How to reduce hiss with phono at high volumes?

[Dev_Steve]

Hi All

I’m looking into a STU, but I have two more questions that I’d love your guidance on:

1. When digging into the “white noise” issue, I actually disconnected the rcas to my turntable from the Expert Pro. Even without any turntable connected, the Expert Pro still had a lot of white noise. Is that typical?

2. Would power conditioning also help this issue?

Thanks, all! Your input has already been hugely valuable.

[disarmamant]

Hi All

I’m looking into a STU, but I have two more questions that I’d love your guidance on:

1. When digging into the “white noise” issue, I actually disconnected the rcas to my turntable from the Expert Pro. Even without any turntable connected, the Expert Pro still had a lot of white noise. Is that typical?

2. Would power conditioning also help this issue?

Thanks, all! Your input has already been hugely valuable.

1. Yes, with inputs open there may even be a slight increase in the noise. If you have some RCA shorting plugs you could plug into the inputs you would see the minimum noise level of the phono amplifier.

2. The noise is mostly from the solid state devices themselves in the high gain amplifier. Some of the noise is probably attributable to the internal power supply to the phono stage, but if the power supply is well designed this would be very little. An external AC power conditioner is very unlikely to make any appreciable difference.

An MC step up transformer is going to be the best solution. With your cartridge I’d be looking at something like a 1:20 step up ratio.

I have found that the phono stage in the Devialet is quite susceptible to overload, there isn’t a great deal of headroom.

I found you need to be quite careful with the maximum signal settings in the configurator. I am using a 1:8 ratio step up Lundahl transformer, LL1933, with my Koetsu Black. I found that setting the MM stage at just above the maximum expected voltage from the SUT the phono stage was overloaded (the dB indicator in the display flashes orange) by some LP’s cut at quite a high level.

I set the maximum signal level to 50% more than the expected maximum from the SUT. Which means I need to increase the volume level quite a bit more when playing LP’s compared to a digital source.

So if you go down the SUT route then expect to do some experimentation with the input level. Of course this is quite easy on the Devialet as you can adjust the setting on the fly with an LP playing using the remote while viewing the phono settings menu in the display.



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[NickB]

Can I ask if this is a problem at normal listening volumes or when you turn up the volume to test it, my 1000 can be heard hissing but only at settings that would pin me to the wall if I was actually listening to music. I have bought and tried a Ray Samuels Nighthawk phone stage and it sounds really good but I prefer the simplicity of just using the 1000.

[Dev_Steve]

Hi All

I’m looking into a STU, but I have two more questions that I’d love your guidance on:

1. When digging into the “white noise” issue, I actually disconnected the rcas to my turntable from the Expert Pro. Even without any turntable connected, the Expert Pro still had a lot of white noise. Is that typical?

2. Would power conditioning also help this issue?

Thanks, all! Your input has already been hugely valuable.

1. Yes, with inputs open there may even be a slight increase in the noise. If you have some RCA shorting plugs you could plug into the inputs you would see the minimum noise level of the phono amplifier.

2. The noise is mostly from the solid state devices themselves in the high gain amplifier. Some of the noise is probably attributable to the internal power supply to the phono stage, but if the power supply is well designed this would be very little. An external AC power conditioner is very unlikely to make any appreciable difference.

An MC step up transformer is going to be the best solution. With your cartridge I’d be looking at something like a 1:20 step up ratio.

I have found that the phono stage in the Devialet is quite susceptible to overload, there isn’t a great deal of headroom.

I found you need to be quite careful with the maximum signal settings in the configurator. I am using a 1:8 ratio step up Lundahl transformer, LL1933, with my Koetsu Black. I found that setting the MM stage at just above the maximum expected voltage from the SUT the phono stage was overloaded (the dB indicator in the display flashes orange) by some LP’s cut at quite a high level.

I set the maximum signal level to 50% more than the expected maximum from the SUT. Which means I need to increase the volume level quite a bit more when playing LP’s compared to a digital source.

