Well, I don't ride motorcycles, only bicycles and unicycles. So not full throttle.
The fans are Noctua NF-B9-1600 and run full speed with 12 V. Even at full speed they are very quiet. During the heatsink test, I found that about 9 V moved enough air to keep the temperature at about 41 C. The two resistors on the heatsink were dissipating about 200 W total.
I've built variable power supplies for the fans using LM317 outputting about 7 - 12 V. This will let me adjust the air flow depending on the ambient room temperature.
The fans are Noctua NF-B9-1600 and run full speed with 12 V. Even at full speed they are very quiet. During the heatsink test, I found that about 9 V moved enough air to keep the temperature at about 41 C. The two resistors on the heatsink were dissipating about 200 W total.
I've built variable power supplies for the fans using LM317 outputting about 7 - 12 V. This will let me adjust the air flow depending on the ambient room temperature.
Thanks, Dirk. Yes, lots of aluminum. I just weighed the case and it is over 20 lbs (9.5 kg). With power transformer, choke, and other parts, each monoblock will be around 40 lbs (18 kg).
I will try...this amp
I tested the PSU with nothing hangin' on it. Put the light-bulb-tester in. Light turned off - pooh! Then without light-bulb-tester: I was short to a big boom!
I've got 73.8 V on the second cap. I made a CRC - filter with 2 x 47000µF caps.
The big cans / caps are rated at 80 V - so, I was close to the max. 🙄
But my mistake - I bought the wrong transformers.
230 V~ prim. / 2 x 25 V~ sec. / 500 W
sec. in series = 50 V~
50 V~ x 1.2 = 60 V
50 V~ x 1.3 = 65 V (this was what I've expected by the rule of thumb).
But the transformers put out a bit more than 2 x 25 V~ sec. (o.k. - unloaded).
I am searching.
And I will try to get the dumbness crown!
Greets
Dirk 😀
I tested the PSU with nothing hangin' on it. Put the light-bulb-tester in. Light turned off - pooh! Then without light-bulb-tester: I was short to a big boom!
I've got 73.8 V on the second cap. I made a CRC - filter with 2 x 47000µF caps.
The big cans / caps are rated at 80 V - so, I was close to the max. 🙄
But my mistake - I bought the wrong transformers.
230 V~ prim. / 2 x 25 V~ sec. / 500 W
sec. in series = 50 V~
50 V~ x 1.2 = 60 V
50 V~ x 1.3 = 65 V (this was what I've expected by the rule of thumb).
But the transformers put out a bit more than 2 x 25 V~ sec. (o.k. - unloaded).
I am searching.
And I will try to get the dumbness crown!

Greets
Dirk 😀
to Soundhappy
Hello Soundhappy,
the transformers are from the german company 'Strobelt'.
Strobelt - Ringkerntransformator Steuertransformator Trafogehause
They are only 40km away from where I live.
The trafos are in spec.. But I should have bought 2 x 22V~ sec. ?
Greets
Dirk
Hello Soundhappy,
the transformers are from the german company 'Strobelt'.
Strobelt - Ringkerntransformator Steuertransformator Trafogehause
They are only 40km away from where I live.
The trafos are in spec.. But I should have bought 2 x 22V~ sec. ?
Greets
Dirk
The trafos are in spec.. But I should have bought 2 x 22V~ sec. ?
It's not one audio path transformer at the input ? For example Jensen or Cinemag etc.
to Sondhappy #993
Hello Soundhappy,
Audio-transformer is in: EDCOR 600:600
It is in the right lower corner of the case (a little bit hidden - it is a transformer
on a 'secret mission' 😀).
I also have to build the input-buffer. So still some work to do...
Greets
Dirk
Hello Soundhappy,
Audio-transformer is in: EDCOR 600:600
It is in the right lower corner of the case (a little bit hidden - it is a transformer
on a 'secret mission' 😀).
I also have to build the input-buffer. So still some work to do...
Greets
Dirk
to Itsmee #992
Hello Itsmee,
my heatsinks is 300 mm x 400 mm (per channel).
It is a 'cubicincher - modu - 8U - heatsink' 😉.
The hockeypucks (IXYS-Mosfets) also should be able to handle the higher
voltage / amperes. I checked the datasheet with focus on FSOAB.
The optocoupler ? ... I am checking at the moment.
Greets
Dirk
Hello Itsmee,
my heatsinks is 300 mm x 400 mm (per channel).
It is a 'cubicincher - modu - 8U - heatsink' 😉.
The hockeypucks (IXYS-Mosfets) also should be able to handle the higher
voltage / amperes. I checked the datasheet with focus on FSOAB.
The optocoupler ? ... I am checking at the moment.
Greets
Dirk
to #995
I checked the IXYS - datasheet for forward - biased- safe- operating- area so:
FBSOA
little mistake 😕
Dirk
I checked the IXYS - datasheet for forward - biased- safe- operating- area so:
FBSOA
little mistake 😕
Dirk
Excellent Dirk!
If You start test, then 9V1 Zener connected to audio path IXYS can keep them safer
If You start test, then 9V1 Zener connected to audio path IXYS can keep them safer

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