"Superfly" - submini tube version of Doug H's Firefly

[frequencycentral]

Yes, my meter was reading absolutely nothing.

Your meter might need power supply, also..

More seriously, what do you mean with "nothing"..??

  It isn't reading a voltage at the power input of the amp. Nowhere on any other part of the circuit either.

'Nothing' is a metaphysical term, as this is science that we're doing, we're dealing in scientific terms. ie what is the voltage? 0V?

[jma38]

0 volts

[antonis]

Did you take PS measurement out of circuit or connected to it..??

[danielzink]

First - have you tested your power supply like this ? :





Second - what sort of power jack are you using ?

Is it a plastic center negative standard power jack like this ? :




And if so....have you tested it with no wires attached to it like this ? :



If yes - to all of these - are you sure you have the proper positive/negative connections to the board configured correctly ?


Dan

[Ben N]

My easiest troubleshoot ever--and biggest 'Doh!' moment, was when my dead new pedal turned out to have the polarity protection diode in backwards. No juice, no sound! Easy to spot: if there's 9v north of the diode, but not in the circuit past that point... Luckily I hadn't plugged the wrong power supply into it, or I would have had to fix a lot more than just flipping around a 1N5817.

[jma38]

Did you take PS measurement out of circuit or connected to it..??

So it turns out the power supply I was using is dead and is just heating up when it's plugged in. I'm waiting on the new one I ordered and I'll give an update after I test with the new one.

[jma38]

New 12 volt, 500 ma power supply came yesterday. I tested it with my meter and it definitely has an output of 12 volts as advertised. I've been using my multimeter to look at voltages on the board and I'm still getting 0 volts when I test the voltage input of the amp. Could this be a sign that somewhere on the board there's a connection that hasn't been made?

[jma38]

My easiest troubleshoot ever--and biggest 'Doh!' moment, was when my dead new pedal turned out to have the polarity protection diode in backwards. No juice, no sound! Easy to spot: if there's 9v north of the diode, but not in the circuit past that point... Luckily I hadn't plugged the wrong power supply into it, or I would have had to fix a lot more than just flipping around a 1N5817.

I tested that area but still reading 0v. Thanks for the suggestion though.

[jma38]

Did you take PS measurement out of circuit or connected to it..??

With the circuit connected to the power supply.

[jma38]

First - have you tested your power supply like this ? :





Second - what sort of power jack are you using ?

Is it a plastic center negative standard power jack like this ? :



I'm using this one: https://www.taydaelectronics.com/dc-power-jack-2-1mm-x-5-5-mm-round-type-panel-mount-dc-099.html


And if so....have you tested it with no wires attached to it like this ? :



I've tested that and I'm getting 0v coming from the female DC connector. Looks like that has something to do with it. I'm not sure what that problem is though.

If yes - to all of these - are you sure you have the proper positive/negative connections to the board configured correctly ?


Dan

[jma38]

I'm getting a reading of 12v when testing the female DC connector connected to power and nothing else but when I test it connected to the amps power input wires I get 0v.

[jma38]

My easiest troubleshoot ever--and biggest 'Doh!' moment, was when my dead new pedal turned out to have the polarity protection diode in backwards. No juice, no sound! Easy to spot: if there's 9v north of the diode, but not in the circuit past that point... Luckily I hadn't plugged the wrong power supply into it, or I would have had to fix a lot more than just flipping around a 1N5817.

I thought this was the right way around to put the rectifier, did I get it backwards?

[GibsonGM]

What part of the circuit is that?  From time to time it's good to repost whatever schematic you're working from if you can.  Just saying cuz I dropped in and am not sure where you're at based on the page 1 info...

[Ben N]

My easiest troubleshoot ever--and biggest 'Doh!' moment, was when my dead new pedal turned out to have the polarity protection diode in backwards. No juice, no sound! Easy to spot: if there's 9v north of the diode, but not in the circuit past that point... Luckily I hadn't plugged the wrong power supply into it, or I would have had to fix a lot more than just flipping around a 1N5817.

I thought this was the right way around to put the rectifier, did I get it backwards?

I can't look at the schematic right now, and I can't really tell from the pic, but it depends if you have the protection diode wired in series with the circuit or across the power supply. The banded end is the cathode = (-). If it's in series, you want the diode to conduct when you feed it +V, so the unbanded side goes towards the +9v supply. If it's wired between +9v and ground, then normally you don't want it to conduct--you only want it to conduct if the polarity of the power supply is reversed--so the banded side goes to +9v and the unbanded side goes to ground.

[GibsonGM]

I'd remove it til I got the thing working, personally...I put that in just about last in builds.   If it's got semiconductors, I put them in after verifying correct polarity, before applying power to them...

If the right side of the diode is connected to "+" and the banded side (cathode) to ground, then it's in wrong in terms of protection diode.

[antonis]

As I see the picture, diode faces to electro cap negative leg..
(an almost short..)
That kind of diode is rated at 1A continous current so a 500mA PS can do no harm to it..
(of course, its output voltage goes deeply down..)

Just lift one diode leg (whichever you like) and repeat measurement..

[jma38]

I'd remove it til I got the thing working, personally...I put that in just about last in builds.   If it's got semiconductors, I put them in after verifying correct polarity, before applying power to them...

If the right side of the diode is connected to "+" and the banded side (cathode) to ground, then it's in wrong in terms of protection diode.

It looks that way judging by the pictures of the original build Rick did:

[jma38]

The schematic is on page one of this thread, the layout is on page 2. Here's the layout:

[frequencycentral]

The diode pictured is (well, should be) a UF4004, and is part of the SMPS which generates the HV. Looks to be the right way around.

[GibsonGM]

^^   Yep, that diagram nailed it - it's the PS, not a protection diode.    Also, that diode NEEDS to be a UF4004 or similar 'fast' diode in order to work.   Sorry if you have already covered this ground...I don't believe a typical Si rectifier diode will do the job.    It's easiest to make this kind of circuit by building the power supply and testing it, then assembling the valve stuff, just my opinion.   

Be aware that is the high voltage switch supply, which can put out 'potentially lethal voltage' within the circuit and at its output...    No fingers in there, buddy.