Hiss in Reduction

[Mmaxed]

My Reduction is causing a hiss.  Sounds like a steady ocean noise.  For the most part it has been playing perfectly for over a year but had the hiss every now and then.  But I would change an amp or something else in the set up and it would go away.  Now it is there if the Reduction is on.  Doesn't matter if a TT is hooked up.  Gets louder as volume is turned up.  Not real noticeable at volume levels I listen at.  Doesn't seem to bother with music playing, but I know it's there and it bugs me.  Moved it to a different system and still there.  Tried all kinds of grounding changes, still there.  Maybe slightly less with stock tubes than with EH6922s.  Any thing I should look at?     

[Paul Birkeland]

I'd start by telling us about the rest of your system. Which cartridge are you using? Preamp, amp(s), speakers?  Is the integration installed?

[Mmaxed]

Grado silver cart, but as I said the noise is there even without the turntable hooked up. 

Right now the ore is a Onkyo p304.  From there it goes to a MiniDSP and to 3 amps.  Tweeter is Hawthorne Audio AMT 700 driven by TPA 3110.  Mids HA SSI 15s driven by ClassDaudio SDS 254.  Woofers are HA Augies driven with a Onkyo ??.

Noise comes though all drivers, but is mostly in the mids, I think because that is where the frequency is at.

No integration yet.   

 Hooked Reduction up to a Adcom pre that I use for head phones and the noise was there.

I have had the hiss off and on for quite a while, but like I said I "think" I have narrowed it down to the Reduction at this point.

[Paul Birkeland]

Hiss would generally be related to the tubes themselves, and would be super present with a lower output moving magnet phono cartridge, but 5mV ought to be enough.  The Integration will increase the gain of the circuit, which does raise the signal to noise ratio, regardless of the tubes themselves. 

If you have intermittent hiss, it could be related to garbage getting in through the power line.  See if you can correlate the hiss to the operation of an appliance or dimmer in proximity to your outlets. 

-PB 

[Mmaxed]

Thanks, I'll keep digging into it.