Schiit Saga vs Freya

[zackthedog]

58 minutes ago, Abtr said:

OK, I found out that (in my system) what I previously thought to be normal tube noise/hum may be produced by the Saga itself! In active as well as in passive mode without a tube inserted, it slightly hums. This hum is most audible at maximum volume (without a source signal playing) and close to a speaker. (Funny that my apparently defective Sophia tube hums loudest at minimum, and least at maximum volume..)

 

Anyway, my system is nearly dead silent when I use (Dave Slagle) autoformers as a passive preamp (without the Saga). I must say that I don't mind the slight noise/hum from the Saga, but can anyone please confirm that the Saga actually does hum as described above, or should I contact Schiit? Thanks. 

 

Interesting.  Sounds like a shielding issue, and that B-grade Sophia was especially sensitive to it.  I have found that when a pot increases hum when turned *down* there's an RF issue involving the combination of the pot and the tube's grid.  Pots can introduce stray capacitances into the circuit.  Moving it closer to a speaker would create some magnetic field noise as well.  The autoformers may avoid that, which is why they are quieter.  But I could be wrong.  I'd be interested to know if you find a better answer.

[Speed Racer]

14 minutes ago, zackthedog said:

 

Interesting.  Sounds like a shielding issue, and that B-grade Sophia was especially sensitive to it.  I have found that when a pot increases hum when turned *down* there's an RF issue involving the combination of the pot and the tube's grid.  Pots can introduce stray capacitances into the circuit.  Moving it closer to a speaker would create some magnetic field noise as well.  The autoformers may avoid that, which is why they are quieter.  But I could be wrong.  I'd be interested to know if you find a better answer.

 

Saga and Freya have no potentiometers.

[zackthedog]

1 hour ago, Speed Racer said:

 

Saga and Freya have no potentiometers.

 

That's true, I see it's a micro-processor attentuator.

[zackthedog]

1 minute ago, zackthedog said:

 

That's true, I see it's a micro-processor attentuator.

 

...though I also see that the screen shot of the board on their web site clearly shows a either a potentiometer or stepped switch.

[Speed Racer]

3 minutes ago, zackthedog said:

 

...though I also see that the screen shot of the board on their web site clearly shows a either a potentiometer or stepped switch.

 

It's a relay-switched stepped attenuator with discrete thin-film resistors.

[Abtr]

19 hours ago, zackthedog said:

 

Interesting.  Sounds like a shielding issue, and that B-grade Sophia was especially sensitive to it.  I have found that when a pot increases hum when turned *down* there's an RF issue involving the combination of the pot and the tube's grid.  Pots can introduce stray capacitances into the circuit.  Moving it closer to a speaker would create some magnetic field noise as well.  The autoformers may avoid that, which is why they are quieter.  But I could be wrong.  I'd be interested to know if you find a better answer.

 

The potentiometer you see on the Saga board is used to control a microprocessor that in turn controls a relay switched resistor-based attenuator. The Schiit Sys passive preamp is a potentiometer-based volume control. I tried it with the Saga and the hum is the same as with the Saga's own volume control, so you may be right in that this hum seems to be related to resistive attenuators in general..

 

Btw, I ran the new Sophia for about 48 hours nonstop and the hum/noise level has dropped significantly, especially at the Saga's max volume setting. This is nice because that's how I bypass the Saga's volume control. The tube may or may not develop the same problem as my other Sophia: excessive hum at the Saga's lower volume settings. We'll see..   

[zackthedog]

1 hour ago, Abtr said:

 

The potentiometer you see on the Saga board is used to control a microprocessor that in turn controls a relay switched resistor-based attenuator. The Schiit Sys passive preamp is a potentiometer-based volume control. I tried it with the Saga and the hum is the same as with the Saga's own volume control, so you may be right in that this hum seems to be related to resistive attenuators in general..

 

Btw, I ran the new Sophia for about 48 hours nonstop and the hum/noise level has dropped significantly, especially at the Saga's max volume setting. This is nice because that's how I bypass the Saga's volume control. The tube may or may not develop the same problem as my other Sophia: excessive hum at the Saga's lower volume settings. We'll see..   

 

I'm really just throwing ideas out there. :-)  I assume you tried the manual's suggestion of lifting the ground?

[Abtr]

59 minutes ago, zackthedog said:

I'm really just throwing ideas out there. :-)

Well, I suppose we all do.

 

Quote

I assume you tried the manual's suggestion of lifting the ground?

Lift the ground of the Saga?

 

[Speed Racer]

The Saga manual says nothing about lifting the ground. It says this:

 

I hear hum, what do I do?

You may have a ground loop. To x a ground loop, try a ground loop isolator or an EbTech HumX. 

[Abtr]

3 hours ago, zackthedog said:

... I assume you tried the manual's suggestion of lifting the ground?

