Korg PitchBlack power out voltage drop question

[slacker]

This guy (gcme93) is right, and yes it does act as a divider, you get smaller amount of Volts adding each pedal. So why not buy something stronger as a supply, read a little more about regulating voltages and that's it!?

I think you're missing the point, his power supply can power all his pedals including the pitchblack just fine, there's no problem with the power supply. The problem is if he plugs his supply into the pitchblack and then tries to run the rest of his pedals off the DC out jack on the pitchblack it somehow limits the current getting from the supply. Compare this to the Boss TU-2 where the DC out jack is just connected straight to the DC in jack, in the same situation you wouldn't have this problem.

Using a more powerful supply wouldn't solve the problem, it might get him a higher voltage then he has now, but what ever it is in the pitchblack that is limiting the current would still be there, so the voltage would still change with current draw.

[garcho]

yeah, the questions is 'why is doing that?', not 'how can I power my pedals?', right?

[GGBB]

yeah, the questions is 'why is doing that?', not 'how can I power my pedals?', right?

Precisely - thank-you for understanding. 

You have 400mA, of which, the Korg uses 30mA and has the rest available if needed. The manual says it needs a 600mA supply which seems like a lot. I'm thinking this is a clue to your problem.

You know already that it isn't a simple parallel branching between the power in and out. My theory put simply is that for some reason, that small filter/circuitry/whatever it is inside needs a certain amount of current to make it's effective output voltage ~9V, and your 400mA supply doesn't quite hack it.

Therefore, when you have extra things in the chain from the power out, the output resistance (impedance) of the "power out" socket isn't as insignificant as it needs to be, and you get this annoying ratio of output voltage decrease when you add another pedal. The output resistance is added in to the equation as a voltage divider, the limiting factor being the current available.

That makes a lot of sense - thanks.

Not true, you can do this very easily, all you need to do is stick a series resistor between the output of the supply and what ever you are powering. The voltage drop across this resistor is then proportional to the current draw of the device V = IR so the voltage available to the device being powered drops as current draw increases, therefore the voltage is no longer regulated.

And also thanks - I think I am seeing the whole picture now.

[sgRED]

I think you're missing the point, his power supply can power all his pedals including the pitchblack just fine, there's no problem with the power supply. The problem is if he plugs his supply into the pitchblack and then tries to run the rest of his pedals off the DC out jack on the pitchblack it somehow limits the current getting from the supply. Compare this to the Boss TU-2 where the DC out jack is just connected straight to the DC in jack, in the same situation you wouldn't have this problem. Using a more powerful supply wouldn't solve the problem, it might get him a higher voltage then he has now, but what ever it is in the pitchblack that is limiting the current would still be there, so the voltage would still change with current draw.

Yeah, Hahaha I'm missing it on purpose! Because he is stubbornly trying to transfer (or pass) a commonly known electrical problems and known issues to a device that says 200mA MAX and make it a somekind of mistery (see more at: http://www.amazon.com/review/RWF45197NEO2S/ref=cm_cr_pr_viewpnt#RWF45197NEO2S also see: http://rexbass.blogspot.com/2012/05/korg-pitchblack-chromatic-tuner-pedal.html)
Now....what was the question? 
OK further reading, (http://www.rig-talk.com/forum/viewtopic.php?f=3&t=101343) you can find that one guy discovered that it is only a daisy chain output from a DC in. So What was the question again? In this poor planet, there are some things that you know for sure but others are just far far away from our imagine! For example, you can know that someone doesn't know what it is talking about when it's asking questions like: "Can i use my 10 pedals on one DC adapter i bought at the cellphone store, and can i use them all inside my PC box enclosure so they can get cooled, because it is for sure the pedals run hot immediately when you plug them in!? I measured a voltage drop of 5V but thy run OK because i don't play them as much, because i just started to play guitar last month when i got a Messa/Boogie triple rectifier for my 18-th birthday!! Next xear in december i'm planing to practice my guitar and to try to learn and master a metal guitar playing style! Come oooon people! 
final question: CAN ANYONE TELL ME WHAT IS AN ISOLATED DC (OR ANY) POWER OUT???
further reading: http://www.korg.com/pitchblack
http://www.rig-talk.com/forum/viewtopic.php?f=3&t=101343
AND OF COURSE I FOUND AN ANSWER: http://www.talkbass.com/forum/f36/korg-pitchblack-power-source-boss-pedals-456968/

Than we can proceed!

[GGBB]

Yeah, Hahaha I'm missing it on purpose! Because he is stubbornly trying to transfer (or pass) a commonly known electrical problems and known issues to a device that says 200mA MAX and make it a somekind of mistery

[gcme93]

I think we'll leave this thread here, it's all getting a bit confused.

The resolution is that the DC out from the korg isn't just a straight daisy chain from the DC in, which is causing some unwanted voltage dividing. Best to daisy chain each effect individually.

Garcho seems to have an idea of what's going on now.

[sgRED]

I assume there is something going on inside the tuner that "de-regulates" the power out

[sgRED]

I think we'll leave this thread here, it's all getting a bit confused.

The resolution is that the DC out from the korg isn't just a straight daisy chain from the DC in, which is causing some unwanted voltage dividing. Best to daisy chain each effect individually.

Garcho seems to have an idea of what's going on now.

you are probably right man! It isn't a daisy, and you'd have to pick the right ones that CAN go in it's DC out and not cause problems...

[garcho]

Garcho seems to have an idea of what's going on now.

Huh?

[gcme93]

Garcho seems to have an idea of what's going on now.

Huh?

Haha I mean't GGBB!  I got confused looking at the "quote from" rather than who was actually writing

[slacker]

So after that amusing diversion we're no closer to answering the original question. It's been fun but I'm outta here.

[Toadbomb]

Edited away for my own stupidity.

[GGBB]

Are you saying that the pedal regulates the DC output providing up to 200mA of current and consumes 370mA of current in doing so?  Do you really think that is what is happening?  Can you explain the electronics behind this?

[PRR]

> 9V 3000mA and it can power up 30 pedals. Now let's calculate. If you got a 30 pedals that go from 30mA to 300mA or even higher, what it can do and what does it means? It means that every pedal has to be "weaker" than 100mA to do this because 3000 divided by 30 is 100mA!

Power is power.

I have a 120 Volt 20 Amp circuit in my house.

Can I plug-in one 120V 1A lamp?

Can I plug-in three 120V 1A lamps?

Can I plug-in one 120V 10 Amp (1200 Watts) toaster, plus three 120V 1A lamps?

Let me know if I can't see my toast.

[monkeyxx]

Hi all,

I just whacked together a power link cable, didn't test it well enough apparently it was completely shorted!, and I let the magic smoke out of Q1.  Smells nasty.  Still puts out a tiny bit of power but not enough to light an LED on a pedal.  Lucky for me, the tuner still works.  I'd like to get this fixed.

I can't find a schematic anywhere.  Does anyone have any idea what component Q1 might actually be?  Doesn't look too hard to replace, I just don't know what it is :-(

[duck_arse]

can you read any numbers on the Q1, or did the smoke take the face off as well?

[GGBB]

On mine it was marked "DA QT".

[monkeyxx]

Thanks for the help

mine's pretty well cooked to death, can't see much, I found this picture of a fresh one on google, you can almost make out some characters