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Post by PinkFloyd on May 13, 2006 14:14:26 GMT
PLEASE DON'T ASK Yeh, I know it looks a bit all over the place but this is what I came up with when listening to the MKlll with AD-843. It definitely makes the amp sound a lot more open, "bigger" and oh so High end sounding (read: "Natural") Whether it's "right" whether it's technically wrong I don't give a shit but here's the recipe from memory: Both channels are treated to same: AD-843 from pins 3 & 7 run a 10uF non polar to ground. Parallel on the following.. 1 x 100nF ceramic, 1 x 4n7 polypropylene, 1 x 220nF polyester, 1 x 3.3pF ceramic and bob's your uncle. Ceramics etc. to be fitted directly onto opamps pins, non polars can be fitted in spare trimpot slot on top of the board but, generally, to be fitted very close to pins 3 & 7 of the AD-843. Rick will probably shout at me when he sees this mess but, and it's a big but, it sounds a lot better "with" than "without"
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rickcr42
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Post by rickcr42 on May 13, 2006 15:25:28 GMT
obviously you never seen any of my "Mongo" amps and why you never will.Something to be said for being the "Man of Mystery" that if i posted the pics would shatter a lot of preconceptions and we can't have that can we ! i have so many holes in my Szekeres amp chassis from all the mods it looks like friggin' cheese and I had to wrap it in hardwood just to avoid the chuckles from visitors.I don't even want to contemplate some of my other "projects" and the word "tidy" in the same sentence in fear of the Taste Police coming to my house and kicking my ass........
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rickcr42
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Post by rickcr42 on May 13, 2006 15:35:21 GMT
test tones : A nice "all in one" free program is here www.pro5.com/hififiles/installb.exeif you don't have MSVBVM60.DLL you will need this for the program to work www.pro5.com/hififiles/msvbvm60.zipif you need more I can provide links to everything from single note to noise to warble tones to multifunction software generators on and on and on and......................
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rickcr42
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Rest in peace my good friend.
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Post by rickcr42 on May 13, 2006 20:32:22 GMT
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rickcr42
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Rest in peace my good friend.
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Post by rickcr42 on May 13, 2006 20:33:41 GMT
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rickcr42
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Post by rickcr42 on May 13, 2006 20:39:34 GMT
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FritzS
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Post by FritzS on May 14, 2006 15:15:34 GMT
Off topic! Hi "Rickmonster" - please can you reduce your signature? :-)
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FritzS
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Post by FritzS on May 14, 2006 15:34:47 GMT
OK Fritz, there's a present on its way to Austria for you I won't be using it so, as you're so keen on the WNA amp, I've sent you the WNA Cascode PSU board along with the construction manual and schematic. This will make your WNA sing and will be something else you can work on (and maybe improve) let me know when the package arrives, it went out yesterday. All the best. Mike. The postman is coming friday and brought a nice package Thanks!!!! I have some LM350 and I think over to use them. And make my order for some parts now ;D
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rickcr42
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Post by rickcr42 on May 14, 2006 16:29:24 GMT
what signature ? ;D
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Post by PinkFloyd on May 14, 2006 17:15:32 GMT
Impossible Fritz ? I only posted the board on the 10/05/06 (last Wednesday) it's there already?? WOW! that must be the fastest ever, UK to Austria in 2 days, whoahhhh!! supersonic Camel style
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Post by PinkFloyd on May 14, 2006 17:16:45 GMT
By the way, Rick.... where's your signature gone?
