[DVV]

I wonder what is the general feeling on DIY audio? I ask for two reasons:

1. We had several related topics here, such as the one how much looks influence buying decisions. Well, in DIY looks are up to the end user, the question of where the money went is obvious - into the hit, assuming an honest source, and

2. Over the years, I have evolved several ideas I feel are very interesting sonically. I took known and documented principles and evened up rough edges, added new features, generally simplified things and in some instances, bent some rules. I worked out that if I were to offer kits for it, the purchase price for a complete power amp kit (but the mean way I like 'em) could be fairly reasonable, and even more reasonable if it applied to components only, leaving the power transformer(s), heat sinks and cases to the end user.

Also, it's my curiosity, I really, really wonder how many people would be willing to make their own, the way they want it (flexible), when they want it (upgradeable from Day 1), with professional quality, epoxy printed circuit boards, with complete plans, instructions, etc.

What say you?

Cheers,
DVV

[Marbles]

Aspen (AKSA) seems to do alright doing this.

[Andrikos]

What say we?
We likee!

DVV, lay it on us and see what follows.
What is it? A gainclone? A discrete transistor power amp?
I'm intrigued!

[JoshK]

I think ASPEN audio and Hagerman are both testimates to the popularity of half-kits.   The only problem with no supplying the heatsinks is that they are harder to come by then transformers and cases.

[DVV]

Aspen (AKSA) seems to do alright doing this.

Quite so, Rob. And I have to say, I'm very pleased for Hugh.

My own experience with his 50W amp was very brief, at somebody else's place and system, but it seems to me from what I've heard that Hugh really knows his stuff.

I hope to be able to check it out in greater detail.

Cheers,
DVV

[DVV]

I think ASPEN audio and Hagerman are both testimates to the popularity of half-kits.   The only problem with no supplying the heatsinks is that they are harder to come by then transformers and cases.

Exactly. The alternative is to offer them as well, but due to sheer weight and size I would need, carting them around the globe will be expensive. As Dan Banquer likes to tease me, I like amps which are capable of driving welding arcs, because of my views on how an amp should be bullet proof against almost anything you care to call a speaker.

Obviously, this can be done, but it costs money - in power devices, in power supplies and in heat sinks. In my book, if I call it a say 50 watt per side amp, it has to be able to deliver 50/100/200 watts into 8/4/2 ohms, and cooling off an amp delivering 200 watts requires some mighty heat sinks. Or forced air cooling.

This is the kind of dilemma I face. What to do?

Magic answer - let people choose from printed circuit boards only, to basic parts as well, to added capacitors, to added custom toroids, to added heat sinks, and the last stroke - to added all aluminium case, 19" format.

Cheers,
DVV

[DVV]

What say we?
We likee!

DVV, lay it on us and see what follows.
What is it? A gainclone? A discrete transistor power amp?
I'm intrigued!

Well, looking into my magic chest I see a number of very interesting projects.

I've gone on record for years for saying I don't like the sound of MOSFET amps, except for two. One I've named, it's a New Zealand's Perraux product dating back some years, and the other I've never named. Won't do it now either, because it has no name, but it does music kinda well. When I got it right, I stopped knocking MOSFETs and banged my own head a few times, because I was the sorry ass who forgot his own rule - it's not the technology, it's how you use it. It's rated at 60/120/240 watts into 8/4/2 ohms, and uses VERY standard IRF 530/9530 output devices, cheap and easily available (three pairs per channel).

Other than that, the chest contains:

2 preamps based on op amp/discrete combinations;
2 preamps based on discrete technology;
5 power amps based on op amp inputs (up to 200/400/800 W 8/4/2 ohms)
2 power amps based on discrete technology
3 headphone amps
2 RIAA eq/amp modules (my pride and joy!)
Worked out rotary switch switching (Listen/Record)
Power supplies gallore, you name it, I got it (I'm a registered freak)
2 power line filters (not happy with them, DeZorel is still better),

plus some odd bits and ends.

While all this may sound impressive, remember that this is the result of years of work, didn't just drop out of the blue, plus the fact that some models are elaborations on lower models.

I am currently entranced with a somewhat novel circuit I've come up with, experimenting with it like crazy. I think it's the best I've done so far, but I still need to test it.

Specifications typically look like this - power amp response is up to 350 kHz at -3 dB, but get a load of this, when working into a 2 ohm load in parallel with 2.2uF! For God's sake, don't anybody try this one, chances are you'll blow your amps into overheating and meltdown.

