PX-8 Audio Signal Issue

[Bostontech]

Hi all, I am the guitar tech for the rock band Boston. Another tech from Billy Joel turned me on to VL a few years ago. So far, great products and I love the line. However, when using a recently purchased PX-8 for a customer pedalboard build, it stopped passing full signal within a week. I am currently in Vienna Austria where 220v/50hz is the norm. I purchased the pedal locally at Klangfarbe, assuming it was right for Europe. However when I look at the manual and the unit itself, no where I find does it state if it is compatible for 50hz. I'm taking a shot in the dark here that something has gone south with the unit based upon this. I did not want to open the unit and start to sus, because VL only offers warranty from the US, not overseas. That being the case, does anyone have a suggestion as to what may be wrong with this unit? There's another company here called Carl Martin, made for this market, 220/50hz though because the customer is a US citizen, wanted to stay US products. The PX-8 has been factory reset via manual instructions, no improvement. It still passes signal though barley audible.

Anyone have any thoughts?

[JohnClark]

It should be no problem at all running it from a 50Hz mains power since the PX-8 takes DC power anyway Is the power supply you are using providing 9VDC?

Is the signal diminished even when all loops are bypassed?
If so you can test where the signal is being interrupted by using the Insert Send and Return jacks to isolate Loops 1-6, or Loops 7-8.
1. Guitar to PX-8 Input, Insert Send to amp. Test for clean signal.
2. Guitar to Insert Return, Output to amp. Test for clean signal.

Also, internally there are a pair of jumpers that allow you to bypass the output buffer completely when moved over to the next set of pins (there is a diagram shown on the circuit board showing the positions for True Bypass or Quiet Switching). If the buffer is what has had a fault, setting these to the True Bypass position should at lest get you down the road until you can get a chance to send it in for repair.

If you are still having troubles after trying the above tests, we would be perfectly willing to take a look at this unit as a warranty inspection/repair.

I hope that helps!

[Bostontech]

Hi,

Thanks for the instructions. Here are the results...

Input/Insert Send path= 40db or so drop on level
Insert Return/Output= No audible signal at all
When I opened the unit and place the jumper to bypass position, all of the above functions correctly.

I will be sending this in for repair, thank you for the offer to take a look at it. Beautiful circuit board btw, looks built extremely well. How should I proceed, or whom do I email for an RA number?

Thanks Again

[JohnClark]

So what was the power supply you were using?

Please feel free to contact us directly at info@voodoolab.com.

[Bostontech]

The power supply is the Voodoo Lab Pedal Power 2 Plus. It was plugged into ACA #2 with dip switch for that out set to normal. I checked the voltage coming from that as well as the rest of the other outs, they all read with spec. Additionally I did a current check live and it appears the only thing w draw is the led's as they are turned on. With them all on I get 112ma. Which seems right according to what is printed on the back of the unit.

I have been working this build from a 220/110 volt step down transformer, because the customer will take this board back to America (he's only here for school). I realize that the 50hz would not matter in the DC conversion, but thought I'd throw that out there as some items even now adays state a call for 60hz. Electronically of course shouldn't matter unless dealing with motors right? None the less the transformer reads correct, and all the other gear seems to function as normal.

Thanks again, I'll email you.