Now, the question is How do we translate this circuit into an all-tube one? F I would love to perform the experiment of placing four identical loudspeakers into two-channel stereo configuration, with the second set of speakers facing the back wall and sitting three feet behind the front speakers... Headphones and Loudspeakers I also note that many DACs offer digital volume controls and that many DACs put out a truly hot output signal. Penguin Cafe resurrected the band in in 2009. The cathode follower output stage stands the conventional transformer-coupled output stage on its head, as the B+ voltage attaches to the output tube plates, while the output transformer's primary center-tap is grounded. The SRPP twist has been applied to solid-state devices for almost half a century, so I expect the technique to be invented soon and used in some $10,000 high-end power amplifiers.... Zen² MOSFET Power Amplifier Like the original Unbalancer, the Unbalancer-Two circuit accepts a balanced input signal and delivers an unbalanced, single-ended output. .. Too-Loud Loudness Compensation Now we can combine the Aikido split-load phase splitter with a totem-pole output stage to create a fine tube-based headphone amplifier.The following circuit would also make a fine linestage amplifier that could work well extremely low-impedance loads, such as Zen power amplifiers or 600-ohm input impedance amplifiers. With the increased interest in push-pull power amplifier, there has been a concomitant increased interest in balanced circuits in general. I discovered this album on Tidal and I am glad that I did, as it is an excellent collection of female tango singers. In other words, the ACF-2 is a unity-gain buffer for those who do not need any extra voltage gain, but do need more current delivery than a passive line stage would allow... Logitech Squeezebox™ Duet & Touch Tubes at RMAF The octal complement to the noval CCDA is here. Capacitance-Multiplier Circuit Last time, I showed a solid-state, unity-gain, single-ended power buffer that maintained a constant-power output-device dissipation... In fact, the current-output version offers a few advantages over its voltage-output brother... Each new circuit gives rise to others, which in turn give rise to others still. Interesting because I came up with the same circuit on my own about 20 years ago, but I never could get it to stop oscillating (big, nasty 50Vpk swings at >500kHz)... Hybrid Headphone Amplifier He provided two links to PDFs associated with the current production of the kit... Error Reduction Circuit This surprised me, as schematics were not rare on the Web, but enthusiasm-dripping e-mails I received told me that something extra was going on. The month January and the word "janitor" derive from the Roman god Janus, the god of beginnings and ends, doors, gates, passages, transitions, and time itself, who—surprisingly enough and unlike most Roman gods—wasn't pinched from the Greeks... Renovating An OTL Amplifier Now let's say that we built such a hybrid amplifier; we would still face the problem of having to house the amplifier. 30 Apr 2018. Instead, my stereo plays an LP that was pressed in 1959, Keely Smith's, I Wish You Were Here. While searching for something else, I found on my hard-drive an interesting patent, which I have no memory of Although I have covered the topic harmonic restoration many times before, the topic admits much more development. Aikido Phono preamp, Rev. Rather than place all the parts on the top of the PCB, I mounted only the tube sockets on the top of the PCB and all the other parts on the bottom. This tube is so popular that I should always preemptively announce whether the circuit at hand can use the 6AS7. I own many, say 30, old-school power transformers that offer center-tapped high-voltage secondary and both 5Vac and 6.3Vac windings. Balanced Cathode Followers Sledding-Bias Output Stage The feed-forward shunt regulator has been covered here before, such as in blog numbers 95, 96 and 97; in addition, it is the basis of the Janus regulator. Phono stages immediately come to mind, but there are many others. What follows is the version with gain... The secret behind all power amplifiers is found in transconductance, the measure of the change in current flow through an electronic device relative to the change in control voltage. Differential Cross-Coupled Circuits I promised a new phase splitter design and here it is, the Aikido phase splitter. Remember the Tringlotron? My last two posts have caused a stir in Tubeland it seems. The PS-12, small bipolar power supply is no more, but it finds its replacement in the PS-19.      Over the years, I have hard-wired together the following circuit many times, as I often have used solid-state rectification in my own tube power amplifiers and I didn't want the 5Vac rectifier winding to go to waste. I have been researching Graham Maynard's amplifier designs, since my last post. The tube sockets and standoffs are all that attaches to the top of the PCB. We could, but it will require more gain. In order to run a pentode in pentode mode, not triode-mode, we must establish a fixed cathode-to-screen voltage. They have no choice but to run in strict class-A and to idle on the sweet-spot of the plate curves... Split-Load Phase Splitter as SE OPS The simplest push-pull V-to-I amplifier would be one that used only two active devices. One subtlety that I failed to consider was the importance of the output impedance, i.e. Living in a Wireless World Well, for me, the best sound means the sound I would most like to take home with me; it was the best because it pleased me most... In other words, my last post was meant to be twice as long, which would have been a mistake. Here's the link. Tal Wilkenfeld Love Remains By nature, I am an essayist, not a diarist Post-It-note scribbler... 22 Aug 2021.       15 Jan 2008, More Classic Articles? How did it work? We can do it, but it will not offer a balanced output voltage. Power is satisfying; it’s like money in the bank, good looks, strength, charm, and wit—more is always welcome. 