More Disruptive Schiit (Vidar)

[schiit]

Hey all,

 

I'm looking forward to seeing what's happening with Chris' amps when we get them back. Or we can just swap them and see if that solves the problem, but I'd rather see if there's a failure involved.

 

To answer some questions, Vidar has a full Zobel network on the output (both series LR and shunt CR), so it's designed for reactive loads. It's also tested for stability into reactive loads, including 2uF/ 2 ohms (to shutdown) and 2uF/ 8 ohms (to clipping, in both stereo and mono modes), so it's not excited by typical "problematic" speaker loads. 

 

Also, the microprocessor management on Vidar is significantly different (and simpler) than Ragnarok, which allows sine-wave testing without de-biasing the output. Bias is set conventionally. So it's unlikely a factor in whatever is happening here. We'll see, though, when the amps come back.

 

(And, Chris, I didn't want to impose on you to send those blindingly expensive speaker cables out to us, but if you want, just contact Amy and we'll get you a shipper so we can get them from you and back to you in short order.)

 

All the best,

 

Jason Stoddard

Co-Founder, Schiit Audio

[schiit]

23 minutes ago, joelha said:

Jason,

 

It's good of you to post to all of us here.

 

Since you have, would you be good enough to state the continuous output of the Vidars as mono blocks into 4 ohms?

 

Those of us with 4 ohm speakers (ok, maybe just me) would like to know.

 

Thanks.

 

Joel

 

We don't rate mono into 4 ohms, since it will hit the protection before clipping. Also, if you run high output into 4 ohms mono for long periods of time, you may run into thermal protection as well. The amp is effectively seeing a 2 ohm load in that case.

 

Now, you may never run into the current shutdown or the thermal shutdown (I don't, on Eminent Technology LFT-VIs, which are like 83dB efficient), but also, you might. We prefer to err on the side of under-promising.

 

Also, for most 4 ohm speakers, there's a simple solution: use just one Vidar. It's really fairly underrated in terms of power output, and its fine for most inefficient speakers (it works fine with our Magneplanar 1.7s, for example--and you can contact Magnepan for their own opinion--they heard Vidar on their .7s at the recent LA show and commented favorably.)

 

And, if you want more detail than any sane person would want on the nuts and bolts behind Vidar, I can refer you to the two chapters in the Schiit Happened book on it:

 

https://www.head-fi.org/threads/schiit-happened-the-story-of-the-worlds-most-improbable-start-up.701900/page-926#post_12997153

https://www.head-fi.org/threads/schiit-happened-the-story-of-the-worlds-most-improbable-start-up.701900/page-1360#post-13508638

 

Hopefully this is permissible. Chris, please feel free to remove these links if this isn't cool, and I'll refrain in the future.

 

 

 

 

 

 

[schiit]

2 hours ago, arcman said:

Jason, Thanks so much for responding. So I assume I will be ok ordering a Vidar amp and running with my ZU Omen Defs and canare star quad cables about 6 ft long each?  I know I can always return if problem arises

 

It shouldn't be a problem. Actually, no cable, cable length, or speaker combo should be a problem, which is why I'm interested in what's happening to Chris's amps. But we use Zu Omens in development, and I believe one of our techs uses Canare Star Quad (from Blue Jeans) on his Vidars.

 

Update on Chris's amps: they've been shipped back to us, together with one of the cables that caused problems. I may miss them, though, since I'm heading out to the eclipse soon and will be away for a few days afterwards. So, to keep things moving, we're shipping another pair of amps to Chris. If those work, I'll see what's wrong with the other pair when I'm back. If they don't, I'll dig into the whole thing when I'm back. But currently, we can't get Vidar to misbehave on any in-house speaker, cable, cable length, or reactive load.

[schiit]

4 hours ago, Zorlac said:

My Vidars have never gone into protection mode, but my KEF Q950 speakers had a horrible buzz.

 

Yggy w/Gen5 USB --> Freya --> x2 Vidar --> Blue Jeans 10ft Canare 4S11 w/banana --> KEF Q950

 

Problem persists when unplugging XLR from each Vidar so just speakers and power is on.

Tried a ground lift on the power to eliminate possible ground loop issue.

 

Schiit recommended I get Blue Jeans 5T00UP w/spades. I ended up getting 10ft again and 10AWG. This mostly fixed the buzz. If I put my ear directly to the speaker cone, I still hear it though.

I am hoping this issue is figured out because my OCD is driving me bonkers. I never had this issue with my Ragnarok.

