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NC400 or Icepower 700AS1+ technical Questions

EB1000

Active Member
Joined
Jan 8, 2020
Messages
100
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66
#1
Hi

I'm new here. I have recently built my first DIY class D using two Icepower 125ASX2 in BTL modes (dual monoblocks). I'm using them with NAD C658 Preamp DAC (XLR) and a pair of Focal Aria 936 speakers. While I'm happy with the overall sound, I feel that I can do better.


I can get two Icepower 700AS1 modules for 700$. These are the same modules used by PS Audio Stellar 700M. But I'm also considering getting two DIY kits of the NC400.


According to the 700AS1 datasheet, it is based on a full-bridge topology, which means native support for balanced input. Other Hypex modules like the UcD700HG are based on a half-bridge topology, therefore they are natively single-ended amps. I've checked the NC400 datasheet, and it does not say if the NC400 is half or full-bridge topology. Also, I could not find any info about the optional HxR add-in modules. So here are my 3 questions:

1. What would be a better choice: Two Icepower 700AS1 or two Hypex NC400 kits?

2. Is the NC400 full or half-bridge topology?

3. What benefits does adding HxR cards to the NC400 have? What are the HxR modules? DC supply Regulators?

Thanks
 
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E

EB1000

Active Member
Joined
Jan 8, 2020
Messages
100
Likes
66
Thread Starter #2
Hi

I'm new here. I have recently built my first DIY class D using two Icepower 125ASX2 in BTL modes (dual monoblocks). I'm using them with NAD C658 Preamp DAC (XLR) and a pair of Focal Aria 936 speakers. While I'm happy with the overall sound, I feel that I can do better.


I can get two Icepower 700AS1 modules for 700$. These are the same modules used by PS Audio Stellar 700M. But I'm also considering getting two DIY kits of the NC400.


According to the 700AS1 datasheet, it is based on a full-bridge topology, which means native support for balanced input. Other Hypex modules like the UcD700HG are based on a half-bridge topology, therefore they are natively single-ended amps. I've checked the NC400 datasheet, and it does not say if the NC400 is half or full-bridge topology. Also, I could not find any info about the optional HxR add-in modules. So here are my 3 questions:

1. What would be a better choice: Two Icepower 700AS1 or two Hypex NC400 kits?

2. Is the NC400 full or half-bridge topology?

3. What benefits does adding HxR cards to the NC400 have? What are the HxR modules? DC supply Regulators?

Thanks


OK, got a reply from Hypex, the NC400 is based on a simple 2-transistor half-bridge topology, which means it is natively a single-ended amplifier. This is very disappointing. There is really no point for a balanced input in that case. There are many advantages to using a full-bridge topology. One important property is the fact that the effective PWM switching frequency doubles at the differential output, making the output filter more efficient.. Only a full-bridge class-d is a true balanced amplifier.


This really made it easier for me to choose the Icepower 700AS1 modules instead.
 

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