Classic 60 plate fuses.

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Kiddo
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Classic 60 plate fuses.

Post by Kiddo »

Hi folks;

I finally popped a plate fuse on my CJ Classic 60. One of the EL34s was cherry red when I hit the power off. Now I can replace tubes, but where on this thing are the plate fuses located? Not on top, and no where I can see (using a flashlight) on the back side either. Does it need to be opened up to change the fuse(s)?

Thank you;

Kim
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Re: Classic 60 plate fuses.

Post by admin »

Welcome to the site. I am not intimately familiar with the Classic 60 but I'm pretty sure it will need to be opened up to get access to the fuses. This seems to be the case with all CJ equipment. I would open her up and take a look.
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Re: Classic 60 plate fuses.

Post by Kiddo »

I talked to CJ and they said take out all the screws on the bottom and remove the feet. The fuses are on their own little circuit board.
This wouldn't be so bad if I didn't live in a nursing home. Anyway, tubes and fuses are ordered and I'll get someone help get it on the bed and upside down to do the fuses. It sure would make sense though if they were on top next to the LED.

Otherwise I have no complaints about my CJ gear. I use a CJ tube preamp too and love the combination.

Kim
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Re: Classic 60 plate fuses.

Post by Big Dog RJ »

Hey Kiddo,

Thanks for sharing that. Certainly good to know where these fuses are located. There are a few things/items cj could have improved on with the classic60 cosmetic wise. Such as plate fuses on the top rather than underneath. When the cover is off, the exposed transformers are butt ugly! They could have placed some nice looking shiny stainless steel caps or simple covers to make it more appealing. I guess this is the classic look...

Anyway, the sound is outstanding, so probably one would forget about all those cosmetic features.
Enjoy that classic 60, it certainly is a true classic.
Cheers, RJ
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Re: Classic 60 plate fuses.

Post by Kiddo »

Thanks for the kind words Big Dog :)

Kim
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Re: Classic 60 plate fuses.

Post by Joe Appierto »

I wasn't aware that c-j had changed the plate fuse location. On both the 11A and 140 that I had, there were two located in the rear of the amp. Each had a red LED above them and they'd glow when the fuse had blown. Not that you didn't already know because normally that channel would be dead. You unscrewed the fuse holder, popped in the replacement, screwed it back down and you were good to go.
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alexwu21
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Re: Classic 60 plate fuses.

Post by alexwu21 »

Hi all,

I would like to replace the fuse for my classic 60 as well. Just want to double confirm before I do anything stupid.

What I need to do is to remove the 6 screws and the 4 feet at the bottom and I should be able to find open the bottom cover, right? Also, do you know what kind of fuses the classic 60 is using?

Thank you

Regards,

Alex Wu
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Re: Classic 60 plate fuses.

Post by alexwu21 »

Dear all,

After carefully consideration, I decided not to do anything on the fuse. It seems to have certain kind of risk to the amp and its physically very difficult because of the weight of the amp.

Thanks

Regards,

Alex
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Re: Classic 60 plate fuses.

Post by Big Dog RJ »

Hey Alex, came across your question.

You need to replace the fuse only if it is blown out. Which means the associated led will light up on that channel. This also means a bad tube, in which case you actually need to replace the pair of tubes on that channel. It is not easy to identify a bad tube unless one was glowing a hot red right throughout the grid. You can visually identify this when the whole tube is glowing red hot. Needs to be replaced immediately! The fuses are there to protect the output transformers, and that's when the associated led indicating a blown fuse will light up.

You cannot just replace the fuse and expect the amp to perform fine. Also you need to order the fuses from cj directly because these are special types of fuses and are not stocked in general electrical stores. Tubes can be ordered from either cj or a reputed tube dealer, just make sure they are matched pairs, gives the amp a better balance when biasing new tubes.

Why did you want to replace the fuses in the first place? And then suddenly decide not to replace because of the weight? Doesn't make sense. .. if the fuse is blown, you would need to do the replacement procedure anyway.

If you don't like to do the replacement yourself then perhaps your dealer can help. Also read up the manual, it clearly explains the fuses required and the best way to go about it. I hope you were not trying to replace the fuse thinking you would achieve better sound. ..

This would be a very risky move and will not be an original design for any cj amp. Don't do that.
Hope that helps. Have a good one,
Cheers, RJ
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Re: Classic 60 plate fuses.

Post by alexwu21 »

Dear RJ,

Thanks for your reply.

I originally decided to do it is because I was trying to make my system to sound better(haha, exactly the reason which I really shouldn't). I am located in Hong Kong and we have an audio shop where I always go to. They recently have imported a lot of different kinds of high quality fuses. I bought a few and tried them on my DAC, CAS, CD, Bluray player, and even my TV. The result was amazing and all have very obvious improvement. So the evil side of me thinking to try on my ET3SE and Classic 60SE and that's when I wrote my last post.

When I tried to open my Classic 60, its heavy weight really coz a lot of trouble to me to open the bottom cover. I don't have a workshop and I have to do do it over my bed. Also, the circuit seems to be a lot more complex than something I can handle. There are 5-6 fuses for Classic 60 alone. Therefore, I don't think I can do that a few times to try on different brand of fuses to see which combination is best so I give up the idea.

Now that I am cool down and think back, I am glad that I did not do it and thanks for your wonderful advice. I will not do this again.

Keep in touch and Happy listening.

Regards,

Alex Wu
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Re: Classic 60 plate fuses.

Post by rjhd3 »

Reviving an old thread for slightly selfish reasons. I recently acquired a power protector (Furman) with a delayed amp on circuit. I wired in an ET3SE and Classic 60SE, and then hit the power.

Oops. Delayed on was reversed and the preamp came on after the amp with a pop. Out went the fuse on the left channel. Pretty sure the tubes and rest are fine.

But...and here's my dilema... CJ staff are all at CES for a week and I selfishly don't want to wait two weeks to hear my gear.

Does anyone know what the Classic 60SE fuse set is, or ideas on where to buy them without waiting for CJ?

Thanks
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Re: Classic 60 plate fuses.

Post by Big Dog RJ »

Hey mate, that's a tough one.
Sorry to hear about the loud pop, I certainly feel your pain and have experienced far greater sadness when it comes to high-end gear. I miss those days back when I had the NAD/Musical Fidelity/ Marantz & Paradigms, never had any issues with them whatsoever...

You could try to open the bottom cover, although a mighty pain in the A, and have a look at the fuse types. They are clearly marked on the fuses itself and depending on your location, if you are in the US, you should be able to source the very same fuse types & values. However, if you are located in Australia or in a galaxy far far away... then my best option would be sourcing from c-j directly.

My best advice-overall, having been in this hobby/passion/obsession for nearly 4 decades, I would just sit tight and wait for c-j to get back.
Better to be safe than sorry, and I have been in that sorry zone numerous times.
Hope that helps a bit, have a good one,
RJ
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