Single ended amplifier mosfet

I wanted to construct an amp that had zero negative feed back 0NFBwas pure Class-A and definitely single-ended.

Nelson Pass has done a lot of work in this area with his Zen builds, but I wanted to go beyond Zen. Was I trying to find the holy grail of amps - the straight piece of silver wire that has pure distortion-free gain? Well of course there has to be some active components in an amp in order to get the gain to be called an "Amplifier".

I was always impressed how simple single ended tube amplifiers could be. A single valve, a resistor or two and an output transformer. So I fashioned a FET amp around the same simplicity of design. The schematic for the amplifier section is shown in Figure 1. A schematic and pin diagram for the 2SK is shown in Figure 2. The four 10W non-inductive wire wound resistors act as the load.

The four resistors are 15ohm and 10W each which I wired two in series for 30 ohms and then the two sets of 30 ohms are wired in parallel to give a total resistance of 15 ohms. These get extremely hot and burn about 30W at idle. Yes, Class-A amplification is very inefficient. I burn over 20 Watts to get only about 4. The heatsink I used is rated at 0.

Bias is provided by a K pot and a 1M resistor. It produces the most purest sound. I have no idea of distortion levels etc. Bass is better than the design predicts and the amp drives my 12" 63L based 3-way speakers with ease. Not quite Zero Components but close to it. It plays all acoustic instruments with an incomparable earthy natural quality.

December - Mike also from Australia sent me an email to let me know he also built this amplifier. I pleased to read his positive comments. January - John sent me an email and some pictures of his build of this amplifier. August - I came across the best looking builds of this project to date which have been put together by Alex Kap. July - Dinesh has also completed the ZCA project.

See the ZCA project completed thread on the forum for photographs and listening impressions. August - Taoybb in Thailand has also put together the amplifier using premium capacitors. Here are some photos and the power supply used.This circuit looks like a complementary amp, but isn't!

Build a Hybrid Tube/MOSFET SE Amp

In fact, our chameleon is a single-ended SE amp with a dynamic load. Punch for Practice. This amplifier combines the simplicity and fidelity of SE design with easy-to-acquire parts. The circuit isn't particularly efficient, but it packs enough punch for a practice amp. No Phase Splitter. JFET Q1 is the input preamp. Only equivalent devices will work. No phase splitter is necessary, because we're only driving one output device, Q3.

MOSFET Push Pull Amplifier

Figure 1. To optimize fidelitythis circuit includes source resistors at the Q2 and Q3 outputs. At the expense of gain, these resistors reduce distortion.

Negative feedback through the resistors opposes non-linear effects that arise during amplification. Dynamic load Q2 loafs along at its half-bias point. No more radiator-size drain resistors! The load gate connects to a bias network and a filter capacitor.

What results is a C-multiplier that behaves like a bypassed load resistor with high stability. The transistors must run cool to slightly warm. You must drive this circuit with a preamplifier probably two JFET stages. In this design, local parts availability is a high priority.

Single MOSFET Class A Power Amplifier Circuit

Our amplifier uses mostly Radio Shack parts. The output is typically an N- and P-channel totem pole.

single ended amplifier mosfet

The bias adjusters are linear taper pots. Before testing the amplifier, set each pot at midrange never at the end of its range.Free Return Within 30 Days. Man-made damage or misuse. Audio accessories and consumables such as vacuum tubes. If you are satisfied with our products and service please leave a 5-star. Feedback is very important to us just like our lives, please DO contact us before you leave a neutral or negative feedback, we will provide better solutions until you are satisfied.

Great sound! Store Category. Join Our Newsletter Receive our email newsletters about new items and special promotions! Sign Up Now! Item description. This is mono channel amplifier, for stereo need buy 2 pieces. Features: Perfect inspired by classic PassA30 circuit. Integrated the volume control potentiometer link. Add a midpoint trimmer to the differential input link Finished machine with about 2KG of heat sink, while the whole machine is all aluminum design.

We are NOT responsible for any import tax or customs delay. Most item will be shipped within 2 working days.

About us. As a professional audio company, we are dedicated to design and produce the best products at the lowest prices to make HiFi affordable.

Contact us Please don't hesitate to contact us if you have any questions or comments about our items. And our working time is from Monday to Friday between am to pm Beijing Timewhich means we can keep on-line at:. During holiday, please allow us to response you early next week.

If it's different, please leave us message in PayPal or eBay when checkout. Add to Favorites Seller Join newsletter. Amplifier voltage gain: 11 times.HiFi Stereo Power Amplifier 2. Free Return Within 30 Days. Man-made damage or misuse. Audio accessories and consumables such as vacuum tubes.

