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Can I get some help finding a Denon part?

dslavey

dslavey

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I am looking for a posistor for a Denon POA-6600. Murata PTH487A01BD222TS. I am having no luck on the web. I can't even find the specs on it. Rare bird it seems. Any help would be greatly appreciated.
 
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dslavey said:
I am looking for a posistor for a Denon POA-6600. Murata PTH487A01BD222TS. I am having no luck on the web. I can't even find the specs on it. Rare bird it seems. Any help would be greatly appreciated.
Click to expand...

See if the part is in any other Denon gear. If so search, you can then widen your search to include all the gear containing the part you need for your unit. With any luck, it was used in one or more of Denon's more popular and mainstream units with a current presence in used and junk markets. Good luck.
 
Its tough because this is a mono power amp and only has one of those thermistors (or posistors). Unless it has burnt, or a lead broke off they are usually fine. If its a broken lead, try to measure the DC resistance when it is at normal room temperature.
 
Looks like P001 (the PTC) increases in resistance, tripping the +/- 60V rail breakers. If you still have a good PTC, you could research how to test it and pick a PTH that would trip the protection properly.
 
Well, I ended up buying this amp from @dslavey , and a working one as well. To his credit, he disclosed that parts are hard to find.

Murata no longer makes thermistors with lugs on them like the one that was missing from this amp. However, they still apparently follow the same coding convention for them. So, I selected one with the coding BD, which is the curie point, and 222 which translates to 2.2 K ohm.

Then to make it a lug mount I cut open a ring terminal:
20180902_202731.jpg

Then I put the thermistor inside it and expoxied it:
20180902_203045.jpg

Here it is mounted on the heat sink assembly:
20180907_163852_HDR.jpg

The amp had suffered catastrophic failure; 6 of the 8 outputs had shorted, 2 shorted drivers, many open fusible resistors and a bad zener. It and its companion are now making music, and I've got to say that even on my bench speakers these things show a lot of refined grunt!

The moral of the story is that when some things aren't available you just have to improvise.
 
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Very nice job! Glad to see you have it running and are enjoying the pair. Refined grunt is a very good description.
 
I've the same need.
Where did you find the murata BD 222 ?
Any idea for a substitute ? Does the 2.2k ohm has an impact here ? A 100 ohm with a curie point at 80° C would not do the same ?
 
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