Ask MetaFilter questions tagged with amp

Speaker Output of Amp A to RCA Input of Amp B

forallmankind — Sat, 07 Nov 2009 11:35:06 -0800

Is there any way I can take the speaker output from underpowered combo CD/ amp A and run it into the RCA input of power amp B? If not, what is the difference between what is running out of a speaker output vs what is running out of an RCA output?

I can hear the ocean

uncleozzy — Thu, 05 Nov 2009 06:48:01 -0800

You are not my amp tech, but maybe you can help me diagnose the source of a strange noise on a brand new guitar amp. Yesterday, I got a tiny tube amp in the mail. After letting it come up to room temperature, I plugged it into a cab (yes, with the right impedance) and played away. No problems at all; made some really nice sounds, by the way.

The next time I turned it on (an hour or two later), there was an awful static noise--sort of like rushing water, or waves crashing--even with the volume all the way down and no guitar attached. Playing through it produced pops and crackles and unpredictable volume changes, and the static continued.

It's got 2 12AX7 tubes (and a funky setup--V1 and one triode of V2 are the preamp, and the other triode on V2 is the power tube). Best I can tell (which is not saying much), they both look normal, glow a healthy orange, aren't microphonic.

Now, the head is brand new, so there's a really good chance it's going back to the vendor as defective, but out of curiosity (and future diagnostic needs), what could the problem be?

Speaker Cables?

god particle — Fri, 11 Sep 2009 09:00:46 -0800

I have a Sonic Impact T-Amp 2 that works really well but I'm wondering what kind of cables I'm supposed to get for it. I don't know much about sound systems, so I don't know exactly what kind of cables I need to plug into the amp. Right now I have a pair of banana-plug cables that plug fine into my speakers, but on the amp end I had to cut off the plugs and basically shove the raw exposed copper cable into the amp. The problem is the cable is too thick to fit in properly and I have a lot of connection problems with the sound cutting out. It frequently requires me messing around with cables until the sound starts working again (which is really frustrating in the middle of a party). So what sort of cables should I be looking for?

Here's what the back looks like.

Buying a keyboard amplifier

Tlogmer — Mon, 03 Aug 2009 16:55:37 -0800

I'm looking for a keyboard amplifier for use in a rock band. Is the roland kc-150 (65W) going to be loud enough or should I spring for the KC-350 (120W)? Or should I look for a bass amp?

How can I come up with some creative phrases using the word "amped"?

niles — Mon, 20 Jul 2009 14:45:30 -0800

Can you help me find phrases that include the word "amp" or "amped"? I'm part of the planning team of a one night convention, and we want to call different parts of the event by different phrases. I've done this before with a theme of "Break", and used things like "Tax Break", "Summer Break", "Break a Leg", "Take a Break", and so on. This year the theme is "Amped", and I have nothing better than "Amp it up" (and of course, "These go to eleven.").

If anyone has suggestions of phrases/catch-phrases/quotes using amped/amp, I'd love to hear them. I'd also love to get ideas on how to further generate ideas...is there such thing as a phrase dictionary out there?

Thanks!

Bass Amplification by Simulated Emission of Reverberation

shoebox — Mon, 29 Jun 2009 13:55:15 -0800

What exactly is the difference between a guitar and bass amp? If I were to get the latter, could I plug in the former instrument and still get similar bitchin' sounds out of my rig? I am interested in learning to play the electric bass and am set to get a beginner model + practice amp. The problem is, I have a (really) shitty guitar from a while back that i can hack out a few tunes on, and would like to amplify it as well. I would much rather not invest in a separate amp for each instrument.

My readings tell me that putting a bass into a guitar amp is not the best idea because it might explode. But how about a guitar plugged into a bass amp? wouldn't that suffice? (research doesn't turn up much) would there even be any difference in sound or anything? If so, what cheap solution can I use to compensate?