 

I can have only one component of my audio system grounded, otherwise I'll create a ground loop. Currently the Saga is grounded. I tried grounding the power amp and lifting the ground of the Saga and it made no difference. Lifting the ground of *all* components doesn't reduce hum either and introduces some strange static electrical phenomena in my system. E.g., tapping the metal casing of the DAC or preamp produces audible crackling sounds through the speakers..   

[Abtr]

So I contacted Schiit about the slight hum coming from my Saga. Their quick reply:

 

Quote

In passive mode I would expect the Saga to be completely silent, other than possible interference from another source it cannot create noise. The tube could definitely add some noise.

 

Being that it is such a low level I wouldn’t consider the noise completely unrealistic.

 

 

I explained that the noise/hum is actually audible in passive mode, even without a tube inserted, and the level varies with different volume settings, so the source of the hum must be located before the Saga's volume control circuit. I don't think it's the DAC because I don't hear it with autoformers, so I would say it is most likely some small residual AC current from the DC power supply of the Saga.

 

My question remains, is this hum/noise normal for the Saga? If it is normal then I will live with it. It's inaudible at regular listening distance and it may well be within the SNR > 108dB spec which I suppose is audible at a distance of 10 to 15'' from speakers that are connected through a 500W power amp (class D which is extremely quiet). But I'm not sure..  No reply from Schiit yet..

[Abtr]

Reply from Schiit:

 

Quote

It could be noise generated in the Saga, it may well be below the noise floor at the amps volume setting per our rating.

 

The autotransformer is going to be the quietest volume control due to the nature of using a transformer.

 

 

The last paragraph is not correct. Autoformers are *not* transformers, and the autoformers are quieter than the Saga because they are truly passive attenuators, unconnected to AC mains power. I think that the Saga simply can't be completely silent in 'passive' mode because it must power the microprocessor and switches of the volume control.

 

Anyway, I'm happy that Schiit appears to confirm here that the Saga actually generates audible noise in passive mode. It relieves me of the nagging uncertainty that something may be wrong with my Saga.  

[Abtr]

Earlier I mentioned a strange electrical phenomenon in my system. Tapping the metal chassis of the Saga produced crackling sounds through the speakers. At first I thought this was related to lifting AC ground/earth, but even with proper grounding after prolonged use, touching the metal chassis produced these crackling sounds.

 

It now appears that the cause was a reversed polarity of the mains power connection to the Saga (reversed live/phase & neutral prongs) . This mistake is easily made with a European (CEE 7/4) mains plug. I reversed the plug and the problem seems to be solved. Just thought I should mention this here.

[crenca]

On 7/11/2017 at 0:25 PM, Abtr said:

Earlier I mentioned a strange electrical phenomenon in my system. Tapping the metal chassis of the Saga produced crackling sounds through the speakers. At first I thought this was related to lifting AC ground/earth, but even with proper grounding after prolonged use, touching the metal chassis produced these crackling sounds.

 

It now appears that the cause was a reversed polarity of the mains power connection to the Saga (reversed live/phase & neutral prongs) . This mistake is easily made with a European (CEE 7/4) mains plug. I reversed the plug and the problem seems to be solved. Just thought I should mention this here.

 

Thanks for the update Abtr - your issues had me doubting my hearing and thinking about getting tested...something I should probably do anyways

[Abtr]

17 hours ago, crenca said:

Thanks for the update Abtr - your issues had me doubting my hearing and thinking about getting tested...something I should probably do anyways

 

Well, the Saga still produces a slight hum/noise in active as well as in passive mode. In my system, this is only audible with my ear less than a foot away from a speaker and I think Schiit confirmed that it would be within the Saga specs so it's really not 'an issue'. I guess the issue of the clearly audible hum from the Sophia tube must have been a defect in the tube, making it sensitive to whatever it is in the Saga that causes its slight hum. The new Sophia still doesn't hum after at least 400 hours of use.

 

The reversed mains power polarity issue, causing strange static electrical phenomena when touching the Saga, was solved by reversing polarity, and crackling sounds were only clearly audible with the Saga set at max volume. But it's remarkable that a modern piece of consumer electronics has such a polarity sensitivity. I wonder if  this has something to do with general valve circuits? It is some static electrical charging of the Saga chassis (which appears to be connected to mains ground/earth via a 10K Ohm resistance).. 

[Abtr]

I recently installed balanced AC power for my audio system (using  a balanced isolation transformer). By now I honestly think that *balanced power* might be the holy grail of modern (computer) audio. The audible/analogue noise floor must have dropped at least 20dB. I have been listening mostly to noise! Every audiophile should try balanced power! (http://www.equitech.com/articles/bpng.html)

 

Anyway, even with this superior powering and grounding scheme, the Saga produces a slight (normally inaudible) hum/noise in active mode as well as in passive mode, which is minimal or absent when the volume is turned to maximum. But whatever the cause and consequences, I must say that it's clearly evident that my current balanced powered system sounds better with the (active) Saga in it.

