New member "pro quality" DIY question(s)

So, where do I begin? My 20+ year old HK integrated amp just bit the dust the other day and a local guy wants $200USD to fix it. This got me shopping around online and I stumbled upon a lot of talk about Onkyo's UK spec A-9010 integrated amp. Queries as to whether or not these UK spec'd amps can be acquired Stateside have gone unanswered. In the meantime, my mind has got to running - my username will tip my hand to some in that I am an avid cyclist that likes steel frames. Not only do I like them, I also build them. Implying that I'm somewhat handy. I know, brazing up a steel frame and bashing out a quality electronic device are not quite the same thing but I also had some electroncs repair training in the Marine Corps way back when and when I read the article today about building a power supply things like the number 1.41 jumped out of my memory. Also, the cycling fabrication thing has intoduced me to things like laser etching, DIY aluminum anodizing, and machining.

One of the things that I'm liking about the Onkyo A-9010 (oh yeah, I forgot to mention that while in the USMC I brought a huge 250wpc Onkyo M509 power amp back from Japan bitd so I like their stuff) is the simplicity of the front of it with the big metal volume knob. All this has got me to thinking how hard would it be to machine out a face plate, hack off a piece of aluminum bar stock for a volume knob, anodize them black, get some laser etched graphics done and get a pretty professional looking amp? The only question is can I pull off the innards? Or more specifically, can a (beginner) DIYer achieve the same sound quality as the above mentioned A-9010? Are the parts like Wolfson DACs and like like available to the DIY market?

Thanks ahead of time for any input.
 
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tomchr

Member
Paid Member
2009-02-11 12:58 am
Calgary
www.neurochrome.com
So.... You have the creative juices flowing and fabrication skills. That could be a match made in heaven.

A chip amp or a kit may be a good place to start. There are pitfalls associated with them, but they provide plenty of power and are reasonably fool proof.

Beware of the eBay kits. Many of them implement the "typical application" schematic shown in the data sheet for the chip amp, but not the components that are necessary to make the amplifier work well. Many of them arrive with no instructions and no support.

Wolfson was acquired by Cirrus a few years back. You can still buy their DACs. Just beware that it takes more than a DAC chip to build a functioning DAC. You can get a good idea of what's needed by looking at the evaluation board schematics for the various DAC chips.

Tom
 

xcj999

Member
2014-11-08 4:37 pm
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Arty

Member
2011-02-24 5:04 pm
the verry short answer is an absolute yess.

you can DIY a higher quality thing than most of the commerical stuff.
and you can make it look just as good or better than those.

i must allso mention, most possibly it will cost more than a commerical unit.
if you want cheap and dirty, high power amplifier, then DIY is for you.
one can get killowatt range power for quite a decent price.
if You are looking for quality, then DIY is for you.
most probably even a tda7293/94 will sound just as good as a higher quality commerical unit, for a cheap price compared.
and you can achieve some ultra low distortsion and if needed high power amp for cheap vs commerical ones.

when DIY does not pay off is when you look for nothing special, just the varage guy wanting an absolute avarage amp.
in that deprament price wise nothing kills commerical.

saving money might not be a goal, in that case DIY is allways better.
I suggest as a first step, to clarify what is your goal,
then you can look for options to reach it.
thinking about power range, what impedance it should be able to handle, and what quality you want. there are some design considerations, as verry high power and verry clean sound usualy don't mix well.
most low power but super low distortsion amps are class A, for a good reason.
but anything past say.. 10 or so watts is more likely class AB, and verry high power is the realm of class D.
meanwhile distortsion is hard to describe.
like take tubes for example, tube amps have high THD, but in exchange have a warm sound coloring that many like.
precision instrumentation amplifiers adopted to hi-fi can produce a surgically clean sound, but allso can be verry boring.

the most important is, there is no single best.
no best soud, no least distortsion, and so on.
it is allways subjective.

this allso brings up a question, is it public adress, or for your private joy ?
for PA its better to choose a commonly available setup, as those are made to be enjoyable for the widest public possible.
I for example dislike tube sound ..
 

tomchr

Member
Paid Member
2009-02-11 12:58 am
Calgary
www.neurochrome.com
Thanks for the feedback. Tell me about this Neuro chrome stuff?

Well. I started Neurochrome back in 2011-ish. I was making some circuit boards for myself and figured they'd be useful for others as well. So I put them up for sale. Neurochrome went from a self-sustaining hobby to a business that allows me to pay the bills while I pursue my second career.

I make world class amplifiers. I deliver products that are well designed, well prototyped, well tested, well documented, and well supported. You can see my products on my website: Neurochrome Audio: Precision High Performance Audio Circuits For The DIY Market..

The deal is that you order boards from me and the documentation that I provide, you'll find a link to a project set up with Mouser Electronics (Mouser Electronics - Electronic Components Distributor). Click the project link and order your parts. It's almost as convenient as ordering a kit, but I don't have to maintain the component inventory and don't charge the associated overhead.

My semiconductor-based amps are composite amplifiers. In the composite architecture, a precision op-amp is used to perform error-correction on a power amp. This results in extremely low THD, extremely high power supply rejection ratio (PSRR), low noise, etc.

The most beginner-friendly circuit I offer is the Modulus-86. That combined with the Power-86 is what I use for my main amp. It's the best amplifier I've built to date, and I've built quite a few.

Tom