megajocke said:The reason the different voltage parts are identical in all other parameters is probably because they really are the same device and then graded after the production depending on which breakdown voltage the batch got
Thats possible, but an Ashly amp i have has the higher rated parts (K135/J50) in it and they look physically larger in size. The base (mounting plate?) is thicker and seems oversized compared to regular TO3's.
Are they bigger than 134/49?
The case of the 2sk135/2sj50 mosfets (at least the ones I've seen) is different than modern TO-3:s at least, made of aluminium instead of steel that is used today. And yes, I remember the baseplate is much thicker than old Motorola aluminium BJT:s. I only have 2sk135/2sj50 types here so I can't compare them to the lower voltage parts.
Seems strange if they are different, but could just be due to different production dates.
The case of the 2sk135/2sj50 mosfets (at least the ones I've seen) is different than modern TO-3:s at least, made of aluminium instead of steel that is used today. And yes, I remember the baseplate is much thicker than old Motorola aluminium BJT:s. I only have 2sk135/2sj50 types here so I can't compare them to the lower voltage parts.
Seems strange if they are different, but could just be due to different production dates.
In my hand I am holding a J49, J50 and an Exicon 10P20. They are all the same length and width, and their pins are the same length. The Exicon's flat body plate is slightly thinner and its round "top hat" is not quite as high as in the Hitachi devices. So the overall height of the Exicon is slighly less than that of the Hitachis. Ditto for the N-channel devices.
For years it has been my understanding that the MOSFETs sold in the UK and Europe, since Hitachi ceased manufacturing them, have the same internal die, the same printed circuit inside them, as the original Hitachi devices.
What you have noted is just the slightly different packaging of them.
The Exicon I have has a steel case, as do the Hitachis.
Actually, none of this is relevant as they all function and mount the same.
For years it has been my understanding that the MOSFETs sold in the UK and Europe, since Hitachi ceased manufacturing them, have the same internal die, the same printed circuit inside them, as the original Hitachi devices.
What you have noted is just the slightly different packaging of them.
The Exicon I have has a steel case, as do the Hitachis.
Actually, none of this is relevant as they all function and mount the same.
Dick West said:In my hand I am holding a J49, J50 and an Exicon 10P20. They are all the same length and width, and their pins are the same length. The Exicon's flat body plate is slightly thinner and its round "top hat" is not quite as high as in the Hitachi devices. So the overall height of the Exicon is slighly less than that of the Hitachis. Ditto for the N-channel devices.
For years it has been my understanding that the MOSFETs sold in the UK and Europe, since Hitachi ceased manufacturing them, have the same internal die, the same printed circuit inside them, as the original Hitachi devices.
What you have noted is just the slightly different packaging of them.
The Exicon I have has a steel case, as do the Hitachis.
Actually, none of this is relevant as they all function and mount the same.
I looked as well, and they seem to be pretty close if not exactly the same size. There might be a slight difference in shape, but that is it.
How do you like that Exicon compared to the original Hitachi transistors? Do you prefer one over the other?
As I stated in a previous message, I hear no difference with them compared to the original Hitachis. I wouldn't mix them with Hitachis in a matched pair or triplet. I am using a customized DH-200 with 6 MOSFETs per channel and the 3 P-channel devices in each channel are Exicons. They work just fine.
http://www.diyaudio.com/forums/showthread.php?postid=1583868#post1583868
This describes my DH-200 monoblocks. They sound great!
http://www.diyaudio.com/forums/showthread.php?postid=1583868#post1583868
This describes my DH-200 monoblocks. They sound great!
So I'm getting ready to make my parts list and I have a couple of issues maybe you guys can help with.
First of all, TB401. It's a thermal breaker and that is pretty much all that I know. I did some looking around the Mouser Catalog and I didn't come up with much. Any information and input would be very helpful.
My second issue is with the parts list that I do have. Almost all of the capacitors are listed as mfd, which I assumed meant mF. But, that would be TOTALLY wrong so I now am assuming mfd actually means uF. Is this assumption correct? (I'm just double checking here.)
Thanks
First of all, TB401. It's a thermal breaker and that is pretty much all that I know. I did some looking around the Mouser Catalog and I didn't come up with much. Any information and input would be very helpful.
My second issue is with the parts list that I do have. Almost all of the capacitors are listed as mfd, which I assumed meant mF. But, that would be TOTALLY wrong so I now am assuming mfd actually means uF. Is this assumption correct? (I'm just double checking here.)
Thanks
YOu need a thermal breaker that is normally closed, but opens up when it gets too hot.
Some of us don't think this thermal switch is real important if your amp is not abused. I've used almost 100% Hafler amps for 20 years and only once, ONCE, did a thermal switch open up to shot off the AC to the amp. This was because I was fooling around with a 1st order series crossover which presented a too low impedance to the amp. Otherwise, I've never had a shutdown.
What this means to me is that you could just ignore this part of the circuit.
Why do you need a thermal switch. Don't you still have the ones that came with the amp?
If you wish I probably can find a pair here to sell you for $10 plus postage.
Some of us don't think this thermal switch is real important if your amp is not abused. I've used almost 100% Hafler amps for 20 years and only once, ONCE, did a thermal switch open up to shot off the AC to the amp. This was because I was fooling around with a 1st order series crossover which presented a too low impedance to the amp. Otherwise, I've never had a shutdown.
What this means to me is that you could just ignore this part of the circuit.
Why do you need a thermal switch. Don't you still have the ones that came with the amp?
If you wish I probably can find a pair here to sell you for $10 plus postage.
Dick West said:
I'm not really concerned with the thermal breaker in my Hafler (as you said, they might not even be necessary), but I have a H||H amplifier that uses them to control the fans. So in trying to figure the thermal breakers out I noticed that I can't find them on Mouser/Newark. Which peaked my curiosity.
All of my projects at the moment are more me being curious about every aspect of amplifier design, function, and protection. Being a hands on learner I decided to recondition this amplifier. It was a part I didn't know that much about, and it seems to be an odd ball to find.
Doesn't Hafler use this kind of thermal cutout?:
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=317-1087-ND
They are about as standard as it gets, you can find them inside almost any amp with thermostats Most home amps don't have thermal protection though...
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=317-1087-ND
They are about as standard as it gets, you can find them inside almost any amp with thermostats
Most home amps don't have thermal protection though...
The link I posted? I don't know which temperature Hafler used, I just wanted to post a link to something similar.
The upper side in the picture is screwed down against the heatsink and the cables are connected to the fastons on the bottom. It's upside down in the picture and that part with the wings is not firmly attached to the rest of it. Sometimes the switches have the mounting wings permanently attached to the body of the device. Some have the faston connectors vertical, some horizontal.
The upper side in the picture is screwed down against the heatsink and the cables are connected to the fastons on the bottom. It's upside down in the picture and that part with the wings is not firmly attached to the rest of it. Sometimes the switches have the mounting wings permanently attached to the body of the device. Some have the faston connectors vertical, some horizontal.
megajocke said:Doesn't Hafler use this kind of thermal cutout?:
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=317-1087-ND
They are about as standard as it gets, you can find them inside almost any amp with thermostats
Thanks for the link.
This is a link that I found, but it is open then shorts when the temp rises.
Jaycar
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