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DIY Amps: A Roadmap for Beginners (2017)
- JKCalhoun 7y agoHappy to see a couple of tube amps among the kit listings. I've enjoyed building many, many tube amplifiers in the past two decades or so. Initially they were kits, later I did rolled my own point-to-point amps and later still laid out my own PCB's for some PCB-based tube amps. While the high voltages might seem intimidating (safety-wise) I hope that doesn't keep people from pursuing this class of amplifiers. If you're smart about it, you'll be okay. And there is nothing like the sweet music of non-quantum sound amplification. (When consider that my other hobby involves a table saw I'm beginning to wonder what might be behind some of my life choices…)
- pthreads 7y agoI love tube amps. Would like to start building my own. Could you please share your favorite resources if any? Thanks.
- vibrolax 7y agoDid you want to make hifi amps, or guitar amps? The electronics knowledge and construction techniques are nearly 100% transferrable, but the design lore diverges, and the online DIY communities can be very diverse. I've built a dozen or so guitar amps, preamps, etc. I don't personally build hifi stuff, but I love John Brodskie's tubecad.com for the analysis of classic circuit topologies, and tons of original ideas. He offers nice looking PCB's for preamps and power supplies. For me it was useful to determine what I wanted to build first, and find the related online sites and communities.
- pthreads 7y agoHiFi. Short anecdote: I once went to a tube amp repair class. After about 5 minutes I realized this was only for guitar amps. I just pretended to be a guitar player and sat through. It was awesome though. Anyway the TubeCAD site looks very interesting. Thanks.
- opencl 7y agoPete Millet's site is a pretty good resource, he's posted a lot of different designs ranging from preamps to power amps to headphone amps. His "Starving Student" design was my first foray into building a tube amp about a decade ago, though that one is really a tube/transistor hybrid and it's designed for headphones but I used it as both a speaker and headphone amp. http://www.pmillett.com/ http://www.pmillett.com/
- ur--whale 7y agoThe age old question: besides the obvious aesthetic attractiveness, is there really any kind of objective advantages to tube-based audio amps as opposed to solid-state semiconductor based ones?
- soulofmischief 7y agoObjectively speaking, if the subjective enjoyment of your music is generally increased, then that's a net positive. So it at least depends on the target audience.
- jacquesm 7y agoIf the target audience is over 35 than chances are their wallets are fat but their ears are already shot. That won't stop them from blowing a lot of money on stuff that doesn't make a difference at all (either measurably or subjectively) but if it makes someone feel better they should be free to waste their money as they see fit.
- soulofmischief 7y agoHa, yeah there's a lot of snake oil in the business. However, there is definitely a difference in sound, however subtle to some, between most tube and solid state amplifiers when it comes to recording music, as musicians tend to try to draw out certain sounds that are a consequence of the design of the amplifier, whether by overdriving the input or exploiting analog flaws, etc. Even when comparing just tube or solid state amps, there can be a lot of variance between them. This doesn't really apply to consumer-grade amplifiers where the goal is perfect sound reproduction. A good tube amp and a good solid-state amp shouldn't sound different to an untrained ear. But amplifiers used in production often try to differentiate themselves in some way sonically.
- michaelt 7y agoWhat if I'm balancing an increase enjoyment from feeling I've got better sound against a decrease in enjoyment from feeling I've being taken for a fool by snake oil salesmen?
- vt102 7y agoI know a little about tube guitar amps, and my understanding is that they are desired due to their “defects” compared to more accurate solid state transistors. I would assume headphone amps would want pristine amplification— why would you want tubes, then?
- billfruit 7y agoI am no EE, but transistors also have problems giving precise accurate gains as well.
- detaro 7y agoTube amps (as do transistor amps) can vary quite a bit in how much they change the sound, e.g. part of the appeal of tube guitar amps is that you can drive them out of the area they work "most precise" into distortion, and that distortion sounds interesting. And some people like the sound changes tube amps cause for listening.
