The switch is a three-position toggle with an on-off-on structure. Robyn Hitchcok is a Britt singer who is hard to categorize... maybe punk, maybe folk, maybe rock, maybe pop. Everyone says, "Thank God 2020 is over." For example, a headphone or line-stage amplifier might only need a gain of +12dB or 1:4... The distortion will be quite a bit higher, as the idle current will have to be reduced to keep within the 6AS7’s plate dissipation limit, but this may not be a liability in all situations, as musicians may prefer a little grunge in the mix... The first was the MBL 101 E MKII, which I have heard called the "Huge Garlic Clove Speaker." Uses for the Aikido Differential Amplifier This year's tenth issue of MJ Audio Technology held an interesting OTL power amplifier circuit design by Mr. Kadou Teppei that I examined in blog number 121. Really?     04 Jan 2005 Well, I finally got around to running some SPICE simulations on the Broskie OTL circuit. 22 September 2009.     13 Sep 2006, Book Review: Building Valve Amplifiers (Jason is a TCJer and he even used my software in designing his tube headphone amplifier.) Actually Building Projects And it does provide gain, making the voltage amplifier answer partially right. In the last post, we saw several single-ended IMCs designed to present 300-ohm loads to the tube-based headphone amplifier that had been optimized for a 300-ohm load. I was about to title this section "My Passive Line Stage," but this is a really a stage-less design. I used to belong to the AES, but no longer. The tube sockets and standoffs are all that attaches to the top of the PCB. Since the topic of my last post was the Super-Triode configuration, wherein a triode strives to maintain a constant idle current by controlling the output of a power amplifier... Super-Triode Bastode Hybrid Amplifier In post 494, we saw a wild-looking hybrid gain stage. In contrast, if he wears an analog wristwatch, he often strives for an elusive precision, stating, "It's 7, 55, no 7, 56." The conversion require that the output be taken from the center-tap of a floating power supply and that the MOSFETs' sources be grounded. A conservative guess would be that 99.9% of tube power amplifiers use the grounded-cathode amplifier configuration, with the load attaching at the plate, not the cathode; the output tubes working as amplifiers, not buffers. The following is an interesting circuit. Thus, the two triode create two-stage amplifier that offers an extremely low input capacitance and, if choose the part values carefully, a supremely good PSRR.... CF & Gnd-K Cascade with Dissimilar Triodes Whereupon, your soul plummets.... What is a Hybrid Amplifier? 18 Mar 2006. More Tube Output Stages She is German and sings beautifully in English and her harp playing is lovely. It allows the greatest gain from the cathode follower and it buffers the cathode follower from the negative power supply noise. In addition, we must use two resistors to set the idle current, as that allows for push-pull operation... This, too, is not a non-gratuitous SRPP design, as the SRPP output stage has a low-impedance load to drive, the output transformer's primary impedance... No-Signal Transformer SRPP Amplifier The 1-ohm resistor is a 4W device, so the maximum current output is 2A.... Dead Quiet For example, since many tubes, such as the 6SN7 and 12AU7, hold two triodes, we face the problem of what to do with the second triode, a problem the SRPP solves nicely... Super SRPP What makes it interesting are three features: a class-A output stage and a wonderful PSRR and a free heater power supply.... Heater Madness Recently, I have been thinking about extremely simple line-stage amplifiers, which would hold one twin-triode tube per channel. No matter what the stator is made from, it must get in the way of the sound.... Inside-Out Electrostatic Loudspeaker I made more than a few mistakes. Here is something that I have wanted for myself for the longest time; its a rotary switch for phono playback that presents three positions: mono, mute, and stereo.... PS-10: All-in-One Tube Power Supply Must it look sexy? My old neighbor (in his 70s), who has many health problems, is supremely indifferent to Wuhan Virus and makes no effort to avoid it.... More Flat-Pack-Power Supply Circuits         07 Apr 2012. I like things artful, crafty, cunning, sly, slick, snazzy, stealthy, tricky, and wily. Such an OTL would require a 100-ohm load, which the impedance-multiplier circuit could create out of an 8-ohm load. Right near the top of the list was Anouar Brahem's album, The Astounding Eyes Of Rita.... Often the only difference between a moving-coil pre-preamp and a power amplifier's input stage is a difference between scale, as in bigger voltages and bigger currents and, often, bigger tubes.... Tube Current Mirrors You have to Sound Good First of all, tango is not just a dance, as it is a music genre as well. If no problems are encountered with the 35.25V output voltage, then we can move on to the high-voltage version.... 