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rickcr42
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Post by rickcr42 on May 14, 2006 23:36:02 GMT
vaporised by Marvin the Martian
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FritzS
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Post by FritzS on May 20, 2006 13:21:46 GMT
PLEASE DON'T ASK Yeh, I know it looks a bit all over the place but this is what I came up with when listening to the MKlll with AD-843. It definitely makes the amp sound a lot more open, "bigger" and oh so High end sounding (read: "Natural") Whether it's "right" whether it's technically wrong I don't give a shit but here's the recipe from memory: Both channels are treated to same: AD-843 from pins 3 & 7 run a 10uF non polar to ground. Parallel on the following.. 1 x 100nF ceramic, 1 x 4n7 polypropylene, 1 x 220nF polyester, 1 x 3.3pF ceramic and bob's your uncle. Ceramics etc. to be fitted directly onto opamps pins, non polars can be fitted in spare trimpot slot on top of the board but, generally, to be fitted very close to pins 3 & 7 of the AD-843. What OP amp use you in railsplitter? Now I think about to use the railsplitter or dual PSU? My list of order is 80% ready - some parts still indistinct Transformer - should I use a 15 VA or a 30 VA toroid or a similar EI type? I know about a parallel thread here
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FritzS
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Post by FritzS on May 26, 2006 11:06:38 GMT
I bypassed the Evox Rifa PHE 450 100nF with WIMA FKP2 10nF/63V and the Nichicon FG 100uF with Evox Rifa PFR 220pF But heared no difference in sound, I think the Evox Rifa PHE 450 100nF are a very good choice With a "sidestep" to AD-843 I am not happy, the trap-brass in Eva Cassidy "Live At Blues Alley" are more detailed, accurate (fine differences) with the LM6171 - with AD-843 I missed fine differences in cymbal, more tszszszszs - with LM6171 more precise tsz-tzs-tsz I use the basic MKII design without inner NFB (330k) and without zobel network, output cap is a 1000uF BG without bypass, input cap not used - instead of C1 - 1,02 kOHM Holco H4 www.stockhammer.at/hifi/wna.php
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FritzS
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Post by FritzS on May 27, 2006 14:14:44 GMT
DIY's fatefulness and doubt - I went back to the AD-843 after all and heared some of my old but very good music for example: Misa Criolla, Jose Carreras, Philips 420 955-2 and Graceland, Paul Simon, WE 925 447-2 WOW!!!! It sounds!!!! Mike you have right! Next time I will modify my amp to a diamond buffer ;D
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FritzS
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Post by FritzS on May 27, 2006 14:22:40 GMT
I found this and it works well: Multisine The program Multisine is an audio signal generator. All signals are calculated offline. After the calculation it is possible to store the data in a .wav file or playback data with your soundcard. The application is written in C++ and uses the VCL library and Win Api calls. softsolutions.sedutec.de/multisine.php
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rickcr42
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Post by rickcr42 on May 27, 2006 19:19:52 GMT
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Post by PinkFloyd on May 27, 2006 20:48:11 GMT
DIY's fatefulness and doubt - I went back to the AD-843 after all Oh yes, give it a while to stabilise and there's really no going back to the LM6171 IMO. "Plus" you now have the advantage of no input / output caps and very little (negligible) DC offset. You have bypassed the power supply leads of the 843 to ground right? 2u2 and 0.1uF in parallel from both +Vs & -Vs to ground. Yes, I know Just be sure not to over egg your pudding Fritz. The biggest mistake is to think that adding "every" latest and greatest tweak will make your amp sound great, this is why so many amps sound shite as the designer thinks that slinging together all the "best" tweaks will result in some super amp.. wrong! It generally results in a piggin' mess. As the Doctor used to say "evolution rather than revolution" One step at a time Fritz and if it sounds good then leave it.
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rickcr42
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Post by rickcr42 on May 27, 2006 21:40:06 GMT
not to piss anyone off but if there is ONE THING that is laughable it is how lemming like audiophiles are and looking over various forums I see "diamond buffer" mentioned everywhere as if it is the holy grail of audio-------NOT ! just had to say it,don't shoot me.......................
