But you can't blame that on the power amplifier.OK, so replacement of all these parts every 5-6 years is a good engineering?
I have a friend who had this amplifier. It was also blow output transistors while pushing Apogee.
It was always on the floor with no ventilation issues, just always has failure
And again this indication "Hot", that's everything from to. Electron tubes can reach 250° without any problem, and that's ok. How warm are your capacitors really and how many hours of operation have they already been running?One of my amplifiers is SE class A based on 4 6336 output tubes.
I made it by myself about 50W.
Everything is extremely hot and no fault. No capacitors, resistors issues and if course no valves issues
I wasn't talking about luxury cars, but about sophisticated sports car engines, which is something completely different.From the beginning I said that for me the warmth of the SMPS of the SMSL seems too much for only half Amper consumption, I was not too worry and I was wondered if someone has a failure SP400, just in case it is a real problem.
Yes, it is common, specially for western luxury cars, watches etc to be serviced event short periods.
Price of being comfort (and I am not suggesting buying Lexus).
If you will read the datasheet of 6336 you will notice each valve has filament consumption of 2.5A.
I have 4 6336, and puts about 50W on 8Oohm, so it is really hot.
Each valve section draw about 125mA, so totally of about 1 Amper for all 8 sections. B+ is 400V.
What I am saying each monoblock dissipates about 500W, all together with the front end and driver.
It is extremely how but all capacitors are 105 Celsius.
Just look on Amazon and the reviews. I've been using this for my needs (kitchen, hobby, etc.) for a few years:I had a thermometer of UNI-T of my friend which is infrared but you always need to put this factor of emissivity I was always not sure what is the correct temperature.
This factor you need to enter has a lot of impact on the temperature
Do you have a suggestion for a good thermometer that can just read simply ?
Hi Roland,I wasn't talking about luxury cars, but about sophisticated sports car engines, which is something completely different.
We used to repair, pump and manufacture power tubes for radio and TV stations, so I know completely different performance classes.
But we're talking past each other, your capacitors in the tube power amplifier can have an operating temperature of 40° or 90°, without measuring you don't know anything. You have different heat zones with such a device, which should be taken into account when setting it up. Sometimes they lose 20-40° of component temperature with 1 cm more distance from the tubes.
Just look on Amazon and the reviews. I've been using this for my needs (kitchen, hobby, etc.) for a few years:
Eventek Laser Infrared Thermometer, -50 to +550°C
I have already compared it a few times with the calibrated industrial device (up to 1750°) in our company, and it always differed by less than 1°.
I don't think this 50 degrees is an issue. I think it is too much for such a device that should be more efficient. It is surprisingly mainly the SMPS that is hot.
0.95 is ok.Hi Roland,
I bought UNI-T infrared thermometer model UT301A+.
The measurements shows case temperature of 42.2 Celsius (bottom).
I guess internally it might reaches 50 degrees. Not terrible but for me it seems high. No good reason for that.
There is an emissivity parameter, that I put 0.95. I am not sure about that value, you know the metal of the SP400 is plated black, so I think 0.95 is fine..
What you are using for this parameter in your thermometer?
Thank,
Guy
I didn't open the device, what I have measured is from outside, near the SMPS. It is at a room temperature but here, now, it is about 25 degrees Celsius0.95 is ok.
At what ambient temperature did you measure the device?
What is the temperature on the top of the device?
I asked for the temperature of the top of the device, not inside.I didn't open the device, what I have measured is from outside, near the SMPS. It is at a room temperature but here, now, it is about 25 degrees Celsius
Ahh... I checked. Not important, top or bottom, or side, but near the SMPS area it is about 42 Celsius. Could be 2 Celsius variation.I asked for the temperature of the top of the device, not inside.
You said 42.2 Celsius bottom.
I bought a 5k thermistor for my Agilent DMM in order to measure temperature also by coupling. More or less the same, 40.1 Celsius at bottom after half an hour of coupling. Gives little better than emissivity of 1 in the UNI-T.I asked for the temperature of the top of the device, not inside.
You said 42.2 Celsius bottom.
40° at 25° ambient temperature is completely OK. The internal temperature will only differ by a few degrees and will not be 50°.I bought a 5k thermistor for my Agilent DMM in order to measure temperature also by coupling. More or less the same, 40.1 Celsius at bottom after half an hour of coupling. Gives little better than emissivity of 1 in the UNI-T.
Like a black hole .
With the SP400 with this THX circuit I assume that the amplifier section is biased. This is why the heat does not increase significantly during operation under load.At the beginning of my posts I asked if someone has a failure in this device because of the heat. That was my original question.
I don't think the temperature is not acceptable, it will not prolong the life of the internal capacitors for sure but it is still acceptable. I am not going to drill holes at the plastic top or at bottom.
It is a surprise for me that SMPS of relatively low consumption device reaches such temperature. The efficiency of SMPS is normally very high and for such small amount to current the PS needs to be cool, like my DO300EX, that really run cool (and had only one PS). This is the designer choice and maybe the situation is improved in their new H400.