15 Mar 2017. Well, with the exception of the first definition, I'd say that I have been doing quite a bit of each with my memories of the 2014 RMAF... It holds two sets of output coupling capacitors and two B+ RC filters, one per channel... Aikido Cascade No Third-party Cookies supported. All class-A output stages, either single-ended or push-pull, run in consant- transconductance; all class-AB push-pull amplifiers do not. More Phono Preamps for Ripping I do not want to confuse any newcomers to tube audio electronics, so I will offer an explanation of the word "Aikido" in the title. The Aikido aspect of this configuration lies in the phase splitter's two outputs holding identical amounts of B+ noise, which the output stage, being a difference amplifier, largely ignores, resulting in a noise-free output.... Aikido SLPS Headphone Amplifier In addition, all the phono stage parts have been shifted into better positions on the board.... Tetra & Positive Feedback GlassWare Products, Available both as Web pages (click the title) and as PDF files for easier printing (click PDF), Available both as Web pages (click the title) and, in a few cases) as PDF files for easier printing (click PDF), Single Articles After mentioning so many great jazz bass players, a reader asked if I was familiar with Tal Wilkenfeld. It has deeply influenced singers as diverse as Aretha Franklin, Frank Sinatra, Johnny Cash, Elvis, Madonna, and Stevie Wonder.... (Well, that’s an easy question to answer: Aikido amplifier. Tidal Many tube lovers falsely believe that the only signal input a triode can accept is at its grid. Gold miners, no doubt, are often surprised by how deep runs a rich vein of gold through the hard rock, which is how I feel after the last three posts on constant-power designs. And it is capable of swinging positive and negative current swings into a load in excess of its idle current, making push-pull operation and, thus, making a portion of the phase splitter answer seem reasonable.   For example, most CD players and stand-alone DAC units that sport balanced-output DACs are not balanced themselves at their outputs, with a single RCA jack per channel as an output. Yes, yes, I know that their setups my indeed sound much better than their previous solid-state or tube line stage. I was once asked what my favorite ten albums were. But then I saw the answer was in fact, yes. Which topology? Why? The ladder attenuator's job is to provide six fine steps of attenuation, each step being -1dB; the series attenuator, eleven coarse steps of attenuation, each step being -6dB. Although I made that post last February, my memory said it must be years older. The only stipulations are that the article be well-written (almost all of the articles before 1965 are), that the article deal with tube electronics and be interesting, and that the article be out of copyright.   03 Jul 2020. He had seen the discrete-transistor design post 484 and wondered if an OpAmp could not be used instead.... Music Recommendation: Linn Records   Since the NW-A45 can function as a USB DAC, I finally ended up hooking it up to my stereo... Music Recommendation: Just as input signals can float, i.e.   26 Sep 2018. Gospel music is a sub-genre of Christian music born of Christian hymns and Negro spirituals. Was that possible? (My son, who has an immune system made of titanium, fell ill and recovered in less than eight hours.) At least that’s the seductive promise. It will get hot and the heat must be wicked away or the LM3886 own thermal management circuit will shut the amplifier down. And no doubt one of Great Britain’s tcjers will find the link to a PDF of the complete patent and relay it on to the rest of us... Improved Followers (line stage and headphone amplifier emphasis) In general, a fat, short heatsink is better than a tall, skinny heatsink. E A good starting point is to take all that you know about voltage amplifiers and stand it on its head. I realized that something more than one short article a month was needed. Tube Clock I wanted a tube-based headphone amplifier that could power (without an output transformer) my 25-ohm Audioquest headphones, with a SPL sensitivity: of 99dB/mid-woofer; besides, I had been sitting on the unused PCBs for far too long.... OTL Output Stages For example, we won't accept any hum or buzz or hiss, only the natural linear cascade of harmonics produced so famously by single-end and class-A, push-pull amplifiers. My quick guess was 4W, which assumed an 8-ohm load.... Here is a new circuit born from the rib of the Aikido amplifier topology. A simple, textbook cathode follower consists of only two key components: a triode and a cathode resistor. Ultimately, we want to keep the 12B4’s delicious delicacy and add the heroic heft and unperturbed might of a 400W solid-state power amplifier.... SuperTriode Meets the Aikido Moreover, today's power-supply reservoir capacitors are staggeringly superior those used 70 years ago. The high-voltage portion used a voltage-doubler circuit one of the two primaries, while the low-voltage secondaries powered the low-voltage regulated negative power-supply rail voltage.... Five Fullrange Driver Loudspeaker RMAF 2013 Letters to the Editor I have to say again; it's amazing just how amazing LPs sound. While 48Vdc is just barely suitable for tube-circuit use, it can easily power a solid-state audio device, even a power amplifier... Chromecast Update Perhaps because so many standalone DACs sport balanced XLR output jacks, many audiophiles decided to give them a listen and liked what they heard. The solution is more B+ voltage.        