yes. and the lower the impedance of the load/speaker the greater the temperature rise will be.
take note that the headphone jack board employs series resistors to lower the output level to your headphones but that also means increased impedance so less current draw.
The article you linked to said the TDA7265 IC (the power amp IC) is mounted on an aluminum bracket that is screwed to the case. That is why the case behind the IC bracket gets hot. Pretty cheap way to cool an IC. The IC draws 130 ma idling, so with +-20 v rails that is 5.2 watts for no sound yet. A heat sink with fins outside would be better. This amp is great on style, not on guts. Leave your volume knob @ 20%.
The 70 w/ch amp I listen to sometimes 14 hours a day has two 17 cm x 13 cm x 2 cm heatsinks on the back, one for each channel. Each has 15 fins. That is why the M-2600 is selling for $100 + freight in blown up condition on ebay. Higher power amps with smaller heat sinks have fans.
You want to see a heatsink, access the farnell.com website for your country. type heatsink in search box. You want thermal management section. farnell has pictures of the parts.
The 70 w/ch amp I listen to sometimes 14 hours a day has two 17 cm x 13 cm x 2 cm heatsinks on the back, one for each channel. Each has 15 fins. That is why the M-2600 is selling for $100 + freight in blown up condition on ebay. Higher power amps with smaller heat sinks have fans.
You want to see a heatsink, access the farnell.com website for your country. type heatsink in search box. You want thermal management section. farnell has pictures of the parts.
Past a certain point, you're kind of asking us to do what I call "psychic diagnosis." You're providing us with very little information to work with and asking us to figure out what's going on with an amp that it may be none of us is familiar with. That's a very different question from what you were asking originally, which is how much power you need for speakers.
I would say that, generally, no an amp generally should not get hotter simply because a speaker load is plugged in, but I mostly deal with older amps. Past that, I think you'd either need to contact the manufacturer of the amp or another owner to find out if this is "normal" for that amp model. Things are changing rapidly in electronics. Does this amp have some circuit that senses whether or not a load is attached and turns the output chip-amp on and off? I have no clue.
If you had even minimal test equipment, you could determine whether or not current is flowing through the speakers with no audio signal.
If an amp runs cool with nothing connected, but runs hot as soon as the speaker is connected without music playing it is probably oscillating. Chip-based amp designs are often poorly implemented because the designer makes too many assumptions and overlooks things - so it CAN happen. To see if that is happening with minimal test equipment, connect a peak detector circuit in parallel with the speaker (1N4148 diode and .01 uF cap) and measure the DC output. A properly working amp should read zero with no music. If you get several volts of output that you cannot hear it would explain why the amp runs hot.
Some of these chips run hot anyway with no music playing - but if it is oscillating it will run hott*er*. A lot hotter.
The speaker will draw very little from the amp with a large ultrasonic signal. The tweeter’s voice coil impedance goes high and inductive so not much power makes it into the speaker. It is the chip frying itself that causes the heat - if that is occurring. If this does turn out to be the problem it is a DESIGN issue that needs to be addressed. If it’s not the problem you‘ve got to keep digging.
Attachments
From what memory i have left, that number is much the same as the Dared (not the same name on it) i had thru here.
dave
As a general rule i pay no attention to the power rating and listen to see how well an amplifier & a speaker work together regardless of the power output of the amplifier.
Do note that the comment about the volume setting is a red herring. Wher the volume control is set has to do with th egain structure of your system and is only periperially related to power output. With a traditional potentiometre, typically they track better near full rotation, if you are typically seeing it at less than half you could use less gain
dave
My Technics receiver at a normal room volume is usually at between 9 o'clock and 12 o'clock.
Background level is around 7-8 o'clock setting.
However, at "full up" it's very loud, yet undistorted, enough to bother the neighbors next door.
This is driving my floorstanding Advent Maestros.
60W per ch gives plenty of headroom in a living room setting, even with carpeting and thick "traditional style" furniture.
Even my 17w/ch tube amp compares in loudness.
But ya know, the "wattage wars" of the 70's/80's made people hunger for something they don't really need for the most part.
Marketing = more is better crap.
So true. An excersize with NAD 3020 and the first Carver Cube in the late ‘70s had me thinking a lot about the futility of that race.
dave
It seems that you just might have an oscillation going on...I take it your not really a "techy type", don't have a DVOM, (Digital Volt Ohm Meter)...nor any other kinda stuff? It is somewhat hard to diagnose these things by "remote".
The TDA-7265 does have a built in thermal shutdown at 145 degrees C, with a nominal upper operating limit of 85 degrees C. We can see how they arranged that power-chip inside with a somewhat crude rather thick angled chunk of aluminium, & attached it directly to the chassis...not the best of ways to do it. Many commercial amps will try to stuff things inside too tight, making servicing nor modifications easy or possible. Those of us who build-em ourselves, it is much easier to use an oversized chassis, fat fingers & all.
