For measuring IC's like the AK4393 the finger will be the best method to measure temperature. Anyhow for the 4580's In and Output OP's.
Why ? By using a IR-Thermometer you should know the following:
Make sure that the target (The IC) is larger than the spot size the unit is measuring. The smaller the target, the closer you should be to it. When accuracy is critical make sure that the target is at least twice as large as the spot size.
Distance to spot ratio. The optical system of an infrared thermometer collects the infrared energy from a circular measurement spot and focuses it on the detector. (Take care also on the color and material of the target ! If glossy metal put a scotch over it and then measure)
The optical resolution is defined by the ratio of the distance from instrument to the object compared to the size of the spot being measured. Called (D:S ratio). The larger the ratio number the better the instrument's resolution, and the smaller the the spot size that can be measured. The laser sighting included in some instruments only helps to aim at the measured spot.
--> Usual low price IR-Thermometers have 8:1 (D:S ratio) For example my one Voltcraft IR-340
A recent innovation in infrared optics is the addition of a Close Focus feature, which provides accurate measurement of small target areas without including unwanted background temperatures.
So in the case of measuring with a low cost IR-Thermometer the displayed Temperature will allways be lower the it's in reality.
I tested this on a regulator IC wich is as big as the 4580's. It burned nearly my fingers, while the IR before was displaying 36°C.
The Fingermethod is allways expressive.
Why ? By using a IR-Thermometer you should know the following:
Make sure that the target (The IC) is larger than the spot size the unit is measuring. The smaller the target, the closer you should be to it. When accuracy is critical make sure that the target is at least twice as large as the spot size.
Distance to spot ratio. The optical system of an infrared thermometer collects the infrared energy from a circular measurement spot and focuses it on the detector. (Take care also on the color and material of the target ! If glossy metal put a scotch over it and then measure)
The optical resolution is defined by the ratio of the distance from instrument to the object compared to the size of the spot being measured. Called (D:S ratio). The larger the ratio number the better the instrument's resolution, and the smaller the the spot size that can be measured. The laser sighting included in some instruments only helps to aim at the measured spot.
--> Usual low price IR-Thermometers have 8:1 (D:S ratio) For example my one Voltcraft IR-340
A recent innovation in infrared optics is the addition of a Close Focus feature, which provides accurate measurement of small target areas without including unwanted background temperatures.
So in the case of measuring with a low cost IR-Thermometer the displayed Temperature will allways be lower the it's in reality.
I tested this on a regulator IC wich is as big as the 4580's. It burned nearly my fingers, while the IR before was displaying 36°C.
The Fingermethod is allways expressive.
Moby said:
I had that kind of "cheap multimeter with temp" in the past. Very bad.
Have you take a look on eBay, they sales this kind of pistol for around 45$. Try to find one with 2 infrared beams.
I've a IR-380 myself. Not bad. I compared the result with an iButton temp sensor from Maxim. It's accurate.
But I'm sure that you don't have a problem. if something was wrong, your DCX will have already burnt.
.
stef1777 said:
I had that kind of "cheap multimeter with temp" in the past. Very bad.
Have you take a look on eBay, they sales this kind of pistol for around 45$. Try to find one with 2 infrared beams.
I've a IR-380 myself. Not bad. I compared the result with an iButton temp sensor from Maxim. It's accurate.
But I'm sure that you don't have a problem. if something was wrong, your DCX will have already burnt.
.
Guys thanks for comments. Of course buying 1000$ thermometer for measuring cheap Behringer is not a deal so IR-380 is...Stef you are right, unit works for an hours and doesn't fail, it will probably work for a long time but I have a feeling that too hot op-amps (in A/B class) is not normal. I'm think that some more filtering around chips can maybe help if some RF is causing that chip overheating. Also, since output board is "stealing" PSU from DSP board maybe will be cool to add some small and quality caps at the end of the flat cable. Also, can ferrite beads over cables improve this? I didn't add any of them... Are they working on the "DC cables"?
IR-Thermometer
Your opinion about this one :
http://cgi.ebay.com/ws/eBayISAPI.dl...sid=m37&satitle=370042712341&category0=&fvi=1
Suitable or not with our DIY projects ?
Many thanks
Your opinion about this one :
http://cgi.ebay.com/ws/eBayISAPI.dl...sid=m37&satitle=370042712341&category0=&fvi=1
Suitable or not with our DIY projects ?