Also, past ask threads have been very useful in helping me pick out models, but if any of you have recommendations for certain brands/products, please feel free to shout across the room/

I know, I know, you're jealous.

tmcw — Sun, 14 Jun 2009 17:14:19 -0800

I just lucked out huge on Craigslist. Sitting next to me is a combo organ and a Fender Princeton Blackface, which I got for free (tried to offer money, but it was refused). Now how to get the two back to working conditions... Question #1 - what can I plug in here? The organ is a Doric combo organ of Italian lineage (has Italian on the inside of the case, even) and I don't know what to think of this power adapter. It was long before the Euro plug design, obviously, 60s area, and I don't know even if it is a power plug, as it might be the plug for a dedicated power supply. I'm going to search through Italian historical plugs, but any assistance would be greatly appreciated.

The Princeton turns on sort of, and has a nongrounded plug, and makes noise, but not music at this point. Plugging it in at one point (well, putting the power plug near the outlet) resulted in sparks, possibly caused by the polarity of the plug, which is not noted at all. As far as this goes, I would be totally cool with paying a hundred or two hundred dollars to get this shipshape - it's a hugely awesome amp which I have a definite use for and it appears to be all-or-mostly original. So, any places in the DC area (preferably not requiring lots of driving, I don't have my own car) which I could bring it to a genius who will hand it back to me sparkling and awesome?

Thanks for all your help!

How to determine speaker impedance?

Pressed Rat — Sat, 10 Jan 2009 11:01:32 -0800

Vintage GUITAR AMP/SPEAKER Impedance - A friend has a (1) Wards Airline GVC-9035 combo head w/speaker (Jensen) and a (2) Mid-70's Custom 100 speaker cabinet w/2 speakers (Jensen), but he hasn't been able to find out what the impedance of the speakers are & needs help ..... Here's the deal: He want's to be able to determine the impedance (4-8-16 ohm) of the Wards cabinet, in order to match it to an amp's output impedance, but the Jensen speakers' aren't individually labeled so he can't calculate it by determining if they're wired in series or parallel. Simply putting a volt-ohmeter across the leads won't cut it, right? He's wondering if anyone knows what the output impedance of a Custom 100 head is, presuming that the Custom 100 speaker cabinets would have matched impedance.

The Ward's combo head/speaker cabinet he wants to install some snappy transformer upgrade to (and can apparently order it pre-set or can adjust for 4-8-16 ohm), but has a similar problem in that the speaker (which appears may have been replaced) has no markings to indicate what it is. Online search for schematics yields some that show the amp circuit and output impedance, but not for his model.

Any suggestions? Thanks!

Save me from the audio snake oil salesmen.

jlowen — Sat, 03 Jan 2009 14:46:07 -0800

I am a budget headphone audiophile with $250 to buy myself a toy. I do not want upgrade my amp or source at this point, would the AKG 701 headphones be a wasted investment? My current setup is an iTunes library full of lossless audio feeding a Headroom total bithead (amp/dac combo) and a pair of Grado Sr-80's headphones. I am attracted to headphones because they provide a much more affordable and accesible audiophile listening environment than speaker setups. Now that the Akg 701 headphones are dropping in price to less than $250, I am very tempted to snag a pair.

I've read alot of reviews and am becoming very tired and distrustful of the sonic snake-oil that seems to be passing for advice in audiophile message boards. Many in the community claim that you need thousands of dollars worth of amps and cable upgrades to create a quality listening environment. I have never seen a decent review of any audiophile grade product that took into account the law of diminishing returns or any measure of restraint.

The fact is that I am never going to upgrade my source past lossless digital audio files and I would very much not like to buy another headphone amp or DAC. Given that would it be a foolish waste of money to buy the Akg 701's? Would I notice any improvement over the Grado cans I already own?

playing with myself

jak68 — Fri, 26 Dec 2008 16:44:50 -0800

need recommendation for headphone amplifier for an electric guitar... I need a tiny headphone amp (rockman style) but I havent played in a while and dont know what sounds good out there. Mostly I'm playing rock and blues (blues to REM to black sabbath). I was looking at "Dean Stack in a box" and the rockman (whats the difference between 'guitar ace' and 'metal ace'?). Of course I'd like something that can at least approximate tube amp punch. Anyway so any recommendations? The Dean stack is only 30 bucks (cheaper the better!) at amazon, does anyone know how it compares to rockman? Are there any other brands out there that I need to consider?

