\n \nLike most Malaysian audiophiles, I look forward to \nA few correspondence on KLANS later got me REALLY \nAha! Time to brush up my electronics! But my \nAnother benefit of Pass’ website is the various \nThis point in time, I was dead set on Class A and \nLegend has it that Bob built an average-sounding amp \nIt’s easy to see the popularity of the Darling. \nThirdly, another DIYer, Gary Kaufman, organized \nWhich brings to this DIYer-wannabe. After visiting \nI began to acquire all the parts I need. As a \nUtilizing some bench drills at the workplace, I \nA couple of late nights later, I finally got it \nPressed ‘play’ and… hooray! I have music! It’s \nA few consultations on the Net later, I began \t<\/span>\n<\/ol>\n \nI tried all 3 and hum is gone. I’m happy! I have \nSo I thought… Then I hear hum again. This time \nThis bugged me for quite a while until one day \n[As an aside, please be reminded that this \nThere you have it! My journey to ecstasy! SE \n <\/span>\n<\/p>\n \nPart 2. Romancing the Darling…<\/a><\/span><\/span>\n<\/p>\n \n <\/span>\n<\/p>\n \n <\/span>\n<\/p>\n \n <\/span>\n<\/p>\n \n <\/span>\n<\/p>\n \n \nIt was not until a year later that I had my chance \nThe sound is good, the sound is nice. Any \n \n<\/p>\n \nThe first upgrade I did was change the coupling \nThen came the next upgrade. I took out the \nOut came the Jensen and in went the Auricaps. And \nBut then I read that paper-in-oil capacitors need \nSo I thought.<\/span>\n<\/p>\n \nA week later, took out the Auricaps and put in the \nNope. It was totally different from the previous \nHowever, please bear in mind that this in no way \nThe next step I did was to put back the cathode \nMuch louder! All this while, without that \n \n<\/p>\n \nAs I enjoy myself with this journey so far, I \nSo is Norah Jones’ voice raw and edgy? Sweet and \nSo what does this leave us DIYers? Our frame of \n \n<\/p>\n \nThe journey continues! Then I got myself some \nThe character changed so much I simply can’t \nFew weeks passed by, then some NOS output \nOh well, this is not the end of the world. \nYeah, enough of techno babble. After some REALLY \n \n<\/p>\n \n Not really but I had to rebuild my \n \n<\/p>\n \n \nSignal circuitry still remains unchanged but \nIt took only 2 days to build but a few days to \nWith all that done, there’s still an evil 1V \nI did exactly that and it was the toughest part of \nOh yeah! Took the opportunity to wire in the \n \n<\/p>\n \nGlorious! Actually I can’t actually remember much \nI tend to agree here. <\/span>\n<\/p>\n \nImagine a few hundred micro-farad in the power \nBut in a system of much lesser capacitance, the \n \n<\/p>\n \nAnyway, this is just what I think. It’s worth \n \n<\/p>\n \n \n<\/p>\n \n \n<\/p>\n \n \n<\/p>\n <\/p>\n","protected":false},"excerpt":{"rendered":" My DIY Darling journey.<\/p>\n","protected":false},"author":1,"featured_media":73,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[6],"tags":[1523,1298,1413,1459],"class_list":["post-72","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-learn-learn-learn","tag-1523","tag-papa-darling","tag-power-supply","tag-the-darling","has_thumb"],"yoast_head":"\n
\nWhen CK Kok, resident guru on DIY Den had an article on a very simple 2A3 based
\nsingle ended amplifier, I don’t have to tell you there’s this bloke here
\ngrinning ear to ear. Like what "Tok Guru" said, once you listen to
\nsome low-power SE magic, your life’s changed for good! You won’t go back to
\nanything else after that. I know the day when audiophiles appreciate the magic
\nof SE amps and high efficiency speakers is a long long way to fruition. After
\nall, the very idea of so few watts bringing so much magic is alien to this
\nindustry where the likes of mega-power behemoths with electrical consumption
\nhigher than your electric kettle is hailed. So, here let me share with you
\nmy journey on an amplifier that consumes less energy than this PC I’m typing
\non…<\/span>\n<\/p>\n
\nThursdays as every Thursday is The Star’s Audiofile day. That particular fateful
\nday is when Audiofile had an article focusing on DIYers. Hmm… the idea
\nappealed greatly to me. If gears are expensive, why not build one yourself?
