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Post by PinkFloyd on Dec 11, 2006 20:47:52 GMT
Something I do over the Christmas period. Was in the German supermarket chain Lidl today and bought 6 wooden chopping boards on a holder for £2.99. Thing is, the wood is far too nice looking to chop on so I'm thinking of making an uber cool amp enclosure out of them (as good an excuse as any to try out my new drill, bits, cutters and saws) I have always wanted to go crazy in the X-CAN V2 but, as you know, room is limited. My idea is to house the X-CAN V2 boards (side by side) in this chopping board enclosure with maybe a third board which will house any extra bits and bobs I may be throwing in to the mix. One thing's for sure I'll definitely be fitting a stepped attenuator, some enormous caps, quality chassis mount phono sockets, good quality hook up wire, an obscene OTT gold knob, some crazy gold feet....... you get the idea ;D Will also be fitting high quality valve bases into the top of the enclosure so valve rolling will be a lot easier. The insides of the wooden enclosure will be fully lined with high quality copper tape and I may even fit an onboard transformer so it'll be a one box effort...... Yeh, sounds good now just have to get my arse in gear and get it done
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rickcr42
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Rest in peace my good friend.
Posts: 4,514
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Post by rickcr42 on Dec 11, 2006 23:03:30 GMT
or do what I do and come up with a great idea,take so long actually getting to it you forget just what it was you were going to do then one day you come across the same idea and think "Hey,I wish I thought of that ! Damn fine idea !" ideas are easy it is the building that is a bitch
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Post by PinkFloyd on Dec 11, 2006 23:25:32 GMT
I'll have it up and running in two days man, I don't mess around once I get around to a build. So eager am I to complete it I work at it non stop till it's complete. No way could I do a bit today.... put in on a shelf for six weeks then do another little bit.... put it on a shelf for three months and do another little bit.... that's not in my make up, I like to see it through to completion in one go. I'm not sure if my present state of mind (deep depression) is the right time to go into this but, hopefully, it'll kick my arse back into gear once I get started..... I've got the parts (100 times over) all I need now is the get up and go... the va va vrooom! Hell man can't we both come up with something original something small and easy to ship but something that kicks arse.... now I've been designated "member of the trade" on Head-Fi I'm gonna make bloomin' sure that label is warranted
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xerxes
Been here a while!
Posts: 1,115
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Post by xerxes on Dec 12, 2006 0:39:16 GMT
I seem to recall someone else suggesting that quite some time ago. ;D All you need to do is come up with an amp that blows everything else on the market, regardless of price, completely out of the water, but only costs a tenner and can be assembled in 20 minutes. How hard can it be? Please include me in any market research/listening tests.
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rickcr42
Fully Modded
Rest in peace my good friend.
Posts: 4,514
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Post by rickcr42 on Dec 12, 2006 1:43:32 GMT
Hmm.....something like an AD825 mated to a class-a current pump output stage with an adjustable output stage bias point setting for Home/Portable duty so you don't kill batteries on the road but don't cut your own throat in SQ at the home front ?
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rickcr42
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Rest in peace my good friend.
Posts: 4,514
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Post by rickcr42 on Dec 12, 2006 1:44:59 GMT
.......................would never sell unless you shrank it down to impossible size (for REAL output power) then prettied it up with boutique parts which would make it way over priced without adding ANYTHING to the SQ that is good
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rickcr42
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Rest in peace my good friend.
Posts: 4,514
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Post by rickcr42 on Dec 12, 2006 1:49:22 GMT
or maybe the Mini-Pentode/Mosfet portable i play around with the design of from time to time ? seems folks want a tube portable even though they can't tell you why and even though it makes no sense being easily WHIPPED by an average opamp headphone amp when it comes to nine volt battery operation........
anything I make is either a serious Class-A current hog or it is lacking in sonics and if I could ever get the two to meet only THEN we would have something special.The pentode could go to DC-DC converter but the output stage if kept discrete Class-A NO FKN WAY MACAROONIE !
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Post by PinkFloyd on Dec 12, 2006 12:22:16 GMT
.......................would never sell unless you shrank it down to impossible size (for REAL output power) then prettied it up with boutique parts which would make it way over priced without adding ANYTHING to the SQ that is good I'm thinking along the lines of something quite small "with" socketed opamp so the end user could play around in this area should he want to. Forget PCB, this will be all point to point wired to extremely high standards. Could be mains powered could be battery powered or both. Not portable but small enough to be easily transportable. No gadgets just an amp with 1 set of inputs, a volume control and a headphone socket. Nope, not even an LED or on/off switch just a little, brick shithouse build, amp that delivers the sonics. Point to point would give me a lot more satisfaction to build over populating a PCB with parts, more time consuming maybe but a real good way of using the soldering iron to its full potential with each amp being unique.... could even turn the point to point wiring into an art form, won't improve sound quality but shows the end user that some real skill and dedication went into the build, something that'll last a lifetime. This won't take off with the ipod brigade but I think will be appreciated by the middle aged connoisseur who values quality over quantity. To sit populating PCBs would drive me insane but producing spaghetti art would definitely interest me
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rickcr42
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Rest in peace my good friend.
