Schiit Vidar Amplifier Review

[ferongr]

I see two trimpots on the board, presumably for bias current adjustment. Seeing how there's a fancy microcontroller on the board, couldn't biasing be controlled by that? Or even actively controlling bias current depending on operating conditions for lower distortion?

 

[Chrispy]

Have you seen the latest Denon AV review? It measures a whole lot better

https://www.audiosciencereview.com/...ds/denon-avr-x3600h-av-receiver-review.12676/

so even more sonically transparent!

 

[typericey]

Am I the only one who is getting his OC triggered with the variance of SINAD between the 2 channels in an amp?
Is this a result of bad design or bad QC?
Can it be fixed?

FWIW, my Rotel amp has a louder hiss/hum on the left channel, ears against speakers, but totally inaudible in the listening position. And I do acknowledge that even speaker measurements have a variance. I remember my dad's Celestion SL12Si's came with a printed frequency response tied to each speaker's serial no. Gone are the days. I digress...

 

[amirm]

Am I the only one who is getting his OC triggered with the variance of SINAD between the 2 channels in an amp?
Is this a result of bad design or bad QC?

It is very common for the two channels to not match in that respect in amplifiers. This one is a bit on the high side at near 5 dB difference but still for the category, I don't lose sleep over it.

 

[Wombat]

A little more to that:

http://www.ominous-valve.com/vtsc.html

http://www.ominous-valve.com/tour.html

Our member @PaulD could make that really sing.

 

[Dana reed]

Hopefully the computer controlled protection works .... I am old school and if I was going to the trouble and expense of running mono blocks into 4 ohms I would get an dedicaded mono block rather than a bridged stereo amp. In any case sounds like you are having fun... Enjoy

Definitely having fun. Though honestly with the lockdown, I never get the house to myself, so I can’t really turn it up loud anyway
So it’s been more headphones lately. Back and forth on my HE6E, LCD2F, and Grados

 

[luisma]

The only way an XLS1502 has a high noise floor is with very efficient speakers or near field. No way is it muddy. It even has bass management built in.

My take is the Vidar is OK, but for about the same money I would go with a pair of Emotiva PA1's. No heat and a little more power.

Hi Ron, would you mind elaborating on the noise floor relation to high efficient speakers? I have read about this but I don't understand the relation myself. Genuinely interested on learning why and if this affects all high efficient speakers in general

 

[somebodyelse]

Hi Ron, would you mind elaborating on the noise floor relation to high efficient speakers? I have read about this but I don't understand the relation myself. Genuinely interested on learning why and if this affects all high efficient speakers in general

The amplifier has an output noise voltage that doesn't vary significantly if you change the speaker. For a given voltage the more efficient speaker generates a higher sound pressure level than the less efficient speaker, so a given amplifier will sound noisier with a higher efficiency speaker. Whether this is a problem will depend on how noisy your room is, how close to the speakers you are, how irritated you are by noise etc. which is why we get some people complaining about 'noisy' active monitors and others saying the same model are fine.

 

[luisma]

The amplifier has an output noise voltage that doesn't vary significantly if you change the speaker. For a given voltage the more efficient speaker generates a higher sound pressure level than the less efficient speaker, so a given amplifier will sound noisier with a higher efficiency speaker. Whether this is a problem will depend on how noisy your room is, how close to the speakers you are, how irritated you are by noise etc. which is why we get some people complaining about 'noisy' active monitors and others saying the same model are fine.

Thanks, I think you are on target with the explanation, exactly my case as I suspected, the amp and preamp if these are high gain the effect is augmented (I tried different preamps and it made a difference)
Have to add especially with tubes

 

[luisma]

Thanks, I think you are on target with the explanation, exactly my case as I suspected, the amp and preamp if these are high gain the effect is augmented (I tried different preamps and it made a difference)
Have to add especially with tubes

I have to add I hear buzzing noise coming from the speaker about 10 ft away that's a lot for me, only when music is not playing

 

[Thomas savage]

This issue many hifi brands have is maintaining a product range that provides scaled financial entry points , when bring out new products you don't want to undermine what's already on offer.

One would not want to design a $600 amp that out performs the $1200 one we launched 6 months ago.

I'm sure many many companies have to intentionally make things worse in order to fit the pre existing products hierarchy.

So schiit made this amp to fit into their product range. A good and attractive performer .

 

[Dacapalooza]

Hi, Thanks for the review. I bought one for center channel use temporarily. One of my 3 * 10 YO Krell mono S-150m broke. So mismatched amps.

I will get another next year and use for surrounds is my plan. I will probably get 3 * AHB2's for fronts next year as well. This year I already updated my sub & DAC. Maybe a Purifi amp.
My source will be Okto DAC8 I ordered in Feb but still hasn't arrived. Currently Trinnov Demon is my DAC.

I am assuming 2 things: Trinnov will compensate the mismatch amps & keeping on my ref level of -25 DB I don't have to worry about 400 watts being too much power for my revel F208 (I use 3 including center) that recommends max 200 watts.

