— Since 1999 — Welcome to over 50 articles on amplifiers, tube-based preamps, crossovers, headphone amplifiers, single-ended amplifiers, push-pull amplifiers, Circlotron circuit design, hybrid amplifiers, cascode circuits, White cathode followers, grounded-cathode amplifiers, tube series regulators and shunt regulators, the Aikido amplifier, tranformer coupling, DACs and tubes — and hundreds of vacuum tube circuits that use 6SN7s to 300Bs, all explained in careful detail. 14 December 2017 Post 405.

The PS-3 power supply has been revised to include a house-ground circuit, just like the PS-1. This is good news for me, as this is the power-supply that I use most in my own projects, as it small, but powerful. The PS-3 holds a regulated heater power supply and an RC filtered B+ voltage power supply that contains either two 470µF/250V or two 150µF/450V reservoir capacitors. That is a lot of juice. I decided to make some minor changes to the Tetra Sans PS PCB, changing its size and adding some extra functionality. It is now half an inch shorter.

I wanted the PCB to be able to fit in more enclosures. For example, the Hammond extruded enclosure is 8.66 inches long and a bit over 6 inches wide; with some care, the new Tetra PCB will fit inside.

Oct 10, 2008. This class seems to be going by pretty fast. Only 4 more classes, and then I take the permit test. All of the material is simple to understand (with an exception for insurance.) and I'm sure I will pass the test. I am so excited to really be getting some progress on beginning to drive. I still have to wait. Mar 16, 2012. One of my favorite vintage drivers' ed/rail safety films. When my brother and I were driving home from the Galleria Mall in Taunton, I saw some teenagers walking on a railroad trestle; THAT sure caused my heart to start racing!). I know, another one of my random 'needed an idea for this journal' posts:P.

I have used this extruded box many times before, for example with my 12Vac Aikido PCB, as shown below. I liked the so much that I decided to add it to the Aikido Noval PCB, making a new All-in-One design. I own many, say 30, old-school power transformers that offer center-tapped high-voltage secondary and both 5Vac and 6.3Vac windings. They languish. They just aren't suited to modern tube circuits that use both solid-state rectifiers and regulated eater power supplies.

Or, at they weren't prior to the arrival of the, 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. The PS-Tube-SS has a brother PCB. (I started to write sister PCB, but the 5Y3 tube rectifier made me change my mind. Sometimes a cigar is just a 5Y3, but not this time.) Where the PS-Tube-SS was designed for those who wish to build a tube power amplifier, the PS-Tube was designed for those who wish to build a tube-based line stage or phono stage—using a tube-rectifier-based power supply. Like the original Unbalancer, the Unbalancer-Two circuit accepts a balanced input signal and delivers an unbalanced, single-ended output. Besides performing the conversion from balanced to unbalanced, the circuit provides a little gain (usually, about 1.7 or +4.6dB) and exhibits an exemplary CMRR (Common Mode Rejection Ratio), which means that it largely ignores common-mode signals.

It's a familiar problem: you would like to build a tube power amplifier, but you are daunted by the thought of having to deal with the high-voltage power supply. The amplifier's input and driver stages are simple enough, as is the output stage, but the power supply must offer several B+ outputs and a negative bias voltage for the output tubes. The solution to this problem is the new GlassWare PS-Tube-SS kit. Simple and self-contained, the PS-Tube-SS PCB holds two cascading RC filters for the high-voltage outputs and negative-bias-voltage power supply and 12Vdc power supply for the input stage. The Triad VPT230-110 toroidal transformer holds two secondaries and two primaries. You already know that the standard Select-C switch allows you to switch between output coupling capacitors—in stereo. The new Select-CM allows you to do this in mono.

In other words, this is a special capacitor selector switch that is designed to work within dual-mono setups, either line-stage or power amplifiers. In addition, this switch differs from the stereo Select-C in that the Select-CM offers four positions: mute, C1, C2, or C1 & C2 in parallel.

