http://www.audioresearch.com/ContentsFiles/VT130_BiasAdjust.pdf
Install one matched set on the left channel side and the other matched set on the right channel side.
(V4 - V7 Left Channel) (V14 - V17 Right channel)
How best to place tubes in an ARC VT-130SE
I have two matched quartets of 6550EH Platinums that I am going to put in my amp. One quartet's tubes measure lp: 39 and GM of 5,700, 45 ma. Every tube in the other quartet measures lp: 36, GM of 5,400, 44 ma. There are tube positions of V4-V7 on left and V14-V17 on the right. The quartets are perfectly matched. I want to achieve a "match" between the sides. Anyone with any experience as to where I should place these to have both sides "balanced" with each other? I understand it is identical to the VT-130 as well. Thanks.
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Thank you. The previous owner of the amp advised me to put two of each quartet on each side of the amp, thus "averaging" them on each side, and as well "averaging" each side to the other. Or something like that. The Ruby 6550's in it now seem fine, but I thought I would put new ones in an abundance of caution. |
This amp is manually biased, which I keep a religious eye on. I have manually biased my previous Cary V-12R amp a few times over 10 years, after new tubes. The bias procedure for the output tubes seems pretty straight forward on the ARC VT-130SE given its meters up front. I believe I can handle the task. I will probably get a tech to bias the six other input/driver tubes, as there is no on-board meter for those. What I am wondering is what are the best spots for the new tubes I have? - either a matched quartet on each side, or a positional combination to achieve an "average" on each side? Thanks again. |
Then please explain to the OP where you would install the new tubes, he has, for the best output balance across each channel. Here is the schematic wiring diagram. Here is the owners manual. Jim |