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AU-719 on the bench

sansui au719 said:
Of course John (Hyperion) is one of the rare exceptions to the rule.
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I've been in Customer Service in various guises all my life, so now, it just comes naturally to me. ;) Of course the reverse is also true, when my hair trigger sensor senses I'm not getting good customer service, I don't usually turn green, but I do turn into the service withholders worst nightmare. :D
 
Hyperion said:
I've been in Customer Service in various guises all my life, so now, it just comes naturally to me. ;) Of course the reverse is also true, when my hair trigger sensor senses I'm not getting good customer service, I don't usually turn green, but I do turn into the service withholders worst nightmare. :D
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I'm also guilty of being hard on poor service :(
 
sansui au719 said:
Now I don't want people to think I'm not fond of the Dutch or the English, quite the contrary. but customer service is just not their thing.
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I am monitoring this thread as it is an interresting read about the so called "bullet proof" Sansui transformers and I am curious how the rewinding operation will turn out, but your storytelling is also very amusing..
:thumbsup:
 
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sansui au719 said:
Has anyone ever compiled a list of transformer part numbers ? It'd be good to know if there are any compatible transformers used in other models.
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Not to my knowledge.

I've only seen one transformer failure, coincidentally in an AU-719. Perhaps these amps are getting to the age where it may happen more frequently. I wouldn't think that age would affect transformers, but maybe the shellac they use to insulate the wire they're wound with goes south over time.
 
Ray Gianelli said:
Not to my knowledge.

I've only seen one transformer failure, coincidentally in an AU-719. Perhaps these amps are getting to the age where it may happen more frequently. I wouldn't think that age would affect transformers, but maybe the shellac they use to insulate the wire they're wound with goes south over time.
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My Dad worked on transformers and motors as an apprentice electrician in the late 1950s. His view was shellac would probably break down over time. I guess we won't know until the transformer guys get a look inside. I'm still keeping an eye out for another 719 transformer just in case, although in the worst case another transformer could be used if it's electrically and physically compatible.
 
sansui au719 said:
My Dad worked on transformers and motors as an apprentice electrician in the late 1950s. His view was shellac would probably break down over time. I guess we won't know until the transformer guys get a look inside. I'm still keeping an eye out for another 719 transformer just in case, although in the worst case another transformer could be used if it's electrically and physically compatible.
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I've no experience with shellac in transformers but have been involved with shellac insulated wiring in magnetos. The shellac often breaks down after several decades, but heat or especially humidity is usually the cause.

During long term vehicle storage, the shellac starts to go soft with excess heat or humidity but tends to still insulate. When started it can run OK for a while, but then some of the softened shellac can fly out and impinge on the inside of the housing, especially when the engine is speeded up and the magneto is warm. This can cause failure at any time on the journey. In other circumstances the engine continues to run but the displaced shellac can harden after engine switch-off and jam the magneto so that when starting is attempted again it can appear that the engine itself has seized.

How about that for thread drift - again! :eek:
 
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On topic with your transformer I was speaking to a customer at my work and found she worked at express transformers and controls in Runcorn Cheshire. Literally 20 minutes drive from me. The company can make new custom transformers for just about anything. Never knew they existed and they have been in business for 60 years. Another option available if needed
 
sansui au719 said:
Has anyone ever compiled a list of transformer part numbers ? It'd be good to know if there are any compatible transformers used in other models.
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You know... I have a very hard time with any kind of transformer identification. Whether it be a nice piece of equipment. Or a **** spreader. You just have to check the output(: think im going to invest into some tools to accurately do measurements . I slipped down rabbit hole. Have a collection to mod and improve.
 
Transformer update : The diagnosis given by the workshop was heat damage to the secondary windings. They didn't go into any detail but said the transformer needed to be rewound, at a cost of £133. John suspects we're not getting the full story but it's hard to argue or get a 2nd opinion when the transformer sits on their workshop bench in Surrey and John and I both reside many miles away in other counties. Besides, £78 of the £133 is a non-refundable charge for the initial examination, so in effect it's another £55 for the rewind. At least we're confident they have the facilities to do a rewind. We'll just have to hope they do a good job and the rewound transformer works as it should. Personally I don't like dealing with a company where communication with the client is poor, timeframes are hazy and payment is demanded up front, but they have us by the short hair. Their projected time-frame for repair is two weeks, so we may have some progress after that.
 
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