Hi, I'm looking for plans for a 1 or 2 tube low voltage amplifier to go with a regenerative radio. Does not have to be the best, but needs to...

Hi, I'm looking for plans for a 1 or 2 tube low voltage amplifier to go with a regenerative radio. Does not have to be the best, but needs to drive at least 250 mW speaker, preferably 1 watt or more. Thanks, Dave Australia

I tried to build this Class A amplifier circuit as a learning experience: http://www.techlib.com/electronics/audioamps.html#class-a with the...

I tried to build this Class A amplifier circuit as a learning experience: http://www.techlib.com/electronics/audioamps.html#class-a with the following modifications: 1. I have no MPSW45, so I built a Darlington out of a 2N2222 and TIP31A. 2. 150k resistors: I only had two 100k resistors in my collection. But as long as they're identical, should work...??? 3. speaker: I had only a 10W...

We have a Panasonic cordless set of phones. In the last month, we've noted that occasionally the ringer (speaker, I suppose) sounds very...

We have a Panasonic cordless set of phones. In the last month, we've noted that occasionally the ringer (speaker, I suppose) sounds very rough. My wife finally put it on another circuit for nearly a month. No problems. I think it's another device on the circuit that causes the problem. Here's what's on that circuit. The kitchen circuit containing the phone plug includes: 1. Kitchen...

I want to switch on some receptacles when another one is drawing current. I want my remote controlled TV to turn on the equipment ancillary...

I want to switch on some receptacles when another one is drawing current. I want my remote controlled TV to turn on the equipment ancillary to the television - converter box, antenna rotor, speaker amp. Ideally something that can sense down to 1 amp or so then energize the other outlets, and uses minimal current itself. These things used to be fairly common to switch off the other comp...

I was looking at a tide table to find minus tides during the daytime to go poke at creatures and I thought that the fairly regular wavelength...

I was looking at a tide table to find minus tides during the daytime to go poke at creatures and I thought that the fairly regular wavelength would make some very boring music. If you sped up the frequency from days to kHz and had feet represent either volts delivered to a speaker, or actual sound waves you would hear something. Probably a very regular tone that varied more in volume t...

I wired up a 556 (two 555 timers on one chip) as follows: Timer A: astable circuit with equal mark & space width, R = 267 ?, C = 1000 µF...

I wired up a 556 (two 555 timers on one chip) as follows: Timer A: astable circuit with equal mark & space width, R = 267 ?, C = 1000 µF (electrolytic with 25 V rating), output: 320 ? in series with an LED, also tied to the reset pin on Timer B Timer B: same astable timing arrangement, R = 100 k ?, C = 10 nF (non-electrolytic), output: piezo speaker in series with a resistor

I want to do an experiment in brainwave entrainment by making a 7 Hz sine wave oscillator out of an XR2206 frequency generator IC and a LM386...

I want to do an experiment in brainwave entrainment by making a 7 Hz sine wave oscillator out of an XR2206 frequency generator IC and a LM386 amplifier feeding a six inch diameter coil-- which should probably fit around my fat head. ;-) The LM386 has an 8 ohm output, so it shouldn't be hard to find a speaker, if I wanted to use one; but I don't know how to make a good 8 ohm coil to radia...

I have an audio DSP filter for my amateur radio equipment. It uses an LM380= op-amp in the final AF amp stage, using a 100K ohm pot as the...

I have an audio DSP filter for my amateur radio equipment. It uses an LM380= op-amp in the final AF amp stage, using a 100K ohm pot as the volume contr= ol. When using a speaker the volume control is fine, but when using headpho= nes, the sensitivity from quiet to really loud is only a small tweak of the= volume know. Anything I can do to reduce this sensitivity for my headphone output? ...

I was reading the ARRL handbook (2010) and on page 4.7 there was this sentence: "it can be said that any device that dissipates power has a...

I was reading the ARRL handbook (2010) and on page 4.7 there was this sentence: "it can be said that any device that dissipates power has a definitive value of resistance" This made me think. I always see speakers modeled 8 Ohms. And this is probably their DC resistance value. But shouldn't the conversion to sound be accounted for somehow since it's a sink on energy delivered? I thought ...

This speaker question kinda goes with my previous question(s) about tubes. I have been looking at tube stuff on the web and some of it really...

This speaker question kinda goes with my previous question(s) about tubes. I have been looking at tube stuff on the web and some of it really appeals to me. I'm a machinist and have a shop so making knobs and the like is easy for me to do. And some of the tube sets with exposed tubes and transformers sure are pretty. So I got to thinking about speakers. I would like to have metal enclosures (...

