ARC LS22 and pre tubes

Hi Elevick,

Thanks for your tip. Do you know exactly how many tube (and which ones) used in LS22 for unbalance? I don't use balance cables so i can forget it and just replace tubes that i need. In the other words, which tubes are for balance purposes?
Thanks for your help.

You need the manual or schematics usually. AR will help if you call them. You need a pair of tubes for the gain stage (Most likely the pair closest to the outputs) and a pair for each input. The sockets should be labeled in some way such as v1, v2, v3 and so on.
If you only use cd, you only need 4 tubes.

Thanks Elevick. I will call ARC and ask for more details.

Ls22 has a pair of input tubes then 2 pairs of voltage gain tubes then a pair of Cathode Followers. The tubes have 2 channels per se and the Balanced uses both for a extra 6db of gain vs the unbalanced inputs.
So V1 and V2 are most important to be quiet and have the sound you like and V3-V6 will increase the gain and shape the sound some more. And maybe someone can learn me on what is important about the Cathode Follower positions.......

Jiceman, FWIW in my SP10 I used 6h23s (low noise/rugged) in the critical positions but I found I can put 'colored' tubes in the cathode follower positions (which do not add any gain and are less demanding on noise issues). I long ago gave up trying to get tone from the critical positions.

The cathode follower tube/circuit provides no gain but affects the output so that you can drive long runs of IC's. Google it - I'm sure there are many thorough explanations there.