What's up in 2016?
Well I don't have good news for you guys...!
Recently, It was time to re-tube my good old VSI-55 so I called my local ARC dealer who said I could easily upgrade from the stock 6550 tubes to KT120 or even better the newer KT150...! To double-check I've called Audio Research directly and here is the BAD news the tech told me: While it will work to re-tube my amp with KT120 or KT150, the power transformer has not been designed for this, thus it will overheat tremendously and this will seriously compromise its lifespan (a new power transformer of this type costs around $500-600 including labor). Instead he recommended to use the 6550's or KT88's... More interestingly, I asked if I could re-tube a VSI-60 (very similar amp to the VSI-55) with KT120 or KT150 and he said the same thing: NOT recommended! Then I asked him why they still offer the VSI-60 with KT120 on their website? He answered that thuis model was discontinued but there may still be some units are resellers. And the newer VSI-60 models had an upgraded power transformer to accomodate KT120's while older ones did not...
So be careful if you think this is a good upgrade... You may have better sound but you will inevitably toast your power transformer!!!
I called back the local dealer about this contradiction, he retracted and said ... listen to the ARC tech...:-)
Anybody had issues ...?
Well I don't have good news for you guys...!
Recently, It was time to re-tube my good old VSI-55 so I called my local ARC dealer who said I could easily upgrade from the stock 6550 tubes to KT120 or even better the newer KT150...! To double-check I've called Audio Research directly and here is the BAD news the tech told me: While it will work to re-tube my amp with KT120 or KT150, the power transformer has not been designed for this, thus it will overheat tremendously and this will seriously compromise its lifespan (a new power transformer of this type costs around $500-600 including labor). Instead he recommended to use the 6550's or KT88's... More interestingly, I asked if I could re-tube a VSI-60 (very similar amp to the VSI-55) with KT120 or KT150 and he said the same thing: NOT recommended! Then I asked him why they still offer the VSI-60 with KT120 on their website? He answered that thuis model was discontinued but there may still be some units are resellers. And the newer VSI-60 models had an upgraded power transformer to accomodate KT120's while older ones did not...
So be careful if you think this is a good upgrade... You may have better sound but you will inevitably toast your power transformer!!!
I called back the local dealer about this contradiction, he retracted and said ... listen to the ARC tech...:-)
Anybody had issues ...?