So if you go down the SUT route then expect to do some experimentation with the input level. Of course this is quite easy on the Devialet as you can adjust the setting on the fly with an LP playing using the remote while viewing the phono settings menu in the display.



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This is great. I was thinking of going with the Ortofon ST-80 SE as I'm not really technically sophisticated enough to dig into the different details on more artisan options. My thinking is that given that Ortofon is putting out that particular transformer for its high-end cartridges, it should do the trick.


Admittedly this may be dumb question, but from my reading it sounds like you change the Expert Pro configurator settings to MM once you are working with the transformer. Is that correct?

[disarmamant]

[quote='disarmamant' pid='78735' dateline='1538900523']
[quote='Dev_Steve' pid='78734' dateline='1538895105']
Admittedly this may be dumb question, but from my reading it sounds like you change the Expert Pro configurator settings to MM once you are working with the transformer. Is that correct?

Hi

Yes, that’s correct. The idea of the step up transformer is to provide a voltage step up at approximately the winding ratio of the transformer.

The voltage step up enables the phono stage in the Devialet to be used on the MM setting with the loading set to ‘High’ with a lower gain, approximately 40dB as opposed to to 60dB or more for the MC, hence lower noise.

I just looked at the Ortofon ST-80 SE. It should certainly do the job OK. The gain is given as 27dB which equates to step up ratio of just over 1:20. Your cartridge would see a reflected load of around 117 ohms with the transformer feeding the 47K ohm load of the MM phono stage which would be about right as well.



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[f1eng]

I use an Ortofon T3000 transformer with my A90, and previously used it with a Jubilee and before that a MC3000 II. My system is to all intents and purposes silent into the MM input like that.
IMO whatever was done when the D-Premier was updated was a downgrade of the phono input. My D-Premier (and then dual monos when I bought a second) were silent on the MC input. I had them "upgraded" to 800 spec and noticed noise on phono so got out my trusty T3000 and changed to MM in the configurator which was then quiet.
I haven't tried the MC setting with my Original d'Atelier since I just connected straight away with the T3000 but don't listen to LPs much anyway, mainly CDs.

[Dev_Steve]

So I've been doing some additional digging over the weekend and wanted to get everyone's thoughts. Still trying to determine if the white noise on my system is in line with what is expected or if the unit is defective. I can hear the hiss on volumes as low as -27. Do you all hear the white noise at levels that low as well?

Thanks all!

[Dev_Steve]

Can I ask if this is a problem at normal listening volumes or when you turn up the volume to test it, my 1000 can be heard hissing but only at settings that would pin me to the wall if I was actually listening to music. I have bought and tried a Ray Samuels Nighthawk phone stage and it sounds really good but I prefer the simplicity of just using the 1000.

Hi NickB

Per the reply all I just posted, I can hear the hiss on volumes as low as -27. I'm now wondering if the unit is defective.

[Greg]

Can I ask if this is a problem at normal listening volumes or when you turn up the volume to test it, my 1000 can be heard hissing but only at settings that would pin me to the wall if I was actually listening to music. I have bought and tried a Ray Samuels Nighthawk phone stage and it sounds really good but I prefer the simplicity of just using the 1000.

Hi NickB

Per the reply all I just posted, I can hear the hiss on volumes as low as -27. I'm now wondering if the unit is defective.

Yes, it’s the same for me at this volume setting on my D250 Pro C/I although I can only just hear it at the listening position when the house is deathly silent. Hiss is obvious when stood next to the speaker. I can just about live with it because it doesn’t seem to spoil listening, but it does irritate. I’m going to experiment with a pair of SUT’s although these bring their own problems to the mix. 

I know NickB’s system well and certainly it has less hiss than mine. I think our speakers have similar sensitivity and you listen further from the speakers at Nick’s so any hiss has less impact.

I do think this problem is a weakness in the design of the various Pro’s. A well engineered MC Phono stage can be completely silent. There are plenty of them out there.

[Dev_Steve]

It’s a huge disappointment. My previous $400 Rega phono stage was silent and this pales in comparison. It wouldn’t be acceptable at $400, let alone almost $20,000. Not sure how I feel about the system because of this.