Roasting Pan Audio Amplifier

When you need a rigid, vibration-free chassis for your amplifier, look no further than a roasting pan. I’ve used cast cement for subwoofers, but using a cooking pan bolted to a heavy wooden chopping board is a cheap way to get a rigid surface on which to build audio gear. The amp circuitry used by [Mark] is not complex, but it gets the job done. The “oxygen free copper cable” and “pure silver wire” are not needed, just make sure you have a solid mechanical connection. In other words, just tin your wires, bend small “u” shapes at each end, hook them together, and apply solder to the heated ends. Alternatively, hold the ends of stranded wires parallel to each other and twist the ends together before tinning, then solder. Test everything with a multimeter while moving wire joints to make sure you have no weak connections. Now you won’t waste your money on hyped-up cabling materials.

Thanks to [Gio] (who seems to have some personal audio projects as well) for the tip.

Comments

  1. ... says:

    I fail to see how a solid state amp could be affected in any way whatsoever by vibrations that would be stopped by using a beefy chassis… Seriously, are you worried about getting voltages induced by minute vibrations in the connecting wires?

    I could see for a phonograph, or even a tube based amp, but a op amp solid state amp!

    Admittedly, a baking pan would make a reasonably decent chassis in general, so long as you don’t mind your gear looking like it was built by a 15 y/o…

  2. TJhooker says:

    That heat sink looks cool. Wonder why it’s still rapped in plastic though. I like to go around and look at peoples synthesizer circuits too.

  3. ex-parrot says:

    This is ridiculous. How does building a gainclone in a roasting dish improve it in any way?

  4. smilr says:

    I think the “heat sink” you think is wrapped in plastic is actually the power transformer – to convert the 110V AC down to 50V AC.

    As for why this thing has to be “mass loaded” to keep vibration down – when doing a solid state amp I haven’t a clue.

  5. bender386 says:

    TJhooker that thing in plastic is a toroidal transformer not a heat sink

  6. So if I take an XBox 360 and mount it on a skillet, does that make the project worthy of a HackADay spot? Come on, I thought HAD was for true hacks, not “Ooooh, I need a surface to build on, so let’s use whatever I have in the kitchen”. Now if the guy had used the skillet to make the diaphragm of a [u]speaker[/u], now [u]that[/u] would be worthy of a HAD spot.

  7. ex-parrot says:

    #5: imagine the frequency response of a baking tray driver ;)

  8. jeff says:

    i like it how its listed in ‘portable’ audio hacks

  9. cliff says:

    if you can’t see how vibrations will affect any circuit, solid state or not, you have very little experience with electronics repair. i’ve fixed the same guitar and bass amplifiers three times over for bad solder joints because tendency is to rest amp heads on cabinets, which induce massive vibrations. stereo amps are the same, put them on/near speakers, or on shelves that can transmit vibration from the speakers to the amp chassis, and you’ll have broken solder joints in just a matter of time, pcb or turret board or point to point. every system that has assembly has a mean time between failure; it’s just that certain systems will take longer to degrade based on construction method and environment. when you introduce vibrations, you’re going to be pushing every mechanical connection, including soldered ones.

    as far as exotic materials for build, fabienne is absolutely right; i’ve heard systems that cost tens of thousands of dollars, and they’re by and large boring sounding unless you’re listening to diana krall or kenny g. there’s absolutely no need for pure silver wire and ridiculous cable unless you have the sound source that will utilize it, a circuit design that will utilize it, and speakers that will be able to project said difference. Then you have a system that’s great for listening to shitty jazz while sipping wine and appearing rather pretentious. solid solder joints, effective grounding, and reasonable parts selection are what’s important.

  10. watever wenever says:

    about how much power are u getting out of this amp per channel??

  11. andrew says:

    #8: Give me *one* audio source which is capable of “utilizing” pure silver connections or oxygen free cables… I was agreeing with you until I came upon that part of the post.

  12. htl2001 says:

    #10 I agree, audiophile snake oil is the worst. If he was really worried worried he would have at least shielded those wires, look how close they are to the transformer… I THINK that might actually cause a difference more than wire type.
    http://en.wikipedia.org/wiki/Electrical_resistivity#Table_of_resistivities

  13. #1 A lot of gainclones actually epoxy the components down.

    #11 The LM3875 chip can supply about 50W/channel.

    #12 You can see gold is not the best conductor. The reason is it popular for connections is that it does not oxidize or tarnish like copper or silver. Snake oil products can be used to change the sound. Good on some systems, bad on others. Tinned copper should me good enough.

    Grounding is very important. An external power supply is ideal.

    For those who are not familiar with a gainclone, they are simple to build at a very reasonable cost and they sound very good. The chips are about $4 each.

  14. TJhooker says:

    Smilr I think bender386 already cleared that up, so cha ya know what? UH UH..

    That’s an obscure form of transformer too. I want to role it in dough and deep fry it.

  15. warpfox says:

    Man, you guys are hating on his pan D:

  16. cliff says:

    #10: i was being sarcastic more than anything. what i was trying to get at is that even if you do make an amp with insane wire, ridiculous capacitors and resistors, and over the top connectors, it won’t help your audio path if you’re plugging a $35 cd player you got from wal-mart into the front end. same with any computer’s on-board sound card, all but the best pci sound cards or even most reasonable cd players.

    my point is that to even start going down the road of trying to justify ridiculous wire and components, you’d have to spend several thousands of dollars on ridiculous audiophile equipment and interconnects to even *think* about claiming superior audio “tone” or “dynamics” based solely on wire selection, all the while not having any shielding for your inputs as shown in the photos of this build. and that isn’t even touching on the issue of speakers and then speaker cables. if you have anything less than insanity throughout, your insanity in your component selection for one part of the signal chain is obviated.

    will i say that certain signal paths sound better than others…absolutely. i put a mcintosh c28 in front of a tube headphone amplifier i built and it sounded like god compared to the tube pre i built. there was definite difference. this was coming out of an echo sound card though, with 320kb/s aac files playing. my shitty mp3s still sounded shitty though, and just as bad. and it wouldn’t have mattered if i used monster cables or the cables i made.

  17. Marva Rini says:

    Rocking ein Ort f?r Junge .. hoffe, dass wahr.

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