It’s been a while since I wrote anything here... Somehow everything didn’t fit in.
But finally we found something that might actually be interesting to someone other than the author.
Frankly, I thought about this topic for a long time... I scoured the internet for everything I could find about this and only after realizing that there was very little really sane and useful information on the topic voiced in the title, I decided to crown my efforts with an epistolary report, for which, first I just armed myself with a camera to capture the process in every detail, trying not to miss a single important moment.
So, I'll start, perhaps, from afar...
It so happened that in more than 30 years of practice in my radio engineering “creativity”, I have never had the opportunity to make a completely tube amplifier.
There were a lot of reasons for this!
I won't list them all. Let me just say that I have had the opportunity to deal with lamps, and quite successfully and productively. But this was associated with pre-amplification cascades and made it possible not to deal with hemorrhoids caused by the need to mount a bunch of hardware in the form of chokes, large trances and the like.
But now I wanted, at least once in my life, to make a classic (and just classic!!!) lamp lamp, with lamps mounted outside that glow beautifully in the dark...
It’s not that I didn’t understand what it would entail for me... But, to be honest, I didn’t realize that, unlike the design of semiconductor (“stone”) equipment, the manufacture of a tube apparatus should rather be classified not so much as electronics, but rather for plumbing work.
But I’m getting ahead of myself...
To begin with, as I said above, without further ado, I typed in the search engine line: “DIY tube amplifier.”
However, having reached (no lies!!!) the tenth page of the search engine results, I realized that the main motive of those who had already managed to tell about their experience of creating tube amplifiers with their own hands was not the desire to teach others something, but rather the desire to show off their own achievements without sharing the secret of such “success” with others.
There is very little real information on HOW to do this, and if it exists, it is very scattered and stingy with details.
Actually, at that moment I realized that they had graciously left me a place in this clearing. J
So, why, in fact, a lamp?
I won’t rant about fashion trends, such as Hi-End. It is clear that this is both fashionable and prestigious, and the sound of tubes really compares favorably with transistors. What?... - Not here with this question! If you just want to “decide for yourself”, brainstorm your friends who have such devices, or managers in salons such as the Purple Legion.
And if you decide that you want this, but are not ready to spend on this “miracle” the money that those who sell it usually ask for this kind of equipment (and who cares, for what reason you are not ready!..) , then this article will probably be useful to you...
So, where to start?
Perhaps in this case you can easily determine the sequence of actions!
In cases with “stone” devices, everything was somewhat different. The filling was collected there first, and only then did we think about the cases for our creations.
In the case of tube amplifiers, everything is exactly the opposite, since for these machines the amplifier body is, first of all, a structure that carries all the main elements. So, first of all, decide how you would like your amplifier to look as a result, that is, decide on the case!
I must say (I know from my own practice) that this is the most difficult issue in our “fatherland”. Alas, in Rus' finding a decent housing for radio equipment is an almost impossible task. L
I wasn’t exactly lucky... But at one time I brought a lot of such iron from “under heaven”. Therefore, I was lucky enough to avoid this problem. And I’ll even say more! I can probably help some of you solve this problem too! ;) Well, yes, this is all only in private...
In the meantime, having decided on how our creation should look, it’s worth solving the second, most important task - deciding which amplifiers to assemble?
There are simply an incredible variety of schemes, ideas, not to mention opinions!
And figuring out right away which idea to grab onto is incredibly difficult.
In such cases, it is worth starting with the simplest and, at the same time, material that has been worked out not even over years, but over decades...
But as the practice of studying the issue has shown, there are many such cases.
And here, perhaps, it’s worth starting to share your own experience.
There are a lot of established stereotypes in our minds. So, for example, driving a car at high speed inevitably evokes an association with Michael Schumacher, and the racing car itself inevitably evokes a red Ferrari...
Likewise, in a situation when it comes to tube Hi-End, the first thing that comes to mind for people who have already come into contact, at least to a minimal extent, with this topic is, of course, Audio Note.
