Ask MetaFilter questions tagged with stereo and electronics

Table Hockey in the dark?

DrAlbin — Wed, 05 Aug 2009 23:12:18 -0800

Table Hockey in the dark? I was cleaning out my workshop today and came across two identical devices packed in separate bags, that for the life of me (or Google), I can not figure out what they are. There isn’t a pic link, because it really didn’t get to me until I got to work, and now I have hours to ponder with no answers.

Please me-fites, you’re our only hope.

They were in a crate filled with cables (computer, stereo, TV (Direct TV + Cable)). One end there was a 6-8” piece of black plastic shaped like a hockey stick, But with uniform thickness throughout, near the bent end (think: on the top of the hockey stick blade) there are 2 clear LED’s protruding from the plastic. On the other end (think; hockey stick butt end) there was a wire (approx 4 ft long) terminating with a 3.5mm male stereo jack. (Headphone jack). I hooked it up to my phone, just to see if maybe the lights would light up when sound was played, to no avail.

Anyone have any ideas? Or proof that you are the Google ninja?

Lite Rock, Less Talk? I'd like neither, please.

strangecargo — Thu, 15 Jan 2009 00:59:16 -0800

(Electronics|Stereo)filter: What is causing this infuriating noise in my preamp and how do I fix it? Links to sound files and long list of symptoms in extended. I have this preamp and ever since moving to my current apartment in San Francisco, it generates a really loud noise that sounds like a combination of 60 Hz hum and FM radio broadcasts. The noise is loudest when the volume knob is turned all the way down, but it doesn't go away when you turn the volume up. And this is what it sounds like when you go from zero gain to full gain and back. The noises don't sound that loud when played back on a computer, but that level of noise is pretty dang loud when sent to the input of a power amp.

The maybe pertinent facts (numbered because there are a lot of them):

1. I recorded the linked sound files by plugging in the output of the preamp into the line in of a MacBook Pro. No mixing or diddling with the file other than that.

2. You can clearly hear the station identifier for KOIT in the first sound file I linked. This is an FM station. What the heck? I was under the impression that FM was way too complicated for equipment to randomly pick up unless it was designed specifically to, you know, receive FM radio.

3. Changing the vacuum tubes inside the preamp doesn't change the nature of the noise.

4. I have other audio equipment (both solid-state and tubed) that doesn't make this sort of noise.

5. The noise is generated independent of what I have connected as an input or output (or if there's anything connected at all).

6. I can't seem to reproduce this noise outside of my apartment (friends' places, hifi shops, etc). Whenever I try, the preamp is noiseless and dead silent.

7. Physically moving the preamp around my apartment doesn't seem to change the noise either.

8. I live in an old apartment without grounding in most of the electrical sockets, but the noise doesn't change if I plug the preamp into a grounded outlet. I've checked that the grounded outlets in my apartment are indeed grounded with one of these devices.

9. I live sort of near Sutro Tower (but who in SF doesn't?). Wikipedia tells me that KOIT broadcasts from Sutro Tower. I also live right next to the N Judah MUNI line. Sometimes my lights dim when it goes by. I suspect the power is probably kind of dirty.

10. Using a different power cable doesn't do anything.

11. For what it's worth, here's a look at the circuitry inside the preamp.

I've been investigating this problem on and off for the last year or so and I still haven't figured out what's causing the problem. Do any electrical engineer types have an suggestions for further testing or solutions to this problem? I have a digital multimeter and oscilloscope at my disposal for the collection of further data.

I'm quite attached to this preamp (more so when it isn't making this noise), so please don't tell me to replace it.

cell phone static and home stereos

minicloud — Sat, 29 Mar 2008 12:17:38 -0800

Why does my cellular phone cause my home stereo speakers to make strange noises? Sometimes it happens when a call is about to come in, but mostly it just happens periodically for seemingly no reason. It sounds like strange beepy static and it happpens much more frequently now that I switched to an iPhone. Is there a way to stop this besides throwing my iPhone across the room?

Home Audio 101

10ch — Tue, 20 Nov 2007 06:49:09 -0800

What components do I need to buy to have a solid stereo system for my home? I know nothing about home audio and I want to buy a quality turntable for playing records (including 78s) as a gift for my one and only.