 

If you're having trouble, contact Nick at [email protected], and we'll get you taken care of.

[schiit]

2 hours ago, The Computer Audiophile said:

Good news. The new pair of @schiit Vidar amplifiers arrived today. I connected them to my TAD CR1s with three different pairs of speaker cables and they work perfect.

 

I can't reproduce the issue I previously reported with the first pair I received. 

 

Now, on to the fun :~)

 

Good to hear, but weird. I'll report back on what I find with the other two amps when I'm back in the office on Thursday.

[schiit]

Hey all,

 

Okay, so I'm back in the office, and I spent some time with Chris’ problematic Vidars. And yep, there’s something up with them, something that’s triggered by the cable he sent us. Apparently the cable’s combination of capacitance and inductance sets the amps off, even though Vidar has (a) a full Zobel network, and (b) is tested into punishing reactive loads.

 

What’s weird is that we can’t reproduce the problem on any of the Vidars we have currently in stock.

 

Because of this, I dug into Chris’ amps some more:

• Tested the Zobels to make sure they were connected and not fried—they were fine
• Replaced the Zobels with current production parts—no change
• Changed the compensation capacitors to current production parts—and that fixed it

Now, this makes no sense. Changing a like-for-like part shouldn’t make any difference. Unfortunately, I didn’t keep the comp caps I took out of Chris’ amps to measure (and you can’t measure them in circuit, they’re tiny, low-value 0805 SMD parts.)

 

So what happened? I’m not completely sure. Perhaps some amps got the wrong comp caps in them, even though they are surface-mount and robotically placed, and you’d think that would be very unlikely. The parts are unmarked, and most small SMD caps look the same, so they can’t be identified visually.

 

Because of this, we’re adding a new stability test to the Vidar production process, using an RLC network that mimics the cable Chris sent us. This is in addition to the standard process which includes automated instrumented test, load testing, 1 day burn-in, and a listening test. We’ll also notify Vidar owners in the same batch as Chris’ amps that if they are experiencing operational oddities, we’ll swap them out at our cost.

 

But, in any case, if you have Vidars that are behaving oddly, contact us and we’ll get you taken care of. Sorry for the trouble!

 

(Oh, and Chris, we'll get the cables back to you today.)

 

All the best,

 

Jason Stoddard

Co-Founder

Schiit Audio

[schiit]

10 minutes ago, Speed Racer said:

@schiit

 

Is there any way to test for this at home? I am not having any issues now, but who knows what speaker cables I might use down the road.

 

If you're having trouble, contact us anytime and we'll get the amps taken care of. 

[schiit]

If you've gotten a ticket number from us, and we've responded, have you responded back to us? Because if you've already done troubleshooting, it's time for us to have a look at it. They'll direct you to the place to start the process at schiit.com/contact/service

[schiit]

Actually, I looked into the ticketing system. Here's what really happened. (I will not cut and paste actual responses, though I can if we really need to.)

 

Sunday at 9:35AM, we received an email about Vidar hum. Tom responded at 10:06AM, asking about swapping cables and system troubleshooting. There were a couple other responses that day, until the customer asked if we were serious about using a ground loop isolator to eliminate a possible ground loop problem.

 

Tom escalated this to Orders, since the date of the order wasn't given. 

 

Since Tom thought he was waiting for a response from the customer, something like, "Yes, I've gone through system troubleshooting and I still have the problem," he didn't escalate it to a return/replace, where we issue a call tag and send another amp out. Today, we got an angry email about poor customer service.

 

I have responded to the email and connected him with Amy, who will arrange a return/replace or 100% refund, whatever the customer wants.

[schiit]

Hey all,

 

If you're having trouble with your Vidar, please contact us via [email protected], or the distributor you purchased it from, and we'll make it right. 

 

Some thoughts: 

 

1. There shouldn't be any mechanical hum audible at the listening position, unless the transformer is bad or there's really something odd with the AC line. Check the AC line for DC on the line, proper phasing, and proper voltage. If that's all good, contact us or the distributor for a transformer swap. 

 

2. If you're getting significant hum from the speakers, it's most likely a ground loop. Unplug everything from Vidar, including all inputs, and turn it on. If the hum is gone, you're either looking at a ground loop, or you have a source with residual hum. Try an EbTech HumX or other ground loop breaker to eliminate the ground loop. Note: Some small amount of low-level hum may be present if you are using very efficient speakers, but again, it shouldn't be audible from the listening position.

