Vacuum-Tube Valves Circuits |
Page 4 |
|
-
One of the advantages of hosting a hobby website is that you meet people through email who have similar interests as you. Ever since we posted Bruce`s first OddWatt project on the site I have communicated with a number of DIY hobbyists who have built the various OddWatt amplifiers and have had nothing but very positive comments about the sonic qua .
Last year I built and reviewed the low cost Oatley Electronics K272 Tube Stereo Headphone Amplifier Kit. In conversation with Oatley Electronics (located in New South Wales Australia), they told me that the kit became very popular and sold pretty much all over the world. The little headphone amplifier kit was based around new old stock Raytheon J .
Oatley Electronics in New South Wales Australia makes a few kits based around the Raytheon JAN 6418 sub-miniature valve (tube). I decided to try out the $27AU K272A Stereo Tube Preamplifier - Headphone Driver kit. [Note - the K272 has been replaced with the K272C Stereo Tube Headphone Amplifier Kit which costs $40AU (December 2013). ] A photograph .
This past summer I saw Transformers: Revenge of the Fallen and I was inspired to build an enclosure for a vacuum tube amplifier that incorporated the Decepticon logo. The tube amplifier replaces a solid-state amplifier which was driven by a tube preamplifier. For the tube amplifier circuit I used a cutoff pentode (6SJ7 or 6SD7) driving a beam powe .
The PCB for this amplifier can be purchased from Spare Time Gizmos for $16US. In a single afternoon you can have the whole board assembled and dropped into a chassis of your choice. The value and type of component is laid-out in the parts list. But what I like to do is to put my own twist on each amp I build. If you are not an experienced valve am .
that used a SRPP (shunt-regulated PP) driver stage I started to do some research and modeling on a SRPP. The advantages of such a line stage are much the same as those when a SRPP is used as a driver. Good linearity, low distortion, low impedance output, good power supply noise rejection and modest gain. The research also indicated that the gain n .
This project is related to the other tube amplifier projects I have posted. It has more than a casual similarity to the first Push-Pull EL84 (6BQ5) Oddwatt project from nearly two years ago. Both tube amplifier projects use EL84 / 6BQ5 tubes and the earlier one used a ECC802S driver while this one uses 5751 driver tubes. The basic circuits are rat .
This is a project that I always wanted to do, but managed to put off for a long time. It has been over a year in the doing. Partly because there are so many good phono preamps in existence and I was slightly concerned that it was beyond my design skills. It took over a year to get it up to my satisfaction. There were several iterations and lots of .
The power supply has been simplified. Power transformers and rectifiers have been omitted and some parts have been omitted from the MOSFET voltage regulator circuits: 1N5242 zener diodes between the source and gate and 10k resistors in series with the gate. These parts serve as protection in case of accidental short circuits, but don`t affect the .
Electron tubes How Electron tubes work, Early tube history, The triode, The tetrode, Beam power tubes, The pentode, Combination tubes, Tube parameters, Ionization (gas-filled) tubes, Display tubes, Microwave tubes, Tubes versus Semiconductors Electron tubes This site is dedicated to Electron Tubes of all kinds. Here you will find information about .
This article includes a list of references, but its sources remain unclear because it has insufficient inline citations. Please help to improve this article by introducing more precise citations. Valves (also known as vacuum tubes) are very high input impedance (near infinite in most circuits) and high-output impedance devices. They are also hig ..gif "Valve audio amplifier technical specification")
The given circuit of a current controlled LED tube light uses a couple of high voltage transistors which works on a very basic principle for implementing the required current control operation. Resistor R2 is placed forconvertingthe rising current to voltage across itself. This voltage is sensed by R2 which immediately conducts and grounds T1s .
An amplifier built to drive my Sennheiser HD-600 headphones. Because of the relatively high impedance of these phones, I wanted plenty of voltage available to drive them. Because of the large dynamic range possible with these phones the system had to be very quiet. A high amount of resolution is available with these .
By sufficiently lowering output impedence of a circuit and supplying enough current to drive cables, it does not suffer the same problems as passive designs. As such, it seems to solve the many of the problems inherent in both active and passive preamps without causing too many additional problems of is own. The problem that I encountered in... .
The circuit was taken from one of the old elektor electronics magazine and it is indeed a very cute little circuit which may be used for creating high intensity lighting effects during festivals, parties and fun gatherings. Diodes D1 and D2 along with the capacitors C1 and C2 form a voltage doubler circuit which creates a voltage level twice the v .
A regenerative radio works by feeding back a small amount of amplified output of the detector back into the input. Thus it achieves sensitivity far beyond what only a detector could alone. This simple regen radio uses a single tube as it`s detector and amplifier; the "Audion". It`s a great first project for those wishing to bring back some nostalg .
The common wiring method had one side of the line cord going to a pin on the rectifier tube and the other side going to one terminal of the on/off switch. The other terminal of the on/off switch went to chassis. Suppose you plugged it in so the chassis was "cold" when the radio was turned on. That would mean that the bottom prong of the plug was c .
It`s a power amplifier configuration that was developed in the 1950s. It is called a circlotron because the original idea diagram was drawn as a circle. The best I can do with my graphics program is to show it as a bridge. It`s promise is very low distortion. It`s cost is a total of 3 power supplies, none of them connected in common. Some... .
You see that the feedback is DC coupled, not through a capacitor, from the plate of the second triode to the cathode of the first. An earlier design used AC coupled feedback. This version was unstable at low frequencies. Bode analysis showed that a 3 microfarad coupling capacitor would have been needed to make it stable. The 220 k ohm resistor... .
You may be wondering why I am using four tubes. The reason is to get 50 watts without pushing them right to their limit. My tube manual gives two setups for EL34s in ultra linear. Both require a 6 k ohm transformer. Both setups use exactly the same voltages but one says you get 20 watts at 0. 34 percent distortion and the other says you get 34... .
Vacuum tube electronic circuits operate from comparatively high DC voltages (150 to 600 volts). The Electric Utility supplies 120 volts AC. We have studied transformers and, therefore, we know that the 120 vAC line voltage could be stepped up to the necessary range but it would still be AC. The internal circuits of any device you can think of... .
This stage may be driven by another resistance coupled amplifier stage in which case the resistor on the left labeled RC is RCf for the previous stage. The resistor on the right labeled RCf is the grid resistor of the next or following stage. The resistor labeled RC serves one purpose; that is to hold the grid at, or very near, ground potential. T .
New Circuits
-small.png "CMOS Circuits Tutorial")