Click title to read one, or click date to read all below it.
07-12-09
I do not envy you, it is a pain. my last bout was resolved b ... Richard_stacy
07-12-09
Have you ruled out bad tube on the preamp (or simply a defec ... Millicurie999
07-12-09
Although it is a bit technical, the following paper provides ... Almarg
07-12-09: Rsasso
To Millicurie
amp and preamp are plugged into separate outlets
Rsasso (Threads | Answers | This Thread)
07-12-09: Rsasso
To Millicurie
I substituted a small Tono preamp for the big Ming Da...result was LESS hum (and higher frequency)...but still some hum. I am not sure what that tells us.
Rsasso (Threads | Answers | This Thread)
07-12-09
Iirc, plugging the amp and pre to separate lines is a very g ... Swampwalker
07-12-09
At the risk of being too obvious - have you tried a cheater ... Newbee
07-12-09: Rsasso
To Millicurie
OK: I substituted the interconnects between amp and preamp with heavier shielded cables and that had no effect. The hum is NOT there if the amp only is turned on.
The hum is there when the preamp is on, even with no components connected to it, as soon as you turn on the amp.
If you TAP the preamp when the amp/preamp is humming...there is a ringing sound out of the speakers. If you even gently tap the ceramic bases of those 6SN7 tubes, there is a louder ringing through the speakers...now THAT can't be right.
Does that speak to defective tubes, or, more likely, a defective preamp????
Rsasso (Threads | Answers | This Thread)
07-12-09: Rsasso
To Newbee
Someone stole my cheater plug. I will get one at the hardware store and give that a try. Thanks
Rsasso (Threads | Answers | This Thread)
07-12-09
that's typical of a microphonic tube (or tubes). hum can al ... Tvad
07-12-09
I would try another preamp, if you can get your hands on 1. ... Fplanner2000
07-12-09: Rsasso
To Fplanner2000
I have to share my ignorance. Don't you need XLR input/outputs to connect the preamp and amp with balanced IC's? These components have RCA connectors.
Rsasso (Threads | Answers | This Thread)
07-12-09: Rsasso
To Tvad,
I dont have any of these 6SN7's to rotate right now. The microphonic tube you mentioned as common; is that normal as well? The microphonic effect of tapping the tube doesnt mean the tube is damaged, correct?
Rsasso (Threads | Answers | This Thread)
07-12-09
that's a good question. many of the most sought after and e ... Tvad
07-12-09
As swampwalker mentioned, amp and preamp in two different ou ... Millicurie999
07-13-09: Rsasso
To Tvad,
Thanks again for your very knowledgable input on my setup. It is appreciated, and I will get some 6SN7's and try out your suggestions.
Rsasso (Threads | Answers | This Thread)
07-13-09: Rsasso
To Millicurie999
Since the amp is about 10ft away from the preamp,it would take an extension cord, but yes, I can get everyting (sources included) into the same surge protector.
Out of curiosity though, if that is the problem, would a cheater plug on the amp (plugged into its own outlet as it is now) diagnose the problem...would I expect the hum to disappear if the separate outlet situation is causing the hum?
Rsasso (Threads | Answers | This Thread)
07-13-09
yes, it might. with components that are connected via sing ... Almarg
07-13-09
One other potential cause of hum would be a cable tv that sh ... Goose
07-14-09
Another thing to check is whether the tubes are propertly se ... Cleaneduphippy
|
|