I took a look at other mefi questions about turntables and found some good resources, but I quickly realized that there's a lot of vocabulary and hip-bone-connected-to-the-assumptions going on that leave me clueless. I need someone that isn't trying to sell me something to help me figure out what I need.

Fer'instance... am I better going with separate parts (and if so, what are those parts specifically) or with a "home system" (I want to avoid crappy parts just to get the 78 feature, for example).

Here are the things I'd like the system to do, in priority:

- Cost around $500
- Sound good
- Play records (78s, 33s and 45s)
- Play cds
- Play cassettes
- Play FM/AM radio
- BONUS, BUT NOT REQUIRED: Record across the above (ideally on CD)
- BONUS, BUT NOT REQUIRED: Be aesthetically pleasing

Speak jargon as long as you provide clarification (parenthetically). Links and specific make/model recommendations are appreciated. I'll be happy to converse in thread if I'm leaving details out. Thanks for your help.

Crass consumerism strikes again

FelliniBlank — Fri, 27 Jul 2007 19:34:25 -0800

Tell me how much I need to spend on audio preamp(s) and amplifier(s) to make my home stereo system sound jaw-droppingly great. Ze muzeek, she eez my life, so two years ago I upgraded some of my very low-end stereo components to these moderately better ones:

Goldring GR2 turntable

NAD C542 CD player, and

Orb Audio speaker system (two "MOD2" double-satellite assemblies + a subwoofer)

WAY better sound, baby, but that's when the money ran out, so I couldn't replace the basic Onkyo receiver with a nice preamp(s) + amp(s) to make the most of the other components.

Now I have some pennies saved and have started looking at equipment and reviews. This is where you come in. I might could swing $1500 tops for the whole enchilada if absolutely necessary, but I'd like to spend as little as it takes to get good quality gear -- new or used -- that actually makes an audible improvement to my non-audiophile, non-engineer ears. And even if I do drop the whole $1500, I'm not exactly sure how to divide it between the different components so that I'm investing the right proportion in each one.

The question:
To get preamp and amp equipment that is of comparable quality to the rest of my system and that will help it live up to its full potential, how much should I be looking to spend on each of the following:

1) phono preamp
2) line preamp
3) or instead of 1+2, a single preamp with phono stage
and
4) monoblock or two-channel amp(s) with max 110 wpc output (25-75 watts is probably plenty for my small, decently efficient speakers in a 13x20ish foot room)

Or if you think the existing Onkyo receiver is up to the job and I should put my wallet away, g'head and say so.

Other info:
-- This is just for music; I have zero interest in home theater audio. My musical tastes run the gamut.

-- SS or tube is fine, but I doubt that decently isolated hybrids are within my budget. As a vinyl-loving middle-aged Luddite who digs warm, rich sound, I'm drawn to the concept of vacuum tubes, and the basic Antique Sound Labs preamp and monoblock amps are appealing and affordable. But I don't know if I'd like the reality of tube gear. It would have to go in this type of open rack and would have at most a few inches of clearance above it, and I'm not sure that's sufficient for ventilating tube components. Also, I'd get cranky if I had to let the thing warm up for an hour before it stopped sounding like shit.

Please take it easy on the acousticalese; IANAPhysicist.

Amp/receiver - throw or give away?

ObscureReferenceMan — Sun, 17 Sep 2006 17:45:30 -0800

What to do with a damaged stereo receiver? I've got an old stereo amplifier/receiver (a twenty year Onkyo, TX-26), and the left channel is... gone. I'll be replacing it (thanks, by the way, to the info in this thread - getting the 8222), but what should I do with the old one? Just toss it? Or can it still be used by someone, somehow? Any environmental concerns if it goes in the trash? Thanks, gang!

I'll take "A New Stereo" for $200, Alex.

exceptinsects — Tue, 08 Aug 2006 12:33:02 -0800

So, the stereo I won on Jeopardy is about to break...what should I replace it with? What I already have and would like to hook up:
Surround sound speakers
TV
DVD player
iPod
iBook

I would like to also have a basic CD player [the old one was a 24-disc changer and completely irritating--1 CD at a time is plenty] and AM/FM radio. A tape deck would be nice but not at all necessary.

So...should I get one of those integrated stereo things again? A receiver and separate CD player? A wireless doodad so I don't have to actually plug in the computer/iPod?