For more than a dozen years now, it is the Audionot sound that has been almost a religion among a considerable part of the “sophisticated high-end players”
At one time, many copies were broken in the field of discussions about what, in fact, is the secret of the sound of the creations of Peter Qvortrup (father and one of the main designers of Audio Note).
I remember that this casket was opened just as easily as most of the others.
A relatively small number of experiments made it possible to find out that the main share of colors in the Audinot sound came from the first cascade, usually built according to the so-called SRPP (cascade) scheme.
I didn’t even bother to philosophize, determining that it should be at the entrance and nothing else, although something else could be simpler, but not much.
With an output stage it's even easier!
Here we should proceed from the principle of accessibility. Speaking about accessibility, I mean, first of all, the element base, on the basis of which you can build something quite decent-sounding.
In this case, it is worth relying on the “experience of our ancestors”, which has come down to us in abundance in the form of the remains of old tube televisions and radios (Hello, garbage dump!!!).
As a last resort, this junk, in the form of weekend (TVZ-Sh) and power (TS-180) transformers, is usually found in abundance at local flea markets that take place on weekends in all regions and villages of our “immense”...
And in conclusion, the problem of choosing an output lamp comes down to the understanding that these same TVZ-Sh output transformers were designed to work with almost the only lamp developed in the socialist fatherland, created specifically for sound amplification. Of course, we are talking about the legendary 6P14P or its more modern analogues 6P15P or 6P18P.
However, it’s your choice! You can also supply a “branded” analogue in the form of EL 84. How much the result will be worth is up to you to judge for yourself. Here I will only note that these replacements should not entail any structural or schematic changes. Even the modes of these lamps are almost identical and, most likely, you will not have to adjust anything with such a replacement on an already made and working amplifier.
Since we're talking about lamps, it's probably worth mentioning the light bulb for the first stage.
I’m not afraid of the evil remarks of the “dissenters,” but IMHO there is simply no better candidate for the first stage than the 6N23P-EV. However, I will immediately warn you that the number of people who agreed with me will be approximately equal to the number of those who objected. I’ll just say that if we strive specifically for Audionote sound, then this is it! J
Well, in fact, we have almost drawn our diagram ourselves.
To all that has been said above, it is only worth adding that when speaking about the output stage, I meant specifically and exclusively the triode connection of the 6P14P. It is in this inclusion that this lamp is able to tug at the heartstrings in a way that few others can.
Yes! This will lead to a loss in power. But perhaps I should have said this earlier... Hi-End is not for scoring discos. Moreover! In Hi-End, the quality of the device is usually inversely proportional to the power (read sound volume) at which the amplifier reveals its full capabilities.
In addition, I will reassure you that the same 1.5 - 2 Watts per channel that we can get with a 6P14P in a triode connection, in terms of subjective sound volume, will seem adequate to the 10 Watts per channel obtained from a typical silicon-transistor device.
So, just trust those thousands of people who have already walked this path before you and, believe me, were completely satisfied with the result. ;)
Moreover! I also have much more “serious” devices, which, of course, are objectively better than this creation. But this simple and seemingly completely uncomplicated machine has its own soul, gentle and kind... Capable of touching and warming people’s souls with its very warm voice. J (Evan took me away!.. Sorry again for the pretentious syllable.)
The only question of the circuit design of our wuxia, perhaps, remains the question of “proper and healthy nutrition.” And this, it must be said, is a matter of paramount importance when it comes to sound! Because the sound that we hear as a result, in fact, is nothing more than the power supply of your amplifier modulated by the input signal.
Hence the conclusion - the power supply of a tube amplifier must also be tube power! Which means this is a kenotron! And if we absolutely remain committed to the classics, then the throttle...
And if everything is simple with the kenotron (by summing up the anode currents of all lamps, we get the total consumption, based on which the required kenotron is selected), then with the choke, a problem can really arise...
However, I was lucky. In my bins I found a real choke from some old tube TV. But even if not, then the simplest and most effective solution to this problem would be to buy a banal 18-watt choke for old fluorescent lamps at the nearest construction market for 120 wooden ones. Their inductance of 2 Henry (usually something like that...) is quite sufficient for our purposes.