Have you ever contemplated buying such devices, tools, so you can learn more about electronics, by doing stuff? A fifty 'dollar' DVOM would be a great & ultimately useful tool.
Do you know of a local electronics shop who can hook up your amp, setup an oscilloscope & look at the output of your amp, looking for that oscillation?
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------Rick...
The TDA-7265 does have a built in thermal shutdown at 145 degrees C, with a nominal upper operating limit of 85 degrees C. We can see how they arranged that power-chip inside with a somewhat crude rather thick angled chunk of aluminium, & attached it directly to the chassis...not the best of ways to do it. Many commercial amps will try to stuff things inside too tight, making servicing nor modifications easy or possible. Those of us who build-em ourselves, it is much easier to use an oversized chassis, fat fingers & all.
Have you ever contemplated buying such devices, tools, so you can learn more about electronics, by doing stuff? A fifty 'dollar' DVOM would be a great & ultimately useful tool.
Do you know of a local electronics shop who can hook up your amp, setup an oscilloscope & look at the output of your amp, looking for that oscillation?
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------Rick...
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Planer10, the Nad 3020 is a very powerful little beast.
If this Dared MP-5BT is anything like my old Fatman amp they are a waste of money, valves are just for show and power is pretty reasonable for the size of the amp but they overheat and fry after a prolonged listening session.
And to finish speakers don't pull power from the amp the speakers are passive elements and they may need more or less power from the amp depending on their efficiency rating.
If this Dared MP-5BT is anything like my old Fatman amp they are a waste of money, valves are just for show and power is pretty reasonable for the size of the amp but they overheat and fry after a prolonged listening session.
And to finish speakers don't pull power from the amp the speakers are passive elements and they may need more or less power from the amp depending on their efficiency rating.
Sold mine (original series 1978) about a year ago for good money but still regret the day the Marantz that replaced it with 5x the power is lacking "cojones".
It's simply more superficial "tube" crap resulting from the "hype" about tubes over the last few decades.
Just like that Samsung DVD home theater player/amp that I saw in Sam's Club a while ago.
Two 12AX7's poking out of the top.... illuminated from underneath with blue LED's.
Garbage, uneducated customer eye candy is all it is.
This is not a tube amp. It is a chip amp with a tube front end.
2 x 12AX7, why does it need 4 sections, it should really only be a cathode follower, the chip likely needs no gain.
dave
2 x 12AX7, why does it need 4 sections, it should really only be a cathode follower, the chip likely needs no gain.
dave
When the market expects a slump in revenue, or consumers begin to get bored, they dream up something else to entice the public and gain more revenue.
Shove a couple of tubes poking out the top, light them up with blue LED's, the "new crowd" doesn't know any better and forks out the cash for that garbage.
And no, you don't ever get a schematic anywhere, it's Top Secret Info that even us professionals can't aquire.
Because the manufacturers of this crap don't want anyone to know that they've been duped.
Shove a couple of tubes poking out the top, light them up with blue LED's, the "new crowd" doesn't know any better and forks out the cash for that garbage.
And no, you don't ever get a schematic anywhere, it's Top Secret Info that even us professionals can't aquire.
Because the manufacturers of this crap don't want anyone to know that they've been duped.
Let us not pile on 'Tonythetigger' please...we all started somewhere, sometime. This individual sought us all out for enlightenment & knowledge, we are "bound" to become his teacher, not savage critic.
This chip-amp may very well be functioning "out of spec", hopefully, & not designed poorly. As we all know those "25W" are more than enough to rock out if need be via some future 102+Db speakers.
Let us be constructive, OK?
I read the front end is 6N1P ???
-------------------------------------------------------------------------------------------------------------------Rick...
This chip-amp may very well be functioning "out of spec", hopefully, & not designed poorly. As we all know those "25W" are more than enough to rock out if need be via some future 102+Db speakers.
Let us be constructive, OK?
I read the front end is 6N1P ???
-------------------------------------------------------------------------------------------------------------------Rick...
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What I have found over 100s of CDs is that well mastered rock, pop, jazz has a peak to average range of 18dB. Classical and modern big band can be 22-25dB. More modern pop/rock recordings 14-16dB from average to peak. But from pianissimo to peak? I think for classical it can be in the 32dB range or better.
If possible it's good to measure the headroom you have. See the link provided by Pilli in post #11.
https://www.enjoythemusic.com/magazine/equipment/0306/dared_mp5.htm
They say 2 12AX7 plus the display tube. And 13 watts. They liked it.
eBay says 6N1, 6N2 (bothe dual triodes) and 6E2 (no idea)
dave
They say 2 12AX7 plus the display tube. And 13 watts. They liked it.
eBay says 6N1, 6N2 (bothe dual triodes) and 6E2 (no idea)
dave