\nSounds good. Also, if I could pull this off, this will be one MASSIVE boost to
\nmy ego. Hee hee hee… Also, that particular article led to me this mailing
\nlist, Kuala Lumpur Audio NutS. <\/span>\n<\/p>\n
\nserious into considering DIY. Credit goes to that bloke with a tube nickname…
\nYou know who I’m talking about! <\/span>\n<\/p>\n
\naffinity of falling asleep when holding a
\ntelephone-directory-sized-mashed-tree-pulp didn’t bring much progress.
\nFortunately, for my generation, there is the great World Wide Web and off I go!
\nI found a really wonderful site, Nelson Pass’ http:\/\/www.passlabs.com<\/a>
\nthat explains electronics very beautifully to me. Nelson Pass not only has a
\ngift in electronics, he has also the talent of bringing "life" into
\nthe very dry subject of electronics.<\/span>\n<\/p>\n
\nDIY projects there. Particularly interesting is his 10W Zen amp. Now Nelson
\nPass is a serious proponent of class A and I can’t agree more with him. Class A
\nis most linear with least noise though a lot less efficient, which thankfully, homebuilders
\ncan get away with. Anyway, this got me itching towards
\nbuilding my own Zen amp. Hey, with tag lines like "Less is more", can
\nyou out-Zen Nelson Pass?<\/span>\n<\/p>\n
\nMOSFETs seem to marry the convenience of solid state and sonic quality of tubes.
\nHowever, one day on the KLANS mailing
\nlist this guy, Shamsul Bahrin, was waxing lyrical non-stop about his 0.7W
\nDarling amp. What? 0.7W? Are you kidding? Is this even enough to swat flies? I
\nthen realized this guy must be serious when he’s putting aside expensive makes like
\nJolida and Rogers to listen to his Darling. Hmm… the fact that tubes are
\nmuch sexier to look at is another plus. Hence a few e-mails to Shamsul later and
\nI finally found ‘Papa Darling’ — Bob Danielak. <\/span>\n<\/p>\n
\nbut stumbled across some cute looking tubes in a surplus store one day. He tried
\nthem in this amp and the sound impressed him greatly! After optimizing the
\ncircuit, he gave it freely on his website to anyone crazy enough to go a gaga
\nover 0.7W. One of these guys is Rick Francis who’s used to building huge mammoth
\nsized amps, so when one day he built the still-unnamed-tiny-amp, Rick’s wife
\ntook a liking to it and said "what a darling". And there you have it!
\nThe Darling!<\/span>\n<\/p>\n
\nFirst, the choice of output tube, the 1626 which is an unknown in the audio
\nworld. It’s actually a RF oscillator and the curves don’t look good on paper at
\nall but it is Bob’s ingenuity to operate this tube at a region where it works
\nbest for audio. Kudos to Bob. Secondly, the 1626 is a very cheap tube. Thanks to
\nit’s non-audio pedigree, these tubes are available at next to nothing. How about
\nUSD3 per tube? (The 1626 is a victim of its own success, it’s hard to get
\nthem at USD3 these days.) And this is NOS Sylvania, RCA, Tung-sol, Ken-rad, Hytron…
\nCompare this with a pair of Western Electric 300B that cost 300 times more expensive and it’s easy to
\nsee why it’s popular. Oh yeah, plus Bob utilizes cheap components in the
\nDarling. Any half-baked designer can take some boutique parts and assemble into
\na good sounding amp but it takes talent and vision of a genius to do some with
\ncheap parts. The output transformer is a Hammond 125SE that puts out a sound that
\nbelies its cost. How much to build a Darling? How about less than USD300? Since
\nit’s "cheap and good", we got a winner here. <\/span>\n<\/p>\n
\nmega sales of the 1626. He cut deals with surplus stores and shipped literally
\nhundreds of these "poor man’s 300B" to many crazy DIYers. <\/span>\n<\/p>\n
\nBob’s website, I longed to listen to the Darling in action but Shamsul stays too
\nfar away in Kota Kinabalu. Well? What choice do I have? Build one! <\/span>\n<\/p>\n
\ntotal greenhorn, I really paid more than I had to on lots of components. Next
\ncame the most laborious part – planning. My dad always tell me "when you
\nfail to plan, you plan to fail". Plus the fact that I’m going to deal with
\n260VDC here makes the above words more pertinent… After consulting some tube
\ngurus on the layout, I began to build. <\/span>\n<\/p>\n
\nhad a steel plate cut and drilled but it was really more work than necessary.