Whether it’s long or short, but on the RuNet I managed to find two whole schemes that almost completely meet all the aspects mentioned above. The first of them is built precisely on the idea that I described above. The second differs only in that it has a pair of output lamps installed in parallel at the output, but it has a beautifully designed power supply that fully meets all my requirements.
These are the diagrams:
In essence, strange as it may seem, the essence of my article is not directly related directly to the amplifier circuit... In any case, this is not the main thing for me in this case. The main thing is to talk about how to put it all together?
It is worth noting that the classic approach to building a tube amplifier, in contrast to transistor devices usually assembled on printed circuit boards, is the so-called surface-mounted assembly.
Frankly, for me this has always been the most repulsive factor in the issue of assembling lamp circuits. For me, who was accustomed to making a separate printed circuit even for a separate volume level variable, so that everything would be correct and neat, the very thought of parts dangling loosely in the amplifier body, held together only by soldering and, excuse me, dangling on the snot, was frightening... And When starting to build this machine, I had to overcome some internal barrier and almost figure out on the fly how to secure everything so that in the future I wouldn’t have to worry about whether or not there might be something there one day? ..
Well, everything is in order.
Let's take the case of our amplifier.
First, we should carefully route those connections that we will need later. With your permission, I will omit this stage, since it is specific and does not imply many solution options.
I’ll just present the result as a given. In my case, this was the wiring of the input switch, ALPS for the volume control, and the actual input, output and power connectors themselves.
It is characteristic that at this stage we remove the upper and lower panels of the case. The lower one just gets in the way, and we will need the upper panel as the basis of our design.
Here's what we have at this stage:
It looks like I missed one important point... The fact is that before you start assembling the amplifier, you must first select at least the basic elements of the future machine. They are necessary in order to determine the design of your device.
We are talking primarily about light bulbs, sockets for them, output and power transformers and chokes. About those very elements that are attached directly to the body.
And only after we have completely selected everything we need, having arranged it the way you like, determine the places for these elements and mark the top panel.
This is how I decided to arrange the elements of my amplifier:
I admit, I had an idea to plagiarize the topology of the arrangement of elements from one of the most popular Audio Note amplifiers, but, overcoming this temptation, I decided to arrange the elements according to the classical scheme. The idea of this topology, in this case, is not fundamental. The fact itself is important, as a stage. This must be done extremely carefully, thinking about how convenient the chosen location will be for subsequent internal installation and the mutual influence of the elements on each other.
We are, of course, talking about the magnetic fields of transformers and their direction.
I believe that there is no need to present a short school course in physics... Just remember this. ;)
First of all, we place the sockets for our lamps and determine the size of the holes for them:
Here we are faced with another ambush and a silent question in our eyes: “And how can such HOLES be drilled in a sheet of iron?!”... In my case, this was exactly the case. And I could not find the answer to this question in the articles of “colleagues” who joyfully reported to me about how wonderfully they assembled tube amplifiers with their own hands.
I had to go to the nearest construction market and retrain from an electronics engineer to a mechanic.
I took the data with a regular caliper before going to the market. It turned out that the diameter of the holes for the sockets for finger-type lamps is 18 mm, and the diameter of the holes for the sockets for the octal lamp (kenotron) is already 28 mm!
A study of the issue showed that for drilling holes with a diameter of 18 mm. you can find a classic drill, but for larger holes you will have to use a “crown” made of “Bimetal”.
Here's what it looks like:
Fortunately, I easily bought both of them on the construction market at 350 wooden ones per unit.
JThe holes must be drilled extremely carefully, and always on the side of the top panel that will subsequently face the inside of the case. I say this based on my own experience. Actually, an inquisitive eye will be able to see the consequences of my flaws in the photographs with which I accompany my story...
The drill speed is the minimum. In this case, if possible, it is worth using the auxiliary handle of the drill in order to stabilize the beating of the bit as much as possible.
Naturally, the edges of the resulting holes must be processed to remove burrs that will inevitably remain after drilling the holes.