Posts: 4,514
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Post by rickcr42 on Dec 12, 2006 14:18:08 GMT
not much you can really do to an op amp gain stage that has not already been done and since it is already an entire self contained circuit not much left you can add externally unless 1-it is a bipolar input device then you can add a discrete jfet input 2-you want to up the output current with an external stage 3-ypu add a DC servo (I hates them my precious ;D ) The rest is no more than input network (Z-Set,FRI/EMI filtration,bandwidth setting),feedback network and output coupling/decoupling to protect the feedback network. No PCB would say you need to either go "dead bug" layout using a unetched pcb as a ground plane,works REAL WELL but looks too messy for most who like to peek under the hood,or wire wrap IC sockets if A-you can find DIP pack OAs B-you can find the damn sockets Dead bug would not allow OA rolling without dismantling the entire circuit and redoing it,sockets not without SMD adapters and then you would need to do the bypasses on the adapter or the stray inductance may send the little beasties into oscillation if they are super fast high bandwidth types so as you can see the "simple" just became a real bitch. Trying to make an "open ended" Op Amp based project never really works because the damn "box" is a closed system itself with each year bringing even less user access to the internals (no DC balance pins,no bandwidth setting/compensation pins,no way to access bias,etc) and why if anything was ever joined at the hip with pcb use it is this which leaves what ? Well not much dude.Class-A operation,OpAmp/Buffer,OpAmp/discrete output....all been done to death with the only "different" amp being the Heed but that no more than a bipolar output version of the very Szekeres Amp from the Headwize library in the update where an opamp front end was added. Three channel operation ? No fan here man.Too many downsides that make it less than optimal in the "plug n play" area.Add a goofy tube in like the Little DOT even though it makes zero sense ? Better if you want to do a thing is set down on paper EXACTLY what your goals are then design around a SINGLE part then optimise for that by making all supporting circuits ideal to the actual part and end use or you will never truly get beyond just another CMOY.You may even consider a dual track with track A stricly portable use so setting OA parameters in one direction and the other strictly home use so you can go straight to one of the more current hungry but better sounding chips and optimise THAT for the actual duty it is to perform. Op Amp rolling is a joke mostly unless you have defined goals otherwise you limit yourself to low idling current devices ONLY for road duty leaving out some of the best sounding devices while shortchanging the design for a home based unit having totally different needs. If there is a "cheat" it would be to build for the home system,make the power supply a separate box with that box being an all out assualt then the amp itself more of a "transportable" than "portable" so no wimp teeny tiny fumble boxes or current shy parts which would make for an amp you can take on the road,will have some limited battery operation from an actual "battery pack" but no where near the extended battery life of the minis using dual nines (maybe rechargable from a car lighter adapter ),in essence a REAL AMP but one you can in a pich take outside if you must. with the present shift to efficient cans for true portable use I expect portable amps to be moot in the next couple of years anyway with at most a current buffer/battery to convert the headphone plug output to a lower impedance/higher current though even that may be pissing in the wind considering right now my Grados can be driven from any portable straight out without ANY amp or buffer
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xerxes
Been here a while!
Posts: 1,115
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Post by xerxes on Dec 12, 2006 14:32:06 GMT
Whaaaaat?! Point to point, tubes, portable? No, no, no, I want a "proper amp" dammit!
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rickcr42
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Rest in peace my good friend.
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Post by rickcr42 on Dec 12, 2006 15:13:06 GMT
LM380 bridged mode for 2 watts OTL hooked up to a D-Cell battery pack ;D
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rickcr42
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Rest in peace my good friend.
Posts: 4,514
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Post by rickcr42 on Dec 12, 2006 15:19:34 GMT
cache.national.com/ds/LM/LM380.pdfwas the first true headphone amp I ever built from an article in Popular electronics sometime in the seventies and though i no longer have it being convinced by the press when i was easily swayed that it had to suck I remember a relatively nice sounding amp that being 2W+ was able to drive anything. i also remember banging down to the local Radio Shack a few times to replace the amp chips I ruined when I tried to bend the heat sinking/ground pins up so i could use a small section of copper clad PCB as a heat sink as per the article.Brittle little pricks
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rickcr42
Fully Modded
Rest in peace my good friend.
Posts: 4,514
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Post by rickcr42 on Dec 12, 2006 15:22:19 GMT
cache.national.com/ds/LM/LM380.pdfwas the first true headphone amp I ever built from an article in Popular electronics sometime in the seventies and though i no longer have it being convinced by the press when i was easily swayed that it had to suck I remember a relatively nice sounding amp that being 2W+ was able to drive anything. i also remember banging down to the local Radio Shack a few times to replace the amp chips I ruined when I tried to bend the heat sinking/ground pins up so i could use a small section of copper clad PCB as a heat sink as per the article.Brittle little pricks
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