\nStupid me chose stainless steel and this thing is really tough! I got some help
\nalong the way but only realized how hard stainless steel is when I had to do
\nsome filing myself. You see, octal sockets to fit the 1626 is 27mm in diameter
\nwhile the biggest drill bit available to me was a 26mm. Filing off this 1mm took
\nme one whole hour! (I wonder how tough is "buns of steel"?)<\/span>\n<\/p>\n
\nassembled. The thought of while the rest of the population drifts off to
\nDreamland, and I’m creating magic, makes me
\nfeel good… After powering up (and running away lest it explodes and bring down
\nthe whole neighborhood), all voltages measured okay and I was itching to play
\nmusic already! But you are not going to try on your expensive speakers right?
\nWhere to find cheap speakers? I had an idea but I still feel bad over this…
\nanyway, I went ahead and ripped off my car speakers…<\/span>\n<\/p>\n
\nsinging! Another Darling is born! The Gods must be smiling on me! I still
\nremember the exact date, 10 March 2001, that’s how momentous this has been. (to
\ntell the truth, a buddy had a durian bet with me to complete this amp by this
\ndate after hearing me talk about it for 2 agonizing years.) But something is not
\nright. It hums, badly but its character is there and I could swap tubes! I put
\nin the RCA 1626 and it sounded sweet. Hey, you folks listening to sand amps, try
\nto do this!<\/span>\n<\/p>\n
\nmy mission with vengeance: to eradicate hum from mankind, once and for all.
\nOkay, it’s not that grandiose but the action plan is this:<\/span>\n<\/p>\n\n\t<\/p>\n
\n\t3 knots in an inch. This cancels out, to some degree, stray magnetic flux
\n\tfrom each wire.<\/li>\n
\n\tsome higher potential.<\/li>\n
\nmy music and it’s hum free!<\/span><\/span>\n<\/p>\n
\nit’s more menacing. Sometimes you hear it, sometimes you don’t. Talking about
\nThe Phantom Menance…<\/span><\/span>\n<\/p>\n
\nwhen music was playing and hum was singing, I accidentally touched the RCA
\nshield of my interconnect and… DEAD SILENCE. No hum at all! Huh? I found out I
\nhaven’t grounded the chassis after all! Oh well, a simple wire and that’s it! No
\nmore hum! <\/span><\/span>\n<\/p>\n
\n"one finger poke here and there" tweak is no solution to audio
\nproblems. I had the learning experience of electrolytic capacitors discharging
\nits contents on my fingers not once, but TWICE. Whoever said "once bitten
\ntwice shy" obviously haven’t met me yet.]<\/span><\/span>\n<\/p>\n
\nmagic! <\/span><\/span>\n<\/p>\n <\/span><\/h2>\n
\nRomancing the Darling…<\/span><\/h2>\n
\nAlright! I now have my Darling singing but the fun of DIY has just begun…<\/span>\n<\/p>\n
\nto romance my Darling. You see, I now have my pair of 97dB sensitive Hammer Dynamics
\nSuper 12 up and running! Previously, when driving a pair of 86dBs I had to
\nlisten nearfield and to material with limited dynamic range. Now that my Hammers
\nare up and running, my Darling is able to flex her muscles. Oh yeah!<\/span>\n<\/p>\n
\ndeficiency easily masked by the achievement so far but "itchy hand"
\nstrikes and you are eager to find out how far you can go. But upgrading your DIY amp is different
\nfrom other audiophiles. Instead of buying\/selling amps\/speakers\/CD players\/cables etc,
\nyou focus on the internal organs, the components.<\/span>\n<\/p>\nStep by step<\/span><\/h3>\n
\ncapacitor from a local make to Auricaps. Both are of the same material,
\npolypropylene. Wow! If previously I could hear some echo and an overly
\nemphasized lower midrange. This is now gone! And I thought those were artifacts
\nfrom the Hammers. It is as though a teacher took a cane to discipline her and my
\nDarling behaves a lot more nicely now.<\/span>\n<\/p>\n
\nAuricaps<\/a> and put in the Jensen<\/a> copper foil paper in foil capacitors. Now, this
\nis one massive cap. It’s much heavier and cost more than twice the Auricaps. Put
\nthem in and… my goodness! The sound changed so much it’s like changing amps!
