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Audio Space Ref 3.1 KT88 - biasing

I've just got hold of a Ref3.1 Kt88. Great amp, but want to change the KT88's. Haven't got a manual and can't find anything online about the correct bias setting on the VU meter.

The stock tubes are set at '9' on the scale. So my question is: does anybody know the correct setting and what make the 'stock' tubes are?

I have put a request into Audio Space, but no reply yet and as these amps aren't available in Australia, there's no service advisor.

Thanks in advance.
rennie_perth
jrun
61 posts
 
Yep. My manual says...turn the meter range to v1 position. With a small flat head screwdriver, adjust the bias voltage for v1 by turning the bias pot (v1) located on top of the chassis. Adjust the bias pot until the indicator of the analog meter on the front panel is pointing at the 50mA mark on the bottom scale. Repeat for the three other tubes and you are done! My stock AS tubes drifted bias quite a bit. My Gold Lion KT88's are rock solid. I'm using Sylvania NOS 6SN7's and vintage Telefunken's in the phono. Hope this helps.

jrun
rennie_perth OP
23 posts
 
Terrific info. Makes sense now.

Thanks.
hifi223
26 posts
 
Hi, where did you buy the AS amp from in AUSTRALIA?
rennie_perth OP
23 posts
 
Lucky enough to to pick it up on A/Gon from Singapore (240v)
hifi223
26 posts
 
KC Audio in Melbourne sells Audio space, their web-site at www.kcaudio.com.au
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