Post-Lockdown pedal building

lasermonkey

@rsvmark the volume change with the switch positions should be expected. In the centre position there is no diode clipping, so any distortion is coming from the op amp alone. In the up position there's a pair of red LEDs which will clip at just under 2 volts. This will lower the output as the peaks of the signal waveform get flattened around that 2v point.

In the lower position you have a pair of BAT41 Schottky diodes which clip at around 0.3v. That's significantly lower than the 2v of the LEDs. The sooner clipping starts, the lower the output volume will be. With the lower clipping threshold you get more distortion and compression.

Whenever you have clipping options you have to adjust the volume control to compensate. I assume that you can get unity gain out of it on the BAT41 setting?

roberty

andy1839 said:

rsvmark said:

Update:

https://live.staticflickr.com/65535/50076738952_d4a3a05661_k.jpg ;

Everything built on the board, pots and switch positioned and soldered. So far so good. Checked the circuits and all pots operational, no crackles, and the switch works fine. Yippee....... BUT the volume dramatically drops off using the switch. When the switch is in up or centre mode, its nice and fine and no probs. When it is in the lower position there is a big drop off which i am sure isnt part of the plan! @andy1839 did yours do this? Any suggestions before contacting fuzzdog.

Thanks. 

@rsvmark yes mate, mine does that too, it's only really useable in the 100w setting. The 50w and 25w are too quiet, unless that's by design. 
Mines quite trebly too, needs careful adjusting of the air and eq to tame it. I've been running the treble almost off and the Air higher.

Just seen this on the DIY Stompboxes Facebook group

roberty

roberty said:

My noise gate is sort of working but reduced output when engaged. Hopefully just need to reflow some connections. It's a bit tricky to test because some of the bits need to be soldered in place

The foxxton woods is a total beast. Tried it in rehearsal the other night, I think it can replace both my fuzz and my octave fuzz pedals. Heavier than I expected (half fuzz half metal zone lol) but worked really well in the room

After another afternoon troubleshooting the noise gate I've figured out that Musikding sent the wrong jack type for the key input. Getting a bit messy now with soldering and desoldering but I am confident that the circuit itself is fine. Progress at least

rsvmark

lasermonkey said:

@rsvmark the volume change with the switch positions should be expected. In the centre position there is no diode clipping, so any distortion is coming from the op amp alone. In the up position there's a pair of red LEDs which will clip at just under 2 volts. This will lower the output as the peaks of the signal waveform get flattened around that 2v point.

In the lower position you have a pair of BAT41 Schottky diodes which clip at around 0.3v. That's significantly lower than the 2v of the LEDs. The sooner clipping starts, the lower the output volume will be. With the lower clipping threshold you get more distortion and compression.

Whenever you have clipping options you have to adjust the volume control to compensate. I assume that you can get unity gain out of it on the BAT41 setting?

Thanks @lasermonkey - I haven’t had the change to test unity gain off/on as yet as have only dropped back onto this this evening but your post is really helpful and explains it. Having had a short time with the testing rig I can adjust the volume on all 3 settings to suit (down Position being the quietest) so I expect once I have wired up the Foot switch , finding a unity gain setting for each of the 3 settings will be a twist of the vol knob away. After that it’s A simple case of working out which one is my fave. 

@roberty Thanks. Sorry for the noob questions. So taking @lasermonkey advice, we start off with the op amp, then the leds clipping In the second position, but the BAT41 diodes are kind of a massive drop in fwd voltage by comparison. Which then explains the volume drop. So to address the problem you can add diodes in series to reduce the fwd voltage drop and therefore reduce the voltage drop.  Might be a bit much for my first build but really enjoying the learning! 

roberty

rsvmark said:

lasermonkey said:

@rsvmark the volume change with the switch positions should be expected. In the centre position there is no diode clipping, so any distortion is coming from the op amp alone. In the up position there's a pair of red LEDs which will clip at just under 2 volts. This will lower the output as the peaks of the signal waveform get flattened around that 2v point.

In the lower position you have a pair of BAT41 Schottky diodes which clip at around 0.3v. That's significantly lower than the 2v of the LEDs. The sooner clipping starts, the lower the output volume will be. With the lower clipping threshold you get more distortion and compression.

Whenever you have clipping options you have to adjust the volume control to compensate. I assume that you can get unity gain out of it on the BAT41 setting?

