Schiit Vidar 2 Monoblocks

[MajorMajorMajorMajor]

Hi,

My friend has connected a Freya+ to 2 Vidar amps, and each and is connected to a MartinLogan 60XTi Speaker.

The Pre Amp is set on the differential gain tube setting (maybe you guys could clarify those settings for me? Schiit didn’t respond.)

The amps are in the “Mono” configuration.

When he turns the volume up to about 70%, the amps shut off.

Now, I’m not particularly savvy about this stuff, but I think it’s because the speakers are rated as 4/5 ohms.

But they’re “8-ohm compatible”!

Is there a way to bi wire or something to make the amps run it in a 8 ohm “mode”?

Idk… I feel bad because I kind of recommended this setup to this guy based on how my setup does fine with a lot less power and actually harder-to-drive speakers.

 

[Blumlein 88]

He could switch the amps to stereo configuration. Then the ML's are bi-wirable. So one channel to the woofer and one to the tweeter. You'll need two sets of speaker cables and a splitter going into the amp input. I don't know there is any benefit to doing so. Probably no different than just removing one amp and using the remaining one is stereo without biwiring.

The speakers do get down to 3 ohms or so in an area with high output (100-200 hz) with some reactance. I'm guessing as you did this is causing the protection circuitry to activate.

SoundStageNetwork.com | SoundStage.com - NRC Measurements: MartinLogan Motion 60XTi Loudspeakers

www.soundstagenetwork.com

Now I don't know what level 70% on his system is. Is 70% a level your friend will use very often? In tube setting it has 12 db of voltage gain. Output is 4 times the input voltage. If he can get by with the 0 db gain setting which they call compound differential buffer, he can use the tube setting if he likes, just don't turn it up too much. What is his source component feeding the Freya + preamp?

 

[MaxwellsEq]

The sales blurb says the microprocessor controller protects "from DC offset to over-current and over-temperature faults". Over-current may happen if the impedance of the speaker is low or has serious phase issues. Are the amps getting very hot? Do they both go off at the same point? Has he checked for DC offset from a source (does he have more than one source)?

 

[MajorMajorMajorMajor]

First of all, thank you so much for answering. I feel really dumb because my friend knows I like high end audio and I kind of recommended this configuration to him, so this is really helpful.

He could switch the amps to stereo configuration.

Yes, this is an option, though it would not then be "fully balanced", which was a big reason we went with this configuration...

Now I don't know what level 70% on his system is.

I'm referring to turning the volume knob up about 70% of the way on the preamplifier.

What is his source component feeding the Freya + preamp?

Well, at first it was the SMSL DO200 MKII. Then it started having issues, so we are replacing with the WiiM feeding into the Schiit Modius DAC.

It is supposed to be a "fully balanced" system.

In tube setting it has 12 db of voltage gain. Output is 4 times the input voltage.

^Assuming the goal is to listen to the speaker at a level of 83 decibels or so, and given that the amplifiers fail at higher volumes, does it help to use one or the other? We want to maximize volume (without significantly compromising quality)

Additional Points/Questions:

• This is really bothering me because I ran these speakers on my AVR-X2300W at home and I literally had NO issues. And that receiver is only 100W/channel!
• Would there be a way to take advantage of the fact that the ML60XTi's have 4 binding posts? Like, here's my thought:
  • The so-called "mono" configuration uses both "plus" outputs to run in "mono" mode.
  • This configuration makes it so that the amp loses some kind of capability to push 4 ohm or something like that. (or limits it)
  • Can I somehow take advantage of a second pair of wires to the same speaker and make it think it's running 2 speakers instead?
• (I'm sure the above sounds really dumb - just had to ask.)
• So, the next question, if I abandon the "balanced audio" idea, would I go with the configuration below? And would that work well?

 

[MaxwellsEq]

Have you confirmed there is no DC? Are the amplifiers getting incredibly hot? Are the loudspeaker drivers doing anything odd?