If you are satisfied with our products and service please leave a 5-star. Feedback is very important to us just like our lives, please DO contact us before you leave a neutral or negative feedback, we will provide better solutions until you are satisfied. Great sound!

Store Category.

single ended amplifier mosfet

Join Our Newsletter Receive our email newsletters about new items and special promotions! Sign Up Now! Item description. This is mono channel amplifier, for stereo need buy 2 pieces. Features: Perfect inspired by classic PassA30 circuit. Integrated the volume control potentiometer link.

Add a midpoint trimmer to the differential input link Finished machine with about 2KG of heat sink, while the whole machine is all aluminum design.

single ended amplifier mosfet

We are NOT responsible for any import tax or customs delay. Most item will be shipped within 2 working days. About us. As a professional audio company, we are dedicated to design and produce the best products at the lowest prices to make HiFi affordable. Contact us Please don't hesitate to contact us if you have any questions or comments about our items. And our working time is from Monday to Friday between am to pm Beijing Timewhich means we can keep on-line at:. During holiday, please allow us to response you early next week.

If it's different, please leave us message in PayPal or eBay when checkout. Add to Favorites Seller Join newsletter. Amplifier voltage gain: 11 times.Package includes:. Free Return Within 30 Days. Man-made damage or misuse. Audio accessories and consumables such as vacuum tubes. If you are satisfied with our products and service please leave a 5-star. Feedback is very important to us just like our lives, please DO contact us before you leave a neutral or negative feedback, we will provide better solutions until you are satisfied.

GBPStore Category. Join Our Newsletter Receive our email newsletters about new items and special promotions! Sign Up Now!

Build a Hybrid Tube/MOSFET SE Amp

Item description. This is mono channel amplifier, for stereo need buy 2 pieces. Features: Perfect inspired by classic PassA30 circuit. Integrated the volume control potentiometer link. Add a midpoint trimmer to the differential input link Finished machine with about 2KG of heat sink, while the whole machine is all aluminum design.

We are NOT responsible for any import tax or customs delay. Most item will be shipped within 2 working days. About us. As a professional audio company, we are dedicated to design and produce the best products at the lowest prices to make HiFi affordable. Contact us Please don't hesitate to contact us if you have any questions or comments about our items. And our working time is from Monday to Friday between am to pm Beijing Timewhich means we can keep on-line at:.

During holiday, please allow us to response you early next week. Perfect inspired by classic PassA30 circuit. If it's different, please leave us message in PayPal or eBay when checkout. Add to Favorites Seller Join newsletter. Amplifier voltage gain: 11 times.For a long time I was thinking about making myself a good class a amp, next time after you fix the mechanical failure before the truck and the min, I said something like Pila access your listening pleasure and For a long time I was thinking about making myself a good class a amp, next time after you fix the mechanical failure before the truck and the min, I said something like Pila access your listening pleasure and decided to make this single-ended amplifier 5w amplifier, a long time ago when I was really satisfied me that this was the experimental sound of the amp.

A single-ended amplifier circuit is very simple, but really want a quality work, as much as I can, I tried not to compromise on quality.

I would definitely recommend a similar circuit for those who do. I used a transformer circuit around w 2 x 18v AC outputs the transformer wraps master is really doing a good job, because the transformer with the transformer for the ones who need me, I am the workmanship.

I think the most important part after the transformer feeding, this circuit prototype work I did when I used a simple feeding, leaving severe hum noise. The circuit is a class a operation, naturally comes with heat, especially if the circuit lot 15 Ohm resistor that enables the flow of warm, therefore, must be connected to a refrigerant pressure.

I have seen a site similar to the classic, but darlington transistor-quality hifi amplifier circuit. There are. TDA 3W mono channel output allows a single integrated circuit used in two pieces. Especially Pioneer, Kenwood, Sony, etc. TDA is used in popular brands like car stereo integrated amplifier powered with a simple amp.

Seenserion company produces heat and moisture sensor SHT11 humidity measurement and control circuit is made with. The circuit can be used in many different purposes. Summary; Mucha Elijah that moisture, humidity set on while the relay is open. The humidity value falls below the value in our draws and arranged irrigation starts. Op Amp Designer inverting non-inverting calculation. Particularly with opamp can use a simple calculation program is free sample circuits with electronic information displayed Inverting and Noninverting op amp, a good program can do calculations with ease.

