Amp heats up and shuts off - Help!!

[msrance]

Hello Friends - I know I keep asking these rather basic questions but thats how i would come to par with you guys.

I have this Yamaha AX-596 Integrated Stereo Amp rated at 100 w/c @ 8 ohms. This is being used to power a pair of Sonodyne Floorstanders - Sonus 1601 - which are rated at 80 Watts @ 4 ohms and a Sonodyne subwoofer - Roarr 2 - rated at 100 Watts @ 4 Ohms.

When ever i push up the volume of the amp to anywhere beyond 40% mark on the volume control - its protection circuitry just cuts in and pushes it to stand by mode. I assume this should be due to overheating or overloading - as per the amp literature.

Could you please help me with this one and tell me why does my amp shut down on its own at such puny volume? I hoped it would give me a couple of shattered window panes and a perforated ear drum - instead its giving me a shattered heart !

And there is this added problem - when i play my pioneer DVD player - DV366 - the sound output is reasonable - but when I direct my Satellite radio's output to the amp - thru the tuner connectors - the volume output is 60 - 70% less than the DVD output. What could be the reason for this?

[This Guy]

your amp only handles 8 ohm loads, and here you're giving it two 4 ohm speakers that may go down to even 1 ohm, and im not sure how your powering the subwoofer (passive or active)? But my assumption is that the amp can't handle this speaker load and you need a better amp that can handle low impediance speakers.

-Joey

[karl k]

Hello Friends - I know I keep asking these rather basic questions but thats how i would come to par with you guys.

I have this Yamaha AX-596 Integrated Stereo Amp rated at 100 w/c @ 8 ohms. This is being used to power a pair of Sonodyne Floorstanders - Sonus 1601 - which are rated at 80 Watts @ 4 ohms and a Sonodyne subwoofer - Roarr 2 - rated at 100 Watts @ 4 Ohms.

When ever i push up the volume of the amp to anywhere beyond 40% mark on the volume control - its protection circuitry just cuts in and pushes it to stand by mode. I assume this should be due to overheating or overloading - as per the amp literature.

Could you please help me with this one and tell me why does my amp shut down on its own at such puny volume? I hoped it would give me a couple of shattered window panes and a perforated ear drum - instead its giving me a shattered heart !

And there is this added problem - when i play my pioneer DVD player - DV366 - the sound output is reasonable - but when I direct my Satellite radio's output to the amp - thru the tuner connectors - the volume output is 60 - 70% less than the DVD output. What could be the reason for this?

Guy is right about the amp and the speakers. I find it odd that of the 2 floorstanders available from Sonus, you would pick the one that was 4ohm. Must have been a price thing. Well, you'll have to get a "high current" amp to run those babies... something in a Harmon receiver or equivilent. Must be 4ohm(or much higher wattage capacity at 8ohm) though or you'll have the same prob.

About the mismatch between the sat and the DVD... it may help if the DVD player has it's own output gain control to turn it down to more closely match your sat radio. In doing so, your amp should be able to be turned up but be warned, you will not get any more volume out of the system than you already have w/o the amp overheating. You'll just be able to turn the volume higher to get the same sound and the sat will be closer to the same volume as the DVD player.

Sorry it couldn't be better news...

[msrance]

So guys, what you are suggesting is that fault lies with the low impedence of the speakers - I should have opted for the 8 ohm version. Well, yes, the pricing factor was all important at that point of time.

But its heartening to know that this is a universal problem caused by the physics of electricity and nothing plagueing my particular amplifier.

[F1]

One way to solve your problem is to connect a 4 ohm resistor in series for each speaker. So the connection is like this (from either + or - terminal): Amplifier - Resistor - Speaker. This will give extra 4 ohms total impedance of your speaker and your amp should not trip so easily.

[msrance]

Thanks F1. This seems the most heartening reply to my querry ! I am rather a novice myself at electricity. Actually I hated the electricity physics so bad - i dropped out of my engeneering just coz of it.
So now if you have to some time to spare - would you just let me know what a resistance would look like and how do you put into "series with the speaker" ? How does one connect the speaker cable to the resistor - basically where and how exactly do you put the resistance?

