Same beginner, another 4 pedals

[ghiekorg]

Place Red probe to VmAΩ socket AND set pointer to 200mA scale..

I am quite sure i tried that too  . I tried every position of Ampere and it is always either 0.17 or 1.7 or 17. Or a value similar to it. as soon as i am home (2-3h) i will record and post a clip

[11-90-an]

Place Red probe to VmAΩ socket AND set pointer to 200mA scale..

I am quite sure i tried that too  . I tried every position of Ampere and it is always either 0.17 or 1.7 or 17. Or a value similar to it. as soon as i am home (2-3h) i will record and post a clip

Might there be a chance the internal battery of the MM is drained?

[ghiekorg]

i thought that too. I opened the MM and did the tongue-test on it and it was definitely charged enough. I can't really understand... i will check the  fuses, but i guess it wouldn't even work if they are burned.

[bluebunny]

You could always measure the voltage drop across a known resistor which is in series with your power.  Then use Ohms law to work out the current through it.

[ghiekorg]

here is a test again, with 200mA etc. Still same results.


Also i noticed people's pedals go on when they do this measurement. Mine do not.

You could always measure the voltage drop across a known resistor which is in series with your power.  Then use Ohms law to work out the current through it.

I don't know how to do  it, but i tried. And here are the results:


I don't understand

[antonis]

No...

Set meter to DC VOLTAGE and measure voltage drop across the known value resistor..   

e.g. for a 1V drop across 1k resistor you have 1mA current flowing..

[ghiekorg]

Sorry, I checked online but it's not really clear still. you mean like that?



Then i tried with a 1k resistor and i get 5.54V.
10k = 7.69V



It doesn't seem linear

[antonis]

Then i tried with a 1k resistor and i get 5.54V.
10k = 7.69V
It doesn't seem linear

Of course it isn't 'cause with 7.69V drop circuit can't function properly..
(it's left ONLY 1.3V working voltage..)

You'll have to check it with a resistor of much lower value..
(100R or better 10R or best 1R - for 1R, voltage reading is directly proportional to Current consumption ..)

[ghiekorg]

The smallest i have now is 100R, so I tested some pedals:

B3K: 1.28V (selfmade, commercial unit is around 20mA) tried again later: 1.49V
Tentacle: 0.21V (selfmade, commercial unit is about 2mA) later 0.24V
The depths: 1.39 (selfmade, commercial unit is about 50mA)
korg pitchblack mini:1.36V (commercial, should be 40mA)
MXR studio compressor: 5.35 (commercial, should be 20mA). The lights were weird.
boss geb7: 1.61V (cvommercial, should be 17mA)
boss oc3: i couldn't turn it on no matter what.
boss psm5: 1.30V (commercial, should be around 15mA)


For me still makes no sense. I don't see the proportions between the numbers if the formula is just I=V/R... 

[bluebunny]

The smallest i have now is 100R, so I tested some pedals:

B3K: 1.28V

For me still makes no sense. I don't see the proportions between the numbers if the formula is just I=V/R...

So plug the values in to I=V/R:  I = 1.28 / 100 = 0.0128A (or 12.8mA)

[ghiekorg]

Yes yes that's clear
The problem is the results:
B3K: 12.8 mA against 20
Tentacle: 2.1 mA, It's ok.
The depths: 13.9mA Should be 3 times more
korg pitchblack mini: 13.6mA. Should be 3 times more
MXR studio compressor: 53.6 mA, should be 3 times less.
boss geb7: 16mA, it's ok
boss psm5: 13mA, it's ok.

Thing is: couple of weeks ago i tested the pedal with that  plug with open wire. And it seemed to work perfectly. I had all the results i expected. At the time i also recorded the bitar for 15mA and the Chasm reverb for 60mA. Now i can't understand why it doesn't freaking work anymore.

