Advice re repair

[initialjh]

Dear all,

 

just asking for advice re repairer. I have an Audio Research VS55 amp. The other day when i powered up the amp, it sparked and gave an almighty spark show. luckily, didn't catch fire. I've cycled the part that exploded. I have taken photo of ok side.

 

My questions are:

1) Is this repairable or should i consign to the bin?

2) If repairable, any recommendation for repairer in Newcastle, NSW, or do I take to someone in Sydney?

 

Thanks in advance for advice.

[xlr8or]

It appears the bias cathode resistor has failed for that PP configured 6550 tube. It's definitely repairable as the same thing happened to my VS55 for the same carbon composite resistor/s.

 

Chris Kim @ Kimil Electronics in Croydon NSW would be best your best bet to have it fixed and reviewed for the other 3 tubes not following suit with the same failure repeating itself in the near future. Try also checking your bias on a more regular basis to avoid your 6550 tubes going into thermal runaway when they can no longer be biased.

Edited October 1, 2023 by xlr8or

[initialjh]

31 minutes ago, xlr8or said:

It appears the bias cathode resistor has failed for that PP configured 6550 tube. It's definitely repairable as the same thing happened to my VS55 for same carbon composite resistors.

 

Chris Kim @ Kimil Electronics in Croydon NSW would be best your best bet to have it fixed and reviewed for the other 3 tubes not following suit with the same failure repeating itself in the near future. Try also checking your bias on a more regular basis to avoid your 6550 tubes going into thermal runaway when they can no longer be biased.

thank you. Such wealth of knowledge. Funny, I was thinking recently to check bias and got all the gear together, but, like everything else, " I'll get to it soon" and ever happened.

 

I shall contact Kimil Electronics and drop it down with them. thank you once again.