The Aikido PH-1 returns—and yes, it has been a long, long time. What is an Aikido PH-1? The Aikido PH-1 is an excellent tube-based phono stage. It holds two Aikido gain stages per channel and uses a passive RIAA equalization network in between the two. In other words, four Aikido gain stages reside on the PCB. One Aikido PH-1board is all that is needed for stereo phono pre-amplification. Few stereo systems off a tone control and the few that do hold a bass and treble control, which seldom prove adequate. Babruvahana Kannada Movie Songs Download.

Often a recording is not so much deficient in just the lows or the highs, but out of sonic tilt in terms of frequency, much like a photograph that is tilted. The PS-12, small bipolar power supply is no more, but it finds its replacement in the PS-19. The PS-19 is a tad bit bigger, being 3.2 by 3.7 inches big. Where most of the increased PCB space went to is the lager heatsinks. Either a 1.5 inch or 2.5 inch tall heatsinks are the options.

The Tr-PS-3 is a regulated bipolar power supply that puts out +/-12Vdc @ 750mA. It uses an LM317 for the positive output and an LM337 for the negative output. The PCB-mount power transformer is the same one used in the Tr-PS-1, a MagneTek FS24-1500. 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. The PS-10 is a new All-in-One power-supply kit for tube lovers. It offers both a high-voltage B+ and a regulated 6.3Vdc heater power source. It is an All-in-One due to it holding everything, including the power transformer.

Brother to the Tr-PS-2, the Tr-PS-1 is a low-voltage, regulated 12Vdc (or 9Vdc or 12.6Vdc) power supply, perfect for powering heaters or replacing the wallwart power supply that powers DACs and other small audio gear. The Tr-PS-1 holds its own power transformer. Power supplies, particularly high-voltage power supplies, are often the big stumbling block to a successful completion of a tube-based audio project. Getting a PCB and all the capacitors, diodes, and resistors needed to populate the PCB is only half the problem.

The other half is getting the power transformer. Well, with the new Tr-PS-2 power supply both problems are solved at once, as the Tr-PS-2 holds its own power transformer. 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. Well, the wait is over.

Back in blog number 245, I revealed a clever cathode-coupled-amplifier variation that greatly enhanced the circuit's PSRR. Brace yourself something completely different: the PS-SS, a new GlassWare power supply kit, isn't for tube fanciers, as it's intended use is in solid-state power amplifiers.

The PS-15 is a new GlassWare power supply kit for tube fanciers. What another power supply? Yes, indeed, as it fills a gap. The PS-15 was designed for those who need a high-voltage power supply with two sets of regulated low-voltage power supplies (usually for powering heaters).

Why would anyone need two low-voltage regulators? More than you might imagine. The noval Aikido cathode follower (ACF) PCB now has a brother: the octal ACF PCB. Some just prefer the sound from octal tubes, such as the famous 6SN7, so its absence was felt, myself included.

Recently, I have been experimenting with cathode-coupled circuits that required a high-voltage, bipolar power supply, which is why had the PS-18 PCBs made. The boards are small, being only 4in by 4in, but pack quite a wallop due to the large-valued capacitors used. Two RC-based pi filters smooth the bipolar DC outputs. The octal complement to the noval CCDA is here. The PCB is almost identical to its noval brother, save for the octal tubes and being 1/10 of an inch shorter.

It holds two sets of output coupling capacitors and two B+ RC filters, one per channel. I have a new signal selector switch, the Select-5, which—in spite of what its name seems to imply—allows you select between four input signals and four signal grounds. For those of you who still have old computers running Windows XP (32-bit) or any other Windows 32-bit OS, I have setup the download availability of my old old standards: Tube CAD, SE Amp CAD, and Audio Gadgets. The downloads are at the GlassWare-Yahoo store and the price is only $9.95 for each program. So many have asked that I had to do it. What is that in the image above?

