Schiit Vidar 2 Stereo Amplifier Review

[Bob101]

Hint-it's all anecdotal evidence.

Then it's up to time to tell, I guess... I'm using my class D's (Hypex (Elac) and Purifi (Audiophonics)) power amps every day, sunrise to sunset, 5 and 3 years respectively. Not a single glitch. And they draw less than 5W idle. My AB's (Yamaha A-S1100 and my recapped 1981 Harman Kardon PM650) draw 75W idle and about 50W idle respectively.

 

[mns3dhm]

Power amplifiers are the least reliable components in audio systems due to high voltages, power and heat involved. I have repaired hundreds of class AB amplifiers so they absolutely fail. There should be no automatic assumption that they are better in reliability. They are however much easier to repair.

Thank you. This is the closest anyone has come to actually addressing the question I asked concerning class D amplifiers warranties. Appreciate it.

 

[HalSF]

Based on past replies from them, there's no Schiit interest in Class D. I personally feel they are missing business in the $400-600 amp price segment, perhaps they will again offer something in that range. A lot of the recent Schiit products don't float my boat - the mini-amps are not price competitive with the Chinese class D amps, and the speaker amps are OK but a little over-priced or under-featured. And they took away the one product I was interested in buying, a solid state preamp. The turntable flopped/ended and their CD transport is full-featured but at a very high cost. I love my Modi and Magni 3 products, but a lot of their product line shoots low or high from where my needs are.

I’m puzzled by the sentence I’ve bolded, since one of the newer Schiit components is the Kara preamp, which admittedly also doubles as a headphone amp.

Schiit Audio: Audio Products Designed and Built in Texas and California

www.schiit.com

Schiit KARA Preamp and Headphone Amp Review

This is a review, listening tests and detailed measurements of the Schiit KARA balanced preamplifier and headphone amp with stepped relay control. It was sent to me by the company and costs US $699. Oh wait... that is the picture of our dog, Kara! :D Here is the Schiit version: As I have...

www.audiosciencereview.com

 

[Joe Smith]

I’m puzzled by the sentence I’ve bolded, since one of the newer Schiit components is the Kara preamp, which admittedly also doubles as a headphone amp.

Schiit Audio: Audio Products Designed and Built in Texas and California

www.schiit.com

Schiit KARA Preamp and Headphone Amp Review

This is a review, listening tests and detailed measurements of the Schiit KARA balanced preamplifier and headphone amp with stepped relay control. It was sent to me by the company and costs US $699. Oh wait... that is the picture of our dog, Kara! :D Here is the Schiit version: As I have...

www.audiosciencereview.com

I don't use balanced connections at all, so that functionality in the Kara is not worthwhile for me - and hence the price is out of line with my needs.

What I would really like them to make is an all in one RCA preamp, just like the old Saga S, but with an optional card/slot for a phono pre.

The only thing that's out there that's at all close to my needs is the Emotiva preamp (PT1) - I don't really love the form factor though, was hoping for something more compact.

Fosi or SMSL or Aiyima may eventually offer something like this without tubes...fingers crossed.

I just don't have any need for balanced connection devices and the higher price tag associated with them...

 

[375HP2482]

As @restorer-john pointed out it is the switching power supplies that most likely are not going to last.

Which is why laptop and monitor makers abandoned built-in switchmode supplies in favor of external supplies.

 

[Brian Hall]

I don't use balanced connections at all, so that functionality in the Kara is not worthwhile for me - and hence the price is out of line with my needs.

What I would really like them to make is an all in one RCA preamp, just like the old Saga S, but with an optional card/slot for a phono pre.

The only thing that's out there that's at all close to my needs is the Emotiva preamp (PT1) - I don't really love the form factor though, was hoping for something more compact.

Fosi or SMSL or Aiyima may eventually offer something like this without tubes...fingers crossed.

I just don't have any need for balanced connection devices and the higher price tag associated with them...

I have one of their Saga S preamps. It works great. It was really dumb of them to abandon it in favor of another stupid tube preamp at a higher price for no benefit.

 

[Joe Smith]

I have one of their Saga S preamps. It works great. It was really dumb of them to abandon it in favor of another stupid tube preamp at a higher price for no benefit.

