Raspberry Pi Tube Amp Lets You Use $1300 Headphones With $35 Computer

[Megalith]

Some like the warmth of tubes while others demand neutrality, but I think both groups could appreciate what they’ve done with the Pi here.

The 503HTA Hybrid Tube Amp is a HAT (Hardware Attached on Top) extension to any Raspberry Pi with a 40-pin expansion connector, including the Raspberry Pi 2, Raspberry Pi 3, Raspberry Pi Model B+, and presumably even the 40-pin Raspberry Pi Zero. HAT boards differ from standard Pi shields in that they enable the Pi SBC to automatically configure its GPIO signals and drivers for use with external devices. The 503HTA incorporates a 24-bit, 112db THD PCM5102A DAC that taps the Pi’s I2S interface to drive a single 12AU7 tube gain stage at a 192Khz frame rate. The setup enables audio from 32 to 300 ohms on headphones connected to the 3.5mm jack. A gain select switch offers three gain settings of approximately 2V, 4V, and 6V rms.

 

[N4CR]

Not so keen on a valve output stage - although they are glorious sounding, the hassle factor is not for me. But that is a nifty little piece of audio engineering.

 

[Probleminfected]

I'll keep my Fisher 800c for tube amp listening.

No point in running digital music through a tube amp.

 

[nilepez]

Not so keen on a valve output stage - although they are glorious sounding, the hassle factor is not for me. But that is a nifty little piece of audio engineering.

I doubt I'd by one, but I'm curious what the hassle factor of using an amp with a valve output stage is?

 

[snowcrash]

I'll keep my Fisher 800c for tube amp listening.

No point in running digital music through a tube amp.

I remember reading something like what you wrote one time when tube amp was making a come back two or three years ago. A demand for analog stereo sound (the whole point of using a tube amp) instead of digital and preferably with an LP source. I don't have the time now but this is something I definitely want to try down the road.

 

[Quix]

I'll keep my Fisher 800c for tube amp listening.

No point in running digital music through a tube amp.

Yeah, how are you going to get that lo-fi distorted sound without an vinyl source?

 

[N4CR]

I doubt I'd by one, but I'm curious what the hassle factor of using an amp with a valve output stage is?

Two reasons, one is that they require eventual replacement and something to maintain - they slowly degrade. My current hifi has not been changed since I was a teenager. It just works.
That said, a low power valve like this is going to last a while.
Second reason is it's just something I don't want in a digital stream also - valves have more distortion, mostly in different orders to a typical digital sound. That said, it's much more distorted and some people prefer this - like distorted bass etc... most don't notice distortion bass when it's over 90-100db or so... you can't actually hear it easily as your ear is now at it's limits. That said both can sound excellent. But a high end (properly designed non-gimmicky type) digital amp is a little more clinical and analytic.. you will hear everything as it is. It will reveal any faults in your system, this is where some people dislike digital.

TLDRigital perfect stream will be further compromised spitting it through a valve and the maintenance factor means there's another thing to go wrong.

That said, an analogue source, e.g. guitar, when you want a specific sound, is absolutely stunning through a valve head. Friend of mine has a awfully expensive 100Wx2 Mesa valve head and when I first heard his rather pricey guitar through it, nearly bought tears to my eyes.. the sound is just unreal - I was left absolutely astonished.
But now we have things like axeffect box, which can emulate (extremely accurately) these distortion profiles and sounds of various popular amplifier heads. That's a 3-4k box but the usefulness is invaluable for a professional guitarist or guitar teacher.
That said, I really do not rate vinyl. It's a lossy recording and production medium, a large majority of the records out there are CD transfers anyway...
If you want real studio quality sound, high bitrate stuff is the way to go. The atmosphere and 'air' around many sounds is just superior.

Yeah, how are you going to get that lo-fi distorted sound without an vinyl source?

Lmfao, the most brutally honest appraisal of records I've ever heard.
Yes, you hipsters can keep your wow and flutter, scratchy shit all for 'analogue' which wears out after a few plays anyway.. The digital master race is here to stay!