Thanks!!

Help me buy an amp pedal

jules1651 — Thu, 11 Dec 2008 08:49:36 -0800

I am trying to buy my boyfriend an amp pedal for Christmas but I am clueless about such things. I am going on two google searches he left open on the browser: "Best Fuzz Pedal for Valco Amp" and "Lovepedal Super 6." He has a Gretch amp and a Fender Princeton Reverb II (tube). He has discussed wanting an sound that sounds "turned up" when it's not. Also, a late sixties sound has been mentioned. He's not expecting me to buy one so he isn't being specific. So, any ideas about pedals I could buy? I know I just need to save the receipt so he can return it for what he wants but I really want to try and nail it. Apologies in advance if the previous paragraph makes no sense, this is all Greek to me.

Cheap amp with great clean tone for stereo effects

relucent — Sun, 21 Sep 2008 18:42:18 -0800

Amplifilter: Looking for a cheap SS guitar amp to complement my Fender Deluxe 90 so I can use my effects pedals' stereo features. I have three Boss effects pedals that have stereo-out features that I would like to use (DD-7 delay, CE-5 chorus and BF-3 flanger). The idea is that I would have two amps, each driving the speaker on the right or left of the stage. So when the effects are off, it sends the signal to both equally, but when they are on, the stereo effects kick in (ping-pong for delay, spaciness for chorus, panning for the flanger).

Right now I play an American Deluxe Strat through a Fender Deluxe 90 solid-state amp. I don't care much for the amp's built-in effects or its distortion, but I love the clean channel. I would like to get another amp very cheap (probably used), and all I need is for it to have a similar-sounding clean channel - I won't use the dirty channel or any other built-in effects. Ideally it would be a Fender amp just because that stands the best chance of delivering a similar sound, but I am open to anything as long as it can be obtained for less than $150 used (or new). I am also completely open to discontinued models that are a few years old.

Any ideas? I was considering a 25W Fender Frontman, but I don't know if that will match up to my 90-watt. And the 65W Frontman amp is a little out my price range.

Not so deluxe. More like deFAIL.

littlerobothead — Sat, 13 Sep 2008 15:25:06 -0800

Guitar amp issues, with a long way between me and a tech. Help me know what to say when I call! I've owned a Blues Deluxe reissue since 1996. Loved this amp to death when I first got it, and still do. I never gigged with it, just used it for practice and noodling. I put it in storage when I moved to an apartment in DC years ago, and now it's out of storage and I want to play it again.

Trouble is, when I turn it on, I get no sound. Often, the channel selector light will come on and a faint pop is heard. If I let the amp sit on standby for a half hour or so, I can play. Other times I let it warm up, and the minute I load the amp with a signal, it clips out on me.

I've fiddled with the tubes a bit, trying some replacements a friend gave me. I've also changed to fuse to no avail. This is my first tube amp, and only the second amp I ever bought, so I'm sort of a tube noob. There's no bias adjustment on this amp, so an old friend via email told me swamping tubes should be like changing a lightbulb.

Is my amp dead, or am I overlooking something?

Amp to run 3 pairs of speakers simultaneously.

forallmankind — Sat, 13 Sep 2008 14:13:35 -0800

I want to wire my house for sound - have 3 pairs of speakers running off the same source. I have the speakers, I have the source, I have the cables, but I need the amp - what good amp can I buy (used or new) that'll allow me to run 3 sets of speakers simultaneously? I want to run a pair of Castle Harlechs in my living room, a pair of Castle Durham 300s in my bedroom, and then I have a crappy pair that'll be 1 for the kitchen, 1 for the bathroom. The source is a Sony Pro CDP-2700 which has analogue and digital outputs.