Yeah, Brian, I was surprised when they (Schiit) pulled it. It checks all of my boxes apart from not having phono integrated. I may still get a used one if a similar device does not re-enter their lineup, or get done in some form by Fosi, SMSL or Aiyima.

Alas, I just don't like the Emotiva's dimensions, plus internally everything is on one very crowded board apart from the power supply - the case is mostly empty air, but I guess they wanted the case size to match their Bas X amps.

 

[Brian Hall]

Yeah, Brian, I was surprised when they (Schiit) pulled it. It checks all of my boxes apart from not having phono integrated. I may still get a used one if a similar device does not re-enter their lineup, or get done in some form by Fosi, SMSL or Aiyima.

Alas, I just don't like the Emotiva's dimensions, plus internally everything is on one very crowded board apart from the power supply - the case is mostly empty air, but I guess they wanted the case size to match their Bas X amps.

I will never understand anyone wanting to add tubes to modern devices*. There is a good reason we moved away from them.

*Except in guitar amps. Tubes always add distortion and it can be beneficial to getting certain guitar sounds. Adding more distortion after that is (I won't say it, but it should be obvious what I think).

 

[Milanraf]

Looking at the mostly flat Power vs Distortion profile, it is not clear where the Class A to B transition kicks in. What should we expect at that point? A change in harmonics distribution?
Assuming that the circuitry is class A operating in the low power region, that's also where the higher distortion is. What's the benefit in AB vs bare B in this case? B would perform sensibly worse at low power due to branch switching?

 

[Brian Hall]

Looking at the mostly flat Power vs Distortion profile, it is not clear where the Class A to B transition kicks in. What should we expect at that point? A change in harmonics distribution?
Assuming that the circuitry is class A operating in the low power region, that's also where the higher distortion is. What's the benefit in AB vs bare B in this case? B would perform sensibly worse at low power due to branch switching?

My DAP (Hiby R6 Gen 3) supposedly has two amplifier modes A or AB. I don't hear any difference at all when switching between them. The only noticeable difference is that the battery goes down much faster and the DAP gets a lot hotter in A mode. No difference in audio quality so I see no reason to use the A mode. It may be different with big amps.

 

[375HP2482]

Question for you though: what are your thoughts or comments on the Vidar blowing a fuse? Irrelevant, related to the test methodology or indicative of a problem or shortcoming?

I'll take a stab at it.

When a bipolar AB amplifier goes into clipping, the output transistor is saturated and can "stick" (persist) in this state for a short time after its base drive is reduced due to the excess charge carriers in the base. If this occurs at a high enough frequency, the saturated device may not turn off completely before its opposite transistor begins to conduct, resulting in common-mode conduction and increase in current, with possible damage to the transistors.

The solution (previously encountered with TTL logic) involves preventing the driven output transistor from going into full saturation by limiting the amount of base current drive available, often with some form of Baker (antisat) clamping with a pair of diodes diverting the excess drive current near saturation.

Interestingly, the TPA 3255 chip also has to deal with problems associated with clipping -- in its case, a loss of high-side gate power due to its bootstrap capacitor not being able to recharge ("flat tire"). The chip does this by sensing the clipping condition and inserting a few OFF drive cycles to retain recharging capability.

 

[JeremyFife]

I'll take a stab at it.

When a bipolar AB amplifier goes into clipping, the output transistor is saturated and can "stick" (persist) in this state for a short time after its base drive is reduced due to the excess charge carriers in the base. If this occurs at a high enough frequency, the saturated device may not turn off completely before its opposite transistor begins to conduct, resulting in common-mode conduction and increase in current, with possible damage to the transistors.

The solution (previously encountered with TTL logic) involves preventing the driven output transistor from going into full saturation by limiting the amount of base current drive available, often with some form of Baker (antisat) clamping with a pair of diodes diverting the excess drive current near saturation.

Interestingly, the TPA 3255 chip also has to deal with problems associated with clipping -- in its case, a loss of high-side gate power due to its bootstrap capacitor not being able to recharge ("flat tire"). The chip does this by sensing the clipping condition and inserting a few OFF drive cycles to retain recharging capability.

Thanks for the detail - which is completely over my head

 

[Sokel]

Looking at the mostly flat Power vs Distortion profile, it is not clear where the Class A to B transition kicks in. What should we expect at that point? A change in harmonics distribution?
Assuming that the circuitry is class A operating in the low power region, that's also where the higher distortion is. What's the benefit in AB vs bare B in this case? B would perform sensibly worse at low power due to branch switching?