- C1sc0cat 7y agoThere is an story that when the Beetle's went to record at the BBC there was an argument with the BBC sound recording Engineer that no way was he allowing distortion to go out on the BBC :-)
- holy_city 7y agoThose "defects" is just non linearity in the circuit. At low gain factors (much lower than a guitar amp) it creates prominent 2nd, 3rd, and 4th harmonic distortion (depending on the circuit) which corresponds to the musical intervals of an octave, octave + fifth, and 2nd octave. That sound is typically described as "warmth" and can be quite pleasing. It also increases the RMS of the signal without (greatly) affecting dynamics, which makes it perceptually louder. Some people like the ultra hifi systems with crazy THD+N metrics, with super flat speakers in the deadest room they can find to get the most "pristine" sound they can. Other people like listening through systems that subtly color their favorite recordings to match their taste. Different strokes for different folks.
- 2bluesc 7y agoMy favorite audio resource for those designing or evaluating audio amps and DACs is NwAvGuy's blog[0]. The blog posts explain what performance parameters matter, what don't, and evaluates the performance of various products and components. Equally interesting is the mysterious story about the anonymous author himself [1] [0] http://nwavguy.blogspot.com/ http://nwavguy.blogspot.com/ [1] https://spectrum.ieee.org/tech-history/silicon-revolution/nwavguy-the-audio-genius-who-vanished.amp.html https://spectrum.ieee.org/tech-history/silicon-revolution/nw...
- segfaultbuserr 7y agoI have one Objective-2 amplifier right now on my desktop. Great fidelity, reliable and robust. It's the best DIY project I've ever done. Thanks NwAvGuy!
- kurthr 7y agoThanks for this... I've done some double blind audiophile equipment testing and it's important to have a source to send folks to before and after.
- netvarun 7y agoThe IEEE profile on NwAwGuy had some HN discussions: https://news.ycombinator.com/item?id=7451062 https://news.ycombinator.com/item?id=7451062 https://news.ycombinator.com/item?id=10961061 https://news.ycombinator.com/item?id=10961061
- mikorym 7y agoSource [1] is quite an amazing story. Has there been no update from NwAvGuy since that time (25 February 2014)?
- kpgraham 7y agoI've built a half dozen Fender Bassmans and a few Fender Super amps over the years. I thought the article would be about this kind of amp building, but evidently not many hacker news readers play blues harp through a tube amp. Low tech tube amps are quite easy to build, although they cost a few hundred because the transformers, chassis and tubes can be pricey and the cabs and speakers aren't cheap. The results are great, though, and I'd say go for it if you are thinking about trying. Get everything you need from Tubes and More dot com or eBay.
- dejv 7y agoTube amps are also much more dangerous than 9V battery operated headphone amps. For people that are just starting out those cmoy style projects are awesome. btw there is also 1W guitar amp in style of cmoy.
- wishinghand 7y agoAre Bassman amps actually better at reproducing and projecting lower frequencies? I have a fender amp for my regular electric, and a bass amp for my bass guitar. I also have a baritone and wanted an amp for in between.
- pinewurst 7y agoPersonally I don't think they (the old tube Bassman) are that much better than any other guitar tube amp. Old Marshall amps (JTMs) are based on that same design, btw.
- wishinghand 7y agoAny recommendations then?
- fuzzfactor 7y agoTry different closed-back cabinets and speaker cones with your baritone.
- 7y ago
- nullwasamistake 7y agoA neat hobby in the nostalgia sense but I'm convinced many audiophiles are misled in the idea of audio quality. You can build something with a mathematically perfect decode and EQ using a raspberry pi. You want digital all the way to final amp stage. For the amp stage (especially at low power headphone levels) the best amp option is a nice dedicated amp chip. For a few dollars and little external circuitry you can get a chip that will put out 10 watts into a sub ohm load with less than 1% THD. Class D too so it uses ~1/2 the power. Good example, the old discontinued Sansa Clip, a $20 mp3 player the size of a tic tac box, has one of the best headphone amps tested. Combine it with rockbox firmware and you have a super practical headphone amp that will rival anything money can buy.
- thatcat 7y agoThanks for explaining this, I had wondered why my sansa clip sounds so great.
- nullwasamistake 7y agoNp clip is one of the greatest headphone amplifiers ever produced lol
- vonseel 7y agoI'm curious how something like the headphone amps or what you mentioned compares to the headphone outputs on a high-end audio interface, e.g. the RME Fireface line or similar recording products.
