It’s hard being a kid sometimes. [Young] likes his music, but his dad is an overnight trucker. With his dad sleeping during the day, [Young] has to keep the volume down to a reasonable level. He could have bought some commercial headphones, but he wanted something a bit more customized. Rather than give up on his tunes, he built a pair of headphones with an internal tube preamp amplifier. [German language link — Google translate doesn’t want to work with this one but Chrome’s translate feature works].
Two 1SH24B preamp tubes feed two LM386 amplifier chips, creating a hybrid amplifier. The 1SH24B tubes are designed to work on battery voltage, so a step up circuit wasn’t necessary. However, [Young] still needed to provide an 8 cell battery pack to run his amp. Speakers were a 3 way coaxial of [Young’s] own design. He built the headphone frame using candy tins and cups from commercial headphones. A final touch was a window so everyone can see all that vacuum state goodness. Considering that [Young] is only 16, we’re looking for some great things from him in the future.
If you don’t want to strap the tubes to your skull there are other options. But you have to admit it makes for a cool look. Starbucks here we come.
[Thanks Patrick]
Awesomesauce!
I assume the next project is to steampunk the looks?
wait, so to not annoy his father with noise, he built a preamp for his headphones so they could be louder? am I missing something?
Rather than use his speakers, he built headphones which contain an internal pre-amp.
Really… ??
Has this become some sort of sport around here?
More of a hobby, who ever can waste the most money to get every last bit of quality out of those 96k mp3’s wins and then losses, he said sarcastically.
I like his ambition to do something unique but its to bad those tubes ring so laud they are all but useless unless kept 100% perfectly still which isn’t going to happen being strapped to your head.
I don’t think you understood what I was talking about.
I was talking about the need to complain about every single post on this site even if you have to say something completely stupid to do it.
Seems to be a sport around here. I suppose some people might consider it a hobby, though.
I’m sure he built the preamp so he could get the same quality of sound from fully enclosed headphones that he gets from his regular speakers. Fully enclosed headphones like that don’t leak a lot of sound when listened to at normal volume, and even cranked way up they won’t disturb someone in another room.
In short, he’s not going for loudness, he’s going for sound quality.
Tubes? It is 2014 for crying out loud get with the times already! Leave those glass envelopes in the ancient past where they belong.
Considering the size of the build, I’d say it’s a pretty amazing use of that “ancient” technology.
Just because you don’t like or don’t understand classic electronics doesn’t mean others shouldn’t enjoy it. Telling other people what to do via the Internet is about as childish as it gets, kid.
Yes, tubes. Most audiophiles will tell you that tube preamps have a “warmer” sound than solid-state due to introducing less noise. Sometimes, older technology is better (or at least no worse) than the new stuff.
I love seeing older technology actually being used like this.
“Most audiophiles will tell you that tube preamps have a “warmer” sound than solid-state due to introducing less noise.”
And this is exactly why nobody should ever listen to them.
Yep, exactly. lol
i should post my headphone fail for your fail of the week i love this and it has me going back to the drawling board thanks a pile
I can understand building the headphones for the hell of it as apposed to puchasing off the shelf units, however that’s not really a triaxial assembly if the drivers. Then again the speakers marketed as triaxial today, don’t have the drivers mounted in the same axis as some of the early products did. Where practically ever component or portable stereo can drive headphone without an additional amplifier, I confused why use as well as confused why would use a hybrid design. Anyway the solid state side will faithfully reproduce the distortion created by the vacuum tube side. ;)
Putting a lm386 after a tube preamp is like sticking a yugo engine into a BMW. You lose most benefits of the tube. The lm 386 is a good general purpose amp but it’s not aimed at real hifi.
You are totally right! A well designed transistor stage would sound way better and is not more complicate.
Or even just a better monolithic amp IC.There are plenty that are far better than the LM386
True. But then again tubes aren’t popular for their linearity. The distortion is really their main feature. I’d guess if the LM386 is linear enough over the frequency range, a bit more noise won’t really hurt.
Anyway, very impressive to put a valve amp in headphones! If he could somehow stick it in something the size of a cola can, or even smaller, he might have a device to sell to guitarists etc who want a portable way of bringing the “tube sound” with them. Either with a line-out for passing to further PA / studio equipment, or with a speaker so it can be miked up. Musicians mike up speakers to get a particular sound all the time. So if he sold a tiny, portable tube amp, he might be onto a money spinner. Profit comes from the ridiculous markup you can charge to musicians.
Do those tubes really work on just 12V for their HT supply? That’s surprising! I suppose it affects how much power you can put through them though. Perhaps a higher voltage, driving a transformer or a 64ohm speaker, would allow more volume to drive a speaker.
Finally, the speaker itself. Dunno if it’s supposed to be a joke (those wacky Germans!) but you don’t actually need separate tweeter and midrange when you’re dealing with low power like that. I can only imagine it sounds worse overall than just using 1 properly sized one.
Still, clever. And if he WAS going to, gods help us, steampunk it, an old pair of radio phones would look good with a tube sticking out of the side on each ear.
Yup. But, they’re dirt cheap and a lot easier to find, a fact that’s lost on most of us who can buy more advanced items with no problems.
I agree. The 386 will never do justice to tubes.
I wonder why it’s needed? Surely a valve that big could drive the speakers by itself, with a transformer? Headphones are usually 32ohms, but if the tubes work on 12V they can’t be designed to drive too high an impedance load. Although I realise they’re probably not meant for an audio output stage.