No voltage across power out terminals and speaker playing

Started by Anonymous in sci.electronics.basics11 years ago 50 replies

Hello! I have a Marantz SR4600 receiver.I wanted to measure it's approximated performance with an excellent quality sound card and RightMark...

Hello! I have a Marantz SR4600 receiver.I wanted to measure it's approximated performance with an excellent quality sound card and RightMark AudioAnalyzer. I have a neccessary voltage divider for speaker-to-line levels conversion. My other amp, Technics SU-V4X works ok.No problems at all. With Marantz, I have no voltage reported across speaker terminals when measuring with a multimet...


Audio Amplifier Problems

Started by PDI Dave in sci.electronics.basics11 years ago 40 replies

Please Help Me! I have a few amplifiers that i am having problems with and i need to determine if the amplifiers are bad or if the...

Please Help Me! I have a few amplifiers that i am having problems with and i need to determine if the amplifiers are bad or if the speaker circuits are bad. each has upwards of 100 speakers on them (70.7 volt system) and they keep shutting down (internal circuit breaker tripping). they only seem to do it when all/most speakers are hooked up, but i can't yet figure out why. I've checked the AC...


Cleaning Old Soda Off Of A Circuit Board?

Started by phaeton in sci.electronics.basics11 years ago 20 replies

Hey y'all. Been awhile since I've been here. I've missed the joint. I might be picking up an old SS Fender bass amp from a guy at work...

Hey y'all. Been awhile since I've been here. I've missed the joint. I might be picking up an old SS Fender bass amp from a guy at work for dirt cheap. Like buy him a case of beer and it's mine, cheap. Anyways, I don't know the details, but at some point in its illustrious history, it was laying on its back, and a Wild Cherry Pepsi got dumped onto it. Supposedly the speaker is fine, bu...


Help enclosure for speaker + batteries

Started by Anonymous in sci.electronics.basics10 years ago 4 replies

Hello all We are looking for an off the shelf enclosure which will hold a speaker and have an opening for batteries(battery...

Hello all We are looking for an off the shelf enclosure which will hold a speaker and have an opening for batteries(battery compartment). Other than those basics we are very flexible. All suggestions appreciated Many thanks Denis ___________________________ Centron System Solutions http://www.CentronSolutions.com


Tube Amp

Started by Dave.H in sci.electronics.basics10 years ago 13 replies

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


Dialer problem with a picchip

Started by lerameur in sci.electronics.basics9 years ago 31 replies

Hello, I have a recuring problem when connecting my circuit to the phone line. basically the circuit I use is...

Hello, I have a recuring problem when connecting my circuit to the phone line. basically the circuit I use is : http://ourworld.compuserve.com/homepages/Bill_Bowden/autocall.htm with the exception that I connect B3 to an 8th order low pass filter and the output of that goes to the positive of the transformer. Also I use picbasic to create my DTMF. I connected a small audio speaker to th...


Networking Router near a speaker(magnet) ??

Started by Robert Blass in sci.electronics.basics9 years ago 4 replies

I've asked this question in the networking/router newsgroups and those guys give conflicting answers so I wanted to ask you guys since...

I've asked this question in the networking/router newsgroups and those guys give conflicting answers so I wanted to ask you guys since you'd probably know better. Almost everyone in the etworking/router newsgroups say the problem I have has nothing to do with my router being near my speakers. My router is on top of one of my stereo speakers. It's a 50 watt speaker and is not being used A...


will a dc offset affect a speaker?

Started by panfilero in sci.electronics.basics9 years ago 44 replies

ok... here's my question: If I have a millivolt range audio signal and I add a dc offset to it, and then I take my new signal and send it to a...

ok... here's my question: If I have a millivolt range audio signal and I add a dc offset to it, and then I take my new signal and send it to a speaker with a built in amplifer, will this be the same as sending the audio signal alone to the amplifier? What I think: I think yes... because the way speakers work is by vibrating along with the fluctuations of the audio signal, and since a dc s...


How to test speaker ohms?

Started by muzician21 in sci.electronics.basics9 years ago 43 replies

I want to replace the midrange of a Fisher speaker model ST-440 "Studio Standard Series". No idea what vintage it is - maybe 80's...

I want to replace the midrange of a Fisher speaker model ST-440 "Studio Standard Series". No idea what vintage it is - maybe 80's or 90's. What's on the back is SB-80521-1 L81TNK AFAIK it's a factory speaker. Obviously I want to replace it with the right kind of speaker. I have a multimeter, how do I test it? Only one is damaged - it's been torn since I got them at a pawn shop - bu...


Building a class A audio amplifier - no audio out

Started by Anonymous in sci.electronics.basics9 years ago 68 replies

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...


need a quick ultrasonic noisemaker

Started by Michael in sci.electronics.basics8 years ago 13 replies

For the neighbor's dog. Heard about the ultrasonic noisemakers that are triggered by a dog's bark, but at $50 and several unfavorable comments,...

