Yused Towork
It Used to work until I fixed it...
@tarior You seem to be the snub-master here. I'm working on a 1973 HK930C and (I don't know if it is bad) I am having a circuit storm when powering-on the unit with load attached. Wondering about the snubber. I can't find a cross reference (It is an Okaya CU 120033) I see other (probably newer) models available, but I don't know the specs for this one. My question is: How do you size for a snubber? The rails on this unit are 40vdc fuse is 3amp 250v max watts is 350. Any advice is appreciated.
I don't know what "having a circuit storm" means. The function of a RC snubber array, in this application, is to preserve the switch contacts and not much else.
When it comes to sizing, the most common ones I see on units so equipped from the factory are in the .1uF and 100-150 ohm range, so, that is what I go with.
When it comes to sizing, the most common ones I see on units so equipped from the factory are in the .1uF and 100-150 ohm range, so, that is what I go with.
Yused Towork
It Used to work until I fixed it...
Thanks for quick response! I'm busy trying to diagnose a problems that happens only on power-on with speakers connected & switch engage, Dim bulb stays on, no sound, and without dim bulb owner said the amp blew LH speaker fuse. I'm busy diagnosing, and I see some work has been hacked I mean "done" in the past.... If you power-on and wait a few seconds , then switch the speakers in, the amp seems to work ok normal. I started thinking about this snubber, which is so old I can't find the data on it, and wondered if that may play a part in things.
Yused Towork
It Used to work until I fixed it...
What voltage/current rating do you go with?
I've done plenty of these and they are a 0.1uF cap in series with 120 ohms resistance. I make my own out of two separate parts. That said, the one you show is exactly for what @tarior said, spark supression on the main power switch. There is a similar thing on each audio output amp that may have a bad cap and the amp is going into oscillation, maybe at full amplitude. That can be way above the audio range and can blow out your tweeter(s). Hope not!
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Yused Towork
It Used to work until I fixed it...
Thank you for the answers. The outputs have fuses going to the speakers (3amp), so I have not seen any spark killers on the outputs.
I think I have some of those XY caps you are speaking of, because I have an old National radio to fix that problem of paper cap to the chassis (Death cap). What wattage for the resistor and what voltage for the cap 250v?
I think I have some of those XY caps you are speaking of, because I have an old National radio to fix that problem of paper cap to the chassis (Death cap). What wattage for the resistor and what voltage for the cap 250v?
Any wattage, I use 1/4 watt as the size is more convenient when installing it right on the switch. Nothing wrong with where yours is located on the auxiliary AC sockets. On the cap, at least 250Vac and X2 rated, the latter is very important. As a reference I used these from Mouser but they're obsolete now but give you an idea as to the specs:
667-ECQ-U3A104MG
Yused Towork
It Used to work until I fixed it...
Excellent. I did get some from Mouser also, I have to check where I put them. Thanks
Sorry to butt in here but has anyone in the Marantz community done the Triac mod for these power switches? I have a Nikko receiver that has a dodgy power switch in it. Sometimes the contacts for the main amp power side would weld themselves together on power on and then not shut off. My own fault, I was tracking down a too short protection delay with the help of @sregor and @Warren-Oates and a few others and was turning it off and on a hundred times despite being warned of the switches frailty. I installed a triac in it using the info found in this thread and it has been working perfectly ever since.
I have a Marantz 2238B in my queue to go through and freshen up that belongs to a friend of my son. I’m just wondering if doing it on this would be of value. Or are these switches more robust than the ones discussed in the thread above and not necessary?
Thank you!
Cheers……………………Todd
I have a Marantz 2238B in my queue to go through and freshen up that belongs to a friend of my son. I’m just wondering if doing it on this would be of value. Or are these switches more robust than the ones discussed in the thread above and not necessary?
Thank you!
Cheers……………………Todd
I haven't done one in a Marantz but it should work. The power switches in these aren't really better IMO.