Pioneer QX 8000

[ZeroG]

Hi,

I'm 'restoring' a QX 8000 to the best of my newbie ability, having cleaned the pots, replaced the fuse lamps, etc. I'm looking for help with the subsonic filter circuit. When I press it to either activate or turn it off, there is a pop in the speakers and it takes a few seconds to kick in. I wonder if anyone has encountered a similar problem and how to fix it. I would suppose some caps need changing out but...which ones?

Also, does anyone have any recommendation for capacitor brands for this model?

And, the incandescent lamps are failing. Any ideas on where to get lamps or LEDs to replace?

Thank you for any assistance you might be able to provide.

 

[Decoder Man]

AEL-001 Speaker Lamp Assembly $50.95 - Currently on back-order

AEL-015 Lamp (Dial / Power)
substitute with AEL-110 $3.95 each

AEL-019 Lamp (Functions Indicator) NO LONGER AVAILABLE

E22-002 Lamp (Meter / Tuning / Signal) NO LONGER AVAILABLE


I currently have 100 of the AEL-110 in stock.

Without physically inspecting the unit. I will say you are on the right track looking at a bad capacitor for the popping noise. Look for a capacitor that bridges the switch.

I found this to be a common problem on the SX-626 High / Low Filter switches.

 

[ZeroG]

Thanks for your reply. I'm also looking for a service manual, if anyone knows where one is posted.

What is the AEL-100 that you mention? I didn't see it elsewhere. Also, could you explain what you mean by the capacitor 'bridging' the switch?

Since that lamp assembly is not available it might be worthwhile to try to rebuild it with wheat lamps. Would you have a source?

Thanks again!

 

[ZeroG]

Right, about the AEL-110. Got it. Long day at work, it was.

 

[Decoder Man]

The part numbers I provided in my previous post are Pioneer part numbers and Pioneer pricing. What I failed to mention is that I also carry an imported version comparable to AEL-110. Part number GF-680 for $1.50 each.

I carry a wide variety of lamps but without knowing the type, size, voltage and ampere rating, I cannot offer an alternitive. I usually get this information from a service manual but the QX-8000 is one I do not have.

When the contacts of a switch approach each other a slight arc of current occurs just before contact. In an audio circuit, this will sound like a pop. To elliminate this problem, a capacitor is connected to both terminals of the switch (bridging). To put it simply. As the capacitor charges it absorbs the sudden burst of energy thereby, elliminating the pop.

I have two QX-8000A's. If I remember. I will open one up this weekend and check out the lamps.

Best regards,
David

 

[ZeroG]

Thanks for your reply. The G 0f W sized bulbs that populate the little speaker selector board were measured at 7.1 volts while still active, if that helps. The Schematic does not give a voltage rating for that assembly or its parts. That's why I thought I might need to go LED, but I'm not sure how to change the 7-8V AC to the DC the LED needs. Any ideas? Thanks