\nNo, I’m not talking about subtle changes here but BIG MASSIVE CHANGES. Albert Au
\nsounded so romantic now, while warm sounding vocals like CaiQin becomes too syrupy, too thick. Huh? Looks like the Jensens work great with low husky male
\nvocals while the Auricaps love to gyrate with femme fatales more. <\/span>\n<\/p>\n
\nI played music for days… <\/span>\n<\/p>\n
\nsome hours to break in and that few hours of playing the Jensens surely didn’t
\ndo justice to it. Okay, let the Auricaps play for a week first, familiarize with
\nthe sound first.<\/span>\n<\/p>\n
\nJensens. This time, I got the Jensens in a different orientation. Though they
\ndon’t come with a recommended orientation, Jensens recommend experimentation as
\nto which orientation sounds better. This time I got the foil side connected to
\nthe input. Played music and…<\/span>\n<\/p>\n
\nexperience. The Jensens don’t sound so thick like before but what’s amazing is,
\nyou hear more treble and bass takes more definition. What’s better is, the
\ncritical midrange is smoothened out somewhat. Great stuff here! Albert Au doesn’t
\nsound so romantic like before while CaiQin is a hell lot more listenable than
\nbefore. This
\nis more like it! More hours of playing later and this character remained
\nunchanged. Great!<\/span>\n<\/p>\n
\nendorses the Jensens over the Auricaps. Each system will work with each
\ncomponent. I know of guys whose Auricap worked best while some found Jensens
\nbetter. The keyword here is EXPERIMENT. Also, in a single ended amp, with so few
\ncomponents, parts quality is downright critical. A change of ONE cap is enough
\nto make you go bonkers. The difference is night and day! As such, use these caps
\nlike how you would like spices. A dash here and there to impart its sonic
\nflavour. <\/span>\n<\/p>\n
\nbypass capacitor. You see, when I encountered a problem with the Darling
\nearlier, silly me clipped off the leads of this cap too much. As a result, I
\ncouldn’t use it anymore. Now that I bought some new caps, better fit them
\nin. And the sound…<\/span>\n<\/p>\n
\ncathode bypass cap, input headroom was compromised. Piano edges, transients
\nbecame distorted. With this cap in, the Darling is playing more like a 0.7W.
