How good is DIY audio compared to what you can get in the stores? - Page 3

I think that the point about design stringency ties very heavily in with this. Commercial products with a decent size market are often looked at by larger engineering teams. Consider the Denon 3805 mentioned above....... Denon can expect to sell a LOT of those, share technology between higher and lower end models etc etc. A commercial headphone amp will likely be designed by one person. Often, it will be a one-off design with little shared tech or components.

Bigger markets like speaker amps, you can expect the difference to be a lot less than with headphones.

Personally, I DIY because I enjoy building things - probably moreso than I enjoy listening to them. Sure, I could work more hours, earn more money and easily buy a 'better' commercial amp. But seriously, who wants to work more? I'd rather work less, have more fun, and come out with something I can be proud of.

here's another dirty secret about commercial gear. in big name popular-lines (like home theater receivers) they often have a base design and then *depopulate* the board to create artificial variants of the top model (or some base).

I first ran into this with sony gear and their ES line; probably about 20 yrs ago. I bought a carousel cd player that did not have a digital spdif out; yet the ES version did. I happened to order the repair guide for my model and it included the ES version, as well. I could see the diffs in the $10 (what a deal, seriously) repair guide I bought from sony parts/cust svc. so on the next order to them, I bought 3 parts (something like that) and installed them on the unoccupied silkscreened areas, cut a round hole in the back of the chassis where there was some room there (neat how that worked out, lol) and - whammo - I had an spdif out that brought my model up to the expensive ES line. for an rca jack, trafo and something sony calls 'inductor, small' (no joke, it had no value but was only known by that name, exactly).

as I dug more and more into the model lines I found this to be more common than you might imagine. receivers that are rated at 10 watts difference between them and have an extra setting or switch on the front panel, you can bet those have common pc boards and designs to them.

this is false value. each additional 10w of 'power' from a receiver does not relate to a proportional increase in dollar value. but they make you *believe* it when they say it enough times. why have 1 amp when you can have 10 and have 'shelf spam' as its called (a lot of products taking up a lot of space at a retail store; edging out others).

The eternal question is whether the high end models are just souped-up low end models, or the low end models are trickle-down from the high end......

Often times, they won't even depopulate the board, just burn some traces or some other simple action to "break" the design. It's cheaper to pay for components to be installed on a board/design and disable through some simple method than it is to train/organize/pay for manufacturing/inventory/tracking of different, yet largely similar, products. In high margin computer products, it's not uncommon for all products in a line to be built and shipped exactly the same, with a license key to be the only differentiating factor in features and capabilities...

What's so bad about that? I don't really have a problem with that.

I was told a story about old DEC computers - and I do believe it - that back when they had the vax 11/780 and 750 series, the only real diff between two of the similar sized cabinets was that they had different color skins (these are washing machine sized computers; or even larger) AND the backplane was swapped out by DEC field service just to make the customer 'feel' that he's getting an actual upgrade.

what was the real upgrade? firmware. they removed 'every other' (so to speak) NO-OP codes and this made the system, uhhh, faster.

I kid you not.

this is probably from the early 80's timeframe.

(and the upgrade had a bunch of zeroes in the price tag. doh!)

Actually that is really not that much different than how co-hosting is done today if you think about it. Many systems are setup to allocate a resources based on how much you pay em, the hardware is there but until you pay em they only give you so much.

I have also seen IBM offer servers that you can "upgrade" over the phone much like the DEC you describe, however IBM made no bones about the fact that they sold you a software "crippled" box. It just makes sense for them to do this really. Cheaper for both IBM and the Customer overall.

I've seen IBM turn on a CPU in z Series over the phone. It seems "crazy" but it makes perfect economic sense. What you're really paying for is the intellectual property, knowledge, and experience that went into the overall architecture. Particularly, the ability to "hot-add" capacity. A $1k manufacturing cost for a CPU is a drop in the hat compared to the cost of the overall box and the software running on it. It's not uncommon for you pay more $ for a tech to install something than the component actually cost. Same things for SANs and network routers/switches...

As far as DIY audio, I prefer the "best idea/solution/config wins!" aspect. Yes, there are some very brilliant designers out there, but the more eyes on an open design, and the more encouragement to tinker with said design, the more likely that best of breed will percolate to the top.

That, and I have fun building them! After a decade of being away from rosin fumes, it's nice to get my hands dirty on the weekends...

My opinion is that we DIY so we can use parts not even imaginable in commercial ldesigns - Takman/Rikken resistors, Mundorf Silver (and Gold) caps, silver wire, teflon tube sockets, cryo tubes - you name it. None of that would see the light of day commercially, scale or not.

When at TI, we would build chips - some didn't meet the best spec, so were sold at "B" grade - or, if we'd made all our ship requirements, we'd brand the same perfectly comparable (and tested) chips as "B" stock, to meet demand.

We also DIY because we cannot buy what we want - it doesn't exist, so, necessity is truly the Mother of Invention, or barking pumpkin.

Finally, it is also therapy, and insanity. There is no cure.

so true !!!

manufacturing speaker cabs or chassis for electronics can be expensive. you'll pay for it with commericial gears.

i built a pair of uFonkens with Fostex FF85K drivers and Baltic Birch cabs for a friend for $110. they do many many things better than my much more expensive ATC SCM12, but need a discrete/small sub to fill out the bass. i have half a pair finished for myself. based on your postings, i think you would really like them.

I've heard that RCA used to have the engineers make a progressively cheaper series of prototypes and then have them judged by a focus group of random consumers.

Their TOTL would be the least expensive model that regular people couldn't tell from the most expensive, and the BOTL would be one notch up from whatever model regular consumers found unacceptable.

Absolutely. The sort of flip side to this is that we can use parts that we salvage from other gear and scavenge at swapmeets and crusty old electronics stores.

I find all sorts of cool parts and especially old cases to repurpose. One recent treasure is a military power supply somethingorother. The case is nifty, it has a few salvageable transformers inside, old glass indicator lights and a cool knob.

Cost? $20.

Nothing else compares!

Several video cards produced in recent years are able to have their clock speeds boosted dramatically by simply running a pencil line between various pads/traces. Same thing with some CPUs and their clock multipliers. Some videocards were able to have their number of pixel pipes increased by a simple firmware modification (they were present but disabled in lower-end cards).

This is widely known but I'll throw it in for those who haven't heard - CPUs of various speeds but from the same line are almost always the same CPU and manufactured together. What often happens is that due to low demand for the higher speeds, many times chips that are capable of premium speeds are marked at lower speeds with the lower price. That's why many "budget" CPUs overclock so dramatically, often able to match processors 2-3x as expensive.

speaking of cpus, here's 2 that I overclocked via the 'tape or paint' method:



one had a pad covered with tape; that made the motherboard think the cpu was a 3ghz one instead of 2.4

the other celeron chip had some windshield conductive paint (for rear defrosters) over some pins to connect them and make the system think it was a 2ghz cpu instead of 1.6

there was so much headroom in those particular cpus that you're STILL inside the factory heat specs if you overclock them.