Repository-circuits
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Build a preamp that I want to use to take a 1/4" keyboard line level signal and drive a Leslie 147 amplifier with it. I want to build the preamp using a 12AX7 and 12BH7 based on the design of a Hammond Organ preamp. Here is the schematic to the Hammond AO-28.... -
Hi everyone, just wondering as I am about to build my first tube amplifier is the attached design o.k. and also does anyone know a suitable.... -
I could use some help analysing a circuit. Specifically the frequency cut-off between the bass and treble channels. Is it 500Hz, 1KHz or 5Khz. I`m.... -
I have finally worked out this schematic as an exercise to learn about amps. There are a number of things i am not so sure about and would appreciate.... -
i have a fujiya fl-555 (schematic attached) that i am having problems with. the recorder`s volume is very low even at maximum setting. it was working.... -
An amp that uses 211 or 845. It puts out just over 40 watts. The tube must run in A2 to get this power, which is not a problem with a good driver. The secret is a good follower, you use a 6BQ5, I use a mosfet. You use 7K ohm load on 1000 volts, I use 10K ohm.... -
Hi, I`ve been looking to add a simple 3 band parametric EQ to a tube bass preamp. My initial idea of making a simple OpAmp based EQ isn`t going to fly .... -
i have a tandberg 74b that i just received second hand - everything on the inside is original, excluding previously replaced tubes. when it first.... -
Hello, everyone, new kid on the block here After some tube amp reparations, fixes and minor upgrades (re-capping, fixing bias problems, various.... -
Experimenting with a vacuum tube VCO similar to the one in the link below, but with a few modifications to accommodate the parts I had on hand; I`m using a cascode arrangement instead of the 6AU6 and a 2D21 thyratron in lieu of the 5696. The circuit really.... -
A fully parametric tube EQ and my best bet seems to be `merging` these two schematics into one so that i can get a tube-based gyrator section (with adjustable Q, Freq and Gain) and use ICs for the input and follower stages (going to use this on a home-built.... -
The edcor that seems to make more sense would be the GXPP15-8-8K EDCOR Electronics Corporation. GXPP15-8-8K You are right, Jeff, the little price.... -
hi everyone, my name is mike, i come from a small country called new zealand- i am currently planning to build a 6l6 push pull stereo power and pre.... -
There is a mod to the RC delay circuits some of you may want to consider. If you wish to have a shorter discharge time so that the circuit restarts.... -
Hey Guys, I`d like to build a analog summing amplifier. Perfect would be with tubes. I want to get the typical tube sound, if it`s possible. So I want .... -
Originally Posted by taj Is he perhaps more accommodating than his reputation portrays? ..Todd No.... -
I`m building a tube/MOSFET hybrid power amplifier based on a circuit in AudioXpress by Cozza (5/01) which in turn is based on a design by Borbely.... -
Part of the difficulty is that multiple caps/resistors are in the circuit in RIAA. This is based on the Harman-Kardon schematic: I don`t have the Cit IV info handy, sorry. but there are so few parts in a Cit IV that it`s easier just to replace them all. If.... -
This schematic is modified from an old Bell & Howell projector amp for model 302 - PP 6v6`s with a 12AU7 PI. Can anyone identify the PI circuit It appears closest to "floating paraphase" to me. My only complaint with this circuit is that I`d like more clean.... -
I have looked in all the usual places and can`t seem to find one? Pilot 505. It has a 5AR 4,-4-,EL84`s-and 2, 12AX7`s. Thanks for any help you may.... -
Originally Posted by ide2003 Hi intensate, I`ve been in your shoes before. If you want no op-amp all together I highly recommends you to have ECDesign`.... -
I build the CAT SL1 preamp with the attached schematic Noted that the gain of this circuit has about 26dB. I noted that the new SL1 have an option.... -
Hi there - i`m a newbie here so please be nice if I tread on any toes And please take a deep breath - I have a fair bit to say, so go get some popcorn .... -
Hello Bottleheads, I am building this gain stage from Decware`s Zkit4 to use as a buffer in front of an LM3875 gain clone. The chip amp has plenty of.... -
I have an almost mint condition Fisher 800b hi-fi amplifier that I want to convert into a mic pre. All of the power supply SS diodes need to be replaced with modern, low noise parts. All electrolytic caps. need replacement. The signal caps. may still be.... -
The comment on using the existing phono connector was to not really change anything at all. Just replace the electrolytic and paper caps, add the 3-wire line cord and use the radio as-is. The selector switch on the radio probably has an "Aux" or "Phono".... -
Originally Posted by artosalo My original claim was that pentode connected version is not optimum. NO! You wrote the Mullard 5-10 is not optimum. If.... -
Hi, does somebody have a good 211 / VT4C schematic like Air Tight ATM-211 to recommend ? If it`s possible without interstage transformer and 6SN7.... -
Hi! I want to DIY a 300BSE power amplifier recently, could somebody recomend or provide me a wonderful and robust schematic??? I will use Lowther PM6.... -
I plan on building a ""high power"" amp using the KT88. Found the following circuits: 1) Which will be the better quality one to build? 2) Are .... -
Too much of a good thing can confuse you. I started out looking to build a simple 15W triode / 30W Class AB1 pentode PP amplifer. Class AB1 = because.... -
This design is based upon an ECL86 Amp design posted by Yves quite some time ago. This design uses shunt feedback to reduce the output stage rp and thus better drive the limited primary inductance of cheaper output transformers. Regardless of that, the....
New Circuits
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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.....
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