LOOK, it's a bird, it's a plane, NO IT'S SUPERMAN, no wait, it is a very fuzzy photo of the new Universal Octal PCB and ceramic socket, which includes the black plastic 2in hole trim and four sets of aluminum, hex standoffs and screws and rubber O-rings, but—alas—not the NOS Sylvania 6SN7. My family face the same problem every Christmas: What do you get the man who has everything but commonsense and taste? Quite a big problem that. Well, I decided to give myself a stocking stuffer. I have been eager to try one of my 6in by 6in PCBs in a Hammond extruded aluminum enclosure. I have used this type of box many times before, but never with so wide a PCB.

Below is the result. Always on the outlook for good-sounding coupling capacitors, I recently bought pairs of capacitors from Jantzen Audio (their Superior Z-Cap series), Audyn-Cap (their Plus series), several Japanese polypropylene capacitors, and Cornell Dubilier's 940C series 1µF/1kV capacitors. East Asian Languages Installation Files For Fast more. Every capacitor has its positive and negative attributes. The problem we humans face is that we can readily hear commissions, but fail to spot omissions. Due to popular demand, the SRPP+ is back, minus the power supplies. The new PCB is 6in by 5in and, like all GlassWare PCBs, is crazy overbuilt, with extra thick double-sided PCB material and heavy 2-ounce copper traces. Each channel gets its own large power supply RC filter, whose voltage rating can be a low 250Vdc, perfect for high idle current applications, such as headphone amplifiers; or, 400Vdc, perfect for line-amplifier use.

After many a season returns the Unbalancer. This will be welcome news to many audiophiles, particularly for those who need to convert their DAC's balanced output to an unbalanced output signal, as the Unbalancer can readily receive its balanced signal. If a stand-alone DAC already holds unbalanced outputs, why should I bother using its balanced outputs? The answer is that the balanced outputs are usually taken earlier in the circuitry chain, which allows us to avoid having our delicate signal passing through anymore OpAmps.

This new Aikido stereo PCB is a brother of the Noval Aikido. In fact the PCB is the same size, 6in by 6in. And like the Noval Aikido, the Octal Aikido PCB holds a large RC power-supply filter in each channel, but no power supply. The reason behind this is that you are free to whichever power supply you wish: tube rectification form some, regulated solid-state high-voltage for others. The PS-17 is a new power-supply RC filter. It is not a complete power supply, as it requires an external power supply to establish the B+ voltage.

In other words, it is an add-on for an existing power supply. It could, however, be used with a GlassWare Rectifier-1, which would create complete high-voltage power supply. This PCB uses five cascading RC filters to provide suitably well-filtered B+ voltage for class-A tube circuits. In my previous post, I promised the unveiling of the new GlassWare Tilt Control. Well, here it is. This is a simple affair: a small PCB (1.4in by 2.8in), a stereo, shorting, five-position rotary switch, four capacitors and eight resistors. It is a passive design, which entails a -3dB insertion losses and whose center frequency is 500Hz and its nominal input impedance is 100k.

Almost square, being 6 inches wide and 5.6 inches tall, the new CDDA noval PCB does not hold a raw DC power supply, much like the new Aikido Noval PCB. Note the pattern: no more All-in-One designs. Why yet another Aikido PCB? A very good question that deserves a very good answer. I know that many customers are using four 6DJ8 tubes with the Aikido LV PCB and a 24Vdc power supply, as they write me to tell me about how great their Aikido sounds.

Well, here is the thing: I have tried using 6DJ8 with 24Vdc and they sound so much worse than the 6GM8 tubes in the same circuit that I would never recommend the pairing. Yes, yes, I know that their setups my indeed sound much better than their previous solid-state or tube line stage. The solution is more B+ voltage.

