[AudioGal]

One of the intriguing things about this amplifier is the fact that it is a direct drive amplifier. Tube -> headphones, with NO transformer (OTL) and NO capacitor (OCL) between the output stage and the headphones. Every other tube amplifier that I have ever listened to has had one of those components between the output tubes and the transducers. Jason's drive to hear *just the tube sound* means we'll get to do the same.

Headphone choice is always key, more so with tube amps. I've had great success with planar 'phones paired with tube amps, but it's a fussy arrangement that requires planars with impedances above 50 ohms that are also reasonably sensitive. The good thing about planar transducers is that they have a flat impedance vs frequency "curve" (is it still a curve when it's a straight line?) which plays really well with OTL tube headphone amps. I have had great results with HE400s on a Valhalla 2 and Incubus. I'm enjoying stellar sound out of a pair of LCD3 with my Incubus, sufficient to discern subtle differences between different tube combinations allowing me to zero in on an ideal sound for my ears.

Won't really know how this all "plays out" until the amplifier is here and set up. The anticipation is part of the fun.

 

[Orange5o]

One of the intriguing things about this amplifier is the fact that it is a direct drive amplifier. Tube -> headphones, with NO transformer (OTL) and NO capacitor (OCL) between the output stage and the headphones. Every other tube amplifier that I have ever listened to has had one of those components between the output tubes and the transducers. Jason's drive to hear *just the tube sound* means we'll get to do the same.

Headphone choice is always key, more so with tube amps. I've had great success with planar 'phones paired with tube amps, but it's a fussy arrangement that requires planars with impedances above 50 ohms that are also reasonably sensitive. The good thing about planar transducers is that they have a flat impedance vs frequency "curve" (is it still a curve when it's a straight line?) which plays really well with OTL tube headphone amps. I have had great results with HE400s on a Valhalla 2 and Incubus. I'm enjoying stellar sound out of a pair of LCD3 with my Incubus, sufficient to discern subtle differences between different tube combinations allowing me to zero in on an ideal sound for my ears.

Won't really know how this all "plays out" until the amplifier is here and set up. The anticipation is part of the fun.

Is there a reason for 50 ohms to be the marker? Thanks

 

[JLoud]

with the impedance multiplier it should work with headphones under 50 ohms. Provided they are somewhat efficient. They show a DCA Stealth in the marketing, I will try mine with it when the amp arrives. Hopefully the LCD4 pairs well. Also Jason mentioned he uses Grado headphones with it. They are 32 ohms. 99.8 db

 

[Mike-WI]

Is there a reason for 50 ohms to be the marker? Thanks

I hadn't heard of this site before, but...
https://www.headphonesty.com/2019/04/headphone-impedance-demystified/

 

[DigitalScrap]

Headphone choice is always key, more so with tube amps. I've had great success with planar 'phones paired with tube amps, but it's a fussy arrangement that requires planars with impedances above 50 ohms that are also reasonably sensitive.

Won't really know how this all "plays out" until the amplifier is here and set up. The anticipation is part of the fun.

I had this thought as well. I'll definitely be testing out my LCD-2 with it. No idea what to expect yet, but that is as you said, part of the fun.

 

[ScotchNeat]

I hadn't heard of this site before, but...
https://www.headphonesty.com/2019/04/headphone-impedance-demystified/

If I read this correctly, where it says the best match is typically a headphone impedance that is 2.5-8x the source (amplifier) impedance. Does that mean with 80 Ohm Utopias, the "correct" setting on the FV will be High gain, impedance multiplier disabled? 80/18=4.44x, right in the desired range. Low gain/multiplier disabled would be 10x.

 

[Barnstormer13]

I will be curious to hear about the hd650 and the ethers. Was kind of looking at Ether cx at 23 ohms...I think I'm just insecure about Sundaras with this amp, as I only have these and HE6's so I don't have anything to compare since I can't use the latter. I don't necessarily want to drop another thousand after the amp but don't want to underdo it either.

Edit: I suppose I could also try my old ATH-M50X..