\nPreviously, I must have been listening at something like 0.4W! Also, with this cap, I
\ngained more bass, and smoother midrange as well. This is too good! By the way,
\nthis is the great value Elna Starget. A change later to Elna Cerafine, I didn’t
\nhear THAT much improvement.<\/span>\n<\/p>\nDetour<\/span><\/h3>\n
\nbegin to ask this question. What is the reference? Sure, a change of caps here
\nand there changed the sound but is the change for better or for worse? How do
\nyou know? I mean, I used Norah Jones many times as a reference for my changes but
\nhow do I know I’m attaining the right sound? How do I know her voice is
\nsupposed to be like the way it’s playing in my system? Listening on a different set, that
\nsound is a combination of her vocals, her
\nmusic IN THAT SYSTEM. No matter how transparent your system is (if this is your
\ngoal) your system still imbues its character to the music you are listening
\nto. <\/span>\n<\/p>\n
\nsultry? How do I
\nknow? Of course the ideal way would be to kidnap her and get her to sing for you
\nIN YOUR ROOM, then voice your amp, your system accordingly to best approach her
\nvoice IN YOUR ROOM but, sadly, this is not a practical option. (If only I have
\nmy way…) I heard the designer of Harbeth speakers did exactly this. No, not with Norah Jones but with
\nhis daughter’s voice.<\/span>\n<\/p>\n
\nreference is still an interpretation. Well, after thinking for a while, maybe I
\nshould change my approach. Instead of voicing my system to be transparent
\nsounding, why not voice it to give you the most musical ecstasy? To the point
\nthat the very vocals are still distinct and has its own character, whatever this
\nframe of reference can be. I mean, Diana Krall should sound a lot different from
\nNorah Jones, should sound a lot different from CaiQin and so on… Oh
\nwell…<\/span>\n<\/p>\nBack to itchy hands!<\/span><\/h3>\n
\npower supply chokes. You see, my current power supply is a capacitor-resistor-capacitor
\nfilter. With this choke, I can replace the resistor with it and it now becomes
\ncapacitor-choke-capacitor. Chokes work by regulating currents and in a SE amp
\nwhere there is an appreciable amount of DC current, chokes seem like a godsend.
\nOkay, I took out the resistor and replaced it with a 10H 120mA choke. Played
\nmusic and…<\/span>\n<\/p>\n
\nbelieve it! First, I thought I heard less volume. It doesn’t seem to play as
\nloud as before but more warm-up later, it’s not that I’m hearing less but that
\nthe stage has moved backwards! Previously, when Norah Jones sings, she’s
\nstanding just in front of you, but she’s much larger than life! Now, with the
\nchoke, she’s moved backwards somewhat and she’s more lifelike in scale! The
\nstage begins at the speaker face and extends backwards. Wow! Also, if you listen
\ncarefully, bass does go deeper, there’s more definition there and the sound
\noverall is smoother. Great stuff! Don’t tell me how a simple choke brings about
\nsuch a big change!<\/span>\n<\/p>\n
\ntransformers arrived. At the moment, the Hammond 125Es, due to their 100Hz
\ncutoff, doesn’t allow the Hammers to flex its bass muscles. I thus bought this
\npair of NOS output trans to try and see if it betters the Hammonds. Put them in
\nand… this is disappointing. In place of the Hammonds, the music now is dull,
\ndull, dull. Frequency extension is even more limited than the Hammonds. Forget
\nabout the bass, there’s not much treble either. Looks like a bad purchase.<\/span>\n<\/p>\n
\nRetaining the NOS output transformers, I added the Hammonds in as well and
\nrewired the whole mess so that the NOS output transformers play the role of
\nplate choke while the Hammond resume output transformer duties. Also, fitted
\nhuge, massive, great-for-ego 5uF oil caps. What is all this mess, you ask? <\/span>\n<\/p>\n\n\n
\n ![](\"http:\/\/diyparadise.com\/w\/wp-content\/uploads\/images\/stories\/shuntfeed.gif\")
<\/td>\n Well
\n\t\t\tthis circuit arrangement is called shunt feed, or parallel feed, or just plain
\n\t\t\tparafeed. What we have now here is that a plate choke loads the output tube and
\n\t\t\tallows only DC current to flow through. The oil cap blocks DC from flowing
\n\t\t\tthrough the output trans. As such, when signal is present (AC), it’ll go through
\n\t\t\tthe output transformers. This means that the output trans doesn’t seem any DC
\n\t\t\tflowing through it. As such it doesn’t need an air gap. This should be
\n\t\t\teasier to fabricate, with better material, smaller in size… all the
\n\t\t\tgoodies!<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
\nmessy wiring, played music and… Cowabunga! This is even better than before!