[F1]

I'm not an electrical engineer myself, but let me try. Resistors look like this
http://www.partsexpress.com/webpage....WebPage_ID=141
and you need higher wattage than the common 1/2 watt for normal electrical circuit (the one with rings of different colors). So you need resistor that looks like this
http://www.partsexpress.com/pe/pshow...er=004-4&DID=7
or
http://www.partsexpress.com/pe/pshow...er=005-4&DID=7

As for the connection, place the resistor between amplifier and speaker. With your existing connection for example, unplug the + (red) wire from the speaker terminal, connect one end of the resistor to the wire (put together, twist, tape) then plug the other end of the resistor to the speaker + terminal. Make sure the bare metal is not touching the - (black) terminal (use tape if necessary). By placing the resistor in series with your speaker, the sound characteristics may change a bit. Anyway, resistor is cheap and I think it's worth trying. Good luck.

[jack70]

Different amp topographies react differently with different loads. Some amps wouldn't have a problem with those speakers in parallel. Other amps are even more finicky about capacitive reactance or other complex impedance anomalies. But some amps will drive just about anything. Sorta like car engines... a huge diesel-truck engine, a hi-rpm sports car engine, and an average passenger car engine are all designed for doing certain things best... providing brute force (pulling) power, quick (racing) torque, or gas mileage. So you're right... it's all basic physics.

I agree with This Guy that it's possible the impedance could drop to 1 ohm or less at certain frequencies... the amp might be able to handle that only at very low volumes. I'd play the system with just one speaker per channel. Then connect them in series... it's not something that should give you any better upside, but it's worth trying... you might like the sound better (depends on the music and loudness you prefer).

Using power resistors has some downsides, most of which are dependent on the amp circuitry and how loud you plan to run it. It's not an elegant solution for sure, and could even blow out certain components under high stress unless you know some simple Ohms-law stuff.

[mtrycraft]

One way to solve your problem is to connect a 4 ohm resistor in series for each speaker. So the connection is like this (from either + or - terminal): Amplifier - Resistor - Speaker. This will give extra 4 ohms total impedance of your speaker and your amp should not trip so easily.

The only problem I see is that half the power will be eaten up by the resistor, in which case he needs a high power resistor or it will go up in smoke, and the volume in th espeaker will not get very loud if half the power is in the resistor.

[F1]

The only problem I see is that half the power will be eaten up by the resistor, in which case he needs a high power resistor or it will go up in smoke, and the volume in th espeaker will not get very loud if half the power is in the resistor.

Yes, it's true that the power of the amplifier will be reduced and higher power resistor is needed. 4 watt or higher resistors (see the link above) should be fine, again not the typical 1/2 watt resistor. I would not worry about the volume as he can turn the volume up more if needed. Cheers.

[skeptic]

The effective amplifier damping factor as seen by the loudspeaker will drop below one. Depending on the inherent low frequency resonances of the speaker, this could result in a change which is anything from inaudible to becoming very boomy. I'd probably opt for at least a 25 watt resistor and I think 2 ohms should be given a try before you try 4. In fact, if 2 ohms doesn't work, you could get another pair of 1 or 2 ohm resistors and add them in series with the first ones.

[E-Stat]

When ever i push up the volume of the amp to anywhere beyond 40% mark on the volume control - its protection circuitry just cuts in and pushes it to stand by mode. I assume this should be due to overheating or overloading - as per the amp literature.

It is quite possible that there are no problems at all in your system, other than an unintentional case of overdriving the amplifier. Since your subwoofers are powered units, that would likely rule out the difficult load scenario that some have speculated upon. I believe you may simply be unaware of the relative nature of the gain (volume) control. Full output of most amplifiers usually occurs far earlier than at the maximum position.