Being and freely admitting it of the Harman/Kardon school, which advocates wide bandwidth, I don't have a single amp which can't go over 1 MHz at 1 watt. Preamps go over 3 MHz. That's because I want practically zero phase shift 20...20,000 Hz. Then I do the reverse - first I get it to 3 MHz, then I build in a filter as low as I can without touching the phase shift at 20 kHz, which is usually around 300 kHz. Keeps RF out.

Most important, I have developed full protection circuitry. Some people object to it, and in my view they are wrong, but I feel no power amp is complete without DC and overheat protection. Yes, I routinely use DC servo, but I can't help worrying that something somewhere migh go wrong and fry the speakers with nice DC. Anyway, I guess I could call it an option.

Lastly, instead of the typical 20...50 mA of idle (bias) current, I routinely push out 120...150 mA; I like to lift the class A to class AB crossover point from its typical 0.1-0.4 watts of dissipation per transistor to 6-7 watts. Cleans up the treble like you wouldn't believe.

Because all this is so, I started thinking - why don't I put a fair price on it and sell the stuff?

My friend and colleague Nik is currently on specialization with Bosch, in Stuttgart, Germany, but he'll be back on December 20. Then he gets to do a fully digitally controlled switching, which introduces remote controls into the shebang.

But the ideas I have ... regarding flexibility and upgradeability. Wow!

Cheers,
DVV

[Marbles]

Dejan,

If you ever decide to go to a digital amp, you won't need to ship much.  If it turns out that you would use a toridal power supply, that would be the only heavy part, including the case, and you would probably only need a small one at that..

BTW, the heat sinks on my Kraft 400's weigh about 75 Lb's apiece  

It does sound like you have an interesting design.

Best of luck.

[_scotty_]

DVV,the only down side I can see to this is that in addition to making the amps bullitproof the kits also need to be idiot proof. There are an amazing number of people who cannot follow simple instructions or understand the need to do so. Also there appears to be a decreasing number of people with an adequate education or inclination to pursue the hobby in this fashion. I think you should make such kits available but be prepared to spend a lot of time on providing support to your customers. Good luck.
                                                Scotty

[DVV]

Rob, Scotty,

Hey guys, I said I was THINKING about it. OK, if I saw no rhyme and reason, I wouldn't even think of it, that's true, but I'm still some ways off from actually doing it.

For a start, practically all my project need to have proper PCBs designed, tried and tested, since models were built on proto boards; not at all presentable, but quite functional regarding actual, hands-on testing. This takes time, at least a month or two, so at the very best, I could have the first units by say end of October. Since I know just about everybody I need to know to provide the necessary logistics for a deal like that, the rest should be fairly straightforward.

Then local laws, which are antiquated (to be nice about it) and 316.7% out of touch with reality; finding a way through that maze will be a feat, but I've done it before, so I can do it again. That too will take time. And so forth - you get the drift, I'm investigating my options here.

Not that the local folks here will have anything to complain about; there will be at least one project which WILL be completed, no matter what, the only condition being that I don't lose any money on it. If I don't make any, well, too bad.

75 lbs for heat sinks, Rob? Wow, that's really laying it on line, my 50 WPC units use 7-8 lbs heatsinks, and those are way over "industry norms". Way to go, Rob.

Scotty, the digital amp idea is nice, but in my view, the current crop of Tripath and Sharp based models is still quite some way off the true high end line. They do bass wonderfully, mid is so-so, and treble is definitely lacking, or so I think. It is a technology still in its infancy, it has much development to do yet, not the least of which are still faster switching transistors. Until that happens, say 2-3 years from now, analog audio will still rule in terms of sound quality, as far as I am concerned.

Cheers,
DVV

[JLM]

DVV,

Time is another factor that cannot be ignored.  As you mentioned, digital is still early on the learning curve.  But if you wait a year to release your product the technology will have progressed so much the more.

MY DIY wish list would include having a ready (local) sources for heat sink, cabinets, transformers, and associated hardware already in place (perhaps with a "packages" and special pricing available).  Try to keep the "one stop shopping" concept in mind for those of us who are technologically challenged (and include with simple to follow yet detailed plans).

Ideally a locally built version (with warrantee) would also be available for the really non-DIY crowd and professional reviews.  (How many DIY professional reviews have you seen?)

[DVV]

DVV,

Time is another factor that cannot be ignored.  As you mentioned, digital is still early on the learning curve.  But if you wait a year to release your product the technology will have progressed so much the more.

MY DIY wish list would include having a ready (local) sources for heat sink, cabinets, transformers, and associated hardware already in place (perhaps with a "packages" and special pricing available).  Try to keep the "one stop shopping" concept in mind for those of us who are technolog ...

