Got home tonight and wanted to put on some music and relax and flipped on the Zen lights and one bank of bulbs light up brighter then the other bank and faster! i flipped it off and waited a sec and flipped it on again and one bank of three bulbs just lights up bright immediately. So I am assuming one channel has died? I will have to crack it open tomorrow and investigate.
Zc
Zc
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I had noticed that bank always glowed ever so slightly brighter. But these were built by the Great Oz himself so who was I to ever question it LOL! I have never cracked em open so this will give me a chance to peek inside.
Zc
Zc
Have you measured the bias voltage for both channels? If there is a significant voltage difference, one bank will not be the same in brightness to the other.
N.P. should I remove the screws from the top or the bottom of the heatsink to open? IE will the top panel come off by itself if I remove the wood screws on the left side and the machine screws from the heatsink on the right side.
or should I remove the wood screws on the left side and the machine screws from the bottom of the heatsink and try and pull the top and heatsink off as one piece??
Not sure how it is connected inside if it makes a difference??
Zc
or should I remove the wood screws on the left side and the machine screws from the bottom of the heatsink and try and pull the top and heatsink off as one piece??
Not sure how it is connected inside if it makes a difference??
Zc
underside and more detailed , please
I know that amp and that pic , already
looking at that , all I can tell is - unscrew these top 5 screws and see where that leads you
I know that amp and that pic , already
looking at that , all I can tell is - unscrew these top 5 screws and see where that leads you
Lost a Mosfet...IRFP-040 I am going to have to order one most likely. I am checking my parts stock but that doesn't sound familiar...
Hmm well I do have IRFP140 and 240 devices. but then in doesn't match the other device. I am using these Balanced as mono blocks so If i change one I really should change all 4 to match. I am going to see if I can find some 040's first.
I have mapped out the schematic and verified is is basically figure 15 of the zen light article. some of the values are just slightly different but mine are the 3 bulb 40 watt versions so that may account for some of the differences.
If i remember right, those IRFP 040s were hard to find when the article was written...
Maybe Nelson has a few still floating around his shop?
That is a beautiful amp! How cool is it to have a Pass 1-Off? 🙂
Maybe Nelson has a few still floating around his shop?
That is a beautiful amp! How cool is it to have a Pass 1-Off? 🙂
I bought some IRFP044N's which look to be the closest I can find. I'm still hoping to find someone with one or two of these they would be willing to part with.
The thing that bothers me is that I don't know WHY it failed? I can find nothing wrong with the circuit. all parts seem to be within tolerance. I need to observe voltages at turn on and turn off to see if there is maybe a spike that is causing problems. The heatsinks do run very very warm. and I am running these with a 4 ohm load. So maybe im pushing the limits of what these can do?
The thing that bothers me is that I don't know WHY it failed? I can find nothing wrong with the circuit. all parts seem to be within tolerance. I need to observe voltages at turn on and turn off to see if there is maybe a spike that is causing problems. The heatsinks do run very very warm. and I am running these with a 4 ohm load. So maybe im pushing the limits of what these can do?
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