 

[Blumlein 88]

I read a review of the original Vidar somewhere, and they had issues with the protection being triggered far too easily. I thought that was one of the upgrades for the Vidar 2.

Now your AVR is okay with 4 ohm speakers which these are even if more like 3 ohms in some areas. A single stereo Vidar will likely play them without any issues at all. Without getting too deep in the weeds, when you bridge an amp you give it much more power, but it has less current capability and that is why they suggest only 8 ohms bridged with the Vidar, but 4 ohms in stereo. Your issue isn't power, but current. And bridged you either don't have enough or barely do and it is triggering protection. Seriously your friend should try one stereo Vidar and see what he thinks. It is probably just fine. If he doesn't need the extra power, there is no benefit to even having it. If he does, then he'll need an amp with that power able to handle 4 ohm loads.

At the speaker level your idea about balanced probably makes zero audible difference. It doesn't hurt if other things are equal, but no benefit. The benefit prior to the amp of balanced is lower noise or immunity to noise issues. In this case however, Schitt has done a Schitty thing as you can only use balanced in if you use the amp bridged. It is actually a stupid cheap out design decision according to my opinion. So again a single Vidar is likely just fine. Twice the power is only 3 db more SPL and four times the power is only 6 db. Not nothing, but not dramatic.

As for using the 4 binding posts and tricking it into playing two speakers, I'm not sure. It was something I alluded to in the previous post. Schitt doesn't say, but I'm thinking that would work. However, the one channel would be out of phase with the other. Easily fixed with a cable swap on one pair of the binding posts. As in woofer input and upper range inputs being connected in opposite phase. Also if you do this you only get the same power as you have in stereo. That would let you use the balanced input and not have it shut down.

Also, check the DC as MaxwellsEQ suggested.

Finally, try one in stereo with RCA inputs from the Freya RCA outputs. If you don't have noise issues then no problem.

 

[MajorMajorMajorMajor]

Have you confirmed there is no DC? Are the amplifiers getting incredibly hot? Are the loudspeaker drivers doing anything odd?

Hmm... not sure what you mean. Sorry. What would I be checking about them?

And unfortunately, I'm not even there. I helped my friend setup this system remotely. He lives in another state, so I can't actually check anything.

I did send him a text asking about the temperature so I will report back on that. I believe he was definitely saying that the Freya+ Preamp was very hot, but I don't know if he said something about the amplifiers.

 

[MajorMajorMajorMajor]

Update:

This is what Schiit says:

 

[MaxwellsEq]

Update:

This is what Schiit says:

View attachment 345214

Wow! That's err ... interesting.

 

[MajorMajorMajorMajor]

In tube setting it has 12 db of voltage gain. Output is 4 times the input voltage. If he can get by with the 0 db gain setting which they call compound differential buffer, he can use the tube setting if he likes, just don't turn it up too much. What is his source component feeding the Freya + preamp?

Hi @Blumlein 88 , Can you please explain what you are getting at here? Would running in the 0 gain setting help with the amps shutting down?

 

[MaxwellsEq]

Hmm... not sure what you mean. Sorry. What would I be checking about them?

The information shared about this amplifier stated the protection (which is why the amp cuts out) is for temperature, over-current and DC. So any one of those three could cause a cut out. It's always a mistake to assume it's only over-current. Something further up the chain could be injecting DC, which he can check with a DC voltmeter.

But I think @Blumlein 88 called it right in post 6. You don't need to bridge these amplifiers and if you do they won't cope well with low impedance speakers.

As he suggested, try the amps in stereo single ended and if the noise is inaudible, you're fine. Alternatively go for a proper balanced power amp such as NCore or Purifi

 

[MajorMajorMajorMajor]

As for using the 4 binding posts and tricking it into playing two speakers, I'm not sure. It was something I alluded to in the previous post. Schitt doesn't say, but I'm thinking that would work. However, the one channel would be out of phase with the other. Easily fixed with a cable swap on one pair of the binding posts. As in woofer input and upper range inputs being connected in opposite phase. Also if you do this you only get the same power as you have in stereo. That would let you use the balanced input and not have it shut down.