I know Yamaha did a nice M-series range of amps, some of which had 2, others had 3 stereo outputs, but I read somewhere that these do not support simultaneous output - you can only select one pair of speakers at a time. I'm not 100% sure about this though.

I'm open to suggestions - I've been to Best Buy and the like and they just have multi-channel home theater amps. Obviously I like nice audio equipment, but I'm not going to get all audiophile bent out of shape about the amp - $300 new or used sounds a good limit. That said, I'd rather not drop 3 hundy on some crappy Sony amp that's going to make my nice Castles sound like a boom-box.

How to turn my line out into an external speaker out?

donkeymon — Sat, 30 Aug 2008 06:06:04 -0800

Wiring/music equipment question: I have a fairly cheap 30WVox guitar amplifier with a phone/line out jack on the back. When I plug something into the jack, sounds stops coming from the amp's speaker and starts coming out of whatever I plugged in instead. However, I would like it if the sound would come out of both at the same time. How easy or difficult would it be to rewire the amp so that it works this way? I'm good with a soldering iron, but not too great with circuit analysis.

Dead Marshall Amp

hutta — Mon, 19 May 2008 00:56:00 -0800

Guitar amp problem: Marshall MG100DFX won't turn on. I stuck this (solid-state) amp in the corner and neglected it for a while, and when I came back to it, it refused to turn on. When I give it power and flip the switch, it acts exactly as if it's unplugged. The power LED does not come on, the fan doesn't spin, and it definitely doesn't amplify a guitar.

It worked fine the last time I used it, but I was switching between two amps, so it's very possible that I left it on the last time I touched it, which would have been weeks ago. It was also plugged in to the wall directly, so I suppose a power surge might be possible. It was bought second-hand, and Marshall's FAQ says the warranty isn't transferable.

I'm guessing (read: hoping) it's a fuse, but I'd like to know whether this is something I can service myself. I've been searching with Google and on the documentation on Marshall's website, trying to find information about what kind of fuse is in there, or some sort of information about where to find it when I open the thing up.

Line 6 X3 Live?

KevinSkomsvold — Mon, 28 Apr 2008 07:41:27 -0800

I'm seriously considering ditching my amp-pedalboard setup for a Pod X3 Live. Any Mefi musician-types have any experience with this unit (or the XT board)? I'm trying to avoid having to cart my Hot Rod Deville and pedal board between rehearsals and live shows. This board looks like it will do it all. At shows I'd run it through the PA and have my own floor monitor or run it in my in ear-monitors. User experiences welcome!

Traynor amps in Toronto/Montreal

jules1651 — Sat, 19 Apr 2008 16:12:15 -0800

Does anyone know of a good place to shop for/ try out vintage Traynor amps in Toronto or Montreal? Much obliged.

LAMP, WAMP & MAMP?

crios — Thu, 20 Mar 2008 13:32:57 -0800

What is a good distribution of WAMP? What about LAMP? I'm looking for something that is relatively easy to install and use like MAMP. I'm going to give a non-technical presentation on the technical topic of how to DIY your own dynamic, web 2.0, collaborative web sites. I'm familiar with hosting on a Mac (that's what I learned everything on) but not on Windows or Linux. This is a presentation for school librarians and I would like to show them what is possible if they learn how to do some of this stuff themselves (creating your own blogs, wikis, CMS, etc... with lots of plugins that do all sorts of stuff).

I'm going to show them what free server side software is available but I also need to give them a quick run down of what they need to build all of this stuff, specifically AMP.

Homemade guitar amp filter

Grundlebug — Mon, 17 Mar 2008 09:13:45 -0800

I built this mini guitar amp based on this circuit. But I used a 4 watt speaker rather than the 8 watts specified. What are the consequences of that change? I'm trying to understand the concepts of the circuit, not just how to assemble it. I know Ohm's law, P=IV, series vs. parallel, etc. But I have no idea how to apply it practically.

