That resistor is used to dampen the inductor resonance. A small value series resistor could also work. I like this parallel arrangement though, as he has it. Lower total R on the rails.
So on track for completing in two years, my typical schedule.
Really starting to assemble, looking at parts vs schematic.
Noticed that on schematic there are six 120R resistors, R115, 122, 123, 215, 222 and 223. In the kit I received two 120R resistors.
Am I short 4 resistors, or am I making a mistake? They are the level shift resistors, so maybe I need to use different values?
TIA,
Randy
Really starting to assemble, looking at parts vs schematic.
Noticed that on schematic there are six 120R resistors, R115, 122, 123, 215, 222 and 223. In the kit I received two 120R resistors.
Am I short 4 resistors, or am I making a mistake? They are the level shift resistors, so maybe I need to use different values?
TIA,
Randy
You only need 2 - R115 and R215. R122, R222, R123, R223 are surface mount and are supplied soldered in on the boards.
Thanks. Didn't notice the SM resistors, should have looked harder obviously
Is this the correct way to add bulk caps between the PSU and amp rails? Specifically, wanted to ensure I have the polarity correct prior to blowing something up.
Apologies for the kindergarten level of drawing. 😛
Apologies for the kindergarten level of drawing. 😛
Hi Mightiness,
independent of the amplifier, what capacity should the additional cap bank in the amplifier have?
I have 132mF per rail in the PSU, is 10mF in the amplifier okay?
independent of the amplifier, what capacity should the additional cap bank in the amplifier have?
I have 132mF per rail in the PSU, is 10mF in the amplifier okay?
Finally have completed the monoblock conversion of my build...
It's still early for full impressions, and I'm currently using only GR Research modded Klipsch RP600Ms (my weakest link in the system), but boy, oh boy... these are special and more than worth the time and money to build. 🙂
I ended up having to stuff the bulk caps below the PSU PCB.
I also ended up accidentally miswiring the trafo secondaries, causing a couple of fuses to pop. Fortunately, doesn't seem I caused any permanent damage.
I can't wait to hear these puppies sing with some high-end speakers. I wonder how they'd pair with the Spatial Audio X4 (4Ohm|93dB)?
Really appreciate everyone's help along the way for my first, big boi amp build. Ended up learning a lot. Thx to Papa and ZM! 🙂
It's still early for full impressions, and I'm currently using only GR Research modded Klipsch RP600Ms (my weakest link in the system), but boy, oh boy... these are special and more than worth the time and money to build. 🙂
I ended up having to stuff the bulk caps below the PSU PCB.
I also ended up accidentally miswiring the trafo secondaries, causing a couple of fuses to pop. Fortunately, doesn't seem I caused any permanent damage.
I can't wait to hear these puppies sing with some high-end speakers. I wonder how they'd pair with the Spatial Audio X4 (4Ohm|93dB)?
Really appreciate everyone's help along the way for my first, big boi amp build. Ended up learning a lot. Thx to Papa and ZM! 🙂
I used some high-end thermal paste and Alumina pads just to be safer with temps. So far, it seems the temps are all good.everything fine ........... except - OS parts better on lower 1/3 of height, than on upper 1/3
meaning - exchange pcbs in cases
I also read somewhere that it's actually better to have the heat source located towards the top as it creates almost a chimney effect, allowing the air interface to naturally circulate from bottom (cooler) to top (hotter). Don't know if it's true or not, but it made sense to me.
I'll keep monitoring temperature to make sure, tho.
I do find that the internal temps of things like the trafo housing and PSU is a tad (few degrees or so) warmer with the lid on vs without the lid. Probably expected, and likely don't want even more holes due to structural rigidity, but just an observation.
Measuring the hottest area right behind the IRFP results in about 50-51C. This is at about 210mV at the current sense resistors. I'm thinking of bumping that down a tad actually.
This should be good, yeah?
This should be good, yeah?
Swap the position, or swap the amps out for another Papa/ZM project?
That XA252 SIT looks like it'd be a nice complement to the Sissy after I've entered a diabetic coma with all the sugar it gives to me... 😉
No doubt there are some top secret SIT projects on Mighty ZM's bench, just waiting to come play?
I already have spare pair of 2SK180 & 182... I'm wondering if I should acquire more THF-51 while I still can lol
My R3 under progress and thanks to my friends who gifted me the kit from Zenmod 🙂
Dismantled my F7 clone and using the 18vac 300VA each toroidal to make the dual mono R3. Thanks to @Nisbeth for his 6 cap psu board and using the active bridge rectifiers with LT4320. Unloaded getting around +/-26vdc should be good enough for the R3.
Dismantled my F7 clone and using the 18vac 300VA each toroidal to make the dual mono R3. Thanks to @Nisbeth for his 6 cap psu board and using the active bridge rectifiers with LT4320. Unloaded getting around +/-26vdc should be good enough for the R3.
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