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My 1st Tube Equipment Experience

I just purchased a used Herron Audio VTSP-3A(r02) tube preamp, as a replacement for a NAD M12.  I paired the M12 with a NAD M22 v2.  My first impressions are the M12 has more detail, the VTSP is much warmer, which is what I wanted.  The VTSP sound is definitely different.  And while it lacks the M12 detail, I do like it.  

With the M12, my speakers were dead silent when music was not playing.  With the VTSP, I hear a slight hiss when I put my ear very near a speaker.  With the M12, I used XLR from the M12 to the M22; XLR from my Parasound JC3 jr; and RCA from my Liberty DAC.  With the VTSP, everything now is RCA.

Is a little hiss common when using a tube preamp and SS power amp with RCA cables?
128x128oldschool1948
lancelock
1,093 posts
 
You might have some noisy tubes. Is it the same on both channels?
oldschool1948's avatar
oldschool1948 OP
501 posts
 
They are supposed to be.  I'll check and let you know.
jackd
1,068 posts
 
Did you try both gain levels on the preamp with all three gain levels on the amp to try and find the best match?  Other than that with a speaker of average or higher sensitivity it is not uncommon to hear some small level of tube hiss if your put your ear right up to the tweeter. 
oldschool1948's avatar
oldschool1948 OP
501 posts
 
@jackd. I haven’t tried that but I will.  Thanks for the suggestions.
jackd
1,068 posts
 
Dropping the gain level on the Herron to the low gain position should pretty much eliminate any noise even right at the tweeter. Then you can leave the amp on the default(shipped) position. Should also give you more "travel" on the volume control. 
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