Audio Research vt100mkll question

Update.............. More Help please.

A technician friend and I have dialed in the 6922's almost perfectly. Plus we tested individual tubes to look at plate current etc. All looks good apart from one 6550c running a bit hotter than the rest. (see I even know the terminology now).And one 6922 being quite suseptable to microphony.

However the problem I have is this.... on the .5 Ohm resister which is the testing point for the bias adjustment on the power tubes I can only get max .098Mv on one channel and .122mv max adjustment on the other channel.

Has anyone had simialr problems ??

By the way Sirspeedy, Thanks for your comments Its a shame my clothing empire wasn't as successfull. Maybe I'll try hair/grooming products next.

Final update...............................

Every thing turned out fine in the end. I've had my amp in with a fantastic Auckland based Technician who has replaced my burned out resisters and set everything up for me. The amp now sounds great. It cost me about $60 to get done I'm super happy. :-).

The things I've learned from this are :

1. JJ EC88's do not work in a setup where they are mounted horizontally eg ARC vt100.

2. Always take out the 6550's when adjusting the pre-tubes. This can potentially save you dollars in the long run.

I'm moving into new house soon and I'm looking forward to setting up my room. In the end I've really enjoyed the whole experience (other than the burning out/ blowing up the screen resisters).

Thanks everyone for your advice and help.

Myron.

Borg:

I am happy for you. As I had suggested the resistors were the culprit.
The VT100 MKII is a fabulous sounding amp with surprising power. Enjoy

George

Hi! Please help me How can adjustment the bias output tube and pre-tubes.
Thank you
Keith