[axle11]

I run my Vidar's in mono block, and while they make some noise when powering down I would not describe it as a full thump. I also get some hum from one which is likely the transformer, and when I decide I can live without it for a time I'll send it back to Schiit for a new transformer.

I run my Vidars monoblock as well with a Freya preamp. I turn the volume all the way down before powering off the Vidars.

 

[Jalbert300]

I run my Vidars monoblock as well with a Freya preamp. I turn the volume all the way down before powering off the Vidars.

I've tried turning volume on Saga all the way down prior to turning off Vidar but still has the thump, just as loud.

 

[sam6550a]

I've tried turning volume on Saga all the way down prior to turning off Vidar but still has the thump, just as loud.

I have an original Saga and Freya, neither one creates thumps or clicks in the speakers when switching inputs, operating modes, or when muting. These preamps are used to feed Aegir and other solid state and tube amplifiers. The DC offset out of Saga is less than 1 MV in either passive or active mode.

 

[yonson]

Question, when you say "offset" what is that referring to? And is it the same "DC offset" that @33na3rd refers to?

Oh, and are you specifically saying your Vidar(s) do the thump when turning off, or do you also get the "pops" when switching source/mode/mute on Saga+ ?

I never turn mine off, so I'm not sure about the thump, I get the pops when switching inputs or mute/unmute using Saga+.

 

[Licht]

Hmm. A contrasting opinion. I did not know about the upsampling, and yes, most of my music is 16/44 Redbook. I do have a few 16/48, but not enough to worry about.



I did not know that about Audirvana, but since only about 1% of my music is HiRes being able to stream it is not worth the $96 to me, I would just use AirPlay.

That makes me wonder - you mentioned the Apple TV converts audio to 48kHz. Is that a hardware thing, or is that an AirPlay thing? In other words, does iTunes do the conversion before sending it to AirPlay so it doesn't matter what hardware I use, or does the Apple TV do the conversion when it receives the signal?

Thanks.

Apple TV converts everything to 48kHz.
Upsampling into double frequency like 48k to 96k is no problem, but 44.1k to 48k makes mess.
Think how do you put 44100 pegs in row into 48000 holes in row.
However, if you don't care much about soundstage in speakers, it might not be problem.
And yes, Apple TV is very convenient.

 

[Licht]

Also, I notice you are just using the Raspberry Pi 3 by itself. Why did you choose not to use a HAT?
.

Just I didn't know HAT.
RaspPi was cheap and fun.
Network audio is still not popular here in Japan.
CD/SACD is main source in HiFI audio in Japan. Not me though.

 

[tincanear]

I'll keep that mind, however my hum in speakers is present with nothing connected, no interconnects, just amp and speaker wire.

if the speaker wires are run along the baseboard, there may be ac wiring inside that walls that its picking up hum from.

also, with a preamp connected and powered up, is the hum reduced?

 

[tincanear]

@Licht what amp is that driving the Ether 2's? Schiit's pic for Mjolnir 2 / Lyr look a little different...

 

[Jalbert300]

if the speaker wires are run along the baseboard, there may be ac wiring inside that walls that its picking up hum from.

also, with a preamp connected and powered up, is the hum reduced?

Speaker wires not running along wall, and i've tested pulled away from everything, so dont think any issues with speaker wire picking up hum.

With preamp connected and powered up the hum is slightly louder I think, but not much different really.

 

[Jalbert300]

Great thanks! I'm off to the hardware store to get myself a multimeter and see if I can measure the DC offset on Amp. Then maybe purchase the CMX-2 ( https://emotiva.com/collections/accessories/products/cmx-2 ) depending on my results.

So reading that article it mentions any hum coming from speaker would be related to grounding issue. So in theory even if I have DC offset issue, and the CMX-2 effectively eliminates the Amp hum, I may still be left with speaker hum from some sort of "grounding issue"? When they say "grounding issue", are they specifically referring to ground loop, or are there other sorts of grounding issues that also cause speaker hum. Reason I ask is because I get the hum from speaker even if ONLY amp and speakers are connected, nothing else remotely close to being connected or plugged-in, and even with every other breaker turned off in house.

I picked up a multimeter and tested the DC Offset on Vidar output. I'm getting around +12mV on the Right output, and -0.5mV on Left output. This seems to correlate with my perception that hum is coming from right side of chassis, and right side speaker hum is louder.

Is +12mV considered problematic? Seems like they would both be about the same if the problem was due to power in my house, otherwise maybe its an issue with the amp/transformer(s) in the right channel.

Right side multimeter reading
Left side multimeter reading

 

[macdonjh]

Great thanks! I'm off to the hardware store to get myself a multimeter and see if I can measure the DC offset on Amp. Then maybe purchase the CMX-2 ( https://emotiva.com/collections/accessories/products/cmx-2 ) depending on my results.

