Make sure your cooler surface is perfectly smooth, mirror flat, and don't forget a good thermal past on the two sides of the Mica insulator (some computer's CPU ones are near perfect).
But, if i my feeling is right about the way L.C works, isolators, i suppose, are provided with the First one ?
[edit] Oops L.C. was faster ;-)
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Hi Eric
Correct type is TO-264, size 20 x 25 mm.
Mica thickness is usually 0.075 mm, so 0,1 mm should be fine. Use thermal grease coated thinly on each surface separately.
Thanks LC,
I quickly search and TO-264 comes in 22 x 28mm and the TO-247 is 20x25. Hence my previous assumption for the package.
By the way, what would you think of ceramic insulator ?
Nope, at least could not find these inside my box hence my asking.
LC, very good work. A a small oversight: 19/20(I remember to had lost a little spacer from the VSSA, and how it was a hassle to find a new one ;-)
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Self remark to myself, these wont work mechanically with FO because of their thickness unless same height compensation is made on others transistors.
For the thermal grease, one needs to make sure it is non-conductive electrically and application can be tricky to get good results and not to break the mica insulator.
0.075mm and 0.1mm thick mica are "thick".Hi Eric
Correct type is TO-264, size 20 x 25 mm.
Mica thickness is usually 0.075 mm, so 0,1 mm should be fine. Use thermal grease coated thinly on each surface separately.
look to using <0.05mm thick mica
Thin mica is < 0.025mm thick.
Very thin mica is <0.015mm thick.
Speaker's impedance is likely to be more than 4 ohm anywhere on the curve.
As SMPS500R is softly switched it has less efficiency, more idle dissipation when connected to the First One, so I definitely recommend you to use one per channel, dual mono configuration for sure.
Thanks a lot LC for this information.
I received a nice box from Slovenia today! Two gorgeous First One red modules, impeccable assembly and quality! Stupid customs opened the boxes...
LC, I have a few questions for ya:
- in bridge mode, what would be the lower speaker load suggested
- If I power the modules at 42V, do I have to rebias or re-adjust anything?
- What transformer model/brand would you suggest for non-balanced signal input in bridge mode?
A BIG Thank You LC!!!
Do
LC, I have a few questions for ya:
- in bridge mode, what would be the lower speaker load suggested
- If I power the modules at 42V, do I have to rebias or re-adjust anything?
- What transformer model/brand would you suggest for non-balanced signal input in bridge mode?
A BIG Thank You LC!!!
Do
Hypex caps
I asked Hypex if it was possible to get their SMPS1200A400 with Mundorf caps, or any other 'good audio' brand, instead of the poor Samwha. (It is so stupid to lose money and time, recaping, for those looking for the best).
Here the answer i got:
"We cannot modify the SMPS1200 with these ecaps. We only sell this SMPS as it is."
I asked Hypex if it was possible to get their SMPS1200A400 with Mundorf caps, or any other 'good audio' brand, instead of the poor Samwha. (It is so stupid to lose money and time, recaping, for those looking for the best).
Here the answer i got:
"We cannot modify the SMPS1200 with these ecaps. We only sell this SMPS as it is."
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Hi Do,
if you re not willing to go with Lundhal, I have in the past considered the Edcor.
I have at home 2 XS4400 quad filler which I could sent you for test
Looks like they didn't even replace them in the Grimm speakers. So maybe just maybe they are not terrible to listen too
I received a nice box from Slovenia today! Two gorgeous First One red modules, impeccable assembly and quality! Stupid customs opened the boxes...
LC, I have a few questions for ya:
- in bridge mode, what would be the lower speaker load suggested
- If I power the modules at 42V, do I have to rebias or re-adjust anything?
- What transformer model/brand would you suggest for non-balanced signal input in bridge mode?
A BIG Thank You LC!!!
Do
Hi Dominic
Nice to hear that you like what you see hehe
Well customs guys are very curious, some day you know what, if curiosity killed the cat so ...
Now to the questions:
- in bridge mode min 4 Ohm impedance is recommended, meaning 4 Ohm in average if looking impedance curve, so it can also be less than 3 Ohm somewhere in the bass region, but that's OK if the average is still around 4 Ohm. The limit here is the output current which is 16 Amax and if looking to SOAR chart of the outputs, you can see these are very robust semis, at 100 Vdc they still easily sink/source 2,5 A
- since the modules are calibrated at +/- 63 V, at +/-42 V idle current would be a little bit lower, but still recalibration back to 280 mA (complete module's idle current) can easily be readjusted by trimmer TR3
- definitely LL1540 Lundahl line input transformer
In bridge mode at +/- 42 V PSU voltage you would easily get 500 W/4 Ohm and still be well in a SOAR.
Attachments
Hi maxidcx!
Since I only have two modules for the moment I will not need for now but I will most definitely buy more later. Will let you know, thanks for the offer!
Ciao!
Do
I had Nc400. The First One with SMPS1200A400 is way better, you should look a bit higher for fair comparison.
Hi Dominic
Nice to hear that you like what you see hehe
Well customs guys are very curious, some day you know what, if curiosity killed the cat so ...
Now to the questions:
- in bridge mode min 4 Ohm impedance is recommended, meaning 4 Ohm in average if looking impedance curve, so it can also be less than 3 Ohm somewhere in the bass region, but that's OK if the average is still around 4 Ohm. The limit here is the output current which is 16 Amax and if looking to SOAR chart of the outputs, you can see these are very robust semis, at 100 Vdc they still easily sink/source 2,5 A
- since the modules are calibrated at +/- 63 V, at +/-42 V idle current would be a little bit lower, but still recalibration back to 280 mA (complete module's idle current) can easily be readjusted by trimmer TR3
- definitely LL1540 Lundahl line input transformer
In bridge mode at +/- 42 V PSU voltage you would easily get 500 W/4 Ohm and still be well in a SOAR.
Thanks LC!
Do
Catal... Please remind the words of LC "Guys don't be fooled with a small size of the First One modules possibly holding in your hands just now, got to know this: this is a very BIG amplifier considering sound signature, be prepared to be strongly surprised immediately after turning this little beast alive."
Mount Etna isn't a beast you want to wake up!...
(have fun!)
Mount Etna isn't a beast you want to wake up!...
(have fun!)