 

[Deleted member 93354]

I remember reading something like what you wrote one time when tube amp was making a come back two or three years ago. A demand for analog stereo sound (the whole point of using a tube amp) instead of digital and preferably with an LP source. I don't have the time now but this is something I definitely want to try down the road.

Good luck with the low S:N ratio, warble, wow, limited frequency, flutter and cross talk issues.

Oh and using a digital source like the Raspberry Pi, you're going to have a lot of clock jitter I bet.

Kudos to the creativity factor though.

 

[Zarathustra[H]]

So is this sort of like putting $10k rims and a $20k stereo in a $500 civic?

 

[King Icewind]

Apparently the tube doesn't get 12v (only 6) which means it doesn't do jack for sound. It's all solid state amplification. The only way to adjust volume or anything is digital so you need a screen hooked up at all times. That sucks for a headphone amp.

The tube will light up though.

 

[MongGrel]

So is this sort of like putting $10k rims and a $20k stereo in a $500 civic?

I kind of think that a bit myself, unless you were going seriously old school with a vinyl collection and a real tube amp it seems backwards for anything digital really to me.

Just looks a bit like a gimmick here to me.

 

[N4CR]

So is this sort of like putting $10k rims and a $20k stereo in a $500 civic?

Unfortunately, it's something similar to that. Perhaps more like putting 15x6" chrome rims on a mustang v6. Biggest gimmick I've seen lately as a long time Hifi guy, is this putting tubes on everything, it's making a big comeback for marketing. To the the point, that quite a few are just fake with LEDs below them..

These are especially targeted at the desktop headphones amp crowd, people with money for big hifi but e.g. live in a flat or apartment, couldn't get to use a hifi to it's full extent and spend up big on headphones gear instead.

If King Icewinds' information is correct, is just another one like the rest..


My advice is to check out the various multitudes of USB DACs and do your research. Some amazing bargains to be had if you don't want esoteric stuff, even in the $50-150 range. 6moons.com usually does mostly esoteric but I have seen some cost effective DAC reviews. These guys listen to 200k+ amps/speakers from time to time, so when they rate a cheap USB DAC, it's probably worth listening to...

I'm saving my pennies for a Burson which can do headphones on my desk and run the hifi rig, best of both worlds when someone is sleeping a few rooms down. No valve bullcrap, with discreet op-amps so you have perfectly matched circuits. Comes at a price of course but I probably won't have to replace it for half my lifetime, even then I can run a retro PC to feed it when USB support is gone.. had 15 years+ out of my current rig without issue, it stands up to anything in a similar bracket today - and people like me think a PC lasting 5 years is good HiFi tech has virtually ground to a standstill in core power amp and speaker design.

 

[Zarathustra[H]]

Unfortunately, it's something similar to that. Perhaps more like putting 15x6" chrome rims on a mustang v6. Biggest gimmick I've seen lately as a long time Hifi guy, is this putting tubes on everything, it's making a big comeback for marketing. To the the point, that quite a few are just fake with LEDs below them..

These are especially targeted at the desktop headphones amp crowd, people with money for big hifi but e.g. live in a flat or apartment, couldn't get to use a hifi to it's full extent and spend up big on headphones gear instead.

If King Icewinds' information is correct, is just another one like the rest..


My advice is to check out the various multitudes of USB DACs and do your research. Some amazing bargains to be had if you don't want esoteric stuff, even in the $50-150 range. 6moons.com usually does mostly esoteric but I have seen some cost effective DAC reviews. These guys listen to 200k+ amps/speakers from time to time, so when they rate a cheap USB DAC, it's probably worth listening to...

I'm saving my pennies for a Burson which can do headphones on my desk and run the hifi rig, best of both worlds when someone is sleeping a few rooms down. No valve bullcrap, with discreet op-amps so you have perfectly matched circuits. Comes at a price of course but I probably won't have to replace it for half my lifetime, even then I can run a retro PC to feed it when USB support is gone.. had 15 years+ out of my current rig without issue, it stands up to anything in a similar bracket today - and people like me think a PC lasting 5 years is good HiFi tech has virtually ground to a standstill in core power amp and speaker design.

I personally like Schiit's stuff.

I have their Asgard amp, and at some point want to get around to getting a Bifrost DAC.

I'm not going to bother with tubes though.