\nNo, the character hasn’t changed much but the bass has! I get more bass
\nextension now. This is no more a 100Hz roll-off. It rolls off lower though at
\nquite a steep slope but the fact that it goes lower gives me the smiles! I love
\nthis! Later, I then tried Ultrapath, a circuit configuration that feeds the
\nsignal BACK to the output tube cathode but didn’t hear much difference.<\/span>\n<\/p>\nIs this the end? <\/span><\/h3>\n
\nDarling as I ran out of space to for my DIY fun. This time though, I broke my own rule. I changed too many things at one
\ntime so I really can’t tell which caused what changes. Changes are all in the
\npower supply section. Power supply filter is now choke input instead of
\ncapacitor input. Power supply filter capacitance is greatly reduced. Additionally, tube rectifiers in the form of
\nultra-cool TV damper diodes is now being used rather than the earlier sand
\nrectifiers. Now have 2 power transformers as well, one for B+ while one for
\nfilament. Oh yeah, I took this opportunity to upgrade to a much beefier B+
\ntrans. Used to be 60VA, now it’s 150VA when I actually only need less than
\n30VA… There’s lots of iron now. 2 power trans, 3 chokes, 2 huge ‘sardine
\ncan’ oil caps… All this just for the power supply.<\/span>\n<\/p>\n![](\"http:\/\/diyparadise.com\/w\/wp-content\/uploads\/images\/stories\/newdarling.gif\")
\n<\/p>\n
\nAuricaps were put in instead as they were of a more transparent nature, thus
\neasier to listen to the changes in the power supply. Built the whole thing on 2
\npieces of plywood. One for the power supply (this weigh more than 10kg!) and
\nanother much bigger piece for the signal section. <\/span>\n<\/p>\n
\nreduce all the hum. On wood chassis, it’s harder to work against hum as you
\ndon’t have a metal chassis to ground all the hash away but all rules concerning
\nsignal ground, earth ground and AC filaments still have to be observed. <\/span>\n<\/p>\n
\nripple riding on the B+. On this power supply, circuit simulation showed only
\n10mV but I’m seeing a lot more. So much for simulation… Anyway, tuning the
\nchoke to 100Hz should reduce this ripple by some tenths of dB.
\nThough the choke is rated for 5H at 250mA and calculation shows a 0.5uF cap,
\nputting this cap in had almost nil difference. Huh? Well, 5H is measured AT
\n250mA but we now have only 70mA, so the inductance is actually higher. How much
\nhigher? No idea but slowly paralleling the caps, adding 0.1uF at a time and
\nslowly bring you to the right point. <\/span>\n<\/p>\n
\nrebuilding the Darling. Finally a capacitance of 0.74uF gave total SILENCE on my
\n97dB Hammers. Calculating back, the choke seems to be only 3H… So much
\nfor measurements…<\/span>\n<\/p>\n
\nHammond 125ESE instead of the earlier 125E. Another variable.<\/span>\n<\/p>\nThe sound? <\/span><\/h3>\n
\nabout my earlier Darling sound but there’s unmistakably much more BASS and the
\nsystem is pretty punchy! Bass is quick, I attribute to the low capacitance in
\nthe power supply. JC Morrison used to say those systems touting hundreds of
\nmicrofarad always boast on its ability to release a torrent of energy at a pin
\ndrop but no one ever says how long it takes to recover itself.<\/span>\n<\/p>\n
\nsupply. Yes, the first bass note goes deep, almost exhausting all its charges
\nbut it needs TIME to recharge itself for the next assault. This much capacitance
\ntakes time to recharge fully. If it doesn’t fully recharge, the subsequent bass
\nnotes suffer. <\/span>\n<\/p>\n
\ncharge and discharge cycle can be pretty quick, thus more in time with the
\nmusic. <\/span>\n<\/p>\n
\nSQUAT in the grand scheme of things. Who cares as long as you are enjoying the
\nmusic? And I’m glad to say that the humble little Darling, with its 0.7W worth
\nof Class A SE is worth every 0.1W of them.<\/span>\n<\/p>\n <\/h2>\n