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. "Blogfade" along with "podfade" are new words to describe when a blog or a podcast that had been posted regularly begins to post sporadically and then ceases altogether without neither warning nor explanation. 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... Balanced Output My Well, I did mention it in my last post and now the email flows my way, filled with questions about class-A2. It is time for me to fix a small problem. I like the idea of the cartridge's delicate signal being amplified in a balanced fashion.   And like the Noval Aikido, the Octal Aikido PCB holds a large RC power-supply filter in each channel, but no power supply. Since a constant-current source, much like a high-inductance choke, can also shield the audio circuitry from the power-supply noise, why not get twice the benefits from the constant-current source? Which technology? I do not remember how I discovered the Italian duo, Musica Nuda, but I am glad that I did. The original circlotron circuit held an output transformer and two floating power supplies per channel; which was enough of a pain in the days of mono, but with the advent of stereo, the notion of a stereo power amplifier that required at least four tube rectifiers failed to appeal—big time.     30 Nov 2020. If there is no gain, there cannot be much distortion. The Aikido PH-1 is an excellent tube-based phono stage. Errata In a way, this makes sense, for although I do own a few DHT tubes, none of my audio gear actually uses them.... Music Recommendation: Easy to Remember A 6AS7-Based OTL Eight 4-ohm loudspeakers can be placed in series, as could four 4-ohm loudspeakers or two 16-ohm loudspeakers. I stopped reading audioXpress long ago and didn't renew my subscriptions to Electronics World and MJ Stereo Technic a decade ago. 99.9% of all solid-state amplifiers use three stages: an input stage that provides gain and a feedback input, a second stage that provides gain (VAS, voltage amplification stage) and current gain, and a unity-gain buff output stage. Of course, DACs are not the only balanced-output signal sources, as many new pieces of stereo gear sport XLR output jacks. Since the both of its triodes are in series, the bottom triode must counter power-supply-noise-induced current variations to null the noise at the follower’s output... The following V-to-I amplifier (super-buffed line-stage or headphone amplifier) uses low-voltage bipolar power-supply rails (+/-40Vdc) and a high-voltage B+ voltage (+200Vdc). A goldmine? For example, not every movie soundtrack qualifies as being classical music, even if a full orchestra was used in its making. These all-in-one music centers usually held a record player, radio, power amplifiers, and loudspeakers. Oh well.... Tube-Based MC Pre-Preamplifiers Virtual Ground The first uses the famous LM317 positive, adjustable voltage regulator and a high-voltage triode. Loudspeakers A decade ago, you could buy a first-rate 8SN7 or 12SN7 for a few dollars, whereas the 6.3-volt version of the exact same tube sold for $50 to $100. ... LV Aikido Power Supply Electrostatic headphones, unlike dynamic headphones, require huge voltage swings and trivial current delivery—just what tubes do best, which explains a small paradox... Tube clock? It is a passive design, which entails a -3dB insertion losses and whose center frequency is 500Hz and its nominal input impedance is 100k... CCDA Noval Stereo PCBs     20 Aug 2011, Something New: MP3 of Blog Post A small tragedy this, as I like keeping all my ideas in one place, not on many scraps of paper or snippets of pixels. The PS-12, small bipolar power supply is no more, but it finds its replacement in the PS-19. The Aikido line-stage amplifier, known for its stellar PSRR and low-output impedance, makes a good circuit to drive the Tilt Control. Here is why: 4-ohm driver SPL can be specified in two ways... Shelving Network for Loudspeakers This is a great safety feature in a refrigerator or table saw, but can prove a headache-maker with audio gear. loudspeakers that held a 500Hz crossover frequency. During Christmas Eve, I decided that I could quickly build a project. If you are running a passive line-stage, a power buffer will not do you much good, even if you are running 100dB efficient loudspeakers... Single-Ended Power Buffer If I were a tube guru (or a better businessman) I would never distract you with more phono preamp circuits; instead, I would claim that the Aikido PH-1 phono stage was perfect and that all other phono stages are laughingly inferior. Surely "Triadtron" is such a cool name that it demands an equally cool topology. The standard A3 36-position stepped attenuator is 9 inches long, whereas this new A3 Mini is only 5.8 inches wide, but is otherwise identical. The following item has been available, but I haven't made a big deal about it, so many do not know that it exists. Note the B+ voltage, which is substantially lower than in the pure-tube version.... More on the Broskie Buffer I have made over ten years worth of posts on the Ultrapath configuration, which Google will readily reveal. The sound is fabulous, but weak due to the limited amount of class-A watts available... Quick update on my new audio toy, the Sony NW-A45 personal audio device. Another possible use for the hybrid gain stage whose OpAmp drives a grounded-grid amplifier is as the front-end of a single-ended power amplifier. Just plain chance, nothing more; it was just their turn to shine; next year, they probably won't. In fact, we usually face the opposite problem: too much B+ voltage. The Aikido PH-2 PCBs usually sells for $59; now it is on sale for $29. Back in the late 1970s, the Japanese audio company, Technics, came out with "Super Class-A," which combined a dirty, but powerful class-B amplifier with a clean, but voltage limited class-A amplifier.... Class-G Super Class-A Amplifier The only problem is that the FET cannot withstand the high voltages that the triode can.     13 Nov 2012. Why? Single-Ended Circlotron 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