Basically, all audio systems are composed of multiple amplifiers, each driving the next one in the signal chain. Engineers will usually build in some extra capability in each stage in order to cover variations in other components. In your system, there are three output stages: one in the DVD player (or tuner), one in the preamplifier section of your integrated amp, and one in the power amplier section of your integrated. Most CD/DVD players put out somewhere around 2 volts. In some cases, even more. Your integrated amplifier, however, is likely designed to operate with far less. For example, my NAD 320 BEE integrated can be driven to full output with a .22 volt input. That is roughly one tenth the amount that is being sent to it by the player. Since I'm not exactly sure what you mean by 40%, I will use the clockface as an alternative way to visualize the setting of the gain control. With my Pioneer CDP, I get full output on the NAD at about 10:00 with most content. Moving it further simply pushes it into overload, called clipping. The sound becomes noticeably distorted. Persistent clipping will usually result in the protective circuitry of an amplifier to intercede.

In another system of mine, I take advantage of this situation and simply eliminate the middle stage. The CD player drives the amplifiers directly. In this system, full gain occurs at just below the 2:00 position. In both systems, I am getting the full output of the amplifier being driven, albeit at very different settings on the gain control.

rw

[spacedeckman]

1) If the sub is being driven by the integrated, that is BAD. An integrated amplifier or receiver is NOT meant to drive a sub. Get a powered sub, or add a dedicated amp desiged for woofer applications. Sorry Karl, the h/k would puke on its shoes as fast or faster than the Yamaha. Since the amplifier in the AX596 is pretty good, the h/k would probably shut down faster. Stop running the sub if it is being powered by the integrated for the time being.

2) If you still have a problem, you may have a shorting voice coil. That was the situation with a pair of Cantons a friend had recently.

3) If you are driving two sets of speakers, especially 4 ohm (having no idea of how reactive each is), 10 o'clock on the dial is where you are going to run out of gas. Sounds about right to me...that should be pretty dang loud. I hope your tone controls are set flat.

4) Consider having a crossover built, or finding one that will cross you over about 80 Hz between the speaker and woofer. Then the amplifier is only driving one at a time, and your problems will be somewhat solved. Capacitors and coils, 4 per side will get you a 12 dB slope which will work wonders.

5) you will really need to get a powered sub, or power what you've got. Sub amps are cheap, relatively speaking.

[jeskibuff]

I have a Sattelite Radio from worldspace (http://www.worldspace.com) with a reciever in the general category WSSR11 (BPL Celeste model) - but the sound uotput from the sattelite reciever is very less compared to the rest of the components attached to the amplifier. I could find no literature on the gain of the reciever - but could that be the only variable affecting the final sound output or could there be anymore factors that I am overlooking?

Sorry we overlooked this question when you posted it in your original message...we just got sidetracked on the other issues, that's all!

Your receiver has a downloadable manual at http://www.worldspaceradios.co.uk/celeste-manual.pdf. On page 6 it says that the line-out jacks are not adjustable, so they will always be at a level that is lower than your DVD player (unless you can adjust the output level of the DVD player downwards). There was very little to be found specifically about your Yamaha. The most information I found was at http://www.yamahamusic.com.au/main.asp?sec=products, and that didn't say a lot. It's likely that you can't compensate for input level variances, but if you could find your manual, it might tell you how you can. Or maybe someone else has the same (or similar) model. There's not really a problem with the difference in volume, aside from the fact that you have to be careful when switching to the DVD. It would be nice if the Yamaha could compensate for the differences, but you may have to live with it!

[msrance]

Your receiver has a downloadable manual at http://www.worldspaceradios.co.uk/celeste-manual.pdf.

I am amazed at your ability to drill out relevant URLs from obscurity. I checked out on the Worldspace.com website - and couldnt find a relevant download - so I just let it be. Thanks for this one Pal!!

There was very little to be found specifically about your Yamaha. The most information I found was at http://www.yamahamusic.com.au/main.asp?sec=products, and that didn't say a lot. There's not really a problem with the difference in volume, aside from the fact that you have to be careful when switching to the DVD. It would be nice if the Yamaha could compensate for the differences, but you may have to live with it!

