Conrad Jognson input blled

 I meant' bleed, sorry.  I have a relatively new Conrad Johnson Classic preamp with no phono stage. I have a Musical Surroundings Phonomena II plugged into the aux/ ph input of the preamp and a CD player plugged into the CD input all other inputs are empty. I noticed that when I drop the needle I can hear the music (at a much diminished volume but very noticeable) from every empty input except for the CD selection. When I get to the Aux / PH input the music sounds fine. Is there something wrong with this particular unit that I have or is it possible that the phono stage is too close to the preamp perhaps?



Ag insider logo xs@2xdeadlift
It’s possible that nothing is wrong, and that the bleedthrough is inherent in the design. But in any event the fact that there is no bleedthrough from the aux input to the CD input suggests that the issue could be resolved by putting shorting plugs on the unused inputs.

Googling "RCA shorting plugs" will probably lead you to some suitable low cost choices (as well as some unnecessarily expensive ones). Or you could make your own, by obtaining some ordinary RCA plugs and soldering or otherwise connecting the plug's internal connection points for the ground shell and the center conductor together.

-- Al

I’ve owned several preamps that had bleed through, (just part of the design) as Al stated. Shorting plugs did indeed solve the problem.

NOTE:  NEVER use these on OUTPUTS!!!  Inputs only.


another vote for RCA shorting plugs or equivalent.

Big C-J fan here. The company builds outstanding gear that never dates itself. Customer pretty good as well. It is rumored that they have 1 million dollars in back stock tubes, parts, boards...etc. for every piece ever made!

I have a Classic 2SE and noticed that too,  I just turn unused devices off.... It's not the first preamp I have had that does that so it doesn't bother me, this thing sounds better than any preamp I've ever had.