I would forget about classes when it comes to distortion.
The Class AB (closer a Class A amp according to the designer) Halcro Eclipse has probably the lowest distortion across spectrum that we know off:

• THD <-120 db up to 20 kHz (100 kHz B.W.) at 450 W into 4 ohms.
• THD @ 1 kHz <-134 dB.
• (link, link)

I know that is an edge case made by non audio people but still.

 

[Bob101]

My DAP (Hiby R6 Gen 3) supposedly has two amplifier modes A or AB. I don't hear any difference at all when switching between them. The only noticeable difference is that the battery goes down much faster and the DAP gets a lot hotter in A mode. No difference in audio quality so I see no reason to use the A mode. It may be different with big amps.

The fact that you don't hear any real difference, is mainly due to the fact that the distortion in AB mode is not noticeable to your ears with your system. The heat generated (and power consumption) is typical for Class A. Class A amps are still considered the best when it comes to distortion, because they don't have the crossover-distortion associated with class AB. Well-implemented negative feedback all but eliminates this.

 

[Brian Hall]

The fact that you don't hear any real difference, is mainly due to the fact that the distortion in AB mode is not noticeable to your ears with your system. The heat generated (and power consumption) is typical for Class A. Class A amps are still considered the best when it comes to distortion, because they don't have the crossover-distortion associated with class AB. Well-implemented negative feedback all but eliminates this.

No distortion at all with AB mode. Great sound. Just wondering why they bothered having a Class A option and why anyone would use it. It has low, medium and high gain settings too and medium works great for IEMs and high has no problem driving my HD800 S or HD650.

 

[restorer-john]

Power amplifiers are the least reliable components in audio systems due to high voltages, power and heat involved. I have repaired hundreds of class AB amplifiers so they absolutely fail. There should be no automatic assumption that they are better in reliability. They are however much easier to repair.

Maybe way back in the day Amir, when you were paying your way through college in the 1980s, but since the 1990s on, power amplifiers, integrateds and AVRs have been so reliable, you'd be out of work doing anything other than replacing a fuse or two or resetting the firmware when something locked up.

1970s, 80s, 90s and 00s amplifers are reliable, easy to repair, parts are mostly available and they outlast just about anything you can dream up in 2024. At least you know that.

Take a Purifi or Hypex module. Can you fix it? Nope. You cannot. Straight to the scrap heap.

 

[AaronJ]

I have one of their Saga S preamps. It works great. It was really dumb of them to abandon it in favor of another stupid tube preamp at a higher price for no benefit.

According to Jason, the Saga is coming back with a headphone jack. Really hope if they insist on having a tube in it that it can run without one like the Lyr+, but without all the ridiculous heat that thing generates.

 

[DSJR]

Maybe way back in the day Amir, when you were paying your way through college in the 1980s, but since the 1990s on, power amplifiers, integrateds and AVRs have been so reliable, you'd be out of work doing anything other than replacing a fuse or two or resetting the firmware when something locked up.

1970s, 80s, 90s and 00s amplifers are reliable, easy to repair, parts are mostly available and they outlast just about anything you can dream up in 2024. At least you know that.

Take a Purifi or Hypex module. Can you fix it? Nope. You cannot. Straight to the scrap heap.

To answer those who yearn for something more expensive than the tiny chip amps, durable, yet cheaper price used than this Schiit model which itself is well priced I think, what experience have you got on the say, Yamaha pro power amps which I think look great and apparently perform well too (don't they have meters as well - lol? I only ask because here, the mid priced audio market is now dominated by good used gear rather than new and of course the fact the far eastern made amps do seem to last well, the top models especially I feel. My future audio buys will almost certainly be used I suspect...

 

[Joe Smith]

According to Jason, the Saga is coming back with a headphone jack. Really hope if they insist on having a tube in it that it can run without one like the Lyr+, but without all the ridiculous heat that thing generates.

Yeah, I am really not wanting to introduce tubes into my life. I would rather have one of my old basic preamps reworked with new components than get a new Schiit one with tubes.

But I have no opposition to them adding a headphone jack!

 

[MajorMajorMajorMajor]

This is a great amplifier, but the lack of balanced inputs for bridged mode made one of my friends return it.