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Mini Portable Guitar Amplifier - Can be fitted into a packet of cigarettes. Also suitable as Fuzz-box __ Contact: Flavio Dellepiane, fladello @ tin.it
Miniature Class a Amplifier - The philosophy behind this minimalist design has been explained by Flavio Dellepiane on his highly interesting site 1. I have myself written an article about this fleapower amp from Italy in the American magazine AudioXpress 2. All relevant details __ Designed by Aren van Waarde
Mini-box 2W Amplifier - This amplifier was designed to be self-contained in a small loudspeaker box. It can be feed by Walkman, Mini-Disc, iPod and CD players, computers and similar devices fitted with line or headphone output. Of course, in most cases you will have to make two boxes to obtain stereo __ Contact: Flavio Dellepiane, fladello @ tin.it
Mini-MOSFET Audio Amplifier - Including Preamp, Tone Controls and Regulated dc PS 18 Watt into 8 Ohm, 30W into 4 Ohm loads __ Contact: Flavio Dellepiane, fladello @ tin.it
Mono Audio Amplifier with TBA820 - This circuit will use IC TBA820M, which be power amplifier IC model mono. By use force against watt at 2 watt have 34 dB. The bandwidth expansion ratios 20Hz-20KHz use. The power supply since 3-16V and use, current 4mA only just.
Mono audio preamplifier using single 2SC732 transistor - schematic only __ Designed by Petra
OCTAL Phono Preamp - This preamp design started out as a conventional three stage cascade with feedback RIAA equalization. I decided on 6SL7's running into 6SN7's. I figured it would be a good match (electrically and asthetically) for my 2A3 Amp. After thinking it through I thought I might just try passive RIAA. (Even a better matchno feedback!!!) I noticed a neat RIAA preamp circuit in the back of the RCA Tube Manual RC-19 that used a single 7025 per channel __ Designed by Bob Danielak
One Watt 2.3 GHz RF Amplifier using a Mrf2001 - Simplicity and repeatability are featured in this 1-watt S-band amplifier design. The design uses an MRF2001 transistor as a common base __ Designed by Michael Micili
One Watt 2.45 GHz Linear Amplifier - Schematic: Reversed PCB pattern: BOM: Schematic Reference Value Package Capacitors C1 1 µF electrolytic, 10%, 16V SMT or leaded C2, C3 1000 pF ceramic, X7R, 50V 0603 SMT C4 22 pF Johanson ceramic 5%, 100V 0504 SMT C5 3.3 pF __ Designed by www.gbppr.org
Op-Amp Microphone Preamplifier - A high quality microphone preamplifier using a single power supply, suitable for dynamic or electret microphones. The op-amp used can be any low noise, high performance type, e. g. NE5534, TL071, OPA 371 etc __ Designed by Andy Collison
Phono Preamp - Tube design
Portable Headphone Amplifier - 3V Battery powered High Performance unit __ Contact: Flavio Dellepiane, fladello @ tin.it
Portable Headphone Amplifier for MP3 Players - Fixing Transformer Buzz In The Class-A Amplifier __ SiliconChip
PortaPAL Public Address System-Part 2 - Here's the good oil on putting it together and getting it to work. We even describe an easy way to build a box. __ SiliconChip
Power Amp using a TDA2003 - Here is the circuit diagram of a 10W audio amplifier using the popular TDA2003 IC from SGS Thomson. The IC can easily deliver 10W to a 4 Ohms load at 18V DC supply voltage. The IC can be also operated from 12V and that makes it applicable in car audio systems
Power Amplifier Clipping Indicator - At some stage, we will all find ourselves pushing hi-fi equipment just a little too hard, and if lucky, will just find that the sound has become "dirty". If this happens too often or is too severe, tweeters are the first to gothey are damaged by the excessive power generated by a combination of "power compression" and the harmonics created when an amplifier clips. The same may well happen to one's ears, but the effect is much more subtle (and cannot be fixed !). __ Designed by Rod Elliott ESP
Power Down for Portables - 06/21/01 EDN-Design Ideas James Prescott Joule first formulated the relationship between electrical current and dissipated power in the 19th century. Joule's Law states that the power a circuit dissipates is equal to the square of the current times resistance,(P=I 2 R]. The SI(International System]unit of work bears Joule's name in honor of this discoveryCircuit Design Greg Vrana, Technical Editor
Power Supply for a SE 300B Amp - Schematic for the power supply
Power Supply for Battery Valve Radios - A number of visitors to this site have asked about power supplies for operating battery valve radios from the mains. Many later radios use four 7-pin valves and require a 90V HT supply at typically 12mA and a 1.5V LT supply at 125mA or 250mA depending on the valves used. The original batteries are sadly no longer made. __ Designed by Paul Stenning
PreAmplifier Computer Microphone - This circuit was submitted by Lazar Pancic from Yugoslavia. The sound card for a PC generally has a microphone input, speaker output and sometimes line inputs and outputs. The mic input is designed for dynamic microphones only in impedance range of 200 to 600 ohms. Lazar has adapted the sound card to use a common electret microphone using this circuit __ Designed by Lazar Pancic from Yugoslavia
Push-Pull 5687 Amp - This stero amp will give you 4-8W/ch of zero feedback triode power for less than a pair of Chinese 300B's if you know where to shop. For those of you who are unfamiliar with this lil' tube here's the poop. The 5687 is a 9-pin miniature twin triode (a la 12ax7, 12au7, etcbut with different pin-out). Its specs are quite interesting __ Designed by Robert Danielak
Push-Pull 6L6 GUITAR Amp - The schematic for the guitar amp __ Designed by Robert Danielak
Push-Pull 6Y6 Stereo Amp - This is a pretty straightforward PP amp design except for the unique positive feedback from the phase-splitter cathode to input stage cathode.12 Volt input tubes were used because this amp is going to be used in my CAR (with a 250V switching power supply for B+). More info will be added as time permits. __ Designed by Robert Danielak
Pushpull Class a 2a3 Stereo Amp - The input stage is comprised of a both halves of a 6SL7 octal dual hi-mu triode in a differential amp configuration with a 1ma constant current cathode load. I'm using field-effect (constant-current) diodes for simplicity. the diff amp approach was chosen for good power supply rejection, ease of balancing, good gain, and ease of application of *feedback*, if desired (hey, i like to keep an open mind). It also takes care of phase-splitting right up front. Note: I've returned the constant current diode cathode to -9V instead of ground in order to avoid the non-linearities about the pinch-off region (Vpo ~= 1.5V) __ Designed by Bob. D. @ robert.m.danielak @ lmco.com
Pushpull Class a Amp using Type 5687 Dual Triodes - This stero amp will give you 4-8W/ch of zero feedback triode power for less than a pair of Chinese 300B's if you know where to shop. For those of you who are unfamiliar with this lil' tube here's the poop. The 5687 is a 9-pin miniature twin triode (a la 12ax7, 12au7, etcbut with different pin-out). Its specs are quite interesting __ Designed by Bob. D. @ robert.m.danielak @ lmco.com
Quadraphonic Amplifier - This is a four channel amplifier ideally suited for use with quadraphonic equipment such as a Sound Blaster Live card. There is no volume control, audio levels being directly controlled from the sound card itself. __ Designed by Andy Collison
Ruby is an "enhanced" version of the Little Gem battery-powered Amplifier (LM386 based Design) - A refined and updated Little Gem amplifier. __ Contact: holler @ runoffgroove.Com |