It turns out something like this:
To be continued…
We have long been accustomed to the fact that we are surrounded everywhere by microelectronics and transistor technology. In televisions, players, receivers, tape recorders everywhere we hear sound in the speakers, amplified by special microcircuits that are powered by low voltage and produce a very loud sound.
But not so long ago - several decades, these same transistor amplifiers, and then microcircuits, just appeared. Fashionistas proudly wore receivers that were powered by special batteries - anode batteries and batteries for incandescent lamps; it was then simply a miracle that it was possible to receive and hear the radio on the move.
Lamps were very widespread. Cinemas had powerful tube amplifiers, the output of which was usually two G-807, 6R3S, or less often GU-80 tubes.
And the famous mobile film installations "KINAP" made in Odessa for an alternating voltage of 110V, which were powered from a standard network through an autotransformer, at the output of the amplifier there were the famous 6P3S lamps - lamps that were used in home-made transmitters on medium waves and it was a couple of trifles to make it, having also a lamp receiver , a microphone and a wire antenna stretched in the yard, through which it was possible to communicate over the air with a friend from a neighboring street.
But time passed and new electronic devices appeared, which began to slowly displace lamps, but it is not yet possible to completely replace lamps with transistors, because lamps have an advantage in powerful output cascades of transmitters and radar technology, but nevertheless the technical process moves forward.
What attracts a tube amplifier??
The first and most important thing is high-quality reproduced sound. The amplifier has, first of all, low distortion and a high signal slew rate.
What is a good system? According to Alexander Chervyakov, “they put on a record and you can’t hear it, the better the amplifier, the less you can hear it,” that is, you can hear the music, in the smallest subtleties, every instrument is the music around you, you have merged with it and nothing else exists, nervana.
Claw amplifier circuits
Construction scheme
According to the construction scheme, amplifiers can be divided:
1. primarily single-ended or push-pull - in the ULF output stage one lamp or two lamps are used in the so-called push-pull connection. In the push-pull version, it is possible to obtain more power at the output, with good quality of the reproduced undistorted signal.
2. Mono amplifiers or stereo amplifiers.
3. Single-band or multi-band, when each amplifier reproduces its own frequency band and is loaded onto the corresponding acoustic system - speakers.
An amplifier consists of several successive stages, usually:
- preamplifier, sometimes called a microphone amplifier;
- amplification stage;
- repeater;
- bass reflex (for push-pull version);
- driver (for driving powerful output stages);
- output stage with transformer in load;
- load - acoustic system, speakers, headphones;
- power supply for different voltages: filament 6.3 (12.6), anode voltage 250V (300V and higher depending on the lamps used in the output stage);
- case (metal chassis), since the transformer is heavy, and there are at least two of them in the circuit - power and output.
A diagram of a tube amplifier is shown. Input amplifier on a pentode, ECF80 tube (6BL8, 6F1P, 7199), 6AN8A triode, output stage on a KT88 or KT90 or EL156 beam tetrode, 5U4G kenotron as a rectifier. Output transformer for Tanso XE205 single-ended tube amplifier. The power transformer in the anode winding has taps that switch depending on the applied output tube.
Basic specifications tube ULF, an example is shown in parentheses - amplifier parameters on the famous 300B tube.
Power - W, at load in Ohms. (20)
Reproducible frequency band - Hz, kHz (5 -80,000)
Load resistance - Ohm (4-8)
Input sensitivity, mV (775)
Signal to noise ratio (no noise) dB (90)
Nonlinear distortion coefficient, no more than % (less than 0.1 at a frequency of 1 kHz, at a power of 1 W)
Number of channels
Supply voltage, V
Power consumption from power supply - W (250)
Weight, kg
Overall dimensions, mm
Price
Accessories for manufacturing
Accessories for tube amplifier
Output transformer. One of the most important elements of high-quality audio sound design is the output transformer used. Used high quality audio output transformers for Hashimoto, Tamura, Elektra-Print, Tribute, James Audio, Lundahl, Hirata Tango, AUDIO NOTE, etc.
Capacitors. To create the required amplitude-frequency response, the parameters of the component elements are important. Music lovers attach a very important role not only to the brands used, but also how they are included in the circuit: if the capacitor is located between the stages of the amplifier, then the outer lining is connected to a lower impedance, i.e. to the driver, if as a blocking one, then the outer lining is connected to ground, in the picture the outer lining is marked with a stripe.
The photo shows capacitors for low-frequency sound amplifiers Jensen audio capacitors; aluminum, copper, and silver are used as foil; accordingly, the price varies widely. Manufacturers of audio line capacitors: Audio Note, TFTF, Mundorf, Jensen, Duelund CAST and others. Frequency characteristics vary depending on the design: paper case - copper foil, copper case and copper plates, staniol - mylar in oil, aluminum foil in an aluminum case and silver-plated terminals, so fans of high-quality audio make various measurements of the characteristics of parts to determine the best price ratio - quality. Electrolytic capacitors have a wide range of choices: Black Gate, etc. For cathode circuits, Caddock is preferred.
Switches
Resistors. Various resistors are used for manufacturing: tantalum resistors Audio Note, metal film Beyschlag, Allen-Bradley, etc.
Lamps. Since we are talking about tube sound lovers, one of the main elements for construction is the tube. Domestic lamps 6n2p, 6n8s, 6P3s, 6p14p, 6s33s, 6r3s. Passionate about perfect sound, true lovers of tube sound prefer only NOS tubes - these are completely new tubes that were released a long time ago, examples are the 6AC5GT, 45 tubes (the tube was produced from the late 1920s in the USA until the end of the 50s), 2A3 , 300V, etc. A large number of well-known lamps PX4, PX25, KT-88, KT-66, 6L6, EL-12, EL-156, EYY-12, 5692, ECC83, ECC88, EL34, 5881, 6SL7 have been and are used. But many people prefer vintage lamps.
Manufacturers of vacuum tubes.
German - Telefunken, Valvo, Siemens, Lorenz. Europe - Amperex, Philips, Mazda. England - Mullard, Genalex, Brimar. America - RCA, Raytheon, General Electrics, Sylvania and others. Tubes for the amplifier are purchased directly from abroad or through the websites www.tubes4audio.com, www.kogerer.ru, www.cryoset.com/catalog/index.php?cPath=22&osCsid=d721583766160686aa0fa118d03b88fd, www.groovetubes.com, www. iconaudio.com.
There are (have been) many high-quality amplifiers produced in the world.
Audio amplifiers load the speaker system, but there are quite a few who sometimes want to listen to music on headphones, for example MrSpeakers Alpha Dog.
On the picture. Stereo amplifier MB520 20 W, price £ 950 or more, bandwidth 15Hz~35kHz, S/N ratio 82dB, load impedance 8/16 Ohm, size 412x185x415 mm. Preamplifier on EF86, 12AU7 tube used as bass reflex, rectifier for each channel on 5AR4, output tubes EL34. Stainless steel is used. Motor driven attenuator controlled by remote control, position indicated by green LED.
The MB805 is a monoblock amplifier, priced at £5,999. Power per channel (8 ohm load) 50W, signal-to-noise level is -90db.
MB81. Mono amplifier based on GU-81, cost £12,500. The signal-to-noise ratio is -100dB, ripple in the frequency band 20 Hz - 20 kHz - 1dB, load 4Ω - 16Ω. Input sensitivity 600 mV, input impedance 100k. Power consumption from the network 220/240/115 volts average 450watts, 750w max. The output is 200 W into an 8 Ohm load. Input amplifier on a 6SL7, 6SN7 tube, drivers on two EL34.
SE (single-end) - single-ended output, meaning amplification of the signal unchanged.
Video for tube sound lovers
Eimac 250TH Audio Amplifier
Video of a tube amplifier in operation, demonstrating music playback.
So, I decided to try my hand at lamp technology. I found the necessary parts and assembled a circuit using 6p14p and 6n23p lamps, at first just on a piece of iron. The output turned out to be 5 watts, the sound is loud and clear, nothing rings or is cut off. I am completely satisfied with this ULF. It is powered by a transformer taken from the Sirius radio. One filament winding of 6 volts is used, and 250 volts are used to power the anodes of the lamps. Although it has now become fashionable to install so-called “electronic transformers” in tube amplifiers, for beginning tube builders I advise you to choose conventional ones with hardware.As a rectifier - a diode bridge, and as filters - 2 capacitors from a computer power supply, 200 volts 470 uF connected in series, the result is an output of 315 volts on the capacitors. The whole thing is connected to the plus through a 2.7 kOhm resistor in the power supply gap. The power supply to the anodes is approximately 250 volts DC. We shunt the power filter capacitors with a 200 kOhm resistor so that there is something to discharge them after disconnecting the device from the network.
The power supply is made in a separate case from the old tube TV. The tube amplifier itself is made in a casing from a Soviet radio tape recorder, its casing is thick and just the right size.
Sockets for lamps can be picked out from any lamp equipment - they are all standard. We make a large hole using small ones drilled in a circle. We clean the edges with a round file.
The speaker was made on the basis of a 5-gauge paper speaker, with a nominal power of 5 W, the base itself was made of boards, the back part was made of plywood, and the speaker itself on the front panel was mounted on two compressed sheets of cardboard.
I made the legs for all the blocks by gluing pieces of double-sided tape to the body so as not to scratch the surface of the table. See the video below about assembling a simple ULF on lamps:
A 3.5 mm metal plug, “female” type, is soldered to the input. The conductor that goes through the audio input must be well shielded.
I removed the volume control, since it only produces unnecessary noise, and in the sound source itself (in my case, a DVD player), it is much more convenient to adjust it from the remote control!
Don’t forget to put a 200-500 kOhm resistor on the ground at the input, and if you are making a regulator, then use a high-resistance one, I tried it at 1 mOhm and it turned out to be the best.
Perhaps the design will not seem particularly serious to some, but keep in mind that this is my first step in mastering tube ULFs. The next amplifiers will be more impressive. Comrade was with you. Redmoon.
Discuss the article SIMPLE TUBE AMPLIFIER
Today we have a useful homemade product for connoisseurs of good sound: a high-quality tube amplifier made by yourself
Hello!
I decided to assemble a push-pull tube amplifier (my hands were really itching) from the parts I had accumulated over a long time: housing, lamps, sockets for them, transformers, etc.
I must say that I got all this stuff for free (you mean free of charge) and the cost of my new project will be 0.00 hryvnia, and if I need to buy something in addition, I’ll buy it for rubles (since I started my project in Ukraine, and I’ll finish already in Russia).
I'll start the description with the body.
Once upon a time it was, apparently, a good amplifier from SANYO model DCA 411.
But I didn’t have a chance to listen to it because I got it in a terribly dirty and non-working state, it was dug up beyond repair and the burnt 110 V power supply (Japanese, probably) smoked all the insides. Instead of the original final stage microcircuits, there are some snot from Soviet transistors (this is a photo from the Internet of a good example). In short, I gutted it all out and began to think. So, I couldn’t think of anything better than stuffing a lamp there (there’s quite a lot of space there).
Decision is made. Now we need to decide on the scheme and details. I have a sufficient number of 6p3s and 6n9s lamps.
Due to the fact that I had already assembled a single-cycle amplifier for 6p3s, I wanted more power and, having rummaged through the Internet, I chose this push-pull amplifier circuit for 6p3s.
Circuit of a homemade tube amplifier (ULF)
The diagram is taken from the website heavil.ru
I must say that the scheme is probably not the best, but due to its relative simplicity and availability of parts, I decided to stick with it. Output transformer (an important figure in the plot).
It was decided to use the “legendary” TS-180 as output transformers. Don’t throw stones right away (save them for the end of the article :)) I myself have deep doubts about this decision, but given my desire not to spend a penny on this project, I will continue.
I connected the trance outputs for my case like this.
(8)—(7)(6)—(5)(2)—(1)(1′)—(2′)(5′)—(6′)(7′)—(8′) primary
(10)—(9)(9′)—(10′) secondary
anode voltage is applied to the connection of pins 1 and 1′, 8 and 8′ to the anodes of the lamps.
