Roger2, LOVE THIS! To add insult to injury, after they told me what to do with it, I ask them if they would take it as a trade in for something else and their response was NO. Thanks for reassuring me about my amp. Kinda of got "beat up" yesterday in regards to my Amp. I'm BACK... and so is my M504!!
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Onkyo M-504 Recap
- Thread starter CohibaJoe
- Start date
They don't build 'em like that any more Spl, at least not for a price that any regular Joe would want to pay. And those big Onkyos are just plain beautiful to boot...
When you came to AK...you came to the right place
https://www.yahoo.com/lifestyle/watch-golfer-ian-poulter-hit-210000524.html
When you came to AK...you came to the right place
https://www.yahoo.com/lifestyle/watch-golfer-ian-poulter-hit-210000524.html
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Thanks roger2. A good group to be with and great support.They don't build 'em like that any more Spl, at least not for a price that any regular Joe would want to pay. And those big Onkyos are just plain beautiful to boot...
When you came to AK...you came to the right place
Well here is my 2nd. M504 which stop working yrs. ago after returning from a trip (should have never left in the 1st Pl.) My wife said that there where severe T Storms while gone. Came home powered up but no servo light. Eventually got another M504 which I'm using now. This one (with pics) was in storage (at least 25yrs.) finally got it out took some pics. Any suggestions troubleshooting advice
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In order to receive some suggestions for troubleshooting, you need to start you own new thread. Tacking a new series of questions onto the end of an 8 year old thread, even though you're talking about the same model of amp, will not get you much exposure at all. Not many will look, or look again, at a thread that has already run its course.
Just start a new thread here in Solid State. Stick to only one problem, or a group of related problems. Don't ask about speakers and an amp problem in the same thread, use different threads. Post about the JBL speakers in the AK Speaker forum. In your M-504 troubleshooting thread, stick solely to any questions or information that pertains to the problem that you are trying to resolve.
Good luck
ThanksIn order to receive some suggestions for troubleshooting, you need to start you own new thread. Tacking a new series of questions onto the end of an 8 year old thread, even though you're talking about the same model of amp, will not get you much exposure at all. Not many will look, or look again, at a thread that has already run its course.
Just start a new thread here in Solid State. Stick to only one problem, or a group of related problems. Don't ask about speakers and an amp problem in the same thread, use different threads. Post about the JBL speakers in the AK Speaker forum. In your M-504 troubleshooting thread, stick solely to any questions or information that pertains to the problem that you are trying to resolve.
Good luck
I know this is an old post but I just finished re-capping my Onkyo M506RS. It uses four 22,000 mfd 63 v. 4 pin caps The fix for the 4 pin caps is easier than you think. There's no need to change or modify the circuit board. You modify the caps to fit in the original holes. The hardest part is you need a massive soldering iron to melt the huge amount of solder they used to solder these to the thick copper plates. The caps I used are Nippon Chem-con 22,000mfd 80v. snap in caps with 2 terminals. I made a U-shape out of 14ga Romex wire. See photos. Since I put it back together I had a local shop bench test it. It tests fine and sounds good.
Hi,
Onwardjames did you ever replace your power capacitors on your M-504? I'm still dreading the day when I have to replace mine due to the difficulty of having to adapt 2-pin power caps to replace the old 4-pin power caps that aren't sold anymore. I had my Onkyo M-504 connected to a power strip/surge protector which I usually kept turned off when not using the M-504. A few months ago, when I turned on the M-504 after not using in for awhile, the sound would cut in and out and sound very distorted for a few minutes before finally settling down. I was thinking now I'm going top have to change those power caps. But I found out that if I left the power strip that the M-504 was connected to on all of the time then I didn't get any cut outs or distortion when turning the M-504 on, even after several weeks of non-use. When leaving the power strip on all of the time, the initial turn on delay from when you hear sound was about 15 seconds after not using it for a week or two. The delay becomes about five seconds if you turn off the M-504 and then turn it back on a few minutes or an hour later. So I had this problem with the sound cutting and being distorted for a few months. Since I decided to leave the power strip on all of the time now, I haven't had any problems except for a slightly longer delay on first turn on when it hasn't been used for a while. When the sound does come on now, it sounds very clear with no distortion. I was using a CD with the new a-ha instrumental version of Take On Me and it gave me goosebumps it sounded so good with the Onkyo M-504. I can't explain why this should be the case but if you ever start getting cut outs and severe distortion with your M-504, make sure power is always connected to the M-504s power plug and see if this helps. It worked for me and I actually think it sounds much better now since I have been Ieaving power connected to the power plug all of the time. Before when I was turning off the power strip, when turning the power strip and M-504 back on, even after a few minutes, the sound seemed normal but I think there was still some minor distortion as it didn't have that magical sound that M-504 amps are know for. Now that I leave power connected to the M-504 power plug continuously the magic is back as soon as I start getting sound from the M-504.
That's a very peculiar situation, but thanks for sharing. No, I haven't gotten it fixed yet, it still works, just want to safeguard for the future. It has sat unconnected for 6 months or so now, need to get it going again.