For the neighbor's dog. Heard about the ultrasonic noisemakers that are triggered by a dog's bark, but at $50 and several unfavorable comments, thought I'd try to roll my own. Aiming for 16-20 kHz. In a bit of a hurry at the moment, so no C, R1 and R2 chosen yet, but is this a good idea? I've got a couple spare 12V lead acid batteries lying about, and a couple of spare 4 ohm car speaker...


Diodes for 12v battery charging

Started by Stumpy in sci.electronics.basics8 years ago 22 replies

I put in a 12v solar panel to charge up 2 ATV's and a mini tractor. Ran some speaker wire and battery clips to charge all of them in parallel. ...

I put in a 12v solar panel to charge up 2 ATV's and a mini tractor. Ran some speaker wire and battery clips to charge all of them in parallel. The tractor battery seems to not hold a charge very well. I'd like to add 3 diodes to protect the other 2 batteries in case at night with no input current, the low battery would siphon off power. The setup is in a very remote location with no ...


Magnet Damage to LCD

Started by Affan in sci.electronics.basics8 years ago 8 replies

So, I know that speaker and light magnets donot damage LCD like they used to dmage CRT's. However, my daughter a mere 2.5yrs old, took a magnet...

So, I know that speaker and light magnets donot damage LCD like they used to dmage CRT's. However, my daughter a mere 2.5yrs old, took a magnet and was able to make entire area on the screen go completely black. First question... anyway to repair it? second, how could this happen?


building a small amplifier for the first time

Started by Michael in sci.electronics.basics7 years ago 9 replies

I finally settled on this one: http://www.techlib.com/electronics/audioamps.html#computer Questions: 1. Would a 2N2222 work instead of the...

I finally settled on this one: http://www.techlib.com/electronics/audioamps.html#computer Questions: 1. Would a 2N2222 work instead of the 2N4401? I've got a bunch of quad-2s in my bin. 2. Would it be ok to substitute 1-ohm resistors for the 2.2 ohm resistors on the speaker side, if I use a larger speaker? I've got a spare 4-ohm, 10W speaker from when I upgraded the car's audio syst...


Speaker/ Amp impdeance

Started by George Herold in sci.electronics.basics7 years ago 38 replies

There was a question about speaker impedances (8 Ohms vs. 4 Ohms.). On a list server that I follow. Several reponders mumbled about matching of...

There was a question about speaker impedances (8 Ohms vs. 4 Ohms.). On a list server that I follow. Several reponders mumbled about matching of the speaker impedance to the amplifier impedance. To me this sounded like a lot of hooey. I assume modern audio amps have very low output impedance. And that the 4 or 8 ohms is more about the maximum voltage and current that the amp can produce. ...


DIY amplifier+loudspeaker

Started by Man-wai Chang in sci.electronics.basics6 years ago 10 replies

I only need a very very basic speaker, powered maybe by AA batteries, that amplifies the 3.5mm audio output from the iPod Touch. Is this...

I only need a very very basic speaker, powered maybe by AA batteries, that amplifies the 3.5mm audio output from the iPod Touch. Is this going to be cheap? Could I just connect a small buzzer to it? -- @~@ You have the right to remain silence. / v \ Simplicity is Beauty! May the Force and farces be with you! /( _ )\ (x86_64 Ubuntu 9.10) Linux 2.6.39.1 ^ ^ 16:33:01 up ...


class B (or is it AB?) design mods

Started by Recovering Madman in sci.electronics.basics6 years ago 3 replies

Found a circuit: http://openbookproject.net//electricCircuits/Exper/EXP_6.html#xtocid158349 What parts would have to change if I were to use...

Found a circuit: http://openbookproject.net//electricCircuits/Exper/EXP_6.html#xtocid158349 What parts would have to change if I were to use +/- 6VDC instead of +/- 12VDC, and use a 4 ohm speaker instead of an 8 ohm one? Would it still work if I use +/- 3VDC?


LM386 power amp IC question

Started by Kaz Kylheku in sci.electronics.basics6 years ago 20 replies

I found an old LM386 chip in one of my piles of junk, and I'm thinking of putting it into use. All the schematics in the data sheet use an...

I found an old LM386 chip in one of my piles of junk, and I'm thinking of putting it into use. All the schematics in the data sheet use an idiotic, large output coupling capacitor between the chip and the speaker, which just makes me cringe. I'm thinking that since the IC references the output at halfway between its power rails, and since I'm using a virtual reference in the rest of my ...


Convert stereo to mono

Started by amdx in sci.electronics.basics6 years ago 14 replies

I have a new internet radio that has a a stereo headphone jack. I want to drive a single speaker with both channels. Will I cause harm to the...

I have a new internet radio that has a a stereo headphone jack. I want to drive a single speaker with both channels. Will I cause harm to the amplifiers if I just tie the outputs together and use the that to drive the speaker? OR Do I need to add some resistors to isolate the amps from each other before the speaker? Thanks, Mikek Hmm. I'm thinking headphone jacks often...


Noisy Phone (speaker?)

Started by W. eWatson in sci.electronics.basics6 years ago 6 replies

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...