17 Apr 2006, 24-Volt Aikido Amplifier This volume control holds two 11-position series attenuators. The idea is not hard to grasp, but making a big wiring mistake is easy.... Music Recommendation: Sylvie Courvoisier No, what interests in the circuit is the means by which the output stage is brought into balance... The GlassWare Balancer is the inverse of the GlassWare Unbalancer. The sad situation for an octal partisan like myself is that 9-pin twin triodes greatly outnumber octal twin triodes. Wow! A friend asked me how to pronounce "Tringlotron," but I have no exact answer. Well, I got my own answer this last weekend, which turned out to be my dealing with our broken water heater. I was hunting down high-voltage OpAmps and I came across the ADA4700, which can be used with +/-50Vdc power-supply rails. Otherwise, why bother? Last time we saw how an auto-bias circuit could be implemented that forced the tube under test to conduct a fixed current by adjusting its ground voltage, while its cathode-to-plate voltage remained fixed. The 24V Aikido, however, faced a problem: no 6GM8/6N27P/ECC86 tubes; well, at least no moderately-priced tubes. 3rd-Order Crossovers New Mono Step Attenuator I caught some grief from those who thought my idea of an active speaker stand ludicrous in the extreme. While at the CES in January, I was surprised to find so many gargantuan tube amplifiers: huge, massive, expensive amplifiers, many the size of small refrigerators or big air conditioners. Nonetheless, it functions like a circlotron, exhibiting the same Zo, gain, and distortion... This auger motor is designed to fit Englander pellet... Englander Vacuum Shut-Down Switch Part CU-VS I sat at the same table with recording engineer, Todd Garfinkle, at the Hong Kong Cafe restaurant, but didn't know that he was responsible for creating one of the best sounding CDs I own, El Segundo, by Sera Una Noche, which I reviewed in post 423.... This is something of a coincidence and a small tragedy.... Power-Boosted Class-A Amplifiers 6730 Cedar Path Richmond TX 77407 was recently sold. It is not a complete power supply, as it requires an external power supply to establish the B+ voltage. Mighty Diamonds A servo is a self-regulating system or mechanism that employs negative feedback to bring about the desired state or outcome. 14 Jan 2017. The title is "Subject: active DC offset correction." The CD held a tapestry of sonic landscape, strange and bewildering.... The RIAA equalization is actively implemented.... Music Recommendation: Nor do all of them allow phase reversals or tone alteration or narrowing the stereo image or widening it. Having examined the Tringlotron and holding asymmetry so dear, I knew that I wanted a a simple buffer that would not conform to the diamond template. My first attempt at building a super-triode occurred in around 2003, just after we moved from Michigan and I had a proper workbench built up. The Tringlotron admits modification beyond replacing the constant-current source with a cathode resistor. Or, at they weren't prior to the arrival of the PS-Tube power-supply, as this PCB contains a voltage-doubler circuit for the heater power supply and a tube-rectified center-tapped full-wave power supply for the B+ voltage... PS-Tube Few stereo systems off a tone control and the few that do hold a bass and treble control, which seldom prove adequate. Here is a generalization that is mostly true: most class-AB solid-state power amplifiers leave the factory a bit under biased, although a higher bias would result in better performance.   Time for baby-steps or, rather, downshifting. At the top of this blog entry, we see the Aikido phono pre-preamp circuit, but there is no reason that we cannot use this topology elsewhere, in a line stage amplifier for example. It is an auto-bias/driver circuit for solid state output stages, mostly MOSFET-based output stages.... Back to the Aikido Mono Solo PCB The following all-tube, bipolar, shunt regulator uses a 12DW7, a dissimilar tube that holds 12AX7 and 12AU7 triodes. The sharp distinction between land and sea blurs in New Jersey, where insects fly/swim (flim?)      David Lin, of Firestone Audio, has created a gem of a hybrid headphone amplifier, the “Little Country” headphone amplifier... Current-Output Amplifiers     13 Jun 2018.     