[sfox7076]

Hi all.  I have finally completed the move from Manhattan to Brooklyn. I moved my stereo and somehow the right channel on my Ultra 550 has stopped working.  The tube heats up, but no sound.  I have troubleshooted my way to the right channel of the amp alone.  Lucky for me I have an insight 240 to use until I get this sorted out.  However, anyone have any ideas before I send it back to Frank?  And I have no warranty.  On the bright side, if I am sending it back, at least there will be a convenient excuse to get some upgrading done.

Shawn

[Tone Depth]

I'm guessing he should be back from AKF tomorrow or Tuesday.  Give him a call and I'm sure he will help you troubleshoot over the phone.

Hi all.  I have finally completed the move from Manhattan to Brooklyn. I moved my stereo and somehow the right channel on my Ultra 550 has stopped working.  The tube heats up, but no sound.  I have troubleshooted my way to the right channel of the amp alone.  Lucky for me I have an insight 240 to use until I get this sorted out.  However, anyone have any ideas before I send it back to Frank?  And I have no warranty.  On the bright side, if I am sending it back, at least there will be a convenient excuse to get some upgrading done.

Shawn

[charmerci]

In the mean time, two simple things you can try are to switch the fuses and the tubes. They may look good but they could be bad.

[Wayner]

One thing you could do is check fuses, externally as well as fuses inside. It is possible the the move ruptured a fuse strand.

Wayner

[sfox7076]

First thing I checked was the fuse.  It looks ok to me, but maybe it is just my vision.  I also thought because the tube lit up, the fuse would be fine (of course it could be the fuse tied to the output and I just wasn't thinking).  Might as well replace it.  What fuse does it use?  I have a Rat Shack near work and can grab it at lunch.

Shawn

[dB Cooper]

Just don't be surprised if they try to sell you a cell phone along with your fuses    (used to work there)

On a more sreious note, fuses could be checked with a vom or by substitution between channels. I've seen fuses break inside the cap where you can't see it

[sfox7076]

For the price of shipping v. a fuse, I am just going to spend the $2 first.  Is it just 5 Amp fast burning 1 1/4" x 1/4"?

[orthobiz]

I had a bad tonearm wire with a dropped channel a few months back. So, make sure you checked a couple of different input sources!

Paul

[avahifi]

There are two speaker fuses on the back panel near the output jacks.  These should be quick blow type 3AG fuses, no larger than 5 ampere. (No larger than 3 amp for two way speakers unless they are VERY rugged and 2 amp recommended unless they blow often).

There are two internal B+ fuses in an internal dual fuse block on the floor of the chassis near the vertical power supply board.  These should be no more than 7 amp 3AG quick blow fuses.

If replacing all these fuses does not restore normal function, then swap the two tubes from channel to channel and see if the problem follows a tube.  Make all changes with the amp turned off and unplugged from AC and wait one half hour before removing cover to allow the high voltages inside to bleed down.

If none of the above restores the channel and you are sure your input and speaker cables are good, then we will need to see the amp on our test bench for evaluation and possible service.

Please call me at 651-330-9871 for more help.

Best regards,

Frank Van Alstine

[sfox7076]

Changed the fuse and it seems to be working now (only about 3 hours on it right now).  Not sure what happened to that fuse, but it is now in a landfill somewhere.  Glad I didn't have to send it back. 

[jtwrace]

Not sure what happened to that fuse

It blew rather then blowing something else that's more costly.  That's the purpose of a fuse.   

[avahifi]

Which fuse did you change?  The back panel speaker fuse or the internal B+ fuse.  What size fuse did you use?

Thanks

Frank Van Alstine

[sfox7076]

I changed the back panel fuse with the same fuse that was in it.  5 Ampere fast burn.  Something in the fuse must have broken in my move.