I'm not a big audiophile, so it doesn't have to be AMAZING sound quality, and I don't want to spend more than 2 or 3 hundred bucks at most. I also would prefer not to have to build it myself out of parts from Radio Shack. (Do they still have Radio Shack?)

Any advice would be greatly appreciated.

airtunes vs. tivoli deathmatch

luriete — Sat, 07 Jan 2006 19:33:06 -0800

i just bought a tivoli system (kloss model 2, extra speaker and cd) and have it on the bookshelf but some questions: The Tivoli staffperson I emailed said it had an aux in and would work fine with my airtunes setup. However, there's an aux in (for the CD player, I think?) and a "mix in" which is also a single (mono?) mini rca. My old stereo went mini RCA (airtunes) > full size right and left stereo jacks (stereo), so now I've run a single mini RCA cable (on both ends) from airtunes to the "mix in" jack and it sounds just OK. Not as good as the cheapie sony boombox we used to have. Is this because before I had stereo sound coming in and now I just have mono? Is there a better way to hook this stuff together? I really like the warm sound of the Kloss speakers and it looks very pretty, and I like the big knobs ... I assume there must be some way to make the music from my powerbook sound better than it does on my crummy powerbook speakers; right now they sound about the same.

Why does my stereo screech at certain pitches?

agropyron — Mon, 25 Jul 2005 13:48:03 -0800

I recently moved my stereo to a new location. After I reassembled it, it started making screeching noises whenever a certain pitch is hit. The noises are only made by one speaker. It produces an eerie static when a high pitch is reached by the music I'm playing. Here's a picture of the wiring in the back of the speaker, just in case that helps.

Any ideas how to fix this?

Strange Electrical Happening with My Car and Two Car Stereos

mcsweetie — Sat, 29 Jan 2005 12:23:13 -0800

Apologies for CarFilter, however: some weeks ago my car stereo began behaving badly before finally dying. [mi] I fired up the ignition after work one day and my car cd player came on just fine for a bit, but after a moment or two the volume suddenly shot all the way up to maximum and wouldn't turn down no matter how frantically I assaulted the controls. I was finally able to get it to shut off by holding the power button down as hard as I possibly could. when I got home that night, I unhooked the battery for a bit and then reconnected it and everything seemed to work ok but the next day the very same thing happened again only this time the player wouldn't power back on when I reconnected the battery.

I dusted off my old tape player and installed it in my cd player's place and the backlight for the screen would come on but no sound would come out. so finally I just straight up bought a new cd player and installed it but it won't power on at all. I've replaced the fuses and made sure the correct wires were wired together and yet! I suspect there may be some strange electrical issue I haven't considered as the temperature gauge and odometers are also out. I had to replace my alternator earlier last year and ever since none of my dials and guages have really worked right.

my apologies again for carfilter but I am a very, very indebted student and I'm weary of mechanics! and riding around in total silence is a real bummer!

How to find a skipless CD player for my car?

luser — Tue, 14 Sep 2004 05:45:18 -0800

My car CD player (a Sony unit, probably about 6 years old) pretty much stutters/skips every CD I put in it, usually 5-10 minutes into the disk. Should I replace it, or try those lens cleaner thingies? Also, if I go to replace it, what's the metric in CD players' model specs that will tell me how well the lens will handle light scratches and/or burned CDs? I guess I could just get a really expensive one, but the only feature I really care about is that it doesn't skip.

I'm looking at the JVC EX-A1, and want a NAD or a TEAC system. What direction should I take for a quality compact stereo system?

four panels — Wed, 01 Sep 2004 15:06:24 -0800

Looking at the JVC EX-A1, and really wanting a NAD or a TEAC system, what direction could be taken for a quality compact stereo system?

How best should I use these old Zenith Allegro speakers with a modern receiver?

The Michael The — Wed, 17 Dec 2003 08:23:33 -0800

I have an old Pair of Zenith Allegro speakers (50-watt, 8-ohm) with pre-attached cables and RCA-style plugs (male) for connecting to the stereo. I'd like to use them with a more modern receiver (50-watt max, 8-ohm) that accepts straight wire from the stereo; should I just lop off the ends and wire them in, or is there a better method? Also, can I use them with a >50-watt stereo if I keep the volume down, or is that just bad?