So reading that article it mentions any hum coming from speaker would be related to grounding issue. So in theory even if I have DC offset issue, and the CMX-2 effectively eliminates the Amp hum, I may still be left with speaker hum from some sort of "grounding issue"? When they say "grounding issue", are they specifically referring to ground loop, or are there other sorts of grounding issues that also cause speaker hum. Reason I ask is because I get the hum from speaker even if ONLY amp and speakers are connected, nothing else remotely close to being connected or plugged-in, and even with every other breaker turned off in house.

Yes, you can get hum from several sources. A ground loop is one possible cause. That's why star grounding is often helpful: it makes all the various ground circuits the same potential, so no more ground loops. As has been said previously: your system could also be picking up noise from some other source, my biggest problem child is the refrigerator on the other side of the wall. Cable routing, as mentioned, can help.

I'll keep that mind, however my hum in speakers is present with nothing connected, no interconnects, just amp and speaker wire.

If your system is picking up noise from outside, your speaker wire would be acting like an antenna carrying the noise signal to your amp, which then amplifies is and sends it to your speakers.

 

[Pietro Cozzi Tinin]

I picked up a multimeter and tested the DC Offset on Vidar output. I'm getting around +12mV on the Right output, and -0.5mV on Left output. This seems to correlate with my perception that hum is coming from right side of chassis, and right side speaker hum is louder.

Is +12mV considered problematic? Seems like they would both be about the same if the problem was due to power in my house, otherwise maybe its an issue with the amp/transformer(s) in the right channel.

Right side multimeter reading
Left side multimeter reading

Try an offset killer. Don't kill yourself about this.

 

[Licht]

@Licht what amp is that driving the Ether 2's? Schiit's pic for Mjolnir 2 / Lyr look a little different...

Standard Mjolnir2, paired with Gungnir Multibit.
Now Amperex Bugle Boy. Some times Miniwatt. Both recommended tubes by Dan Clark.

 

[Jason Stoddard]

Hey all, I posted about this a while ago. Yes, there may be some slight pops due to the preamp interacting with DC offset--but big pops are usually going to be due to upstream DC. Small clicks and pops won't hurt anything. Bigger stuff should be investigated.

With respect to hum, let's differentiate: it can be mechanical hum (from the transformer vibrating) or electrical hum (coming through the speakers.) If you're talking mechanical hum (from the chassis), yes, some small mechanical hum is normal. It should not be audible from the listening position. With respect to electrical hum, it can be a ground loop, or, noise from upstream components, or, noise from other components that create a magnetic field (stacking a preamp directly on top of a power amp, for example, may cause hum due to field from the large power amp transformer. Also, depending on the sensitivity of the speakers, there may be some slight hum if you put your ear to the speaker no matter what you do. There should be no audible hum at the listening position, however.

The offset measurements you've made are within spec and have nothing to do with hum. They will change from channel to channel depending on the input transistors, temperature, and aging (which, like all electronic devices, are variable).

All that said, if you're having trouble, please contact info@schiit.com, or, if it's a recent order, orders@schiit.com so they can help you. Please let's not make this a tech support area, unfortunately I don't have enough time to monitor and respond to it.

 

[Jalbert300]

Hey all, I posted about this a while ago. Yes, there may be some slight pops due to the preamp interacting with DC offset--but big pops are usually going to be due to upstream DC. Small clicks and pops won't hurt anything. Bigger stuff should be investigated.

With respect to hum, let's differentiate: it can be mechanical hum (from the transformer vibrating) or electrical hum (coming through the speakers.) If you're talking mechanical hum (from the chassis), yes, some small mechanical hum is normal. It should not be audible from the listening position. With respect to electrical hum, it can be a ground loop, or, noise from upstream components, or, noise from other components that create a magnetic field (stacking a preamp directly on top of a power amp, for example, may cause hum due to field from the large power amp transformer. Also, depending on the sensitivity of the speakers, there may be some slight hum if you put your ear to the speaker no matter what you do. There should be no audible hum at the listening position, however.

The offset measurements you've made are within spec and have nothing to do with hum. They will change from channel to channel depending on the input transistors, temperature, and aging (which, like all electronic devices, are variable).

All that said, if you're having trouble, please contact info@schiit.com, or, if it's a recent order, orders@schiit.com so they can help you. Please let's not make this a tech support area, unfortunately I don't have enough time to monitor and respond to it.

Thanks Jason,

I'll reach out to orders@schiit.com, I was chatting back and forth with info@schiit.com on my "issue" but hadn't heard back in a few days hence why I started exploring other avenues.