Great job! One SONY owner once asked me what condition the VFETs and how well matched they were in his amplifier? I said that it doesn't matter because there are no others VFETs anyway. If there is no too much heating, all voltages and currents are fine, then he does not need to worry about it.
Sony had a different philosophy. The Sony vfets are no where as closely matched as those in the Yamaha. This also makes it possible to find replacements for Sonys with a greater success than being able to find the same for Yamaha.
One question, you said the V-fet most likely failed due to the power switching transistors . You said some were replaced and then said the reason they failed is they were underpowered . Now did you mean the replacements were underpowered or the originals are? It wasn't clear to me .
Very informative. Thank you for the detailed explanation and showing multiple methods.
Glad it was helpful! There will be a follow-up at some point.
thank you so very much for the valuable information ⚡☂
Glad it was helpful!
Great job! One SONY owner once asked me what condition the VFETs and how well matched they were in his amplifier? I said that it doesn't matter because there are no others VFETs anyway. If there is no too much heating, all voltages and currents are fine, then he does not need to worry about it.
Sony had a different philosophy. The Sony vfets are no where as closely matched as those in the Yamaha. This also makes it possible to find replacements for Sonys with a greater success than being able to find the same for Yamaha.
Great video Pete!!! Athanasios
One question, you said the V-fet most likely failed due to the power switching transistors . You said some were replaced and then said the reason they failed is they were underpowered . Now did you mean the replacements were underpowered or the originals are? It wasn't clear to me .
Originals undersized for the job. Operating on the upper end of the SOA for many years until they fail.
So what your saying is the ones in my B-1 may be unsafe as they are old and tired . What are suitible replacements ?@@atelier_HiFi
i wish those tests could be done with more modest testin equipment ..I dont have access to that pricy gear .yet i need to restore my amps
It can be done with simpler tools but the risk is the same.
You should not attempt to rebuild a b1 if you do not have experience.
@@atelier_HiFi i am awaiting for you to show how a Tonkin SITcan be use as a replacement