I guess, You are right - I will have to live with the lack of gain compensation. Actually, the only problem is - as you say - when you switch to DVD from Tuner - the change in volume level is not for the faint of heart !!! Sometimes a guest accidently changes the inputs - and then he's in for a rude shock!!

But tell me, do the changes in signal strength affect the sound output of these satellite recievers? I mean if I get a 4 bar signal strength or a 2 bar - will it affect the final sound output and the Clarity of the output?

[jeskibuff]

I am amazed at your ability to drill out relevant URLs from obscurity.

Well, as seen earlier in this thread, I missed that Rroar II link even when it was staring me in the face!

do the changes in signal strength affect the sound output of these satellite recievers? I mean if I get a 4 bar signal strength or a 2 bar - will it affect the final sound output and the Clarity of the output?

No. Your volume control is very able to compensate for the lower signal strength coming out of the satellite receiver. With input gain compensation, you're actually boosting the signal level twice...once as the signal initially enters the preamp's input section, then again with the setting of the main volume control. The only bad thing about a low signal level coming in is the possibility of a higher noise floor. It's nice having a good strong signal coming in, because when you amplify a weak signal, you're actually boosting any noise on that line as well. What I'm saying is that you'd probably get the same output quality whether or not you have gain compensation on the Yamaha.

[msrance]

Your volume control is very able to compensate for the lower signal strength coming out of the satellite receiver. With input gain compensation, you're actually boosting the signal level twice...once as the signal initially enters the preamp's input section, then again with the setting of the main volume control. The only bad thing about a low signal level coming in is the possibility of a higher noise floor. It's nice having a good strong signal coming in, because when you amplify a weak signal, you're actually boosting any noise on that line as well.

Thanks for that one Jeski !! I seem to know so much more about Audio than I knew a month back.

[msrance]

Hello again Jeski! I know I am such a bother - but now there's this new problem that I just noticed - with the DIY 8 ohm speakers I was so happy about.
The speakers make an aweful resonating sound when pushed hard - just the LF drivers - that is. I was today playing this pop album (The only pop album I ever bought - but then TATU are barely pop - they are so overtly Popular Rock that I decided to go for them). Anyways - so when pushed close to max the speakers made this godaweful sound - that I can only describe as a flutter - and when I took off the panel to check out the driver state - they were actually fluttering ( like we say in medicine - there are normal heart contractions and then there are flutters - that is when the heart is contracting so fast that is doing nothing useful with the contraction - just harming itself) - so these HF drivers - all 4 of them at 8" were doing nothing worthwhile - but fluttering at an enormous rate and resonating witht he cabinet - and it felt like the whole assembly is gonna fall to pieces any moment now - but when pulled back to a decent volume they became alright - next time I did an experiment with it again - and this time - they started giving way earlier than the previous attempt.
Whats with this buddy? and how do I handle this? apart from the evident way of not pushing the volume too hard.

[jeskibuff]

do the changes in signal strength affect the sound output of these satellite recievers? I mean if I get a 4 bar signal strength or a 2 bar - will it affect the final sound output and the Clarity of the output?

Oops...I think I mis-read this question when I first replied to you. Yes, incoming signal strength (off the satellite) probably WILL affect the sound quality. I don't know much about satellite reception, but if it's digital, you may get dropouts on a weak signal and if it's analog, you should get noise and/or distortion. Sorry that my earlier response may have been off-base!

when pushed close to max the speakers made this godaweful sound - that I can only describe as a flutter

This sounds to me like the drivers can't handle the volume, especially with low frequencies. The Yamaha's telling them what to do, but they don't have the ability to respond properly. Being DIY speakers, this could be just inadequate design. If you could "roll-off" the bass level to just these speakers, that would probably help, but I imagine the Yamaha doesn't have that flexibility. A possible solution would be to put a capacitor in series with those speakers. That would pass only the higher frequencies and block the low ones. You'd still get the low frequencies from your "A" speakers and sub.

Anyway...that's just my "guess". Perhaps some others will have some other ideas about what's wrong.