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Old 14th November 2014, 04:41 PM
moley moley is offline
Join Date: Nov 2014
Location: Sheffield
Posts: 30
Default Help - Phono 3 Heater voltage Measurements

Hello folks, newbie here seeking some help / direction.

I have just completed a build of the Phono 3 and PSU. It *seems* to be working ok in that I have had it in my system and listened for a whole night. It sounded great and improved as the night wore on.

However there was one measurement on the Phono 3 as per the build manual that didn't tally up and I still can't understand why or where I could have gone wrong especially given that the unit is functioning.

When I test voltage from chassis ground to HTR+ I get 3.4volts and on HTR+ I get -3.1volts. I should be getting around 45 volts at HTR+ as per the manual and the PSU tests fine as does the PSU cable and the pins coming into the Phono 3. I have double checked the socket and can't understand how I am measuring 53 volts coming into the bottom left pin (as seen from the solder lugs) into the grey wire and 60 volts on the bottom right pin (as seen from the solder lugs) going into the brown wire yet when these reach the HTR+ and HTR- PCB points I am only measuring 3.4volts and -3.1volts which is of course no where near the reading of 45 volts as per the manual.

How is this working given the difference in the readings, have i missed something obvious and am testing incorrectly. Measuring between the pins of course gives the correct reading but not from the HTR+ or HTR- to ground.

All other readings appear to be fine in line with the build manuals.

Sorry for the ramble! Many thanks in advance for any help / advice anyone can offer.
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