Many thanks
I finally measured the beast. I borrowed Flir B2 wide angle infrared thermal camera http://www.professionalequipment.co...ng-camera-2430412712/thermal-infrared-camera/(really powerful toy for 8500$ ;-)) Situation is not so great
OPA2134 are really hot, from 65 to 75 Celsius, and AKM DA's are around 65... PSU is 70-75. I checked everything twice and can't find any fault, unit sounds great so I decided to go with small aluminum heatsinks at every OPA and some bigger for AK chips. Also I will add 2 coolers to make some air flow... Also I added 100n for every OPA at both PSU pins since there is just 1 for 4 Op-amp. I will post my progress and if someone have an idea why it's so hot please tell me
OPA2134 are really hot, from 65 to 75 Celsius, and AKM DA's are around 65... PSU is 70-75. I checked everything twice and can't find any fault, unit sounds great so I decided to go with small aluminum heatsinks at every OPA and some bigger for AK chips. Also I will add 2 coolers to make some air flow... Also I added 100n for every OPA at both PSU pins since there is just 1 for 4 Op-amp. I will post my progress and if someone have an idea why it's so hot please tell me Moby said:I finally measured the beast. I borrowed Flir B2 wide angle infrared thermal camera http://www.professionalequipment.co...ng-camera-2430412712/thermal-infrared-camera/(really powerful toy for 8500$ ;-)) Situation is not so great
Sorry to ask a so basic question. Are these numbers measured box closed or open? How could you measure temps for the running op-amps, they are below the board?
I will suggest you to check current use between the PSU and the DSP board. Check currents running from AGND, DGND, and after for each voltages.
Stef...
Did i miss something ?
"OPA134 series op amps are capable of driving 600W loads with power supply voltage up to ±18V. Internal power dissipation is increased when operating at high supply voltages."
How much is the supply voltage ? +/- 15 V ? or maybe higher ?
In my setup the hottest signal conditioning parts are the DSP Chips. And they are about 40..42°C @ surface whiile AKM is about 36°C. (When DEQ is set to "linear" EQ-Position and mostly blocks set to bypass. But when using more settings of DEQ then DSP can get up to 45 ... 50°C. The more calculation the more heat dissipation In someway logic.
Another Question:
While listening to music, are you using the DEQ in balanced operation ? Or do you use XLR to RCA Adapter while using only the (hot +) wire output ? If so, then you could check also your soldering on OPA's for short circuit @ (- Input legs) That could force also power dissipation on the OPA.
"OPA134 series op amps are capable of driving 600W loads with power supply voltage up to ±18V. Internal power dissipation is increased when operating at high supply voltages."
How much is the supply voltage ? +/- 15 V ? or maybe higher ?
In my setup the hottest signal conditioning parts are the DSP Chips. And they are about 40..42°C @ surface whiile AKM is about 36°C. (When DEQ is set to "linear" EQ-Position and mostly blocks set to bypass. But when using more settings of DEQ then DSP can get up to 45 ... 50°C. The more calculation the more heat dissipation
In someway logic.Another Question:
While listening to music, are you using the DEQ in balanced operation ? Or do you use XLR to RCA Adapter while using only the (hot +) wire output ? If so, then you could check also your soldering on OPA's for short circuit @ (- Input legs)
That could force also power dissipation on the OPA.
artquake said:Did i miss something ?
"OPA134 series op amps are capable of driving 600W loads with power supply voltage up to ±18V. Internal power dissipation is increased when operating at high supply voltages."
How much is the supply voltage ? +/- 15 V ? or maybe higher ?
In my setup the hottest signal conditioning parts are the DSP Chips. And they are about 40..42°C @ surface whiile AKM is about 36°C. (When DEQ is set to "linear" EQ-Position and mostly blocks set to bypass. But when using more settings of DEQ then DSP can get up to 45 ... 50°C. The more calculation the more heat dissipation
Another Question:
While listening to music, are you using the DEQ in balanced operation ? Or do you use XLR to RCA Adapter while using only the (hot +) wire output ? If so, then you could check also your soldering on OPA's for short circuit @ (- Input legs)
PSU voltage is +/- 15V. I tried to lower the voltage and they are still hot
BTW I have DCX not DEQ...but op-amp is still op-amp I'm using the unit in balanced mode...One thing is for sure. Problem is something in general because I tried to completely remove analog board and I connected just +/-15V directly. Opa's are still hot. I checked the outputs with oscilloscope and I can't see any oscillation. Just a noise , at lower voltage setting . (I think that at 5mv) That noise is uniform too at all six outputs.... BTW, unit sounds OK
yes, I changed the oscilator op-amps and coupling capacitors. Everything resulted like improovement, especially capacitors. But as I mentioned before I had that on/of nasty thump so i returned back to the stock PSU. Maybe is something faulty with PSU but I bought it completed so I have to investigate. If I remember well noone but me has thump issue... Maybe I'm wrong??
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