Second edit: Focal Elex sounds intriguing, 80 ohms, 104 db efficiency, and a reputation for a little brightness that may be softened by the tubiness...

I bet the Elex will be an outstanding value. I’m still sorry I gave mine away

 

[houdini06]

Patiently waiting for some reviews.

 

[JLoud]

Patiently (ok not that patiently) waiting for mine to arrive.

 

[Mike-WI]

If I read this correctly, where it says the best match is typically a headphone impedance that is 2.5-8x the source (amplifier) impedance. Does that mean with 80 Ohm Utopias, the "correct" setting on the FV will be High gain, impedance multiplier disabled? 80/18=4.44x, right in the desired range. Low gain/multiplier disabled would be 10x.

I was just reading this over and figuring out my usual headphones are lower impedance.

Aeon - 13 ohm
HiFi Man HE-560 - 45 ohm

 

[OhmsClaw]

All depends on how you define performance. We already know it measures like crap, so I’m far more concerned with $ to enjoyment.

I think the cost here is justified for the R&D, low unit production and limited nature.

If it sounds good, it sounds good and who has ever been crazy enough to make this and be upfront about the whole process.

If Jason/Schiit decided to run these out in production I bet the cost could reflect a 1199 MSRP but with this hobby and a Russian ban on tubes (full well deserved) people can throw darts at a wheel and charge whatever people are willing to pay.

 

[Orange5o]

Sorry if this is a dumb question but given that, would very high impedence pair like hd650 at 300 ohms be out of range in the other direction?

 

[GenEricOne]

Sorry if this is a dumb question but given that, would very high impedence pair like hd650 at 300 ohms be out of range in the other direction?

Short answer: 300ohm HD650 is likely a great pairing with Folkvanger. There is no 'other direction'; the headphone impedance should be at least 2.5-8x the output impedance.

Longer answer: The rule of eighths is for figuring the maximum output impedance that works well with your headphone (or vice versa). So a 300ohm HD650 would be best with a source with 37ohm output impedance or lower.

A large number of excellent modern amps have an output impedance of less than 1ohm and work great with 300ohm HD650s. There really is no 'too low' output impedance (the article also says that 'perfect' would be 0 output impedance).

In reality, things can still sound good with an even lower ratio than 8x, as low as 2.5x according to that article. For Folkvanger (with impedance multiplier off), that would mean headphones with at least 18ohm (7ohm x 2.5) impedance that are sensitive enough for low gain, or headphones with at least 45ohm impedance when in high gain.

 

[Orange5o]

Thank you for the explanation. I'm now dangerously leaning towards the LCD-2 High Performance because 1) reviews said its great with EQ and I have a Loki Max, 2) falls within the ampedance range (70 ohm 101 db sensitivity), 3) Jason tried them with the Folkvangr and said it was good, 4) looks nice with the wood. Anyone here have that set that is buying FV?

 

[AudioGal]

Is there a reason for 50 ohms to be the marker? Thanks

Vacuum tubes are high voltage low current devices and tend to work best into higher impedances. Ultimately the lowest reasonable load impedance is circuit and tube dependent. The 50 ohm value is really just a guide value I use knowing from experience that below 50 ohms my choice of headphone is critical for success. My HE400 are ~35 ohm yet work well with some tube headphone amps because they are rather efficient/sensitive AND they are planar drivers so the impedance is constant across their bandwidth. They played well with my Valhalla 2 at moderate volume, and with the right tubes, in my Incubus at moderate volume. However my Focal Spirit Pro 'phones, which are 32 ohms, and about as sensitive as the HE400, won't play well with either amp. Distortion city. My DCA Ether C which are 13 ohms were a giant notgonnahappen.com with either amp. Everything else I have is >100 ohm and plays really well with tube amps. I have a pair of Audeze LCD-3 which have 110 ohm planar drivers, these sound wonderful with the right tubes in the Incubus.

I'm looking forward to finding out how headphone specific the FV might be. Or not be. Going to try the Ether C with it, though I'll start with the LCD-3.