10 and 10′ per speaker. (I didn’t come up with this myself, I found it on the Internet). To dispel the fog of pessimism, I decided to check the frequency response of the transformer by eye. To do this, I quickly assembled such a stand.
In the photo there is a GZ-102 generator, a BEAG APT-100 amplifier (100V-100W), an S1-65 oscilloscope, a 4 Ohm load equivalent (100W), and the transformer itself. By the way, there is a .
I set it to 1000 Hz with a swing of 80 (approximately) volts and record the voltage on the oscilloscope screen (about 2 V). Next, I increase the frequency and wait until the voltage on the trance secondary starts to drop. I do the same thing in the direction of decreasing the frequency.
The result, I must say, pleased me: the frequency response is almost linear in the range from 30 Hz to 16 kHz, well, I thought it would be much worse. By the way, the BEAG APT-100 amplifier has a step-up transformer at the output and its frequency response may also not be ideal.
Now you can collect everything in a heap into a case with a clear conscience. There is an idea to do the installation and layout inside in the best traditions of so-called modding (minimum wires in sight) and it would also be nice to have LED backlighting like in industrial copies.
Power supply for a homemade tube amplifier.
I'll start the assembly and at the same time describe it. The heart of the power supply (and of the entire amplifier, probably) will be the TST-143 toroidal transformer, which I once (4 years ago) tore out of some tube generator right as it was being taken to a landfill. Unfortunately, I didn’t manage to do anything else. It’s a pity for such a generator, but maybe it was still working or could have been repaired... Okay, I digress. Here he is my security officer.
Of course, I found a diagram for it on the Internet.
The rectifier will be on a diode bridge with a filter on the inductor for anode power. And 12 volts to power the backlight and anode voltage. This is the throttle I have.
Its inductance was 5 henry (according to the device), which is quite enough for good filtration. And the diode bridge was found like this.
Its name is BR1010. (10 amps 1000 volts). I'm starting to cut out the amplifier. I think it will be something like this.
I mark and cut holes in the PCB for the sockets for the light bulbs.
It turns out well :) I like everything so far.
This way and that way. drill and saw :)
Something began to emerge.
I found a fluoroplastic wire in old supplies and immediately all the alternatives and compromises regarding the wire for installation disappeared without a trace :) .
This is how the installation turned out. Everything seems to be “kosher”, the incandescence is intertwined, the ground is practically at one point. Should work.
It's time to fence in food. After checking and testing all the output windings of the trans, I soldered all the necessary wires to it and began installing it according to the accepted plan.
As you know, in our life it’s not easy to go anywhere without improvised materials: this is how the Kinder Surprise container came in handy.
And a Nescafe lid and an old CD
I tore out the circuit boards of TVs and monitors. All containers are at least 400 volts (I know that I should have more, but I don’t want to buy them).
I bridge the bridge with containers (whatever were on hand, I’ll probably change them later)
It’s a bit much, but oh well, it will sag under load :)
I use the standard power switch from the amplifier (clear and soft).
We're done with that. It turned out well :)
Backlight for tube amplifier housing.
To implement the backlight, an LED strip was purchased.
And installed in the housing as follows.
Now the glow of the amplifier will be visible during the daytime. To power the backlight, I will make a separate rectifier with a stabilizer on some KRKEN-like microcircuit (which I can find in the trash), from which I plan to power the anode voltage supply delay circuit.
Delay relay.
Having rummaged through the bins of my homeland, I found this completely untouched thing.
This is a radio time relay designer for a photo enlarger.
We collect, check, try on.
I set the response time to about 40 seconds, and replaced the variable resistor with a constant one. The matter is coming to an end. All that remains is to put everything together, install the face, indicators and regulators.
Regulators (input variables)
They say the sound quality can greatly depend on them. In short, I installed these
Dual 100 kOhm. Since I have two of them, I decided to parallel the pins, thereby obtaining 50 kOhm and increased resistance to wheezing :)
Indicators.