But how do we retain the advantages of low-voltage and still get a decent B+ voltage? Well, the Aikido 12Vac is my solution, as the key advantage of the Aikido 12Vac is that it can be operated from a lowly wallwart power supply, yet develop a fairly high-voltage B+ for the triodes. The new noval Aikido stereo board is square not rectangular and does not hold a raw DC power supply, neither for the B+ nor for the heaters. No more All-in-One, in other words. Why no power supply portion? Simplest answer is that because no one size fits all.

Some want to use an external power supply, some want fully-regulated high-voltage power supplies, some want many cascading RC filters and no regulation, some want only solid-state rectifiers, some want only vacuum-tube rectifiers, some want DC on the heaters, but no regulation, some want AC on the heaters. But all want the Aikido circuit. 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. Where the resistors lay flat against the standard A3 PCB, the resistors stand perpendicular to the PCB on the new A3 Mini attenuator. The Aikido Cascode amplifier is a compound circuit consisting of a cascode input stage amplifier and an Aikido cathode follower output stage buffer.

In a nutshell, the cascode circuit offers two huge features: gain, lots of gain; and low, very low input capacitance; thus, it delivers high gain and wide bandwidth. The Noval CCDA has a brother. When I laid out the new version of the noval CCDA, I also brought the Octal CCDA PCB into Rev. The PCB is now 7 by 6 inches (1 inch longer than the old PCB), which allowed me to add an improved B+ and heater power supplies and to add a second set of output coupling capacitors. Last year, I laid out a new version of the noval CCDA PCB, bringing it into Rev.

The PCB is now 7 by 6 inches (1 inch longer than the old PCB), which allowed me to add an improved B+ power supply and to add a second set of output coupling capacitors. I have been playing with OpAmps lately and I needed a small bipolar low-voltage regulator that would fit in small boxes that were too small for my big B-PS-1. The Trim-1 single-channel, stepped attenuator offers 11 positions and can viewed as high-quality replacement for a potentiometer.

Amazing, just amazing. This stereo attenuator offers 36 volume settings, but only holds two 6-position rotary switches and 24 resistors. This cleverly designed stepped attenuator exploits both the series-attenuator and the shunt-attenuator configurations to yield the best compromise between flexibility, performance, and cost.

One of the best sellers at the GlassWare-Yahoo store is the Select-2 three-input signal selector switch and PCB. I love this signal selector, as it switches the grounds along with the signal hots.On the other hand, most audio gear is wired with all the input and output RCA jack grounds tied together at the rear panel by a long strip of bus wire. In other words, you don't get to choose how to handle the ground connections, as the descission has been made for you. In such a setup, the following selector swith can come in handy, as it only switches right and left chanel hots. Moreover, the Select-4 allows up to six input signal sources to be used.

The following item has been available, but I haven't made a big deal about it, so many do not know that it exists. With a balanced system, we can easily flip the phase of the signal with the GlassWare Select-Phase switch and PCB.

I get a lot of e-mail asking if I believe in phase. In other words, do I believe that we can hear the difference that phase reversal makes? The LV-Regulator uses a simple RC filter (1 ohm & 10kµF) as a pre-filter before the LDO regulator and holds bypass capacitors for all the electrolytic capacitors and a 4.7µF/400V polypropylene shunting capacitor at the output. The 1-ohm resistor is a 4W device, so the maximum current output is 2A. This new power supply board is only 2 by 3 inches big and holds a very simple circuit. Yet the PS-7 can pack a wallop, as it can be used to make a power supply of up to 400Vdc and it holds two 47µF/450V capacitors; a lower voltage version holds two 220µF/200V capacitors, for a power supply of up to 170Vdc; and still another version holds two 1kµF/63V capacitors, for a power supply of up to 50Vdc. Good news for the those audiophiles who run balanced systems.

The BM-1 is a new stepped attenuator that I have designed. It uses 24 resistors and two rotary switches: one 11-position, 1-pole, shorting switch; one 6-position, 2-pole, shorting switch. The configuration is interesting, as it consists of a shunt stepped attenuator cascading into two series stepped attenuators, one for each phase. I have a new stepped attenuator design to offer the DIY audio world, the M1 mono stepped attenuator; and I just love it. The M1 stepped attenuator combines both series and ladder stepped attenuators into a single functional attenuator. 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.

