was happier with the sound after replacing C7 (10n) with a 47n cap.

 

[barmalej]

One thing to keep in mind, this is basically a Tubescreamer with no clipping diodes. It's not a high gain pedal on it's own.

Another guy was happier with the sound after replacing C7 (10n) with a 47n cap.

Maybe, but the screamer is at least overloaded, but there is no overload at all

 

[music6000]

The pots are ok(bent to the side), this is not visible in the photo, but they do not touch the board.

Good, To be sure as this is confusing at times, with this pedal the DIRT (DRIVE) pot is on the top left & VOLUME is on the top right.
It changes the pedal's character dramatically.

 

[zgrav]

if turning the DIRT pot is not changing the sound you hear, that pot is not connecting to the parts shown in the circuit diagram (IC1, pin 1 and one side of R19). If those connections are OK, make sure that the other side of R19 is connected to R2 and R15.

 

[barmalej]

I checked again, everything is in ok, then i replaced the IC- no changes, the "dirt"-pot simply add volume, not the slightest overload .

 

[zgrav]

I thought you said originally the volume pot worked but the dirt pot did not do anything. Do both of those pots work to make it louder? If your dirt pot works, does the "tight" pot make any change in the sound? Are you sure you have the right value pots for all three places?

 

[Robert]

I have one of these assembled somewhere around here... I'll hunt it down and see if I can record a clip of how much gain it should have.

There are no clipping diodes and it has a 100K gain pot, it's more of an active EQ than a traditional "overdrive" ...

 

[barmalej]

I thought you said originally the volume pot worked but the dirt pot did not do anything. Do both of those pots work to make it louder? If your dirt pot works, does the "tight" pot make any change in the sound? Are you sure you have the right value pots for all three places?

Sorry, maybe i explained most likely incorrectly: all pots working, but not give the effect that i expected. In the description says, that the effect is similar to savage drive, and this pedal is aggressive overdrive. But "wonder drive" is at the moment, as PedalPCB says, an active EQ, which is most likely what i guess.

I have one of these assembled somewhere around here... I'll hunt it down and see if I can record a clip of how much gain it should have.

There are no clipping diodes and it has a 100K gain pot, it's more of an active EQ than a traditional "overdrive" ...

Thank you, please check, maybe there is not enough gain on the IC.

 

[Robert]

I have an original on the way for comparison.... Don't trash it yet.

 

[barmalej]

Thanks. So, it works like a booster. And where is better to connect it to the pedalboard? At the end of the chain?

 

[music6000]

I think what is at play with this pedal maybe dependent on how early your Amp breaks up & How hot your Pickups are.
I have a customized Tele I modded with S.D Little '59 in the Neck & Custom Shop Little '59 in Bridge position. It is also switchable
on each Pickup to Single Coil. There are a lot of Pedals that I've built that would be classed as Low Gain.
They are Low Gain in Single Coil mode but if I flick the switch to Humbucker mode you are talking Medium to Higher Gain without adjusting anything else.
That's why I always try to find demo's that are using similar Guitar & Amplifier.
Also a Given , you need to hear the Demo in Pedal Bypassed also!

 

[Robert]

Here is a list of component value differences compared to the original unit I have here today.

As mentioned before, this pedal does not create a lot of clipping / distortion on it's own. It behaves more as an EQ or boost than a typical overdrive.

The tone you hear in the demos is the product of the pedal pushing an already distorted high gain amp.




R9 10K
R15 4K7
R19 10K

C1 150n
C7 220n

VOLUME B100K
TIGHT A50K

 

[mnemonic]

Here is a list of component value differences compared to the original unit I have here today.

As mentioned before, this pedal does not create a lot of clipping / distortion on it's own. It behaves more as an EQ or boost than a typical overdrive.

The tone you hear in the demos is the product of the pedal pushing an already distorted high gain amp.


View attachment 325

R9 10K
R15 4K7
R19 10K

C1 150n
C7 220n

VOLUME B100K
TIGHT A50K

Cool, thanks for comparing.

Do you think those changes will make a significant change in the sound? I like mine but now I’m wondering if I should build another.

 

[Robert]

I'll compare the two later this evening.

 

[raydomz]

I just completed this build and am super happy with it! I will do a full test of it tomorrow but in short, it is everything I'd hoped it would be. It can take a super muddy/bassy high gain tone and add all the tightness and bite you need without reducing too much of the thunder. Great pedal.

To address some of the OP's concern, here's what I've found in my 20 minutes of testing: the "dirt" knob is exactly that. It's not a "gain" knob. It does provide a little saturation to the gain already produced by the amp (I'm playing a Randall Thrasher 50) but the majority of the function of this pedal is coming from the bite and tight controls.