For some low-power audio amps, usually less than 2 Watts, I see the amplifier powered by +V...

For some low-power audio amps, usually less than 2 Watts, I see the amplifier powered by +V and ground: http://www.redcircuits.com/Page33.htm For other, usually higher-powered amplifiers, I see a +/- power supply required. http://www.redcircuits.com/Page164.htm Do the amplifiers without a +/- supply continuously provide a voltage at 1/2 V during the silent parts, to allow the speaker room ...

trying to replace left headphone speaker in a set of USB headphones with mic Headphone very like...

trying to replace left headphone speaker in a set of USB headphones with mic Headphone very like this http://www.frys.com/product/4452636 Speaker like this http://www.digikey.com/product-detail/en/AS02808MR-2-R/668-1397-ND/4147321 The circuit board part with solder pads separated from the speaker from a fall to floor and the wires are so fine from speaker part i can not tell where t...

Hi, If I measure the DC resistance of a hi-fi speaker with an impedance of 8 ohms, it comes out at approx. 8 ohms. But when I measure the DC...

Hi, If I measure the DC resistance of a hi-fi speaker with an impedance of 8 ohms, it comes out at approx. 8 ohms. But when I measure the DC resistance of a dynamic microphone with a stated impedance of 50k ohms, it comes out as only 1500 ohms. Another dynamic mic with a stated impedance of 400 ohms reads only 1.1 ohms DC resistance. Why do mics DC resistance seem to measure different...

*Important Note:* If you rather not be involved in activism, anything remotely political etc. PLEASE go to the next post. Shalom. Vaya con...

*Important Note:* If you rather not be involved in activism, anything remotely political etc. PLEASE go to the next post. Shalom. Vaya con Dios. ================================================================== We started a project where The Community (Usenet, Social Media, We The People, whatever that means) will participate by looking for audio/video clips of Mr. Bill O'Reilly,...

The elderly in particular use a cat-deterrent in their garden. It is a small apparatus with a speaker attached to it. It produces a high-pitched...

The elderly in particular use a cat-deterrent in their garden. It is a small apparatus with a speaker attached to it. It produces a high-pitched bleep of more than a 100 decibel. The sound is mostly only audible for children, youngsters and people with ears that are still good. Many cat-deterrents use the same noise as the Mosquito. The sound causes pain in the ears, headache, and ringing in ...

I need a 2.7uf 63V non-polarized capacitor for a speaker crossover. It is a radial lead 10mm x 22mm cap. Ebay has them from China. (slow...

I need a 2.7uf 63V non-polarized capacitor for a speaker crossover. It is a radial lead 10mm x 22mm cap. Ebay has them from China. (slow boat) I've checked Digi-Key, Mouser, Allied, and Newark. I've also checked several speaker part sellers. I have found an axial lead cap, for $0.50 plus $6.95 shipping. But I'd prefer a radial lead. Have any other sources? Refoamed a set of Pione...

I'm replacing a couple of capacitors in speaker crossover. The parts have a glue that holds them tight to the PCB, the glue is still a little...

I'm replacing a couple of capacitors in speaker crossover. The parts have a glue that holds them tight to the PCB, the glue is still a little bit rubbery after 33 years. (Pioneer HPM-700) What can I use that will do the same job, without solvent damage to the electronic parts? Mikek

Is there a way of connecting a Windows PC to a satellite phone so that the = following can be done from software running on the PC: 1....

Is there a way of connecting a Windows PC to a satellite phone so that the = following can be done from software running on the PC: 1. Remotely control the satellite phone from software on the PC (i.e. answe= r call, hang up call, adjust speaker volume, adjust mic sensitivity etc) 2. Receive speaker audio stream as a digital 16-bit signed PCM mono audio s= tream. 3. Send 16-bit signed PCM ...

In my shop I have a a Pioneer SX-434 radio/amp for my listening pleasure. The speakers are mounted high up, screwed to the wall, and are not...

In my shop I have a a Pioneer SX-434 radio/amp for my listening pleasure. The speakers are mounted high up, screwed to the wall, and are not easy to get at. I had to disconnect the speaker wires temporarily from the stereo and stupidly didn't mark the wires for positive and negative. Is there a way to tell which wires are which that doesn't involve ladders and me unscrewing the speakers from...

Since I will be playing a low wattage tube amp through speakers it seems that high efficiency speakers are in order. How can I tell...

Since I will be playing a low wattage tube amp through speakers it seems that high efficiency speakers are in order. How can I tell the efficiency of a speaker from looking at the specs? Thanks, Eric