The Dynaco Mark III is the highest power amplifier that was widely sold under the dyna name. There was a nigher power amp (the Mark VI), but it wasn`t widely available. The Dyna MKIII has a basic design flaw that none of the other Dynaco products have. The capacitors in the power supply are not rated at a high enough voltage for the power transfor
Click here to download the full size of the above Circuit.
mer. This results in the quad cap being run over it`s rated voltage every time the amp is turned on. The first section of the original quad cap is rated at 525 volts and the B+ goes as high as 585 volts during start up. This is due to the fact that the rectifier heats up and begins conducting before the power tubes heat up and start drawing power from the high voltage supply. The capacitor fatigue due to this over-voltage problem just get`s worse with age, and to make matters worse, there isn`t any 525 volt can caps available anymore. The amplifier doesn`t have much room underneath to add a large capacitor bank either. I have devised a printed circuit board that bolts directly under the output transformer without having to move any parts. It can be mounted in place using longer 8-32 bolts and a couple stand-offs or using the original transformer bolts and 8-32 threaded stand-offs. The circuit board uses 8 capacitors, with pairs in series to replace the quad cap. There are voltage equalizing resistors to keep the voltage across each cap equal. There is also provisions on the board for using silicon diodes instead of the 5AR4 rectifier (although I would recommend keeping the tube rectifier). There is also provisions on the board for film capacitor bypass for each of the 4 banks of capacitors. Without the film caps installed the capacitor board can handle B+ voltages up to 800 volts. With the film caps in place the board can...
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
characters left: