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Discussion Starter · #1 ·
Obviously I see a lot of members here that build their own audiophile-grade speakers, but are there other interesting audio circuits that can made for relatively cheap? I am getting through my copy of Electronics For Dummies and all sorts of circuits popped into my head, but namely was a small digital audio decoder/amplifier. Would the circuit be as simple as adding some sort of IC that can decode digital audio, transmit it as line level analog audio, and then go to a audio amplifier section? Please share some of your circuits that sound just as good as professional stuff and that can be assembled inexpensively!
 

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I design and build, or modify much of the electronics in my system. I don't do it to be cheap, but to get the levels of performance and/or a device that does something I particularly want.

Quote:
Originally Posted by zedrein /forum/post/19599949


but namely was a small digital audio decoder/amplifier. Would the circuit be as simple as adding some sort of IC that can decode digital audio, transmit it as line level analog audio, and then go to a audio amplifier section?

A DD/DTS type decoder requires a lot of licensing fees which even big companies struggle to afford, and little to no actual info available on how to reverse engineer the decoders, so DIY is a non going proposition.


Find a device you need for your system, eg a xover or poweramp, find a kit and build it. This is the best way to start in electronics building. Learn from that and go onto something more complex, but learn as much of the whys and hows as you can during that time. Talking about solid engineering, not audiophile stupidity.


Even though it is about tubes, possibly the best book ever written about audio is Morgan Jones' Valve Amplifiers, an exceptional work that explains a lot more than just valves clearly and plainly in a simple a language as possible, from a solid engineering perspective. IIRC, MJ is an ex BBC Engineer. Google Books has a good preview of both that and Building Valve Amplifiers.
 

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Discussion Starter · #4 ·
Tremendous! thanks for those resources, gentlemen! I am a little bummed that a S/PDIF decoder/amplifier would be a difficult proposition, but that's the way she goes. I would love to have a valve amp system, even if it was just stereo! How awesome that must sound.
 

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Quote:
Originally Posted by zedrein
Tremendous! thanks for those resources, gentlemen! I am a little bummed that a S/PDIF decoder/amplifier would be a difficult proposition, but that's the way she goes.
Not difficult but impossible unless you are a large company that meets their criteria. Many of the hardware boards in many AV processors are bought it from companies that design them and sell them on to be incorporated in other products.
Quote:
Originally Posted by zedrein
I would love to have a valve amp system, even if it was just stereo! How awesome that must sound.
Valve amps* have a mystique which isn't really warranted as they just aren't that great. But they are fun to build and a worthwhile starting point, but the book is so good it's worth having anyway.


Also go to www.passdiy.com where there are a number of amp and preamp projects designed by Nelson Pass or his staff.


* I've designed and built hundreds of tube amps and have thousands of tubes, but I only use them now where their characteristics suit the need, and poweramps usually isn't one of them.
 

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Quote:
Originally Posted by zedrein
Tremendous! thanks for those resources, gentlemen! I am a little bummed that a S/PDIF decoder/amplifier would be a difficult proposition, but that's the way she goes. I would love to have a valve amp system, even if it was just stereo! How awesome that must sound.
You only need a license to use Dolby / DTS multi-channel decoders.


If you want to do 2-Channel, then you don't need a license and there are a ton of parts available for relatively cheap. If you're going to do DIY D/A converters, then I would highly recommend learning how to build your own PCB. I would probably recommend starting with a simple volume control since it is a lot more straightforward and would get you going on the whole PCB thing.


Btw, most every D/A converter out there usually has an evaluation board (sometimes called eval kit) available from the manufacturer, which has the board and a bunch of other sub-circuits so that you can quickly get the circuit up and running. The plus side is they come with schematics too.
 

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 Elliot Sound Products has a lot of neat (and potenially useful) designs. The plans are free, but he sells PCB's for a nominal value should you so desire them.
 

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Unless you're an electrical engineer who's been designing circuits in the audio industry for years, I think you're in a little over your head. Unless of course you're a genius like Tony Stark, then I guess it could be possible.


*Note: I'm an electrical engineer.
 

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Quote:
Originally Posted by yelnatsch517 /forum/post/19609172


Unless you're an electrical engineer who's been designing circuits in the audio industry for years, I think you're in a little over your head. Unless of course you're a genius like Tony Stark, then I guess it could be possible.


*Note: I'm an electrical engineer.

wow talk about condescending...



Building and designing circuits can be fun and challenging and NO you don't need to be a pompous engineer to do it...


I have plenty of friends (including myself) that design and build their own electronics, and the careers of them vary between iron worker, electrician, biochemist, physicist, software engineer, MMA fighter....


Go take your pompous pretentious attitude elsewhere!




Matt
 

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Diyaudio.com has a great DIY amp/electronics forum.
 

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Quote:
Originally Posted by Steve_Vai_rules /forum/post/19609370


wow talk about condescending...



Building and designing circuits can be fun and challenging and NO you don't need to be a pompous engineer to do it...


I have plenty of friends (including myself) that design and build their own electronics, and the careers of them vary between iron worker, electrician, biochemist, physicist, software engineer, MMA fighter....


Go take your pompous pretentious attitude elsewhere!




Matt

Wow, talk about being overly sensitive.


How am I being pompous? I barely graduated a year ago...

I'm merely letting him know that as an electrical engineer, I understand what's involved in circuit design and he shouldn't take it lightly.


FYI, building electronics != to designing circuits just like building speakers are different from designing speaker drivers. Maybe I read him wrong. If he's planning on just purchasing electronic components and soldering them together based on existing designs, then that's fairly simple.
 

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Discussion Starter · #12 ·
Oh no! I've done and started a fight!! You know I do take advice from engineers seriously so if I really am over my head I'd definitely like to know it. My basic philosophy is that if I can build audio circuits that are just as good as consumer level stuff, then I'd think investigating this stuff might be worthwhile, but if it's more financially viable to just buy an audio receiver etc. from a manufacturer, then I'll just go that route. It's all about means to an end, which is high fidelity audio!


PS: And yes, MBentz, I only desire to construct a 2-channel digital decoder/amplifier for my uses. I'd like to get ahold of a digital decoder chip that can read the now outmoded 32kHz sample rate and then send that signal to an D/A converter and finally amplify it cleanly. I wouldn't even want something that big, just enough juice to power some nice bookshelf speakers!
 

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I have thought about building a proven class A amplifier to go with those incredibly efficient waveguide speakers I'm going to build, and right after that...Seriously, I think it would be a great way to learn. I am all for it, and hope to do something like that some day.
 

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Quote:
Originally Posted by yelnatsch517 /forum/post/19609643


Wow, talk about being overly sensitive.


How am I being pompous? I barely graduated a year ago...

I'm merely letting him know that as an electrical engineer, I understand what's involved in circuit design and he shouldn't take it lightly.


FYI, building electronics != to designing circuits just like building speakers are different from designing speaker drivers. Maybe I read him wrong. If he's planning on just purchasing electronic components and soldering them together based on existing designs, then that's fairly simple.

So you are an electrical engineer without any real world experience.. maybe get a job in the field too and come back and wow us with your knowledge....



Electrical engineer isn't a world of just engineers, in fact plenty of advancements come from back yard hobbyists with out engineering degrees, just a desire to learn about technology. This isn't medicine, the knowledge is largely open source, so you don't need to be an engineer to do this.....


I say go try your hand at building circuits, there is lots of information available online to get you started. It's really not as tough as our super knowledgeable engineering friend would have you believe.




Matt
 

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IMHO its not worth it if you are trying to save money, I built a gainclone a bunch of years ago and while its decent it just doesn't deliver the power the my amps do now.


Used amps are so cheap and most of them are built like tanks.
 

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Well, I'm an EE as well. *Disclaimer


If you can find a well-designed circuit out there, there is absolutely no reason you shouldn't attempt it if you feel your soldering skills are up to par. It's when you start branching into the unknown, the design of new circuits (or modification of existing ones) that things start to get challenging.


Now don't get me wrong--I'm a firm believer that there's no such a thing as a 'secret sauce' that only those with a certificate or degree can use. If I did, I never would have found my way into home brewing, woodworking, and speakerbuilding. But just because anybody can do it, does not mean it will be easy. Raw circuit design, especially analog, is quite the challenge, and would likely take a considerable time investment--enough to the point where buying equipment would probably make more sense. But hey, that's never stopped me
. Very often when I need a circuit, I look for something sombedy else has already done that gets me close. 90% of the time this gives me 90% of the solution. The trick is learning enough of what to change to make it fit your needs.


I kinda want to build a tube amp--not so much because they are actually all that good, but because it's an excuse to have one more thing that glows
.


Bottom line--if you don't have much circuit experience, I'd recommend sticking with a proven design. Anyone can do that with a bit of gumption. Feel free to branch into developing a new circuit, but be prepared to spend a LOT of time getting it right (comparable projects in school had teams of three putting in ~100hrs each into them--and we already had taken the circuits courses!).


Steve_Vai_Rules--I thoroughly agree with your handle
.


stgdz--I kinda agree. It's very difficult to make a business case for building an amp, or most other electronic audio circuits for that matter. But I for one enjoy the learning process and the satisfaction of having put together a circuit or design myself.
 

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Quote:
Obviously I see a lot of members here that build their own audiophile-grade speakers, but are there other interesting audio circuits that can made for relatively cheap?

There are lots of options out there. The Audio DIY community regularly build:

Amplifiers (tube, solid state, class D, others).

Pre amps.

Buffers.

DACs.

Volume controls.

Power supplies.


You can purchase ready built modules, or kits that you assemble with a soldering iron, or you can follow published designs and build from scratch. The world is your oyster, and you will easily find something that will match your skill/ability.


Like speakers, with a bit of ingenuity, you should be able to build something satisfying for way less money than comparably sounding equipment that you can buy from audio stores.


Some highly regarded examples:


Nearly ready made Amp: classdaudio.com CDA254 Kit


Self build DAC: twistedpearaudio.com buffaloDAC


Buffer/Preamp, purchase the PCB then source your own components: passdiy.com B1 Buffer


I built this with little electronic knowledge:








Some parts were scavanged from a cd player, some modules were purchased complete, some I soldered up myself, some aspects I "invented".
 

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Arcadia--Welcome to the Forum! As fine a first post as I've ever seen, with that sexy beast
.


Good project suggestions as well. Are those what's inside of your beauty there?
 

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Thanks - I have been a frequent reader of this forum, but is was only today when I tried to post that I realised that I had never joined up.


The project above consists of a Marantz CD63, feeding a Diyparadise Monica 2, and on into a Diyparadise Charlize amp. There is also a USB converter and an aux digital input, so that I can make the most of the DAC.


The examples that I listed before were to illustrate the range of options.


I am about to embark on a new build, and the classdaudio amps were a close contender, but in the end I have decided upon Hypex 180HG hxr units, with the Hypex SMPS power supply. This will be more expensive, but more compact. I will be using the Nelson Pass Buffer, for sure. It can incorporate a volume control, and more importantly it will impedance match the amp and dac perfectly. My dac will be a Diyparadise Monica 3. This will be fed by a Twisted Pear Mux reciever, which should make a better digital source selector than the plastic switch used in my first effort. The main source will be canabilised from a Cambridge Audio D500SE. This will be re-clocked by a Tentlabs XO3. Filtered power lines, and super regulated supplies should nail it. No need to upgrade again, and I will be able to input a SONOS, or similar, for convenience.


I would have liked to have posted links to my suggestions, but new members can't do this.


There really is so much out there.


Anyone wanting to attempt something like this should look long and hard at everything available, and select components slowly and carefully. This part is fun, and if you don't change your mind a few times, then you are not trying hard enough. Just like building speakers, there are compromises to be made (usually cost).


Of course my speakers are DIY also: AOS Studio 12XL, Humble Homemade Hifi Optimos, and Fostex FX120en Fullrangers (currently back in their boxes, awaiting better cabs).
 

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Quote:
Originally Posted by starkiller4299 /forum/post/19613399


well, i'm an ee as well. *disclaimer


if you can find a well-designed circuit out there, there is absolutely no reason you shouldn't attempt it if you feel your soldering skills are up to par. It's when you start branching into the unknown, the design of new circuits (or modification of existing ones) that things start to get challenging.


Now don't get me wrong--i'm a firm believer that there's no such a thing as a 'secret sauce' that only those with a certificate or degree can use. If i did, i never would have found my way into home brewing, woodworking, and speakerbuilding. But just because anybody can do it, does not mean it will be easy. Raw circuit design, especially analog, is quite the challenge, and would likely take a considerable time investment--enough to the point where buying equipment would probably make more sense. But hey, that's never stopped me :d. Very often when i need a circuit, i look for something sombedy else has already done that gets me close. 90% of the time this gives me 90% of the solution. The trick is learning enough of what to change to make it fit your needs.


I kinda want to build a tube amp--not so much because they are actually all that good, but because it's an excuse to have one more thing that glows
.


Bottom line--if you don't have much circuit experience, i'd recommend sticking with a proven design. Anyone can do that with a bit of gumption. Feel free to branch into developing a new circuit, but be prepared to spend a lot of time getting it right (comparable projects in school had teams of three putting in ~100hrs each into them--and we already had taken the circuits courses!).


Steve_vai_rules--i thoroughly agree with your handle :d.


Stgdz--i kinda agree. It's very difficult to make a business case for building an amp, or most other electronic audio circuits for that matter. But i for one enjoy the learning process and the satisfaction of having put together a circuit or design myself.

+1
 
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