The program was tested on windows xp professional. In order to make the Operational Amplifier Windows 3. This form is provided for your feedback. If you have any comments or suggestions on the program, please use this to communicate that information. Electronics Projects Tags Contact.

Electronics Circuits. Electronics Projects. Tags: audio amplifier circuitstransistor amplifier. Op Amp Designer inverting non-inverting calculation Particularly with opamp can use a simple calculation program is free sample circuits with electronic information displayed Inverting and Noninverting op amp, a good program can do calculations with ease.

The program was tested on windows xp professional Opamp Desinger program In order to make the Operational Amplifier Windows 3. Electronic Circuits projects, circuit diagrams.

This site uses cookies: Find out more. Ok, No Problem.Single-Ended The solitary-intentioned topic continues. Before we go off in new directions, let's go back to the basics. In its purest form, a single-ended amplifier uses a single, solitary active device, such as a triode, pentode, MOSFET, or transistor to do all the work of driving a loudspeaker. Adding more devices in parallel does not change the basic operation, as it only effectively makes for a more capable output device, by increasing its transconductance.

The original 2A3 holds two internal triodes in parallel. What makes a single-ended amplifier so ear-pleasing is that at idle the output device sits at its sweet-spot, exactly at half its maximum current and voltage peak swings.

single ended amplifier mosfet

It is by necessity pure class-A and it offers a constant output impedance due to its constant-transconductance operation. A push-pull output stage, in contrast, is most often run in class-AB, as it allows for greater power output and lower heat dissipation at idle, which in turn allows for smaller heatsinks and power transformers. The problem with class-AB lies in the output devices idling near their cutoff, where they are less linear. In addition, the region of device overlap, where both output devices are on at the same time results in gm doubling, which halves the output impedance in the overlap zone of operation the class-A window of operation and creates two transition points, where one device turns off during as the output voltage swings up and, then, the other device turns off on the downward swing.

The problems we face with single-ended output stages are low output power, low efficiency, high heat dissipation, and, in the case of triode output tubes, poor PSRR. Since so few will follow links within a paragraph, here is a longish quote from that article.

In the simple grounded-cathode amplifier, the plate resistor defines the load into which the tube works. If there is any noise at the power supply connection, some of it will make itself known at the output, as the plate resistor and tube define a voltage divider. The lower the rp of the tube, the less noise at the output. Low rp is one reason why triodes can be much quieter than pentodes. For example, a 6BX7 has an rp of ohms and it is rare for any pentode to have an rp of less than 50k; in fact, most are closer to being ideal current sources, i.

This low rp of triode is a great boon, when the circuit is a Grounded Cathode amplifier and the load is a plate resistor. But in a transformer loaded SE amplifier, the low rp now proves to be a detriment to low noise operation.

The signal voltage that develops across the output transformer primary, once it has been stepped down through the transformer, is what the speaker will see at the secondary.

The greater this signal is, the greater the output will be. So, too, the greater the noise voltage developed across the transformer primary, the greater the noise at the output. Here's the rub: the low rp, which proved wonderfully advantageous in lowering the amplifier's output impedance, now proves to be a hindrance to low noise operation.

Of course, feedback will lower not only distortion and Zo, but noise as well. Still, the lower the noise prior to the application of feedback, the lower the noise at the output after feedback. High impedance devices like pentodes yield much smaller amounts of noise to the speaker because the primary impedance is so small compared to their extremely high nearly infinite internal impedance.

In other words, we want the output triode to exhibit a constant-current draw in the face of power-supply noise, as the output transformer's primary is a current-variation-sensitive device.

No current variation into the primary, no output signal on the secondary. By making C2 mu triode's amplification factor times larger than C1, we achieve the magic ratio that results in a power-supply-noise null.

For example, a 6BX7, with a mu of 10, would require that C2's value be 10 times greater than C1's value. The constant-current source is not essential, as a simple cathode resistor could be used in its stead. It is, however, essential in the following design. I came up with the above design in an e-mail exchange with a reader, Doan, from Viet Nam, who wants to run his single-ended output tube in class-A2, wherein the output tube experiences positive grid voltage.

For example, note how if we limited ourselves to no positive grid voltages in the above graph, the red idle-current plotline would have to be moved to the right and lower, while the load-line would have to be less steep.

The output tube must have a grid resistor, which is the resistor that spans from "ground" to the grid, and which provide the DC voltage path to either ground or the negative bias voltage. We can readily measure this resistance; usually it's some value between k to 1M. The triode's grid, on the other hand, does not present a constant resistance, as its resistance depends on the voltage between the grid and the cathode and the voltage between the plate and cathode.