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FritzS
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Post by FritzS on May 28, 2006 11:32:24 GMT
Today I had only the bypassed the Evox Rifa PHE 450 100nF with WIMA FKP2 10nF/63V nearby - and bypassed the Nichicon FG 100uF with Evox Rifa PFR 220pF - as seen at www.stockhammer.at/hifi/images2/wna_P1000392_M.JPGThe Evox Rifa PHE 450 100nF is a fast polypropylene cap with dU/dt 700 V/us You have right - but I am an "Faust'scher Geist" (the spirit of Faust - J.W.Goethe) and aspire to the absolut perfection But you have heared both headphone amps - without and with diamond buffer ........ I ordered some AD evaluation boards and will make a copy of the headphone amp for test and evaluation ...... It gives two streamings - one use parts over parts to make the best - others use least parts (as Pass in ZEN amps), only one active FET. Some other questions: * should I remove the ferrite bead between the OP and the output transistors when I use the AD843 * is the Zobel filter implicit necessary - I dont use them currently * should I use the "inner" NFB 330k resistor when I use the AD843 - I dont use them currently
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FritzS
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Post by FritzS on May 28, 2006 11:37:32 GMT
but the diamond buffer is an old thing designed from Walt Jung - on of the "pope's" of OpAmps in HiFi The maxime is to use few as possible active parts in the line, the other is to reduce the load of the OpAmp
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rickcr42
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Post by rickcr42 on May 28, 2006 12:59:28 GMT
which is not even neccessary 1/2 the time.There is such a misunderstanding of the "why" of audio circuits that most who want to sound smart and dress up as "make beleive audio electronic emgineers" will cull circuits known to perform well,use them in combinations then call it a "new design" The Jung buffer is fine straight from the original magazine article but to copy it exactly would mean trampling on the intellectual property of another person so in order to make a buck our local boy geniouses need to make little changes so they can call the design their own. Go to headfi and what do you find is THE upgrade to every single audio application ? Diamond Buffer ! They can not tell you WHY it is an improvement,can not tell you why they even need it but still are hell bent to "improve" every amp on the planet with one even if it is a step back and/or the design itself seriously flawed. If an opamp already has enough current to drive the expected next stage why add another stage ? If the opamp does not have enough current to drive the next stage or you want Class-A operation,something BTW IMPOSSIBLE to have at any legitimate current levels in a portable device yet we see "diamnd buffers" added anyway even though at no more current that a straight opamp. Hell I even see chatter on taking what is known as "The 47 Amp" (a design straight from the BB App.notes originally using the OPA2604) and meant to double the current then adding a buffer or diamond buffer to the output ! I defy any human on the planet to explain to me in any terms that make sense why a person would want to double the current of the opamps then add another current stage on the output which is meant to increase the current. The original design was from a time when current output capabilities in opamps were on the low side so if the end use was to drive a tough load some means of increasing the output current was needed. The "correct" method would have been to add a discrete output stage but BB in its wisdom realised most would have no clue how to do this properly so came out with two ways to get there.Both using the OPA604/2604 "Audio" op amp. Example #1,the OPA2604 dual op Amp : focus.ti.com/lit/ds/sbos019a/sbos019a.pdfOutput current is listed @ 35 mA per opamp.Fine for most apps,marginakl for driving cables or a low impedance transducer so the "fix" is the "47 Amp" focus.ti.com/lit/an/sboa031/sboa031.pdfExample #2,the OPA604 single Op Amp : focus.ti.com/lit/ds/symlink/opa2604.pdfsame +/- 35mA output current but this time a buffer is used to "up' the output current focus.ti.com/lit/an/sboa065/sboa065.pdfThose two Burr-Brown application notes are the bassis for 99.9% of all DIY "for profit" efforst with the final 1% coming directly from this article waltjung.org/PDFs/WTnT_Op_Amp_Audio_2.pdfBecause the word "diamond buffer" is way more sexy sounding than "buffer" or "voltage follower" it is the be all end all of output stages even though most a very badly designed and in fact sound worse than what went before. there is no universal stage to cure all ills and that includes the diamond buffer which to be honest can be equaled in most apps. with a simple LH0033 "monolithic" diamond-buffer with far less oppurtunity for the self proclaimed "engineers" to muck up the sound or even the LT1010 run class-a.Neither method suitable for portable duty unless you want to lug around a serious battery pack. To increase the output stage current but to starve the circuit in the power supply section is so retarded on so many levels........ the other "rip off stage" is from Sheldon Stoke's SDS Headphone amp design found at the Headwize Project Library.This is a proper adjustable bias mosfet Class-A stage but again proves the point that those selling amps are mostly copiers and not designers who take a little of other designs,cob them together then call them personal feats of audio engineering. what do all of the above have in common other than some taking the designs and then calling them their own because they made a change or two ? The hype surrounding each so profit can be made and no more and why each "copy" claims to be even better than the original or a universal "upgrade" to all things audio even when leaving shit alone actually sounds better If you read certain web forums the diamond buffer is considered the holy grail of audio and no matter how crappy your amp it will be improved by the simple addition of which is pure bullshit. again just my opinion but for me personally a well designed properly biased discrete Class-A output stage whips the shit out of every "cobbed together" Diamond Buffer out there but because it is harder to actually design and does not sound as sexy,is not a "universal" but a case -by-case design is not in the running for improving opamp based headphone amps.not because it is not as good but because there is no money in it and that is what really drives the hype.