I used standard indicators, with standard backlighting
I mercilessly copied the connection diagram from the original board and used it as well.
This is what I ended up with.
When checking the power, the amplifier demonstrated an output voltage of 10 volts of an undistorted sine wave with a frequency of 1000 Hz into a 4 ohm load (25 watts) equally across channels, which was pleasing :)
When listening, the sound was crystal clear without background and dust, as they say, but too monitory, or what? beautiful, but flat.
I naively believed that he would play without timbres, but...
Using a software equalizer, we managed to get a very beautiful sound that everyone liked. Thank you all very much!!!
Author of the article “homemade tube amplifier with your own hands” Vyacheslav Tkachenko.
You may be interested in the following materials.
Hello, Datagorians! Oddly enough, transformers usually inspire me to create a new tube design. So this time we have put together a rather interesting selection.
Firstly, from some connected equipment I found a couple of transformers on Sh12x16 permalloy.
Secondly, friends gave me a couple of power transformers from some cash register equipment, PL25x16 iron, and a 62 mm window.
And finally, I came across a power transformer from the Vega 122S amplifier on PL25x20 hardware, 88 mm window.
When assembling, I adhered to simple “feng shui” principles of amplifier construction:
1. The most complete symmetry for a push-pull amplifier.
2. The shortest possible path.
3. Full triode amplifier.
4. No negative feedback.
The article, with many photographs, describes the process of creating a miniature tube head based on the Fender Champ.
The cabinet for the modified 4GD-28 speaker was made in the same style as the head.
The source of inspiration, spare parts and original nameplates were the Yunost-301 tube electrophones, raised from oblivion.
Hello, comrades! Happy May holidays of Peace, Labor, Radio and Victory to everyone!
In the first part of the article about mine.
In the second part of the article I will talk about the organization of remote control of the volume potentiometer and the MP3 module.
My main idea was to use the remote control to adjust the volume level of the amplifier without introducing additional distortion and interference into the audio path.
To do this, I decided to connect the potentiometer to the motor, assemble a control circuit and remote control.
After a long search on the World Wide Web, I chose a circuit based on the PIC12F629 microcontroller. Fellow Datagorians helped adjust the engine control circuit.
Dear Datagorians, I want to tell you about my new phono preamplifier. This device is not an essential item, but if you are partial to vinyl records, then you cannot do without it.
You can buy a ready-made phono preamplifier of factory or original design, or you can make it yourself, which is much more interesting!
Hello dear readers of our favorite portal site! I haven't been heard from for about a year. During this time, I managed to become a father and the time for amateur radio suddenly became less.
But I did not abandon my radio-electronic research, but brought to life one of my most ambitious projects in the field of ULF.
There was a lot of time for thinking and little time for practical implementation. The project was carried out slowly, so the quality of the details was as high as possible. I didn’t spare money to achieve the result I needed and didn’t make compromises to reduce the cost or simplify the design.
"BRASS"- because everything lives in a body made of polished brass 1.5 mm thick and varnished. For other funny translation meanings, see the English dictionary.
The project includes:
- The main stereo ULF block according to the Nobu Shishido circuit with a push-pull output to 6P3S.
- Tube RIAA stereo vinyl corrector for 6N2P.
- MP3 block operating via USB with flash memory.
- Remote control of the MP3 unit.
- Remote control of the main amplifier volume potentiometer using a brush motor.
In the first part of a series of articles, I will talk about assembling the main amplifier and corrector circuit for connecting a vinyl player.
05/08/18 changed by Datagor. Schemes have been corrected and archives have been re-uploaded.
I used the Datagor article as a basis. Thank you very much for the diagram and explanations, since the diagram turned out to be quite feasible for me.
Dear residents of Datagoria, I congratulate everyone on all the New Year holidays!:bye:
I was prompted to write this article by the desire to share with you my research and experience with the wonderful Soviet triode 6S45P-E.
The reason was also the need to create a sound-reproducing “two”. For my daughter’s 25th birthday, I gave her a vinyl turntable, which she had long dreamed of.
