Dunlop 535q wah schematic

[ziggy007]

G'day all.
Am trying to source the schematic for the 535q wah. Asked Dunlop with a pretty please but no luck.
Thanks in advance
Gavin.

[Jazz P Bass]

Dunlop 535 Q Schematic

Wah Pedal Schematics!

[Jack W.]

Dunlop 535Q wah schematic

We are in need of this schematic as well..however this the link doesn't seem to work.

Any help..we get no reply from Dunlop yet...

Thanks

[Jazz P Bass]

New 535Q: http://www.aronnelson.com/gallery/ma...serialNumber=2

Older 535Q: https://blog.so-net.ne.jp/_images/bl...vch/tegaki.jpg

[Jack W.]

Thank You!
Its an older one but both schematics will come in handy!

[Henry909]

Jazz P Bass

Thanks for posting that 535Q schematic. I did something with the power supply (not sure what) and blew out a resistor. The schematic helped me identify the correct resistor to replace (the 100 ohm R22). I replaced the resistor and the pedal worked again.

Maybe someone can help me figure out what happened. As you know the 535Q needs an 18volt DC regulated center negative power supply. I have a power supply from a router that is output DC 17volt 700mA center positive. I cut the wires to the plug and switched them around figuring that would make it center negative. when I tested the output with no load it was 23 VDC. I removed the power supply from the AC outlet and went to put the power supply plug into the pedal jack to make sure they matched. When I touched the plug to the jack I saw a spark and smelled burning. Tested the pedal and it didn't work. What happened?

[Audiotexan]

Maybe someone can help me figure out what happened. As you know the 535Q needs an 18volt DC regulated center negative power supply. I have a power supply from a router that is output DC 17volt 700mA center positive. I cut the wires to the plug and switched them around figuring that would make it center negative. when I tested the output with no load it was 23 VDC. I removed the power supply from the AC outlet and went to put the power supply plug into the pedal jack to make sure they matched. When I touched the plug to the jack I saw a spark and smelled burning. Tested the pedal and it didn't work. What happened?

I've chopped many a dc psu to flip the leads...the big thing is making sure you verify intended operation and parameters post alteration. (Which you did.)

Unfortunately however, whoever informed you that you need an 18v source, did you wrong. The 535Q only requires 9vDC. The adaptor that's recommended is 9VDC @ .67a (Dunlop ECB003US)

As stated on the Dunlop 535Q page here

Powered by 9-volt battery or Dunlop ECB003 adapter (not included)

Side note, I've got 4 older linksys routers sitting beside me, and they're either 9vAC or 12vDC, so that's got to be one helluva router to require 17vDC @ 700ma! Old rackmount by chance?

[Jazz P Bass]

Which 535Q do you have?
The old one or the new one?
As the 'Older 535Q' schematic shows an 18 volt dc supply, I would have to question that information.
Then again, hand drawn as it is, it does show (2) 9 volt batteries in series.

[Henry909]

Jazz P Bass and Audiotexan:

Thanks for the replies.

It is an older one. Definitely 18 volts. It works with anything between 9 and 18 volts but sounds better with 18. That schematic is definitely the one for my pedal. It really helped. Thanks again. I attached a couple of pics of the back plate.

Audiotexan:

In regard to the power supply, I was wrong about it being from a router. It was on a shelf next to the router, but I looked again and found the router power supply. So I don't know what that power supply was from. But definitely output DC 17 volts 700mA center positive. I am afraid to try it again.

Why would the power supply blow out a resistor when the power supply was not even plugged in?

[g1]

The supply must have had a stored charge in it's capacitor(s).
Still, if it read 23VDC unloaded, no reason it should fry anything by discharging into the pedal.
Did you verify the polarity with your meter?

[Henry909]

g-one:

Good question. I drew a diagram of the polarity of the pedal and the polarity of the power supply which is attached. Since the polarities of the two are opposites. I reversed the wires on the power supply and assumed that I would then have an appropriate power supply for the 535Q. After reversing the wires I tested it by putting the black probe into the center pin hole of the jack and the red probe on the outside barrel and the reading is as follows: 23.1. Is that what it should be?

[Jazz P Bass]

23.1 what?

[Audiotexan]

It is an older one. Definitely 18 volts. It works with anything between 9 and 18 volts but sounds better with 18. That schematic is definitely the one for my pedal. It really helped. Thanks again. I attached a couple of pics of the back plate.

Ahh...thanks for the pics!! I didn't realize they had changed voltages.
Which is odd to me given that almost every wah out there (barring fuzz/wahs like my old Nu-Wah by Rosac) uses a single 9v. But given the Nu-Wah actually has two separate circuits (one for fuzz/one for wah) it makes sense to have two 9v. The only reason I can think of for having 18v is improved headroom for the ic....

Audiotexan:
In regard to the power supply, I was wrong about it being from a router. It was on a shelf next to the router, but I looked again and found the router power supply.

Ah. No worries. Was just a minor curiosity!

[Henry909]

+23.1 volts on the multimeter

[Audiotexan]

+23.1 volts on the multimeter

I think what JPB was referring to, was making sure whether it was AC or DC...
But also, whether tip was negative or positive if DC.