So I used a lower resistance speaker. Will this increase my current through the whole circuit? Does that change the power output of the amp? Will that drain the 9V battery quicker? Is it louder than the 8 ohm speaker would be? Does it clip the sound signal at lower volume?

Bonus Question 1: And how about all those capacitors? I understand they are low and high-pass filters, but that's it. Will fiddling with those change the quality of the sound produced by the amp?

I've read a bunch of websites on speaker impedance, but they're generally geared toward home audiophile types and aren't answering this low level questions. And websites dealing with the low level concepts don't seem to step up a level to practical applications.

So any tips on resources for hobbyist level electronics, especially sound related, are also appreciated.

Where can I find an inexpensive turntable and amplifier?

punchdrunkhistory — Fri, 07 Mar 2008 19:07:12 -0800

Help my family find a decent turntable + amp in the $100-$300 range. We just want to listen to records! We have a good set of speakers, but an amplifier and turntable that date back to the 1970s and desperately need replacing. Given our small budget, is it possible to buy a new turntable with a built-in amp (that would connect directly to the speakers) or a turntable AND amp that would fall within the price range? Price is the biggest issue - we're certainly not hardcore audiophiles. It would be nice to have a USB output or similar CD-converting options, but those aren't necessary.

(I've seen this question, which was helpful, but didn't specifically answer my amplifier question.)

Mi a di stamina daddy fi all di gal pikini

isopraxis — Fri, 07 Mar 2008 08:57:03 -0800

What is that quintessential dub percussion sound and how do they make it? It is often the echoic 3rd beat that provides a nice counterpoint and texture to the rhythm of dub:
To me it sounds like the striking of an amp with reverb turned up, but I'm only guessing. Is it just a mic'd snare with the reverb cranked up, or is someone really smackin' an amp?

Example: A Hundred Pounds of Collie (Songza.com)
Dubheads, fill me in.

Which is the best speaker for my bass amp?

IZ — Wed, 13 Feb 2008 13:32:13 -0800

Bass Amp Filter: 2 x 10 or 1 x 15? Hi,

For live performances, I'm thinking or purchasing the new Ampeg BA600 combo amp which comes in both a 2 x 10" speaker version and a 1 x 15" speaker version.

My main experience has been with a high end 4 x 10" speaker and separate amp, which I love, but for me in the end it's all about the deep low end. I play sixties and seventies style funk and soul music and I really dig that traditional fat sound. I know, I know, I should buy a vintage tube amp. But if you forget about that for a moment, which speaker should I choose in my new combo amp?

(and, yes, although I should probably try it out first, I still appreciate your advice).

Thanks!

Double-amping with two amplifiers -- will it work?

humblepigeon — Mon, 04 Feb 2008 06:44:34 -0800

Double-amping fun with Class-T amps: Can it be done? I'm continuing my experiments with the Sonic Impact Class-T amps, as detailed last week.

They arrived but one was faulty, so had to be returned. I'm expecting the replacement this week.

It turns out that they don't go very loud on my speakers, and if the dial goes past half-way, distortion creeps in, especially on the high notes.

My CD player has no less than three line outputs, so what I'm thinking of doing is what I call (perhaps incorrectly) double-amping -- one line out to one amp, another to the second amp, and connecting both in parallel to the speakers. NOT bi-amping. Both high and low inputs on the speakers get 2x amplifier voltages.

Is this going to damage anything? I'm thinking more about the output from one amp going into the second amp if it isn't turned on, for example.

SF Peninsula tube amp repair

UlfMagnet — Mon, 26 Nov 2007 12:19:32 -0800

Tube amp repair tech on the San Francisco Peninsula? I've got a vintage Ampeg B-15N "fliptop" bass amp that needs fixing. Can anyone recommend a reliable amp repair person in the Palo Alto area?

FYI I've tried contacting the folks at Vacuum Tube Valley (http://www.vacuumtube.com) and haven't gotten any response yet.