- nullwasamistake 7y agoThere's people that have done some independent testing of audio outputs. The quality varies widely so paying a lot is one way to make sure you have good outputs. A lot of phones have notoriously weak/bad audio jacks. Some built in motherboard audio outputs suck as well. However, in general, any dedicated audio card, even the cheapest soundblaster will have audio outputs just as good as extremely expensive audiophile stuff. Maybe not as much power output, but that only matters with high ohm headphones. Ditto with any Apple products, they've been known to have extremely high quality Cirrus Logic audio chips for a long time
- m0zg 7y agoBuilding headphone amps doesn't make any sense, IMO. You are not even going to outdo a $1 opamp with all this tube stuff. For headphone amp I use a Mackie Onyx mixer that I bought used on ebay for $80. It also includes a bunch of ADCs and, you know, the entire mixer. And it's more similar to the stuff that was used when actually mixing the songs I listen to. Where tube stuff still _does_ make sense is guitar amplification, where particular flavors of distortion and frequency response nonlinearities are a feature, not a bug.
- shereadsthenews 7y agoWell building anything with tubes makes no sense at all but that doesn’t rule out making headphone amps. Many small devices are unable to drive many kinds of headphones so you need something to bridge that gap. The other reason you might have is devices that can drive your headphones but have a lot of coupled noise from nearby digital electronics. This goes for most laptops. As an example I have a Zoom F4 portable recorder. It has a headphone output but it can’t drive 30-Ohm headphones worth a damn and even with high-impedance headphones there is audible noise that doesn’t exist on the recording itself. So if I want a realistic feedback on what I am recording I have to monitor through an external headphone amp.
- m0zg 7y agoYes, I should have said "building tube based headphone amps" makes no sense. Opamp based ones make sense for low impedance headphones if the source is not designed for low impedance loads.
- mb_72 7y agoThese days modelling (Helix etc) has reached the point where tube amps, cabs and individual FX pedals can be replaced by a single piece of hardware. As a bass player I ditched my SVT and individual pedals in favour of a Helix Stomp; it's the best musical purchase I've ever made.
- vonseel 7y agoGuitar/bass player here. I own a few tube guitar amps (Fender Blues Jr, Peavey Ultra 410) and also have a vintage 70s Ampeg V4b. For nearly 100% of my daily playing and recording needs I use Helix Native; it's simply easier, more versatile, and sounds better than anything I can do with my real amps.
- madengr 7y agoI built this stereo amp kit a few months ago. Uses single ended 300B tubes with class A bias. Very high quality kit and manual, though I expected that from Japan. Fed directly with a CD player. https://www.elekit.co.jp/en/product/TU-8600R https://www.elekit.co.jp/en/product/TU-8600R Also built some single driver, folded horn speaker kits. These pair will with the tube amp. https://www.madisoundspeakerstore.com/full-range-speaker-kits/fostex-bk-12m-folded-horn-kit-pair/ https://www.madisoundspeakerstore.com/full-range-speaker-kit... I pretty much only listen to string quartets with this setup, and it sounds great.
- microcolonel 7y agoClass T wins. Choose a modulation frequency high enough and you won't need to worry about analog gain controls.
- k_sze 7y agoAre there good resources for DIY amps for stereo speakers? Are those much harder/more dangerous to build than headphone amps? I have a pair of KEF Q100 bookshelf speakers that are still collecting dust.
- swimfar 7y agoThe DIY Audio Forum is a good place to start. https://www.diyaudio.com/forums/index.php https://www.diyaudio.com/forums/index.php Some speaker amps will use mains power and transformers, which means working with high voltage which can be dangerous. But there are some designs which use external purchased power supplies which provide a lower voltage.
- mikorym 7y agoIn South Africa almost all of our electronics are imported. Given the high amounts of unemployment, the technical recession, lack of secondary industries and manifacturing, the brain drain and scarcity of technical skills, etc., I would really like to see something like this develop into a viable business. Of course after that it would not be DIY anymore, but I like the spirit of learning and productivity which at the same time would be refreshing to see it developed into a viable product. If you buy a high end powered speaker or amp here, expect to pay 50% more that the price you see on Amazon. So, you basically have a 50% profit margin even if your cost is equal to the sales (!) price in the US.