You've just summed up my entire reasoning. My idea is to offer everything in parts, so you almost tailor-make your own amp, but also as a one-stop-shop deal, including an all aluminium 19" case, fully predrilled and silk screened.

It irks me when you are called on to make a say preamp with literally zero expansion potential. There's no need for that. Why can't you add a say balanced line input, or a phono RIAA eq/amp, at some later date? Or change that XLR line input for another phono section, or vice versa. Or add a high quality headphone amp, if you already haven't? and yes, even tone controls (I am ready for the flames, gimme all you guys got!). Tone controls are not NECESSARILY bad sound, not if they are done within reason and by the book.

But the most elaborate, highest quality level should be sold only ready made; it's too complex for 99.9% of the DIY guys. Too many sensitive adjustments to be made, requiring measuring instruments.

Oh man, you read right through me. You into voodoo, JLM?

Cheers,
DVV

[Carlman]

ohhh... so you would supply everything in one place... That's not how your original post sounded to me... just that you were going to provide circuit boards and light electronic parts... and try to avoid shipping anything heavy....

What you are talking about could be a web-driven shopping experience like when you buy a PC... where you buy the base part and then add/subtract custom items to it that you want.  If you want to develop or implement this idea, PM me since web design and ecommerce is my specialty.

So if you provide a one-stop situation, with multiple options and a really nice looking finished product line, yes, you will have much of what is necessary to have a successful business venture.  However, it will cost a lot and likely will take a long time to turn a profit.

There's lots of considerations to make as to whether it will be a worthwhile venture... How much do you enjoy being a business manager?  Since that will be your primary function, consider whether you want to take on that job.  If you consider it an unfortunate situation or 'necessary evil' you'll likely be unhappy with your business' results.  

This is just a general comment that doesn't apply to any one person:
Many people want to go into business because they're good at what they do but don't realize they're making a big change in their career and don't realize they aren't particularly good at their new career; running a business.  Some realize they need a business manager, marketing, etc... and you can do all of this to varying degrees.  There is a lot of risk and luck involved.  Anyway, enough of my rambling... best of luck.

-Carl

[JohnR]

Doesn't this thread belong in Market Square?  

[Carlman]

I think so.

[DVV]

Doesn't this thread belong in Market Square?  

No, I don't think so. John, I'm NOT selling anything, I am interested to hear what people might want in DIY audio. Not which circuits, not at what price, but in terms of facilities, expandability, upgradeability and general features.

Even if I wanted to, I couldn't sell more than a single item right now, because that's all I have completely wrapped up as a project, including PCBs. And I didn't even mention what it was - and I won't, not here, because that COULD be taken as soliciting a sale.

And I will not be the one to misuse this or any other similar site.

Cheers,
DVV

[DVV]

ohhh... so you would supply everything in one place... That's not how your original post sounded to me... just that you were going to provide circuit boards and light electronic parts... and try to avoid shipping anything heavy....

What you are talking about could be a web-driven shopping experience like when you buy a PC... where you buy the base part and then add/subtract custom items to it that you want.  If you want to develop or implement this idea, PM me since web design and ecommerce is my special ...

Thank you kindly, Carl, but if and when it gets to the point of actual sales, and even if it does, it's at least two months yet, I'll take the liberty of contacting you personally, not via this site.

As I see it, then it will be a commercial venture, so it will require a far different approach than it does now.

At this point, all I'd like to hear is what people might look for in DIY audio - what features, specs, power outputs, facilities, etc. In short, I'd like to keep it just informative and strictly non-commercial just now.

Cheers,
DVV

[JoshK]

Myself, I'd like to see a really good full featured pre amp kit that doesn't cost more than off the shelf products.   A transport kit would rock!  DAC kit would be very cool as well.   Basically, I would like to see items for which there are very few choices in the DIY kit world.  Those would be my votes.

[Figo]

I would also like to see pre amps/DACs.  Especially tubed ones

[Scott F.]

I would also like to see pre amps/DACs.  Especially tubed ones

You won't see those designs out of Dejan the tube hater  

Hey Dejan, what I would like to see is what we talked about years ago. A pre-amp that contained it's very own crossover(s). Variable slopes, variable crossover points, variable gain for each band and last but not least a remote control that allows gain control for each band (for us lazyphiles). You could make them in bi and tri amped versions. Something absolutely unique to the market.

For the money Marchland charges for his dedicated crossover (not to mention the cost of a good used XO) you could offer a quality kit for not much more money.

And if you really got adventurous, you could offer a tubed version.

OK, I get commision on the first million bucks you make ..... Right?