Soundlab A3s and thoughts.

The comments by @kingdeezie are spot on.  As a long time owner of A1's with the old transformers, and then updating to the newer back panels, the sound is magnificent with big tube amps.  These speakers and tube amps are a match made in heaven.

I adjust the bias similar to what was described above: 1) Turn the bias pot clockwise until the crackling sound just starts; 2) Identify the setting with the hour on a clock, e.g., 11 o'clock: 3: Turn the bias counter-clockwise to the equivalent of the clock's previous hour to the one identified in step 3, i.e., 10 o'clock; 4) This process should allow you to be near the highest sensitivity without always needing to tweak the bias which is also sensitive to humidity changes throughout the year.

Hope this helps.  And enjoy!

John

jafox has it right. The setting depends entirely on humidity. You turn up the bias (diaphragm voltage) until you hear arching then back off until it stops. You might hear some arching when it rains! 
jafox you do not want to turn the speakers off. First of all they draw almost no current as there is no current flow you are just putting a charge on the diaphragm. It costs nothing to keep them on. There is a period of time for the charge on the diaphragm to settle down perhaps 10 minutes or so. Keeping the speakers on does not decrease the life of the speakers at all. Letting them arch continuously does not decrease the life span at all it just sounds snappy. In order to damage a Soundlabs panel you would have to take an ice pick to it.

Hi All, Dr West replied to my email personally Welcoming me to the Soundlab family and sending me the user manual. The Manual states that the cracking noise cannot damage the panel. In fact the bias procedure asks you to turn the adjuster all the way clockwise then back off until you cant hear any cracking. However Ive just done as you suggested which is to turn until cracking is heard and then back off until it goes away. The Manual Also says that good results can be expected with OTL amps, which indeed ls Ralphs( Atmas) area. Ive had some interesting discussions with Ralph in the last few years. I'm sure his amps would be a good match. The speakers continue to surprise in their presentation even with my little old 22watt SET as long as I don't try to push the volume on Electronic Bass heavy tracks. Leonard Cohen sounds fabulous. I'll check in from time to time and let you know progress re amps and so on. There is a Bryston Local that might fit the bill. Thanks all for your thoughts and advice.

Myron.