17 October 2001     PDF In general, every time I post on tube phono stages, tube headphone amplifiers, or the Circlotron circuit, I can expect a big reaction. The constant-current-draw is a compound circuit that consists of a grounded-cathode amplifier directly coupled to a cathode follower. Fortunately, we have SPICE. Used tractors for sale in North Carolina, USA. It uses 24 resistors and two rotary switches: one 11-position, 1-pole, shorting switch; one 6-position, 2-pole, shorting switch. 11 Nov 2020. Others would pick and choose only a few. The center rotary switch controls both channels and presents coarse decrements, while the two flanking switches afford fine volume decrements for each channel.... PS-6 Practical Different-Differential Circuits The following cathode-coupled amplifier solves two problems: poor PSRR and the dissimilar cathode-to-grid voltages.... Ultra-Low Input Capacitance I own three different Teflon-based coupling capacitors. I am sure that he was right.... Class-G² Circlotron I have been writing about the cathode-coupled amplifier for a long time now and many have asked for a PCB based on this circuit. The quick answer is yes... It sounds impressive. If so, sorry. The topic of driving what is normally seen as a balanced circuit with an unbalanced signal provokes more interest than I expected... MOSFET-Based SRSFPP Circlotron Like many others, I had to wait before I could get my new 80G Zune, as no one had them in stock. Unlike a transformer, they do not isolate. and Sliding Idle Current Want another example? But as so often happens, I ran out of time before I could finnish what I had intended to write... Book Review: Tubes and Circuits Consider this, 99.9% of hybrid amplifiers just pass the signal from one technology to another—usually from vacuum tube to solid-state, but not always. Simple Phase Inverter Circuit Another approach is to use the cascode topology, which was created to achieve many of the same goals as a pentode circuit, such as low-input capacitance and high gain, but without the pentode's higher noise. What the Heck is Aikido Anyway? Electrostatic Headphone Amplifier Well, we can build an all-tube high-voltage shunt regulator. And who—other than capacitor manufacturers and vendors—would argue otherwise? A reader in Russia, Alexey, kindly sent me a link to the following schematic, which appeared at a Russian electronics forum, VEGALAB. What a hunt it was... 300B-Based Triadtron Headphone Amplifier Then Bob Prangnell’s Moskido hybrid push-pull power amplifier, which united the Aikido and a MOSFET push-pull, source-follower output stage. I like the sound, although I could complain about its overly likable quality, as truly beautiful faces do not require gobs of makeup. Well, the same can be said the Tube CAD Journal and myself... New Mono Octal PCBs All-in-One LSA/HPA Update   We will use a 6AS7 double-triode tube in the following examples, as it can draw a lot of current at relatively low plate voltages—and it is relatively cheap and widely available.... Bastode Anti-2gm Power Buffer Yes, the SRPP appears to encompass a cathode follower of sorts, making the unity-gain buffer answer seem at least partially right. Yet, many counter examples exist, great sounding tube-filled pieces of equipment that hold cathode followers. Wrong turn The idea was simple: each channel would get its own Chromecast Audio puck, then I would group both pucks in Google Home app on my tablet... Could it be used... E-mail from Erno Borbely The Equipment Why? His design incorporates two negative feedback loops between the driver stage and the output tubes' plates, along with a global negative feedback loop that includes the output transformer's secondary.... Aikido Mojo Push-Pull Frontend Of course, we can also get high gain from cascading two triode stages. In a nutshell, the SRCFPP achieves push-pull operation by using the bottom triode's cathode resistor as the current-sense resistor, as all the AC current that flows through external load impedance also flows through this resistor, which causes the voltage drop across the cathode resistor to vary with the output signal, which in turn forces an anti-phase current conduction by the bottom triode.... Non-Gratuitous SRPP Headphone Amplifier and Cathode-Coupled Fronted If they are made of Masonite, they must be perforated and made electrically conductive, and sealed to prevent moisture in the air making them soggy. More recently, in 1980, the great James W. Bongiorno patented the basis of the clever Sumo Nine power amplifier he designed... Thorens TEM 3200 Impressive. Mind you, I don't mind changing my mind. Is there a compelling reason for not pursuing this? Who cares what name a circuit has, as long as the circuit is awesome? I was about to write "about 30 years ago," but the more I think about it, it was closer to 40 years ago that I came up with a radically different phono preamp design, but which I never successfully assembled, as I didn't have access to SPICE back then. Katie Melua was born in Kutaisi, Georgia, then part of the Soviet Union, and moved to Belfast, Northern Ireland when she was eight....  