Speaker hiss

I'm also in a heavy RFI environment. IME some components are more and less sensitive to picking up RFI. Same thing with cables. Some of the fancy cables I see in catalogs and online stores are actually garbage in terms of shielding. If the cable is well shielded, the manufacturer should detail exactly what the shielding is. If they don't, or won't answer questions about it, or if it's a "naked" cable with no real shielding, all bets are off.

And yes, the ferrite beads will help but you have to experiment where to put them. You can even put several of them on your RCA cables but ideally you want to put them at a specific distance to reject certain frequencies. This was explained to me by an engineer, but I forgot what the relative distance between the beads should be on the RCA cable. Perhaps someone wants to chime in on this.

RE: hiss, most phono preamps will have some degree of it and then there is also the noise floor of your amp(s). If you think you have RFI, a surefire way to know you have it is to hear faint bits of signal going through the hiss, e.g. voices, music off the radio, etc when you crank up the volume and listen closely. If you're not hearing that, it may not be RFI that is the main problem, but just the natural amount of hiss through a high gain phono pre as others said.

My 2 cents.

 

Mechanical hum from the power amp is probably transformer humming from DC on the AC line. Not likely to have anything to do with hiss from the preamp.

 

I have the jumpers in the 58db slots

You can see all of my equipment in my profile

 

Why did you lower the gain of your phono preamp in the first place?
You're amplifying a piddly signal, noise is inevitable.

 

Guessing this is as you may have stated, OCD working well!

 

I have the same and it helps with level of hiss.

 

I was experimenting.

 

As far as the power amp having a mechanical hum from DC being on the AC line, had anyone tried the Emotiva CMX-2?
Or any other DC offset unit?
Will this do any damage to the transformer over time if left untreated?

 

Very nice rig. I tried the 20/20 and was blown away. Then this deal for the Duo came along and had to take it.

 

I have a DC blocker.
It gives the toroidal transformers in the various bits a kit an easier ride.

Having a DC offset on your mains won't damage your amp's transformer.

 

Could this be a star grounding issue?

 

What is the signal to noise ratio of the Sutherland?

I wouldn't mind trying an iFi Micro Phono 2, the specs look amazing and the reviews are very positive. Supposed to be about the quietest phono section there is.

 

Frankly I doubt some of the claims about that thing. There is another manufacturer that claims a S/N over 100dB for a phono preamp. I would love to know what they are doing to achieve those numbers. Perhaps some kind of revolutionary filtering or something, or perhaps bunk or perhaps taking away some of the music.

Still another manufacturer claims high S/N, around 90dB IIRC. Independent bench tests on an AP analyzer confirmed this also.

Honest, conservative specs go a long way. The maker of my phono stage lists unweighted S/N done on a similar analyzer, so no funny business.

I said this before and perhaps you know this, but the signal coming off a record is maybe 70dB if we are lucky and all cartridges are limited on S/N ratio by how much inherent electrical noise. You can even calculate that for your own cartridge(s).

SYclotron Audio | RIAA Noise Calculator

 

RE: hiss in general here is a tip which might be obvious to some folks but perhaps not all.

When you plug in your AC cord for the phono pre, try turning up your amp with no record playing. Listen carefully. Then unplug it, flip the polarity of the two-pronged adapter, and see if it's less hissy and quieter. If you are outside the U.S. this may not apply to you as you might have different style plug.

 

Any difference in performance. I read that it can take some power from the amp

 

My dealer also offered me a deal on a duo when I was looking at the 20/20 but I could not fit physically the two boxes of the Duo into my component set-up.

 

Improved clarity.
How can it take power from the amp?

 

I'm not going to pretend I understood it but apparently to remove the DC from the line is like adding 500 get of wire or something to that effect.
I went ahead and ordered the Emotiva CMX-2. It has a 30 day return policy.

 

With DC offset blocking it's definitely best to hear its effects in your own environment.

 

I sort of had the same thought, that is why I wouldn't mind giving one a try.

 

Before I found the phono stage I'm using now I looked into this unit. More than a couple reports of faulty wall wart power supplies causing units to die and poor customer service after it happened. Frankly it was enough to put me off the IFI brand entirely.

 

Well, back to the OP question.

I'd suggest playing an album or two at the higher end of your typical listening levels, noting the position of your volume/gain knob.

Now, with the stylus resting on a non-spinning album (so nothing is playing) return your volume/gain knob back to that spot and at your listening position, you shouldn't be able to hear much of anything. A very faint hiss, fine. Much more than that, and I'd continue to look for anything contributing to the noise.

I can do that with a $130 Bellari PA550, you should be able to at least match that sort of performance easily.

I wouldn't tolerate hiss/noise with the expectation that the music will conceal it, lowering your noise floor as much as possible pays dividends.

 

There's a low hiss that I can't hear from the listening position. I think every thing is good with the phono stage.

My concern is the hiss from the pre amp an all inputs. It should be silent.

 

"My concern is the hiss from the pre amp an all inputs. It should be silent." I agree and maybe I looked at the wrong gear but your preamp is all high level inputs and no built in phono stage. The preamp is the source. The added phono stages boost it. Was it ever quiet?