The result is that 66 attenuation settings are possible. In other words, we can set the attenuation to any value from 0dB to -65dB in -1dB decrements. 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.

The circuit is a simple voltage doubler that converts the 5Vac into 12Vdc for the power amplifier's frontend circuitry. Like its unbalanced predecessor, this stepped attenuator offers 36 steps of attenuation for two channels of signal.

The center rotary switch controls both channels and presents coarse decrements, while the two flanking switches afford fine volume decrements for each channel. The PS-6 power supply offers a low-voltage bipolar output (up to +/-50Vdc), suitable for solid-state power amplifier or OpAmps; in addition, the PS-6 power supply holds a voltage quintupler that yields a single high-voltage B+ output voltage roughly equal to five times the rail voltage. I ran out of this PCB a while ago. I then made a few improvements to the PCB, so it is now in Rev. A and in stock at the the GlassWare/Yahoo store. I tested the new board by building a tube-based headphone amplifier, this time with 6N1P and 6H30 tubes. I am running the output tubes hard and I am using a higher B+ voltage (+240Vdc) than last time (200Vdc).

It sounds impressive. The bass is rock solid and it slams. I swear I can feel the bass notes in my chest. The music comes out alive and forceful.

On the other hand, my octal equivalent sounds more mellow, in a radiant, glowing way, which is altogether beguiling. It isn't sloppy by any means; it's just more yang than yin. These two HPAs prove that no one HPA can ever be perfect, as different music requires different amplification. The old 24V Aikido PCB was a hit. I sold many PCBs and kits and I have gotten great comments from users.

(I still listen to headphones with it and it sounds amazingly good as a line-stage amplifier.) The 24V Aikido, however, faced a problem: no 6GM8/6N27P/ECC86 tubes; well, at least no moderately-priced tubes. Not too long ago, the tube was selling for $5, or less; today, they go for closer to $25 to $30; next year, $40 to $50? Moreover, when a supply of a trendy tube grows small, two things happen: obviously, the price goes up and, all too often, the quality goes down. Diminished quality?

High voltage power supplies are a pain. One thing that I love about OpAmp circuits is being able to hook up two 9-volt batteries and run, with just a single bypass capacitor across the positive and negative power supply pins—no lethal voltages and no heater power supply to worry about.

Low-voltage power supplies are a breeze. On this small four by four inch, extra thick (0.094), 2oz-copper traces, USA-made PCB resides both a simple high-voltage power supply and a low-voltage power supply and low-voltage regulator, with each finding its own raw power supply, including the rectifiers and power-supply reservoir capacitors. The low-voltage regulator is meant to power the tube heaters; the high-voltage power supply, the rest of the tube circuit. I have received many requests for an octal All-in-One LSA/HPA PCB like the 9-pin version that weds a PS-1 solid-state, high- and low-voltage regulator to a 9-pin Aikido stage on one PCB.

But I decided that since octal tubes seem more retro than 9-pin tubes and the Janus regulator is a pure-tube design that even uses a tube rectifier, why not wed a Janus regulator to the Aikido stage instead? Is it a piece of artwork, worthy of window display in exclusive art galleries? Or is it the long-awaited analog replacement to the famed Tice digital clock? Or is it a chronometer of exceptional precision? Or is a timepiece of uncanny beauty, suitable for adorning walls of Beverly Hills mansions and Manhattan penthouses? Or is it something like a badge of affiliation to an almost cult-like adoration of vacuum tubes?

Well, it’s all of the above. It is also my latest kit offering. I have created small, 4 by 6 inch PCB that holds a low-voltage bipolar regulated power supply for solid-state use. I have been experimenting with OpAmp circuits lately and I needed a killer low-voltage, bipolar power supply.

