Champ 12 - which circuit?

[Chicago.Blues]

I have this awesome little Champ 12 in Snake Skin – probably 20 years old. It has the sweetest tone especially after replacing the tubes 1½ year ago. Meanwhile a few days ago I was playing at really low volume on the drive channel (my neighbors already hate me and it was way past midnight) and I experienced a significant change of tone. The tone suddenly included a high shimmering and the sweet midtone was ruined. The volume was as low as possible and the gain maybe at 3-4. It was so low you could feel the amp almost not being able to play. Somehow I overloaded my little sweetheart. Ever heard of overloading an amp at really low volume?

So – I have just ordered new tubes and as you see – one stick out a little (12AT7EH).

1 x 12AT7EH
1 x 12AX7 TungSol Russian Issue
1 x 6L6GC-SV

The idea is that this tube is lees distorted and will create a more full bodied warm tone. The 12AT7EH should be positioned at the first stage of the circuit – but which socket is that??? When looking from the back into the amp – is the left or right socket??

Thanks in advance guys- and girls!

Lars

[phsyconoodler]

Looking at the back of the amp,the furthest right tube should be V1.A 12AT7 is not the best choice.Try a 5751 or a 12AY7.They are more musical sounding than the 12AT7 which is better for reverb and phase inverster use.

[Chicago.Blues]

Thank you for your suggestion - I have just corrected my order and will do a bit of testing with the two suggested tubes :o)

Thank you!

Lars