advertisement


Speaker hiss caused by pre amp

A

alcarmichael

pfm Member
I bought a pre amp from these forums a while back, yesterday I finally got round to trying it out. I love it but for the hiss, it’s audible at minimum volume and it increases in volume through my speakers as volume control is increased, when I select mute on the pre the hiss is no more. When music is being played at a reasonable output it’s not apparent.

Initial research led me to potential noisy valves but it appears the previous owner had a new set installed just before I bought it.

BAT VK-3ix
LDA 300B mono blocks

New valves are JJ Electronic E88CC
 
Last edited:
Some pre amps have a low level permanent hiss. Naim for instance. Older Exposure ( 17 19 21)more so. Could be a problem if you leave system on all the time plus sensitive speakers that are close to you but not playing music. Not a problem really. Some think otherwise though. My ancient pioneer A400 exhibits no hiss. But a hissing Exposure 17 / 18 super pretty much trounces the integrated. As they should.
Currently my nac52 DV hx1.2 combo is hissing a wee bit if I go next to the speakers. No problem once the music is playing - and that's going to be right now.
 
It's normal for pre amps to hiss. The amount will vary hugely with the design and can be below audibility with many or pretty obvious with no music playing for others.
 
It is clearly audible from 10’ away and that includes during quiet passages of music. I can’t see that being classed as acceptable?
 
One possibility is that the gain of the power amp is rather high and you are amplifying the hiss from the stage after the volume control.

Cheers,

DV
 
Initial post edited to correct the hiss being constant irrespective of volume input. Hiss does indeed increase as volume control is increased.
 
Many pre amps over the years. I prefer the hissers.
And a good few will say bin the active pre amp. Just adds colouration ( and hiss).
So far I prefer active pre amps and need anyhow. 2 inputs. CD and av pre amp left right into 52. Double pre amps ! Yikes !
 
Not impossible I suppose but doubtful. I listened to my system with the Croft in place on Friday and swapped that out for the BAT on Saturday.
 
Update: I disconnected everything other than the power amps with the same hiss being produced. I then swapped out the four E88CC valves, again, same result.
 
The larger two valves in the centre haven’t been swapped out.

87a4d92b7e115a307116ff470210dd5f.jpg
 
You must log in or register to reply here.


advertisement


Back
Top