Thanks @lasermonkey - I haven’t had the change to test unity gain off/on as yet as have only dropped back onto this this evening but your post is really helpful and explains it. Having had a short time with the testing rig I can adjust the volume on all 3 settings to suit (down Position being the quietest) so I expect once I have wired up the Foot switch , finding a unity gain setting for each of the 3 settings will be a twist of the vol knob away. After that it’s A simple case of working out which one is my fave. 

@roberty Thanks. Sorry for the noob questions. So taking @lasermonkey advice, we start off with the op amp, then the leds clipping In the second position, but the BAT41 diodes are kind of a massive drop in fwd voltage by comparison. Which then explains the volume drop. So to address the problem you can add diodes in series to reduce the fwd voltage drop and therefore reduce the voltage drop.  Might be a bit much for my first build but really enjoying the learning! 

When you put diodes in series the forward voltage adds together :-) no idea why or how but it does lol

roberty

roberty said:

roberty said:

My noise gate is sort of working but reduced output when engaged. Hopefully just need to reflow some connections. It's a bit tricky to test because some of the bits need to be soldered in place

The foxxton woods is a total beast. Tried it in rehearsal the other night, I think it can replace both my fuzz and my octave fuzz pedals. Heavier than I expected (half fuzz half metal zone lol) but worked really well in the room

After another afternoon troubleshooting the noise gate I've figured out that Musikding sent the wrong jack type for the key input. Getting a bit messy now with soldering and desoldering but I am confident that the circuit itself is fine. Progress at least

I figured out what I was doing wrong and got it working.  Musikding did send the right bits. Got it all soldered up, but the pot shaft was bigger than 6.35mm and the knob got stuck on the shaft, then I destroyed the pot trying to remove the knob. I had to snip the dual LED to lift the PCB and desolder the pot. A catalogue of errors! Hilarious

rsvmark

I had a few spares in case I cocked up..

https://live.staticflickr.com/65535/50083546882_3cf069afcf_b.jpg ;

But the first one went on ok. Brushed with a little diluted pva, positioned, quick check to make sure the pots were at the centre of the markings....

https://live.staticflickr.com/65535/50083969971_ea15a03d64_b.jpg

And waiting for it to dry. Added advantage is that pva will 'rub off' where it oozed out

roberty

Finished the sunny t extreme from fuzz dog. This is one of the ones that got dumped on the footpath by the wind when clear coating lol. First attempt at wiring up without a daughterboard, and probably my last too haha. Total pain

rsvmark

And done! 

https://live.staticflickr.com/65535/50092826013_e70cc03531_c.jpg

https://live.staticflickr.com/65535/50093639907_30b224eb9a_c.jpg ;

https://live.staticflickr.com/65535/50093863653_9a4a7fa068_c.jpg

Whats next?

roberty

Looks smart @rsvmark ;

Finally got my noise gate working. Was a total headache but worth it for this alone

https://youtu.be/u9M94OqovfM

stickyfiddle

 

Loving the GB tune  

roberty

stickyfiddle said:

 

Loving the GB tune  

Bustin' makes me feel good!

stickyfiddle

I tell you what, my old band used to play that at parties. Best crowd reaction EVER.

roberty

stickyfiddle said:

I tell you what, my old band used to play that at parties. Best crowd reaction EVER.

Ha no way, I did that in a party band years ago too! It's a banger

Fuengi

Right, need some help with resistor identification.

Just noticed that some are 100K and some 100R on the instructions! 

Talk me through exactly how to test which is which with my tester please somebody? 

I've just been looking at the colour code charts and that makes no sense to me whatsoever, I can't tell which is supposed to be the fat stripe! 

Fuengi

Which end is which?

stickyfiddle

Set your tester to Ohms, and put one probe on each end of the resistor. 

Depending on your multimeters, you might have a couple of different settings for kOhms and mOhms, so you need to set it to the appropriate range for the what you think the resistor is.

Fuengi

stickyfiddle said:

Set your tester to Ohms, and put one probe on each end of the resistor. 

Depending on your multimeters, you might have a couple of different settings for kOhms and mOhms, so you need to set it to the appropriate range for the what you think the resistor is.

I've got that, was going through sorting out into sizes when I noticed the R or K values on the sheet. I'm just confused as to the difference between 100R and 100K and how test each.

UnclePsychosis

100R is 100 ohms. 
100k is 100,000 ohms. 

Keefy

Fuengi said:

Which end is which?

There are no codes that start brown-yellow, so that has to read left to right brown-black-yellow = 100k.