That was crazy! I’ll bookmark that for those times the Mrs A-Fin says my audio gear is cluttering the living room!
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Have you designed this, or are you buying in… if buying in what product are you looking at
Oh how I wish I’d designed it 
It’s the Feliks Envy, their new TOTL headphone Tube amp that was released late last year. It does have pre-amp out (XLR & RCA) for actives as well. There are a few good reviews out now but the ones from Headfonic and Headfonia are fairly comprehensive. It’s a nice mix of style & tradition. All hand made with point to point soldering. Just takes a while to get them though!
Sounds interesting… let us know how you get on.
In my experience with valve class A amps they are uber sensitive to headphone impedance matching for optimum sound performance… this does mean mixing headphones can require changing jumpers etc on the amp.
Will do. It’s probably going to be at least another month or more yet. Seems like I’ve been waiting an age!
The amp has different impedance settings to cover different headphones. It pushes out 8w at 16Ohm and can drive the harder planar headphones such as Abyss AB-1266 & HiFiman Susvara as well as the easier Meze ones. It was one of the things that attracted me as I love planar headphones so to have an amp that can drive any would be very nice to have.
I’ve had great success with running a DHT tube preamp - Vinnie Rossi LIO w/ 300B tubes and a NAP250DR. Having a traditional power only tube running a linestage sounds great, very unique! Love the combo.
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I very much enjoy magnetic planar headphones too.
If I am honest I prefer solid state amplification on my planars, and valve amplification on my dynamic voice coil based headphones like my Sennheisers. It’s the grunt and slam and fine detail/presence transparency without shine or highlighting you get with quality planars that doesn’t always gel with valve amplification in my opinion.
But a slightly forward or hot dynamic headphone can be suitably tamed with valve amplification. I guess it’s all about synergies.
See what you think.
I wonder if he worries about fuses in his power cords LoL
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Had a Line magnetic 508ia. Beautiful hw but got caught in tube swap mess and missed the benefits of always on and ready as with Naim. When the caps in it eventually exploded I sold it and went to 272/555PS/300DR. Never missed anything else than the glowing tubes of it.
I found this. I had HD-800 running of a HL2/HCdr and thought it was goog (it was). But when I got a Luxman valve amp it was like I had never heard the Sennheisers before. They totally responded to the wakeup call from a different type of amplification.
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My valve amps, puresound 2a3 and P10 with my xs2 .
When it’s hot, the xs2 is on duty, though it’s on duty quite a bit of late! Energy bills to consider.
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It seems heating is a bit of an issue, living in Aus they mightn’t be a good option.
You’ve seen his (5000A) fuse popping video!? I don’t think he worries much.
Hi James, admiring your hifi rack, are they bespoke or available to buy? Thanks Michael
Thanks Michael - it’s from IsoBlue so readily available in various finishes.
I did the same what you plan to do and like you I loved my naims from nait 2 over 122/150 till 252/300. but sometimes it is time for a change and to be honest the Harbeth I own work better with the Audiomat. And yes, the forum is great.
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I have been a Naim guy for thirty years, but I was, as the old ads used to say, tube curious.
In the first summer of Covid I picked up a demo Conrad Johnson cav45 integrated. I have it at my office where I use an ND5XS as a source. At home I have a Nait XS2 / flatcap with an NDX. Speakers are Penaudio Sara S at the office and Kudos something or other at home - similar seas components as the pens.
The Nait beats the CJ in terms of detail and clarity. But the warmth and natural sound from the CJ is beguiling. One thing I particularly like about the CJ is that you can easily adjust the bias - no need to open the casework. Tube sets are also available direct from CJ.
With Naim sources and similar speakers, the differences between the two are modest. There is also a fun ‘wow’ factor with tubes. No one has ever been excited to see my stack of lime slices, but the tubes intrigue people.
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Are you sure you are adjusting the bias. Adjusting the bias out of spec could create bad distortion. You normally require an ammeter and /or an oscilloscope in quality audio setups. The bias moves the gain to the most linear part of the valves gain conduction curve [operating point]. (Obviously differs from class A and class B/C)
Above is a photo and below is from the manual:
Adjusting Output Tube Bias
Biasing the amplifier is a simple procedure that can easily be done by the owner. Only a plastic screwdriver is required (one has been included with your amplifier for this purpose). After replacing the tubes, the amplifier should be connected to a load (your loudspeakers will work fine) and there should be no signal applied to the amp and the volume control turned fully down. Turn the amplifier on. After about one minute, turn each of the four screwdriver adjustable controls (located near the output tube sockets) counterclockwise until the associated indicator LED just goes off. Clockwise rotation may be necessary first to turn the LED on; do not turn the adjusting screw any further in the clockwise direction once the LED has come on.
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Agh… perhaps slight poetic licence on the term bias….
Yes one often can optimise the load characteristics for a valve… I have never heard that called bias on technical equipment, normally it’s called plate loading in my experience.
Perhaps like solid state amp, the setting sets the switch on current on class AB amplification… but again normally done carefully. 3.3 Determining the operating point and bias of a vacuum tube amplifier - Vacuum Tube Amplifiers - DIY
[edit it appears this what is being referred to… but see attachment for performance consideration and the importance of linearity for a quality low distortion amp)
On one of my valve amps, I have a digital display to help optimise my plate loading, and higher end version of that amp model have auto valve loading circuitry, where you press a button (or automatically detects) , and the output load is matched to the driver.
Bias is set at valve replacement time … and requires an ammeter.