 

[arcman]

So I am thinking of the Freya to go with my new Nuforce amp. However, lots of posts here concerning noise, even when not using tubes. My speakers are quite sensative (zu omen defs) and noise will stick out. Is this something I should be concerned with?

[GeneZ]

On 1/27/2017 at 4:24 AM, firedog said:

 

In theory, the digital control should be superior. But it doesn't sound as good as either of the other two modes. Even the manufacturer/designer says that the digital volume control measures better than the analog, but doesn't sound as good; and that the volume bypass sounds even slightly better.

 Curious.... did you try reversing the polarity of your speaker cables when you did this comparison?  When in digital vs the others,  you may have a case of reversed polarity which can happen when circuit types are switched.  If you get a chance to compare again, you might want to try reversing the speaker polarity for the digital.  It may in fact sound better than the others that way.  Some things we just never think of make us wonder why we ever found it out. 

[Trdat]

Hey Guys, 

 

I'm new to this site and its seems like the most informative. Hope you guys can help.

 

I am interested in the Freya as well but Ill be putting it in between my preamp and poweramp section of my integrated amplifier. There is also a crossover as well in between the pre and power at the moment, im sure that can enter the loop as well. There is preouts and main ins on my integrated allowing me to do this.  

Could the Freya be used in this application and more importantly my amplifier is a NADC356 would the Freya be an upgrade or would the difference be minimul?

Regards

[GUTB]

I’m sad and frustrated.

 

I’m currently using a Mjolnir 2 as a pre-amp. It’s fully balanced, and costs more than the Schiit dedicated preamp — so, is it better? Meanwhile I’m missing out on the JFET....but is it balanced? I can’t tell — does anyone know if it is? If it’s just some kind of summed balanced output then forget it, my speaker chain has to be balanced throughout. I can pick up a BAT used for a much higher price, but damn I’ll be mad if it doesn’t make much of a difference. Can someone help me?

[gmgraves]

On 7/1/2017 at 10:09 AM, Abtr said:

 

The potentiometer you see on the Saga board is used to control a microprocessor that in turn controls a relay switched resistor-based attenuator. The Schiit Sys passive preamp is a potentiometer-based volume control. I tried it with the Saga and the hum is the same as with the Saga's own volume control, so you may be right in that this hum seems to be related to resistive attenuators in general..

 

Btw, I ran the new Sophia for about 48 hours nonstop and the hum/noise level has dropped significantly, especially at the Saga's max volume setting. This is nice because that's how I bypass the Saga's volume control. The tube may or may not develop the same problem as my other Sophia: excessive hum at the Saga's lower volume settings. We'll see..   

 

Here's the important question: you say that you hear it when the volume is advanced to maximum and you put your ear close to the speaker. Do you hear the hum (at all!) when playing music at your normal listening level, and from your normal listening position. If the answer to that Q is yes, then it warrants further investigation. If, on the other hand, you don't hear it at normal listening levels from your normal listening position, then it is purely academic and  I say, forget it and go back to listening to music.

[Speed Racer]

No, you are beyond help. 

 

The MJ2 is a mediocre preamp. Saga and a Freya are much better with Saga being better than a Freya. Unless, of course, you want or require fully balanced input or output. Then Freya is your only choice. 

[jcn3]

On 10/19/2017 at 1:51 PM, GUTB said:

I’m sad and frustrated.

 

I’m currently using a Mjolnir 2 as a pre-amp. It’s fully balanced, and costs more than the Schiit dedicated preamp — so, is it better? Meanwhile I’m missing out on the JFET....but is it balanced? I can’t tell — does anyone know if it is? If it’s just some kind of summed balanced output then forget it, my speaker chain has to be balanced throughout. I can pick up a BAT used for a much higher price, but damn I’ll be mad if it doesn’t make much of a difference. Can someone help me?

 

schiit web site says it is fully balanced (or at least "pure balanced" and "inherently balanced"):

 

Pure Balanced, Differential Topology

Mjolnir uses our exclusive, inherently balanced and differential Crossfet topology—the only circlotron-style topology in a headphone amplifier (well, except for Ragnarok.) It’s balanced in and balanced out, with a custom 4-gang RK27 Alps volume pot—providing end-game performance for a mid-level price.

[GUTB]

My Mjolnir 2 is definitely balanced, but is the Freya? The bad stereo separation seems to indicate that it's not.

[Speed Racer]

22 minutes ago, GUTB said:

My Mjolnir 2 is definitely balanced, but is the Freya? The bad stereo separation seems to indicate that it's not.

 

What "bad stereo separation"?

 

Freya is fully balanced and has the same crosstalk numbers as the Mjolnir 2.