Before taking a recommendation to replace caps try dropping the ground if you have not done so. You can also try your new amp in another system to see if it hums there too. Sometimes it doesn't take much and a sysytem hum can be hard to find.
So far, I have had the best results plugging the SA 220 in with ground and the preamp with the ground lifted.
Do any other components in your system have a ground? If so, try floating the ground on all components exept the preamp.
Does the amp hm without any other component pluged into it? You may have to try the amp in anoter system to see if that if it still has a hum. In my experience the hum is either a grounding issue or a cap that is going bad. Remembr that the caps are 20+ years old. If you live in the New Jersey area I know a good tech.
BTW the mods take the amp to a different level and you can do them yourself.
I rolled the 6dj8 tubes... that helped. I grounded the CD player, lifted the preamp ground and grounded the SA 220... very little hum now.
As for the upgrades... I'll eventually do them, but for now I'm happy with the SA 220. Besides, my CJ PV-11 preamp is getting $1200 upgrade... can't afford both at this time.
Who is upgrading your PV-11?
Get a budget line conditioner, I had hum from a computer i was running into my stereo, plugged computer into the LC and problem solved
In House Service Company, East Setauket, NY
Sorry, no line conditioners here...
I have a dedicated circuit for my amp on the front wall between the speakers and another dedicated circuit for the components on the side wall.
Like maybe try 1 for process of elimination ???
So, this isn't really an upgrade, its a mod.
They are replacing all the caps, transformer, tube sockets, power cord, etc., etc.
It appears this is nothing more than another of many out there performing mods and convincing you they know more than the engineers at Conrad Johnson, Audio Research, Wadia, etc.
If you are not satisfied with your PV-11, why don't you sell it, add $1200 to the sales price and buy a better preamp. Once you modify it that money is gone. You will never be able to sell your preamp and get that $1200 back.
GNSC modified my friends Audio Research SP-15 ($5,995 retail in 1988), one of the best preamps out there. And they ruined it with their so called mod.
Go to Conrad Johnson's website, this is the Factory repair center for CJ.
They are not 'modifying' the circuits or circuit path... they are replacing old caps with new caps and old tube sockets with new tube sockets, etc.
I like my PV-11 and I don't plan on selling it any time soon.
Got my PV-11 back... they did a fantastic job! It sounds good, but I'm sure will continue improving as all the new caps break in.
I still have the hum problem with the SA-220. I thought about having this upgraded by AltaVista. I don't know if the upgrade would fix the hum. When music is playing I can't hear it, so it really doesn't matter... I guess.
I have Vandersteen 3A Sig speakers, a VPI table... this system sounds great.