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Pre-amp causing loud hiss from speakers

I have a BAT VK3i with Quicksilver Horn mono-blocks and Klipsch LaScala's. This setup is dead quiet, however when I recently hooked up Rogue Audio M-180 mono-blocks there was a loud hiss coming from the speakers well past the listening spot. This noise was constant even with the volume down to zero and occurred with either balanced or rca connectors.

When I took the BAT out of the equation there was now only a faint hiss coming from speakers but one had to put your ear to it to hear it. After disconnecting all components from the BAT and putting it back in - the noise returns. I tried a Conrad Johnson Classic and there was no noise.

So does anyone have any ideas as to why the BAK and Rogue Audios amps do not play nice together?

Thanks
Ag insider logo xs@2xdeadlift
Ag insider logo xs@2x
deadlift OP
18 posts
 
Just some updates - the balanced cables I was using were Transparent Audio Balanced Musiclink plus. As for the tubes in the BAT they were purchased from Upscale Audio - 4 Electro-harmonix 6922 and 2 Pope 6V6GT.

I will spend some more time this weekend checking cables etc.
zd542
5,339 posts
 
I checked on your IC's. They're fully balanced cables, so there's no need to go further with any checking. Unfortunately, it looks like your fix will be one of the more expensive solutions that some of the others have suggested. But I would still keep experimenting and definitely get in touch with your Rogue dealer. The longer you wait, the more permanent the sale will most likely become.
Ag insider logo xs@2x
deadlift OP
18 posts
 
Wanted to add an update to this: I found a Brent Jesse on these forums and contacted him, he felt it could very well be the 6922's in the BAT causing the issue. I purchased four tubes from him, checked just to make sure the issue had not resolved itself and then swapped in his tubes. Now only dead silence with either balanced or RCA connectors - life is good.

I did add some of those attenuators as well which are working very well. So thanks to all for your help and support.
abucktwoeighty's avatar
abucktwoeighty
1,079 posts
 
Deadlift, the same thing happened o me. Bought a used pre-amp that came with 2 sets of tubes. Turns out both sets were noisy and I thought it was the pre-amp. After purchasing a new set of tubes, I was very happy to find that the issue was the tubes, although I paid a premium price because of the value of the supposedly good tubes. My loss.
Just about two hours ago I put another new set in and they are dead quiet too. Happiness in tubeland. :)
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