[axky99]

Recently the fuse of my ten years old CARY 300SEI has been
blown; I bought this AMP from Audiogon.com. The seller did mention this pair
of Sophia Electric 300B is new;but it should be over 100 hrs. this 300SEI is with power bank.
I bought a pack of 2-AMP,250-volt(slow blown) fuse from Radio
Shack. But it's blown after two days useage. I normal listen music around 2
to 3 hrs per day. I turn it off when I don't listen it. I am not sure if the
fuse, which i bought from RadioShack, is not suitable to 300SEI. Please
CARY 300SEI user advise the right fuse.
I send email to Cary Audio. The technician suggest me to replace all the driver tubes since the 300B's are newer. Replacing the 6SN7's may fix this issue.
As a result, I would like to upgrade all my 6sn7 tubes in my 300SEI. I would like to hear all the good combinations that you every tried or heard.

Thank you advance for all your suggestion and comment!!

 

[SteveA]

Hi!

I don't own a 300SEI but I have stalked them. You are using the correct fuse according to the owner's manual. I'm sure the Rat Shack fuses would work the same as any other so I doubt this is the problem. Sure, it could be one of the tubes starting to go belly-up but more often than not the fuse will go immediately upon turn-on if a tube is faulty.

My guess is you may be trying to exceed the 15 watts per channel this beast can provide. Do you listen at moderate levels and / or use speakers with a sensitivity rating below 90 dB / 1 watt @ 8 ohms?

Regards,
Steve

 

[axky99]

I just use tube AMP about half yr. Could you tell me how I figure out which tube is going belly-up? I put the vol. between 10 to 11 o'clock. So I dont think I exceed the 15 watt per channel; plus, I use it to drive my K1000 only.

There is a switch for high/low gain. Do you think that would cause that problem too?

Any suggestion on 6SN7 combination?

Thank you!!

 

[axky99]

I just use tube AMP about half yr. Could you tell me how I figure out which tube is going belly-up? I put the vol. between 10 to 11 o'clock. So I dont think I exceed the 15 watt per channel; plus, I use it to drive my K1000 only.

There is a switch for high/low gain. Do you think that would cause that problem too?

Any suggestion on 6SN7 combination?

Thank you!!

 

[bozebuttons]

Quote:

Originally Posted by axky99 /img/forum/go_quote.gif I just use tube AMP about half yr. Could you tell me how I figure out which tube is going belly-up? I put the vol. between 10 to 11 o'clock. So I dont think I exceed the 15 watt per channel; plus, I use it to drive my K1000 only. There is a switch for high/low gain. Do you think that would cause that problem too? Any suggestion on 6SN7 combination? Thank you!!

You need to have the tubes tested,I like the sylvania VT231s(6sn7) in the Cary.