5 amp, 120 Volt fusefor all Englander, Summers Heat and Timber Ridge Pellet Stoves. While searching for a SPICE circuit, I found the following circuit, which I have yet to write about here. In other words, we can set the attenuation to any value from 0dB to -65dB in -1dB decrements.... M1 Mono Stepped-Attenuator Applications Well, it’s the 5% difference that interests me the most.... Let's begin with the 1st-order crossover. I recently received an email from a reader, Kurt, who questioned the performance of a cross-coupled design from post 169. Last time out, we saw that class-A output stages are certainly massive and hot, but not necessarily more complicated; in fact, they offer the advantage of easily being auto-biased, unlike class-AB output stages which demand extra effort, especially solid-state output stages; fortunately, tubes are more forgiving.... Class-A Single-Ended Power Buffer Thus, we should incorporate the improvement into the inductor-loaded impedance-multiplier circuit.... Solid-State Still, the single-ended amplifier below will be ultra noisy.... Parafeed and Ultrapath Same topic, but a more precise name. I expected to be used on a bed or sofa, but I mentioned that it could be used with a chair. While most sales reps will claim that the new champagne-colored faceplate on their audio gear constitutes a true advance in the science of home-audio reproduction, truly groundbreaking, pioneering designs were rare, if nonexistent. In fact, after many phone calls and when at last I had at last found one in stock, I had to promise to pick it up within 30 minutes, my Zune being the last one in the store... Sliding-Fixed-Bias Circuits New Design: 12Vac SRPP I have received several great e-mails concerning the topic of digital LP ripping. Below is the bad schematic that I had posted... 6BQ5 issues Fifteen year have passed since my last post on this design, so it is past due for a reexamination. We begin with three sets of bipolar power supply rail voltages, +/-16Vdc, +/-32Vdc, and +/-48Vdc.... Music Recommendation: Paul Lewis   Some clip much more gracefully.     19 November 2001   PDF Interestingly enough, most of the phono preamps that I have built (over the last four decades) have used active RIAA EQ within a global negative feedback loop. Construction Details Soon after creating the Broskie OTL, my first thought was, How good a headphone amplifier would it be? But now I am being hailed as the American tube pope, "Der amerikanische Röhrenpapst John Broskie;" well, at least I am at the German HB HIFI website. Although I like the ease of the class-A, constant-current source approach, I would like to cheat the system a tad, by running a lower idle current and still getting an occasional burst of wattage beyond the strict limits of class-A.... I greatly prefer the simple over the complex, so I would like to get away with just two output tubes, probably EL34s or KT88s. Thus, what I have just written always disappoints. Lest anyone complain that no tubes made an appearance this time, here is a tube-based output stage. Horn tweeters rock—does anyone actually say rock who isn't still dealing with acne?—or should I say horn tweeters diamond? Her name is Jane Greer (September 9, 1924 – August 24, 2001) and she was fine actress, whose studio-given epitaph was 'the woman with the Mona Lisa smile.".      09 Mar 2011. In other words, four Aikido gain stages reside on the PCB. (Even the distortion meter shows a decrease in distortion after the cathode follower, albeit a small one; but when we realize that no global feedback loop is employed, we should be astounded by this result.) Aikido Split-Load Phase Splitter He told me of his many audio projects and his goal of one day being able to build class-A amplifiers, which seemed beyond his abilities due to their added complexity. Stuff Loudness Distortion My goal was to extract the Aikido PP circuit's output stage as a standalone buffer circuit. Like a match bursting into life, briefly burning hot, then quickly smoldering out of existence, many promising blogs begin sincerely and earnestly, with great fanfare, but soon falter, then stall altogether and finally die, littering the web with many grand, but abandoned, endeavors. The feedforward shunt regulator only looks forward, creating a counter noise signal to null the original power-supply-induced noise. In contrast, I have met many tube fanciers who have only owned noval-based audio gear and have shied away from octals due the high prices of NOS 6SN7 tubes... PS-20 Tube Rectifier Power supply PS-SS Only one cable was a high-end creation that cost a stately sum of $30, an outrageous expense back when we paid less $200 in monthly rent... Broskie Cable The first is that audioXpress magazine has just discovered the shunt regulator; or rather, they have re-discovered it, as the title to the article by Ed Simon in the June 2007 issue is “Shunt Regulator: The Almost Forgotten Circuit.” The article is interesting, although not especially well written...