Edit: another detail: when i measure using the "special cable" and the MM set to 200mA i get always 1.7 or so but, when i switch the red/black tips, i get -2.4. Shouldn't i get just the same result but with a -in front?
Edit2: if i use the 10A to do the measurment the pedal does lights on, but the screen just says 00.1, even when the wheel is on 200mA

[bluebunny]

I would imagine manufacturers will over-state the current requirements to avoid complaints from customers when their power supplies wig out.  Think of these specified numbers as absolute maximums.  (This approach is commonplace in Eurorack land where current draw is typically higher and people buy power supplies to accommodate whatever it is they've bought - and may buy in the future.)  What you measure is what the pedals are drawing right now under your test conditions.

[antonis]

To be honest, current draw via series resistor voltage drop should be measured with appropriate voltage at circuit power supply terminal..
('cause many circuits don't function properly with a supply lower than the one designed for them..)

e.g. for a 30mA current draw and a 100R series test resistor, you'll have to power it with 12V..
(3V drop on test resistor and 9V remaining for proper circuit function..)

[duck_arse]

I CAN SEE THE DOT [now]! thanks for the larger pics. does that meter never display in the window the units being measured? that's got to make using it less conveinient easy.

[ghiekorg]

Hi everyone,
I made some stuff:
1) i checked again all the pedals with a 33R and now the results make more sense (not all of them though):
Little Jim   2 mA
Tentacle   2 mA
Shoot the moon   12 mA
8-bitar   13 mA
Pitchblack mini   14 mA
The Depths   14 mA
PSM   14 mA
B3K   17 mA
Studio compres.   18 mA
GEB7   18 mA
Rebote   20 mA
Chasm   44 mA
Dimension P   51 mA
OC3   52 mA

2) i tried the pedals:
- the little jim is too noisy unfortunately. I love it, it's an amazing sounding pedal but even at the beginning of the chain is too noisy. I will try other builds and decide what to do 
- the dimension P is amazing but is boosting my volume level when ON. If i then use the dry and voices switches it gets even louder. Do you know any way to have it to stay at unit (do you say like that?)? That would be REALLY helpful
- the rebote is noisy on repetitions but for now i will keep it. Then if i find a 1590A digital delay for few bucks i will get switch it, i guess there is no other solution.
- the shoot the moon is just amazing. Thank you for the advice. It's probably my fav pedal of all the ones i made (with the chasm reverb which is always on)
- The depths is also really nice. I still have to understand it completely because 5 knobs are a lot of combinations, but i love it too.

Thanks for your help guys. Again, without you i wouldn't have made it through. I love you all <3

I CAN SEE THE DOT [now]! thanks for the larger pics. does that meter never display in the window the units being measured? that's got to make using it less conveinient easy.

No it's a cheap MM i bought some years ago. I went to check for another one but before spending 50-60$ on a new one i wanna be sure i actually need it

[Marcos - Munky]

For the Little Jim, what kind of noise are you talking about? Mine is "noisy", but just similar to other ods/distortions with that amount of gain. Maybe shielded wire can help you to tame the noise.

[11-90-an]

- the dimension P is amazing but is boosting my volume level when ON. If i then use the dry and voices switches it gets even louder. Do you know any way to have it to stay at unit (do you say like that?)? That would be REALLY helpful

"Stay at unity", but I guess you just got a typo..

Here's the schem for reference:



I'm guessing increasing R8, R23, R24 value to say, 68k or more will work...

[ghiekorg]

For the Little Jim, what kind of noise are you talking about? Mine is "noisy", but just similar to other ods/distortions with that amount of gain. Maybe shielded wire can help you to tame the noise.

I will post a clip of what i mean. I think there is not an easy solution for this...

I'm guessing increasing R8, R23, R24 value to say, 68k or more will work...

Thank you. You think there a way to know it will not be too quite (or still too loud) without a try&error method?

[11-90-an]

Thank you. You think there a way to know it will not be too quite (or still too loud) without a try&error method?

Sadly, I think not... 

[ghiekorg]

what if i just add an A100k pot and i connect the CCW lug to ground, the CW to board-output and the middle to jack 3pdt-output? I could use a small pot on the side of the pedal or just use it as in internal trimmer, i set it properly and i leave it inside the enclosure