ZPAXO board potentiometer

cyberpunky · Post by **cyberpunky** » Thu Jun 18, 2009 7:29 am

Hi ppl.
I have a ZPA 0.5 and 0.3. The ZPAXO in the 0.5 has an issue with the freq adjust potentiometer. Where it has been set is worn away. works fine above and below this point. A mate is looking for another pot, but the original he tells me, is hard to source. I have the bypass boards but I dont want to use ext XO, if I can fix this or replace it. I think one on other amp is on way out too. My car won our national SQ championship in 07, before this issue came up, and so don't really want to mess with my current set up.

Does anyone have any suggestions as to fix/replacement ?
TIA
peace
Cyberpunky

Post by **stipud** » Thu Jun 18, 2009 8:24 am

Perhaps someone has another ZPAXO available? Might want to try posting a WTB in the sales area.

Alternatively you could get a bypass card, and find yourself a ZPX2 as well

dBincognito · Post by **dBincognito** » Thu Jun 18, 2009 8:41 am

I have a new one that is fixing to be for sale....probably later today along with a few other things

rolandk · Post by **rolandk** » Thu Jun 18, 2009 5:56 pm

You could remove the pot and put resistors in its place. You won't be able to vary the frequencies but it would track much more accurate than a pot, say 1% resistors vs 20% pot.

cyberpunky · Post by **cyberpunky** » Thu Jun 18, 2009 8:02 pm

Roland. How do I determine resistor values. I don't need adjustability, as I havent moved XO points for years. I would want to set it at 60Hz HP.

I had thought about this option, but wasn't sure if it could be done, although I was pretty sure it could.

DBincog. How much is the card going for ?

Thanks for the assistance everyone. Can't believe I hadn't found this sooner.

peace
Cyberpunky

dBincognito · Post by **dBincognito** » Thu Jun 18, 2009 8:06 pm

cyberpunky

Not sure I'm selling yet......I have a whole ZPA setup that could be for sale....0.3, 0.5, ZPAXO.....still thinking if I want to sell that stuff yet.....I just sold the best ZPA 0.3 I had yesterday......and I am already sad about it....it sold for a good price....but I am still sad

cyberpunky · Post by **cyberpunky** » Thu Jun 18, 2009 10:05 pm

Yeah I feel ya. I don't think I could part with minem as they have been part of my system for so long, and the one time I swapped one out, I wasn't happy with the SQ. I was rep for a few other brands so chucked another amp in. mistake lol

Any idea what price they have been going for when they come up ?

peace
Cyberpunky

rolandk · Post by **rolandk** » Fri Jun 19, 2009 9:00 am

cyberpunky wrote:Roland. How do I determine resistor values. I don't need adjustability, as I havent moved XO points for years. I would want to set it at 60Hz HP.

The pot has 4 rows of 3 terminals. You will need 2 resistors for each row. One will go from the center terminal to one of the terminals next to it, the other from the center terminal to the other terminal next to it. The pot is rated at 10kΩ so the total value of the 2 resistors should equal 10kΩ (2kΩ and 8kΩ for example).

Contact Ben at PG support and see if he can calculate the resistor values needed.

Or you can find a ballpark value yourself by:

- Remove the pot (make sure its set to the position you want). Be very careful because its a double-sided circuit board with thin traces.

- For each row, measure the resistance from the center terminal to one of the terminals next to it. Then measure from the center terminal to the other terminal next to it. Write down your results.

- Repeat for the other 3 rows.

- Since the pot is 20% tolerance, average your results for each measurement (center to one terminal, center to the other terminal).

cyberpunky · Post by **cyberpunky** » Fri Jun 19, 2009 3:19 pm

Awesome, thanks Roland. That may save me from having a lot of grief chasing part. It was trace in pot that caused problem. Not uncommon for these amps from what I have read here.
cheers
Cyberpunky