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Post by PinkFloyd on May 28, 2006 13:15:07 GMT
What Rick said above ^ Do you know that Dr. White didn't really want to add a "diamond buffer" but felt he had to due to the popular demand for one from his customers? "we would like to see a diamond buffer in MKlll" erm....... why??? As Rick says, no need for one and most of these are fitted just to satisfy the punter who wants a "diamond buffer"
Meathead 1: "oooh I have a diamond buffer, a dual rail splitter and a capacitance multiplier it must be good"
Meathead 2: "oh no, that's not good enough, you also need gold plated screws for the chassis otherwise it'll sound crap"
Meathead 3: "diamond buffer? Not good enough you need to stack the buffers, this is the only way to go"
Meathead 4: "stacked buffers are ok but only if they are anodised with zinc"
Meathead 5: "anodised with zinc?? that's so yesterday, mine are gold plated and then cryogenically sealed. essential IMO"
Meathead 6: "gold plated?? nonsense! Mine are the best as Dr. Gilmour personally blows his load all over them, then he encases them in concrete and then he plates them with platinum"
So on and so forth............
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rickcr42
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Post by rickcr42 on May 28, 2006 14:00:59 GMT
Audio as a DIY hobby has gone to hell in the last four years and the spillage is now taking a toll at the commercial end. The 'give them what they want" even when the "want" makes no sense must be obeyed or your product will not sell so better to comprimise a design than to make it right then try to convince the lemmings you are right and they wrong. The simple test of course would be a listening test but we both know that has very little to do with what is considered good added to the fact that if anyone has the audacity to simplify the signal path they will be called crooks and their products overpriced junk no matter the SQ merits. A perfect example is the before mentioned SDS amp.That amp has been around for a while,is a tidy design not overly hard to build,has a good amount of adjustability through biasing the output stage,parts selection and opamp choice,sounds great built "honest" (straight from the project pages/pdf) yet rarely mentioned as a contender until "improved" and called something else even though at heart the same exact amp. I personally consider the original to be a much better amp but the hype machine has done its work well and most consider it unworthy for contention.What would make this "also ran" a "super amp" without changing a single thing ? A new name,pc boards offered for sale at a cheap price then a web page supporting the sales and no more.The "also ran" would now be part of the pop mainstream. Sheldon Stokes works for NASA yet "audio hobbyists" improved the design of his amp enough that they openly call his design 'flawed" or "out of date" (as if there even is such a thing in audio where SET technology from the thirties is in vogue) and everyone beleives it on faith alone I wonder at just how fking stupid people are becoming when at every turn i see a step backwards called a step forward and no one ever questions.a simple "why" would be nice once in a while but when I asked all it ever got back was "f**k you rick you nasty bastard" personal attacks have taken the place of explaining details because it diverts attention from having to explain the facts and causes fanboys to choose sides and follow the leader rather than actually think and come to their own conclusions. Let us not forget COWARDS ! I say that because in my personal experience things that should have been said openly in public were always "I agree with everything you said rick but I don't want trouble so I can't say it in the thread" emails or PMs which in the end leaves the lie out there unchallenged as truth and the main reason I have pretty much pulled back from the DIY audio community as a whole and why I no onger give detailed examples/opinions/design options in general.that and getting a bit tired of seeing my "help" coming out six months later as a commercial product without even a "thanks for the pointers" mentioned openly.No code of honor among this new breed of thieves
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Post by PinkFloyd on May 28, 2006 18:12:30 GMT
Let us not forget COWARDS ! And let's not forget all these little nancy boys "sitting on the fence" frightened to say anything in case the "herd" slaps them on the face for being out of line. Pretty bad when people are "fearful" to comment on things or to go against the grain..... likely they will be branded the antichrist and tarred and feathered right the way up to the city gates before being booted right out of town. Well, sod them, I for one will not be one of the herd and my ethos remains, as always, maximum sound for your pound and I won't become a member of any "team" unless it's team cheap bastard
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