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New purchase BAT VK-60...new buzz

Greetings all,

I just purchased a previously owner BAT VK-60 and am in love already. However, I do have a serious buzz/humm coming from the amp and through the speakers...mainly the midrange. I changed out power cord to a Harmonic Tech and went from a power conditioner into the wall outlet. Less buzz, but still present. I am running high end cables to a single-ended Adcom preamp and my speakers are Genesis.

Thanks for the input.

RichCohan
richcohan
quiobo
2 posts
 
RichCohan,

I have a vk60 and is connected to a pair of 105db efficient horns and I'm not really experiencing any loud humm or buzz. I do have hssssssssss a small bit but not loud enough to throw me off. I have Cardas quadlink 5's which are balanced from VK30 -> VK60. You might want to re-check your preamp or interconnects if it's all good I'd shoot BAT an email. What interconnect are you using pre > amp? have you tried any other?
jfrech's avatar
jfrech
1,816 posts
 
a hiss is likely tube noise. different tubes will effect that. some better some worse. some great sounding tubes will have some hiss. part of owning a great tube amp. I had a vk60, now have a vk75se. I have this buzz as well. must be some sort of group loop. do a search on ground loops and go through that process.

Can you hear the buzz more than 1-2 feet away from the speakers? That's about all I can hear...
tacs
220 posts
 
Suggest you switch to or at least try a truly balanced preamp. Without this you are not getting the best out of the amp. You could even go with the Adcom 750 which has balanced connectors, but better would be a BAT 3i or 5i .
Just a thought.
Tom
tireguy
1,964 posts
 
Does either channel buzz louder? if not I would suggest trying a balanced pre, if one is louder then the other I would try some different tubes(which I would recommend any ways with that amp). Its a great amp that should be pretty damn quiet all the time(I enjoyed mine with NO problems at all).
ultrakaz
187 posts
 
After checking the obvious things as noted in the above posts (connections, ground loop problems, bad tubes, etc.), try biasing the tubes. This is tricky and should be done by somebody who really knows the BAT VK-60 (it is not completely autobiasing, there are taps underneath the amp that can be adjusted). While you are at it check the wiring to make sure everything is where it should be. I had one that went to many different homes and one of the wires had become semi-undone; it was amazing that it still worked.

Also, you should really get a true balanced preamp, not one that just has balanced connectors like Rotel and maybe Adcom. This is an excellent amp and deserves much better than the Adcom.
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