Schiit Folkvangr Review - Measures like shit, but sounds GRRREAT

If we'd like to dig into this a little, I'll bring up a review that Amir did of another OTL (although not OCL), the Darkvoice 336SE.

So, the DarkVoice's SINAD is about a match for Folkvangr's, although you can clearly see from his 1khz tone that there's a boatload more harmonics on 336SE. I also have both amps and they are not close on technicals, Folkvangr is tiers above the $200 chinese amp.

Still, Amir concludes "People though get such products for their subjective qualities. There, I can confirm the appeal of using the 336SE with high impedance headphones of 300 ohm and higher. There is copious amount of power here, and what distortion there is, is masked for the most part. In my experience of either power amplifiers or headphone, how much power you have available determines fidelity first and foremost. Lack of power results in anemic sound which seems to lack impact, and even resolution. The high output voltage of DarkVoice 336SE gives it such a strong advantage that it can override its much higher distortion. With that distortion following perceptual masking, it is not as much of a detriment as it may seem at first."

So power is what makes tubes good? Hmm. 336SE is rated as 1W (not sure on load, but I'll bet 300 ohm) and Folkvangr is 1.2W into 300 ohms. Seems like kinda similar power. Perhaps it is something else? Because the performance delta between these amps is huge. Clearly, if SINAD fails us here, we can't just promote power as the new OneGod™ and conclude based on that rating if something is good. There are clearly other factors at play.

 

I'm just waiting for someone to try and snag two of these and butcher it with adapter cables into some unholy monoblock config. Yeah we know it wasn't recommended, but I bet someone will try.

 

I mean, all these possibilities sound great to me! But if there is no appetite for this, I wonder whether we'll ever see Schiit's take on a DHT SET amp.

We have bespoke DHT SETs from people like Eddie Current and Donald North that people love. But I bet Schiit could do an amazing job of something more accessible. Just by switching to S/S rectifiers and building on a PCB seems like it could create a pretty decent economy-of-scale for a one-box mass-market amp.

 

SS rectifier sure, but DHTs seem to all be low volume/silly expensive nowadays, not sure it would be a good match for a high volume product.

 

Sure, but I've always assumed a big part of that is the labor of a P2P wired amp. Are there any 300B headphone amps based on a PCB? We know it can be done because of the Elekit DIY amps...

 

Not a business person, but I'd hazard a guess the business prospects of a DHT SET aren't stellar.

I believe there is a lot of fixed cost built into DHT SET's due to the carefully paired tubes, caps, and transformers.

You might be able to undercut a little by using assembly line techniques and PCB's, but you'll still be up against similar design offerings from ampsandsound and Woo, and your product is still going to be relatively expensive just from the parts.

High price reduces volume and therefore negates the assembly line benefit, so you're probably not undercutting as much as you'd want.

That's my naïve guess anyway.

 

It's probably not a bad guess. It might be impossible. But if anyone can make it happen, I'd put my money on Schiit.

 

I think for a lot of people, part of the appeal is the hand made, bespoke nature. I have to admit, it’s part of the appeal to me.

 

Who knows, maybe we see something more interesting than their take on a DHT. For business stuff, I suspect the most relevant question was actually "how well is a 2000 dollar headphones-only amp from us going to sell?", and depending on the answer maybe in who-knows-how-many years there's some other sufficiently interesting/unique thing that turns out to be good-sounding enough to justify being built to that price point.

I mean, Yggdrasil is already a big expensive thing that sells well from them, but this is narrower use still.

 

Agree with most of this post but take exception to "poor measurements".
Poor measurements only if we use the outdated 1940s interpretation of THD+N (or SINAD) as having any correlation to audio component sound quality.

From @purr1n 's -20 dBu measurement a more modern interpretation.
First, why -20 dBu? At that level many modern headphones have sensitivities consistent with approximately 80 dBSPL, a more reasonable listening level than 100 dBSPL at 0 dBu. For more information search "the magic of 83 dB SPL".


THD+N is dominated by D2 (2nd harmonic distortion) in this measurement which is 0.56%. Yet D2 is not directly audible to most people until somewhere between 1% and 10%. Some might find D2 adds a low level richness to recreational listening.

D3 on this graph is far down at 0.0025% and 4+HD+N, excluding AC mains noise is a scant 0.003%.
60 Hz is 0.2% but with an absolute of -75 dBu will be inaudible in most ordinary listening spaces with most headphones, especially when considering the ISO contours of equal loudness for the Human Auditory System (HAS). 120 Hz is down another 10 dB and likely inaudible.

I am assuming Folkvangr has a low NFB. Low NFB combined with low 4+HD+N and AC mains below -75 dBu are indicative of a headphone amp that will provide perceived good sound.

It would be very useful to see this same measurement at -30 and -40 dBu. AC mains noise will remain constant. 4+HD+N may continue to drop.

 

Any sense in trying the Folkvangr as a preamp to SS amp and speakers?

 

If that’s all you’re going to do and you don’t intend to use the headphone amp part, there’s cheaper ways to live the dream. Schiit makes some decent tube preamps that will save you the price of a nice speaker amp.

 

On the other hand if you already have it in house, it wouldn’t hurt to try it and see what it’s like.

 

I was sort of toying with the idea, and hoping someone here would try it!

Yes, there are cheaper and my Saga+ does its job fine for what it is. It is not anything near the AI Modulus 2A, however, but that is unfair apples and oranges.

 

Probably not quite the test you were looking for but I used it as a preamp for my Bose Companion 20 desktop speakers. The preamp outs work. Unlike MJ2, you have to pull the headphone connection to get the preamp outs to fire up. I wasn't hearing anything special. Honestly, I prefer MJ2's preamp outs since they make the tiny Bose speakers sound wider and bassier than they are. I feel like Folkvangr's pre outputs are basically utilitarian, although my example is a shitty test.

 

Literally kicking my self for this reason as well... like this is the worse time for me to be buying an amp but f**k as much as I enjoyed Vali 1 this seems like the eventual upgrade I always wanted and so I kinda wanna get one in black asap

 

Folkvangr measures pretty well actually, just a shame that 50Hz isn't tamed a little better.