 

Hope this helps a bit!

 

All the best,

Jason

[schiit]

2 hours ago, Corvo said:

Hi Jason. I appreciate your statement here. But I would guess I read about a dozen posts on forums reg. vidar/buzz/hum. Being in europe I'm hesitating to send the amp overseas without a guarantee (as far as possible) that the replacement will be fine. Judging from the very similar problems described across various forums I wonder if a bad product design can really be excluded from your side? Maybe just a faulty batch, I don't know. Don't get me wrong please,  I really want to keep it. And faulty transformers can happen. But it's kinda hard to believe, that it occured to so many people or that so many have a DC offset at home. I had a lot of amps, never the slightest noise....

 

Corvo,

 

The vast majority of Vidars in the field have zero noise issues. In my experience with them, at the shop, at home, at friends' homes, at the Schiitr, at many shows, there have been zero noise issues. Sure, we get bad transformers from time to time, but those are (at least usually) sorted after burn-in. We do listen-test for mechanical and electronic noise, and all products are measured with ATE (automated test equipment) before shipping. 

 

Of course, that doesn't mean something isn't wrong with your specific amp. Again, as I noted above, if it's mechanical hum, it's an unusual AC problem. It's possible to check it out if you want to be sure. If it's electronic hum, it's usually a ground loop. Costs nothing to check, as noted above.

 

So where to go from here?

 

If you purchased from a distributor, they can inspect and fix it locally. Contact them. No need to try to make it quiet if your AC is up to snuff and there's no ground loop. 

 

If you purchased it from us, we can fix it. Contact [email protected] and link to this conversation, and we'll get it up to snuff, or issue a full refund, whichever makes you happier. Again, no need to mess with the amp yourself. There's no problem showing you, via video, that the amp is running fine at 230V before shipping.

 

Hope that helps!

 

All the best,

Jason

[schiit]

Guys, again, it shouldn't hum. If it does, contact us or the distributor and we'll get it sorted. 

 

Corvo, our offer below stands:

 

On 4/24/2018 at 6:46 AM, schiit said:

 

Corvo,

 

The vast majority of Vidars in the field have zero noise issues. In my experience with them, at the shop, at home, at friends' homes, at the Schiitr, at many shows, there have been zero noise issues. Sure, we get bad transformers from time to time, but those are (at least usually) sorted after burn-in. We do listen-test for mechanical and electronic noise, and all products are measured with ATE (automated test equipment) before shipping. 

 

Of course, that doesn't mean something isn't wrong with your specific amp. Again, as I noted above, if it's mechanical hum, it's an unusual AC problem. It's possible to check it out if you want to be sure. If it's electronic hum, it's usually a ground loop. Costs nothing to check, as noted above.

 

So where to go from here?

 

If you purchased from a distributor, they can inspect and fix it locally. Contact them. No need to try to make it quiet if your AC is up to snuff and there's no ground loop. 

 

If you purchased it from us, we can fix it. Contact [email protected] and link to this conversation, and we'll get it up to snuff, or issue a full refund, whichever makes you happier. Again, no need to mess with the amp yourself. There's no problem showing you, via video, that the amp is running fine at 230V before shipping.

 

Hope that helps!

 

All the best,

Jason

 

[schiit]

15 minutes ago, Ralf11 said:

hey @schiit - you can buy bolts (and presumably) machine screws in bulk with  dab of locking compound on the side - if you switch to those you will get fewer user complaints

 

it does sound like some thicker sheet metal might be wise too

 

Thank you for the input.

[schiit]

22 hours ago, Corvo said:

@schiit, thx for your offer, very appreciated. But I can assume, that the transformer is OK, so it would be pointless to ship the amp overseas and back. It seems, that the mounting somehow wasn't in its favorite position.

 

If I put my ear close to the plugs of my other devices, I can hear them buzz too. But Vidar is more powerful,  has a more or less light metal cover and most of all ventilation holes in front and on top. In fact, by closing those holes with my hands in past and louder days, the noise dropped considerably. I second what Ralf suggested. And I would guess, that if for whatever reason the transformator makes noises, the outer design and the mounting of vidar won't help much.... 

 

I wouldn't assume the transformer isn't the problem. Like I said, the vast majority of Vidars don't have this problem.

 

If you've had this problem from Day 1, and you've ordered from us, contact [email protected] and we'll swap it out. It's really that simple. Costs you nothing. If you purchased from a distributor, contact them and they'll make it right.