I gotta take it to Leesonic up in NJ one day, which is quite the drive.
Wag,
It sounds to me like when you totally turn off power to the unit by turning off the power strip, it allows the filter caps to drain completely. Then when you turn it on, it takes a bit for those caps to charge up.
There MAY be a circuit that keeps them from draining as long as it is plugged in. Course this is just a WAG on my part.
I have a couple of m508 that I know will need this cap replacement done and I am not looking forward to it either.
Good luck.
It sounds to me like when you totally turn off power to the unit by turning off the power strip, it allows the filter caps to drain completely. Then when you turn it on, it takes a bit for those caps to charge up.
There MAY be a circuit that keeps them from draining as long as it is plugged in. Course this is just a WAG on my part.
I have a couple of m508 that I know will need this cap replacement done and I am not looking forward to it either.
Good luck.
I was thinking the same thing. I did find some capacitors that I think will work on Ebay they are new Japanese Elna Lao 10000uF 80V For Audio Electrolytic Capacitors. They are only $6.50 each and are the same diameter as the original but not as tall. Just do a search on Ebay for Elna 10000uf. I think Radar12 had the best idea, he suggested soldering a U shaped wire to the terminals of the replacement cap so you can use the original four holes on the circuit board.Wag,
It sounds to me like when you totally turn off power to the unit by turning off the power strip, it allows the filter caps to drain completely. Then when you turn it on, it takes a bit for those caps to charge up.
There MAY be a circuit that keeps them from draining as long as it is plugged in. Course this is just a WAG on my part.
I have a couple of m508 that I know will need this cap replacement done and I am not looking forward to it either.
Good luck.
I think you have a great idea about soldering a U-shaped wire to the replacement caps to make them fit in the original holes on the circuit board. I'm trying to get up enough nerve to do it but those copper plates worry me. Can you just heat up the solder on all four pins of the original cap and use a solder sucker to remove the solder and remove the cap that way or did you have to remove the copper plate and do some more unsoldering before you were able to remove the old cap?
I'd think it would be pretty expensive as it is very difficult to remove the original four pin caps because they have copper plates soldered in place over the pins. Then the replacement 2 pin capacitors will have to have U shaped brackets soldered to the two pins creating four pins so they will match up with the four holes in the circuit board. I have fairly good soldering skills but I balked at trying to take on replacing the original caps myself. See picture by Radar 12 in his post of Jan 12, 2021 on how you will have to modify the pins on the two pin caps to make them fit into the four holes on the M-504 circuit board. I finally just gave up and sold mine M-504 as I didn't want to deal with it anymore. The sound on mine would be distorted for about the first minute after turning it on, if I let it sit for more than a day or two. I figured it would probably end up costing me around $400 to buy new power caps and pay someone to replace them and I didn't even know if that would fix the problem as there are a lot of other 20-year electrolytic caps used in the M-504 that could be bad or going bad and causing my problem. I wanted the next amp that I buy to not only sound and look good but be easy to repair. I ended up buying a Emotiva BasX A-300 for $400 as it looks a lot easier to repair see attached photo. You can buy this 150 watt per channel highly rated amplifier for $400, probably what it will cost you to buy new caps for the M-504 and pay someone to replace them for you. I'm very happy with it; it sounds very good and I don't have to worry anymore about old electrolytic capacitors. I know this isn't what you want to hear but I saw a guy selling a B&K ST-140 amplifier which has two large extremely east to change power caps and he paid $275 to have them replaced so I can't see anyone doing the eight caps in the M-504 for less than $400. See attached picture of B&K ST-140.
Funny, my amp does the same except everytime I plug in I have to wait a bit. BasX 300 is already my plan B as my preamp is already pt100, I just couldn't resist when I saw M504 being sold for 500. I found all caps for power as well as the amp, a guy in brooklyn sells them for 190, I think I am going to find second hand basX300 and in the meantime attempt fixing 504 myself. The guy provides all instructions in a booklet as well, what's not to like? I like adventures. How much did you end up selling it for. It's just my Klipsch Cornwalls sound so good with 504, i have not experience music like this.
I saw that guy on Ebay selling the kit for $190 and he sends you all of the caps that need replacing. So if you replace all of the electrolytic caps you should have a really nice amp. You are much more adventurous than I am; that is a lot of work. I wish you the best of luck and let me know how it turns out. You probably want to do the power caps first and then check to see if that fixed your problem. They do maybe a few caps at a time and check to make sure it is still working and do a few more. You don't want to do all the caps at one time and then turn it on and find out it doesn't work and then have no idea where to look for the problem.
Good Luck
Good Luck
I actually have a Onkyo P-304 preamp that I think I will keep as it sounds really good. I also have a Schitt Asgard 3 headphone amp that I also use as a preamp and I've did A - B listening tests between it and the P-304 and I can't really say either one sound better than the other they both sound great. Since you already have the PT100, it sounds like the A-300 would be the perfect one for you. No one can deny the beauty of the M-504 with it's large meters; it just looks stunning; and it sounds very nice no transistor harshness. You will have a really nice amp once you get all of those caps replaced.