I have a Pioneer QX8000 that had a number of problems. I've fixed a power supply problem and a failed channel in the control amp and now it is working well with inputs on all 4 channels and on FM and AM. However, the quadralizer doesn't seem to be working properly and I'm not sure how to troubleshoot it. Does anyone have experience of this? Schematic attached.
Pioneer QX8000 Quadralizer
- Thread starter m1keC
- Start date
Help Support QuadraphonicQuad:
Don't expect a whole lot from the "Quadralizer". It is simply a very basic decoder, not sure if it's even designed for SQ/QS decoding. It's more of a "Sythesizer" sending phase shifted signals to the four outputs. I recommend would replacing all of the electrolytic capacitors, they cause most problems along with Deoxing the selector switches. The manuals can be found here.
https://www.hifiengine.com/manual_library/pioneer/qx-8000.shtml
Thanks for that. I was intending to re-cap once I have decided how to deal with the wire-wraps - it's impossible to get at the solder side without disconnecting one end or the other! Is there an alternative to replace the wire-wrap posts?
You could pull off (or cut) the wires at the one end and then solder them back on to the posts when you are done.
That's what I did. I cut them off about 1cm from the post, recapped and then soldered the wires onto the short tail. Pioneer don't make re-capping easy - all the components have short leads that are folded flat onto the solder track. When several leads are in close proximity the leads are often on top of each other. Still, I got better at it with practice.
As far as I can tell it now works. I only have a test file that gives beeps but it sounds about right. Does anyone know of any music file available to download?
As far as I can tell it now works. I only have a test file that gives beeps but it sounds about right. Does anyone know of any music file available to download?
I changed the capacitors and with a test tone it seems to work now. I'm not sure what to do with it now. I also have the Pioneer QX8000 that came with the decoder. I've repaired the power supply and the control amp in that. Maybe sell them together?
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