Adjusting the Bias on the Apetite....

[Jerome W]

Hello folks,

I changed my power tubes and the driver tubes in my Apetite about 2 months ago because I had the feeling that it wasn't sounding at its best but did not adjust the bias.
Bought tubes at Tube Depot : the Apetite was bought used from Des here on the market place so I did not contact any Shindo dealer to buy the same tubes that came with it originally ( I have been told that no original "Shindo" tubes can be bought for used units not bought from a Shindo dealer so I did not even try ! ).
The sound improved clearly, with better dynamics and a fuller, more natural presentation but I was asking myself now about the bias adjustment that I completely ignored !
Does someone know how to do that and what is the recommended voltage ?


On a side note, life is clearly easier with autobias amps like McIntosh. Does this autobias system degrades the sound ? I wonder how it works....
I had some trouble with the bias of my Snappers during a few months, probably until the EL34s become fully broken in. Now I checked once every 2 to 3 months and they are straight on the recommended voltage all the time.
Manley Labs say that the bias should be checked once per month or once every two months like the pressure in your auto tires.
Since Shindo amos are not autobiasing, wouldn't it be recommended to check the bias regularly also ?
Does an incorrect bias level affect the sound quality or does it affect the longevity of the tube or both ? Is it dangerous for the amp when the bias is not set correctly ?

Many thanks in advance !

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