The PS-1 regulator PCBs were part of the shipment; but now the boards are in revision B. I made the PCB half an inch taller, which allowed a fatter heatsink to be used. In general, a fat, short heatsink is better than a tall, skinny heatsink. The intrinsic thermal resistance of the metal is effectively placed in parallel in a fat heatsink; in series, a tall heatsink. The upshot is that the PS-1 regulator now holds the same Aavid Thermalloy 50G heatsink that the Janus and H-PS-1 regulators use.

This chubby heatsink boasts a thermal resistance of only 3.7, based on a 75°C rise in natural convection. I have created small, 1.4 by 2 inch, PCBs that hold a single rotary switch and nothing else, other than termination pads for hookup lead. The selector switch assembly accepts three stereo inputs, with both the hot and grounds of each signal source to be selected. So if a signal source, say a CD player, is not selected, neither its outputs or grounds make any connection to the line-stage amplifier. Finally, after many a tease and far too many false starts, arrives the new PS-1 regulator. The PCB is only four by six inches, yet it holds an all-solid-state two regulated power supplies, a high-voltage regulator for the tube B+ and a low-voltage regulator for the tube heaters. Each voltage regulator also finds its own raw power supply, holding the all the rectifiers and power-supply reservoir capacitors required for feeding each regulator its raw DC voltage.

In other words, except for the power transformer(s), the PS-1 PCB holds all that is needed to make a superb regulated power supply for tube-circuits. The revised Janus regulator PCB features a one inch increase in height and now all four high-voltage electrolytic capacitors hold bypass capacitors. This Aikido phono preamp uses passive equalization, rather than active, feedback-based equalization. By cutting the highs and boosting the bass, the phono stage’s inverse RIAA equalization of the LP’s RIAA equalization curve returns the signal to flat. The passive equalization network sits in between two Aikido gain stages.

13 Jul 2007 Reloaded and ready for action, it's back; but it's not the same—it's much better. First of all, the PCBs are meant to hold resistors on both sides; the switch spacing is now 3” instead of 2.5 inches; and, as a result, the PCBs are now shorter, 1.4 inches tall, and a tad longer, 9 inches long. Now the attenuator will fit within a 1U rack-mount enclosure. Second, the TCJ stepped attenuator now offers many more positions, a total of 66 steps with 1dB resolution, as the center switch now presents 11 positions, rather than the old 6 positions. Third, and most importantly, the old open-frame rotary switches have been replaced by Elma switches. Swiss-made, gold-heavy, precisely-designed and exquisitely-made, Elma rotary switches are justly famous as the gold-standard in switches. And like all things golden, they are obscenely expensive.

But when only the best will do The feedforward shunt regulator only looks forward, creating a counter noise signal to null the original power-supply-induced noise. Unfortunately, it is blind to what develops on the other side of the series resistor. In contrast, the feedback-based shunt regulator sees only the disturbance on the output side of the series resistor.

Now, what would happen if we wed the two approaches together? 24 Jun 2007 If you don’t know what the attenuator is all about, you didn’t follow the link to the GlassWare Yahoo! The attenuator is a hybrid design that uses both series and ladder attenuators and three rotary switches to yield 36 positions of attenuation in -2dB decrements. In the first six positions, the attenuator is just a ladder attenuator, with no more than two resistors in the signal path; thereafter, the attenuator uses both a ladder and series attenuator configurations, with never more than eight resistors in the signal path. With -2dB decrements, a maximum of -70dB of attenuation is accomplished. 26 Mar 2006 Dear Readers, I’ve got good news and bad news.

First the good news: the rumored Aikido printed circuit boards do exist, and they are beautiful. They look fabulous and feel solid in the hand. They are extra thick, 0.093' (inserting and pulling tubes from their sockets won’t bend or break this board), double-sided, with plated 2oz copper traces, clean silkscreen and solder mask. (The comment was made repeatedly that they look “military grade,” as if their intended use was inside a spy satellite, not a line stage.).