Thanks for your answer.
I already use a CRC power supply (based on 6L6 tutorial). I was just curious about regulated PSU for that kind of use.😉
Hi
i measured the toroidal transformer on my aleph j. And it was 68c near the bottom.
55 on top. is this to hot or is it normal. My first build and it was so hot i had to ask 🙂
i measured the toroidal transformer on my aleph j. And it was 68c near the bottom.
55 on top. is this to hot or is it normal. My first build and it was so hot i had to ask 🙂
Sounds like the transformer is undersized for the job.
Or maybe it could be DC offset? (If the core saturates then the secondary won't follow the primary resulting in harmonics which will produce more heat because they're at a higher frequencies?)
Or maybe it could be DC offset? (If the core saturates then the secondary won't follow the primary resulting in harmonics which will produce more heat because they're at a higher frequencies?)
@Nikko03, in your first picture you show a cover for the transformer with the bolt through the top. Is this electrically isolated from the case? If not, you could be creating a shorted turn through the cover.
Your transformer does look small for the job but you should make sure you aren't creating a shorted turn as well - try unbolting it from the case and see if the temperatures are much different on the transformer. What I mean by this is - remove the bolt and cap from the transformer (unsecured so don't move the amp around) and see if it makes a difference.
Your transformer does look small for the job but you should make sure you aren't creating a shorted turn as well - try unbolting it from the case and see if the temperatures are much different on the transformer. What I mean by this is - remove the bolt and cap from the transformer (unsecured so don't move the amp around) and see if it makes a difference.
The transformer is 300va from noratel here in norway. And should be good quality.
And 300va is big enough I think. The cover was insulated from the rest with a rubber band.
And 300va is big enough I think. The cover was insulated from the rest with a rubber band.
And if you disconnect the wires between rectifier bridges and psu inputs, the transfo stays cool?
measure exact AC at bridges and exact DC at rails
what value of CRC you have put on cap bank PCB?
what is Iq per channel?
what value of CRC you have put on cap bank PCB?
what is Iq per channel?
Transformers typically will be spec’d with a temperature rise at rated power. For some it is 50c and others 70c. Note that it is rated in VA not watts. My Aleph J runs about 270va but is biased a little hotter than normal. If you are running 250va and your transformer is rated for a 50c rise at rated output then 250/300 X 50 =41.7C + ambient temp in chassis of at least 25c an you are right where the specs would predict for transformer temperature.
I am running a 400va in mine and it gets quite warm at 270va but not near 60+ c.
If you are uncomfortable with the temp then you could add a small slow running fan to cool it. You should also make sure there is free ventilation from the bottom of the chassis and out the top cover. This can be encouraged by using high feet and making sure there is room around the amp and above it for air flow. A ZENMOD type babysitter fan would also help by lowering the temp of the entire chassis.
As a rule of thumb I like to stay somewhere in the 70-80% of the rating for a maximum. I am currently using an Antek 20v 400va and it is dead quiet mechanically and not running hot, so I am considering turning up my bias a bit, given that my heatsinks are up to the extra heat.
Check with the manufacturer of your transformer and ask them specifically if the temperatures you are seeing are ok. That will give you peace of mind going forward.
I am running a 400va in mine and it gets quite warm at 270va but not near 60+ c.
If you are uncomfortable with the temp then you could add a small slow running fan to cool it. You should also make sure there is free ventilation from the bottom of the chassis and out the top cover. This can be encouraged by using high feet and making sure there is room around the amp and above it for air flow. A ZENMOD type babysitter fan would also help by lowering the temp of the entire chassis.
As a rule of thumb I like to stay somewhere in the 70-80% of the rating for a maximum. I am currently using an Antek 20v 400va and it is dead quiet mechanically and not running hot, so I am considering turning up my bias a bit, given that my heatsinks are up to the extra heat.
Check with the manufacturer of your transformer and ask them specifically if the temperatures you are seeing are ok. That will give you peace of mind going forward.
My 300VA Antrek is considerably larger than that donut:
https://1.bp.blogspot.com/-5xXpdANw...ihTFkwp1rh9wIvsMzQCLcBGAs/s1600/Aleph_J_3.jpg
https://1.bp.blogspot.com/-5xXpdANw...ihTFkwp1rh9wIvsMzQCLcBGAs/s1600/Aleph_J_3.jpg
This has me curious and will have to measure mine. I run mine a little bit on the hotter side, 420 bias with 20v secondaries in a 4U chassis
I think it is this one: RT300-2018
http://www.noratel.com/fileadmin/content/products/toroidal/rt/RT.pdf
10% conversion loss for the 300VA, looks high?
http://www.noratel.com/fileadmin/content/products/toroidal/rt/RT.pdf
10% conversion loss for the 300VA, looks high?
Busy at work today but i will look at this tonight. thanks for all the help i have got so far.
@eddyvb that is the correct trafo. It is supposed to be good quality transformers.
@eddyvb that is the correct trafo. It is supposed to be good quality transformers.
I will check all this soon. But i have to admit i am a newbee. So i have to ask. what do i check to tell you the iq per channel 🙂