If you were to diagram this out, would it go as follows?

A to Hi +, E to Low +
B to Hi -, F to Low +

(..etc.)
?

 

[MajorMajorMajorMajor]

The information shared about this amplifier stated the protection (which is why the amp cuts out) is for temperature, over-current and DC. So any one of those three could cause a cut out. It's always a mistake to assume it's only over-current. Something further up the chain could be injecting DC, which he can check with a DC voltmeter.

But I think @Blumlein 88 called it right in post 6. You don't need to bridge these amplifiers and if you do they won't cope well with low impedance speakers.

Ahhh, okay okay. I see your point. Based on Schiit's answer, it's over-current, right? But, logically, it could be any. Okay... that gives me direction on troubleshooting.

 

[MaxwellsEq]

Ahhh, okay okay. I see your point. Based on Schiit's answer, it's over-current, right? But, logically, it could be any. Okay... that gives me direction on troubleshooting.

Exactly! That seems the only way to read their response.

 

[formdissolve]

Looking at the manual, the Vidars are working as intended. Those speakers are 4ohm.. just because they say compatible with 6/8ohm doesn't mean they'll be running at 8ohm when you turn the volume up. For example, KEF LS50 are rated at nominal 8ohm but can drop as low as 3.6ohm at loud volumes!

 

[MaxwellsEq]

Looking at the manual, the Vidars are working as intended. Those speakers are 4ohm.. just because they say compatible with 6/8ohm doesn't mean they'll be running at 8ohm when you turn the volume up. For example, KEF LS50 are rated at nominal 8ohm but can drop as low as 3.6ohm at loud volumes!

View attachment 345239
View attachment 345240

I feel that the use of bridging is probably making this much worse. They'd probably be OK in stereo node.

 

[formdissolve]

I feel that the use of bridging is probably making this much worse. They'd probably be OK in stereo node.

It definitely is: Look at the specs I posted. It's meant to be 8ohm bridged.

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

www.schiit.com

 

[Blumlein 88]

If you were to diagram this out, would it go as follows?

A to Hi +, E to Low +
B to Hi -, F to Low +

(..etc.)
?

View attachment 345216

Yes this would work, but if you feed it via balanced each half is out of phase with the other. So in your diagram, at the speaker swap B and F on the left and at the speaker swap D and H on the right hand amp. This might help, but I'm thinking probably not enough to prevent shutdown. I think the answer is running one amp in stereo. Which will mean using RCA inputs to the amp.

 

[MajorMajorMajorMajor]

So, we've landed on doing unbalanced bi-amping, which can be done by simply connecting one amp to the bottom half of the speakers and one amp to the top half of the speakers.

HOWEVER, I am going to reach out to Schiit and see if I can return these things and replace them with some 4-ohm monoblock amplifiers that are rated to run 4 ohm speakers in Mono.

Any suggestions, please?

I think this amp is 4 ohms? Outlaw 2220

 

[MaxwellsEq]

So, we've landed on doing unbalanced bi-amping, which can be done by simply connecting one amp to the bottom half of the speakers and one amp to the top half of the speakers.

HOWEVER, I am going to reach out to Schiit and see if I can return these things and replace them with some 4-ohm monoblock amplifiers.

Any suggestions, please?

I think this amp is 4 ohms? Outlaw 2220

I don't think you need to do bi-amping. One amplifier in stereo will probably be enough.

There is not really such a thing as a "4-Ohm amplifier". You need an amplifier with a robust power supply that doesn't run out of current. All the modern Class D amplifiers can handle 4 Ohms as can a Class AB amplifier with a large transformer and big capacitor pool.