2. amps-preamps
  3. 134896-34144

Please give me advice about an ARC VT 200 amp

In a few days I'll be the owner of an ARC VT 200.  I've never owned a tube amp, much less one of this size.  I'm reluctant to plug in this amp for fear that there may be some considerations that I'm overlooking.  I haven't found much info about the operation but I did read that a variac should be used to bring the voltage up, and that a shorting pin needs to be installed in the balanced inputs if the single ended inputs are used.  I've never heard of either a variac or shorting pin, and I'm wondering if you could please give me your thoughts about these items, as well as anything else that I should take into consideration before plugging it in, and during use.  

I will be using the single ended inputs.  The amp has not been turned on for 3 years.  I was told that the owner was fastidious about the maintenance of the electronics and the tubes.  Any thoughts would be greatly appreciated. 

Thanks
irish_tim
jea48
2,944 posts
 
@irish_tim

First tube amp! Wow, did you pick doozy for your first tube power amp.

It should arrive with the tubes removed. You will need to install the tubes. You can’t just install the small 6922 tubes where ever want. Hopefully the guy you bought the amp from marked, identified, each of the 6922 for the tube socket they are biased for. Match the number on the tube to the appropriate tube socket number. Tube socket numbers are on the circuit board near the sockets.
DO NOT JUST STICK THE 6922 TUBES BLINDLY IN THE AMP. You will seriously damage the tubes, and or the circuit boards, and or resistors in the amp.

Hopefully the guy marked, identified, the 6550 power tubes as well. They also require biasing and are matched pairs or matched quads. Not sure on the VT200, can’t remember. Even if they are identified for the correct tube socket, they should be checked for proper bias. Power tubes are somewhat easy. That is for someone that has done it before. Lethal voltages inside.

If the guy did not mark, identify, the 6922 tubes when he pulled them you are screwed! You will have to either send the amp to ARC, or find someone locally that works on ARC VT series power amps.

How to bias an ARC VT200.
http://www.audioresearch.com/ContentsFiles/VT200_BiasAdjust.pdf

ARC VT200 schematic wiring diagram, download.
https://elektrotanya.com/audio-research_vt200_amplifier.pdf/download.html

http://www.arcdb.ws/VT200/VT200.html

Jim
irish_tim OP
50 posts
 
Thank you everyone for the great information.  I feel much better now.  
techno_dude
382 posts
 
I have huge respect for audiophiles that are going with tube amps. I think this is  THE WAY to go if someone wants real and full tube sound. I don t think going tube preamp and ss amp is the right way, as I beleive messing with tube in the preamp signal stage is not the purist way. ( same issue with messing with tubes in the dac).
noromance's avatar
noromance
1,780 posts
 
@atmasphere I am surprised you dismissed using a variac especially with an expensive amp full of electrolytics not used for 3 years. Also surprised about not loading the outputs. If anything was to go wrong, it is good practice to protect the amp. Maybe you can get away with winging it in the lab but isn't it better to give an unwary first time monster tube amp the safest instruction?

j_stereo
119 posts
 
I am surprised about the hesitation to power it up after being stored for only 3 years. That doesn't seem very long at all. We took my father's D-79 that wasn't powered-up for about 15 years and plugged it directly into the wall (didn't have a big enough variac available) and no problem. Maybe just got lucky but ARC tends to use high quality components especially back in those days. It seems 3 years is nothing.
More to discover