Are the assumptions correct?

 

[RammisFrammis]

I see two trimpots on the board, presumably for bias current adjustment. Seeing how there's a fancy microcontroller on the board, couldn't biasing be controlled by that? Or even actively controlling bias current depending on operating conditions for lower distortion?

I believe a previous version of the Ragnarok amplifier did use the microprocessor to control bias, and apparently it was a dismal failure:
https://www.stereophile.com/content/schiit-audio-ragnarok-integrated-amplifier-measurements

The newer version of this amp evidently reverts to the usual way of controlling bias using trimpots like on the Vidar. From what I see, controlling bias using a microprocessor is fraught with problems. Personally, I don't see how it could be successfully done.

 

[ferongr]

There's nothing hard about it. It's easy to do even for someone with basic electronic DIY skills, I don't see how a micro cannot perform the operation. It's no magic. It seems that the implementation was bad in that particular case.

 

[RammisFrammis]

There's nothing hard about it. It's easy to do even for someone with basic electronic DIY skills, I don't see how a micro cannot perform the operation. It's no magic. It seems that the implementation was bad in that particular case.

Fine, then come up with a design. I'm sure the high end audio company I work for would love your talents.

 

[audioeclectic]

HI every one, I have the early Vidar power amp, and I detect a noise on both channels but more in the left channel, is a 65 Hz senoid signal, in my listening position is imposible to dectect or hear, but if you put your ear close to the loudspeaker drivers, you can hear it, and I discovered that noise increment if I pass my big toe close to the XLR, so I suspect there is a voltaje between the negative in RCA and the ground of the XLR, and I verify there isn't any noise from the transformer or mechanical resonance from the transformer. Have any of you had that noise detected?

 

[RammisFrammis]

HI every one, I have the early Vidar power amp, and I detect a noise on both channels but more in the left channel, is a 65 Hz senoid signal, in my listening position is imposible to dectect or hear, but if you put your ear close to the loudspeaker drivers, you can hear it, and I discovered that noise increment if I pass my big toe close to the XLR, so I suspect there is a voltaje between the negative in RCA and the ground of the XLR, and I verify there isn't any noise from the transformer or mechanical resonance from the transformer. Have any of you had that noise detected?

Is the noise still there if you short the inputs of the amplifier using a shorting plug (XLR or RCA)? Some of the audibility of noise will have to do with the sensitivity of the speakers. My particular speakers are about 105dB/W efficient, so the amps have to be dead quiet to hear any amplifier noise. With speakers with more normal sensitivities, the most you should hear is a soft hiss with your ear right at the tweeter.

 

[audioeclectic]

Is the noise still there if you short the inputs of the amplifier using a shorting plug (XLR or RCA)? Some of the audibility of noise will have to do with the sensitivity of the speakers. My particular speakers are about 105dB/W efficient, so the amps have to be dead quiet to hear any amplifier noise. With speakers with more normal sensitivities, the most you should hear is a soft hiss with your ear right at the tweeter.

Yes, a friend of mine have two new Vidars working in mono, and are totally silence, my Vidar keep the noise even is connected with RCA, and it do with different speakers, my suspect is some defective dispositive, I notice it has a relay right next to the XLR connection

 

[RammisFrammis]

Yes, a friend of mine have two new Vidars working in mono, and are totally silence, my Vidar keep the noise even is connected with RCA, and it do with different speakers, my suspect is some defective dispositive, I notice it has a relay right next to the XLR connection

Your amp is noisy even when you short out the inputs of the amplifier, i.e. the amplifier is only connected to speakers and nothing else, and both inputs are shorted - the "hot" side of both inputs to ground? Are *both* sides of the amplifier equally noisy when both inputs are shorted? If both sides are equally noisy, the amp is likely fine and that amount of noise is just inherent in the design - but I doubt the amp is noisy since your friend's amp is quiet. This sounds to me like you are picking up noise somewhere upstream of your amplifier, but if you test with shorted inputs, this possibility would be ruled out.

 

[audioeclectic]

Your amp is noisy even when you short out the inputs of the amplifier, i.e. the amplifier is only connected to speakers and nothing else, and both inputs are shorted - the "hot" side of both inputs to ground? Are *both* sides of the amplifier equally noisy when both inputs are shorted? If both sides are equally noisy, the amp is likely fine and that amount of noise is just inherent in the design - but I doubt the amp is noisy since your friend's amp is quiet. This sounds to me like you are picking up noise somewhere upstream of your amplifier, but if you test with shorted inputs, this possibility would be ruled out.

I have been test in different places my house and a friends house, the noise is in both channels, but much more the left channel, the noise does it with and without connecting the RCAs, obviously the sound is perceived in the speakers, but seated in the listening position I do not perceive it, only by approaching or sticking my ear to the speaker drivers tweeter and mid bass, the electrical energy has a direct physical ground, but this happens with and without ground, And if I put my finger closer to the XLR connector the noise increases, but if I do the same thing by bringing my finger closer to one of the two RCAs, it does not happen that the noise increases.