Buckeye Amps: Hypex NCx500 Official Thread

[Heyu]

What is the filter capacitance as far as the spec on that?

 

[DonH56]

What is the filter capacitance as far as the spec on that?

This is NOT directed at you, but rather a general comment on the question, as it comes up often.

Filter (decoupling) capacitance is one of those things audiophiles ask and marketeers sell but has little impact in real life except when the caps are poor quality and fail early. Another "bigger is better" metric ignoring all the other trades.

Switched-mode power supplies (SMPS') require much smaller capacitors than conventional "linear" power supplies because SMPS operate at frequencies orders of magnitude higher. For example, a typical linear supply recharges the capacitors 120 times a second (120 Hz), whilst an SMPS works from 100 kHz to >1 MHz. There is far less time for capacitors to discharge before the supply "tops them off" so much smaller capacitors can be used. For example, for the same output current and voltage sag, 1000 uF at 120 Hz becomes 1.2 uF at 100 kHz. That makes comparing capacitance among different amplifier types tricky; the one with 100 uF in a 100 kHz SMPS actually has much more effective charge storage than 10,000 uF in a conventional supply relative to supply voltage sag.

 

[LSUGopher]

I currently have a Buckeye 3 channel NCx500 on order and am contemplating changing it to a ET400A model. I have a few questions hopefully some Buckeye three channel ET400A or NCx500 owners can answer.

• There have been multiple accounts of the purifi ET400A amps running cool and the Hypex NC502MP models running much hotter. Anyone that a 3 channel NCoreX owner can comment on their experience with case heat? How hot does it get? My theater/music area is in a room over a garage and gets quite hot during the Louisiana summer afternoons and I am looking to minimize extra heat generation inside the room where I can.
  • The idle load of the 3 channel NCx500 model is reported by one user to be 38 watts while the idle loads of the ET400A 3-channel are likely to be around half that. That will help with heat generation and the low idle watts of the ET400A modules are likely why they run so cool.
  • From the Hypex/Purifi datasheets: SMPS1200 has 9 watts idle loss and the ET400A idle loss is 1.7 watts/channel so the Buckeye three channel ET400A model should have a loss of 14 idle watts.
  • Per the Hypex datasheet, NCx500 have an idle loss of 5.3 watts/channel which sums to 16 watts. Since the idle loss reported is currently 38 watts then the 2k Microaudio SMPS has idle losses of 22 watts (its datasheet from what I could tell is not publically available). That does seem a bit high as the Hypex 3k SMPS has idle losses of 15 watts and the Microaudio 2k in theory should be somewhere in between that and the 9 watts of the SMPS1200.
  • As a point of reference the 4 channel NC502MP per the Hypex datasheet has an idle loss of 53 watts (17 watts per SMPS (2) and 4.8 watts per channel (4))

• I have seen prior pictures of the NCx500 module red LED lights shining through the case. For anyone that uses a Buckeye NCx500 amp, is this noticeable in a dark room when watching movies? I’ll probably have 5-7 inches of room between the top of the amp and the shelf above so I believe any light will be visible coming out of the vent and be a distraction.

The amp will be used to drive Ascend Acoustics ELX towers/Horizon LCR speakers. They are advertised as 8 ohm nominal, but the impedance dips down to ~4 ohms from 90-300 Hz. I don't think are considered a very difficult load (I attached the impedance chart below) They are also rated for up to 400 watts max continuous power so they could take advantage of the extra watts of the NCx500. I generally watch movies around at around -7 to -10 dB, and listen to music around 85-95 dB so from the SPL calculations I have done either model ET400A or NCx500 should work well. The NCx500 has a decent amount more wattage into 8 ohm loads which is why I initially picked it over the ET400A, but if the heat/red light leakage are significant disadvantages then I may switch to the ET400A model.

Thanks for any experiences you can share.

 

[ryanosaur]

I have seen prior pictures of the NCx500 module red LED lights shining through the case. For anyone that uses a Buckeye NCx500 amp, is this noticeable in a dark room when watching movies? I’ll probably have 5-7 inches of room between the top of the amp and the shelf above so I believe any light will be visible coming out of the vent and be a distraction.

I have 5 NC400 amps running in Ghent Chassis... yes different, but the red LEDs are still utilized and I don't see them outside the Chassis.

 

[Buckeye Amps]

• • Per the Hypex datasheet, NCx500 have an idle loss of 5.3 watts/channel which sums to 16 watts. Since the idle loss reported is currently 38 watts then the 2k Microaudio SMPS has idle losses of 22 watts (its datasheet from what I could tell is not publically available). That does seem a bit high as the Hypex 3k SMPS has idle losses of 15 watts and the Microaudio 2k in theory should be somewhere in between that and the 9 watts of the SMPS1200

This is being rectified with Standby control of the Micro Audio SMPS and the entire amplifier section.

 

[MicroAudio]

SMPS2K idle losses without anything connected is 10.5W.

SMPS is ON and all output voltages are available.

SMPS in standby power consumption is 0.2W.

 

[LSUGopher]

@ryanosaur, Thanks for sharing your experience with the red leds on your Hypex amps.

@MicroAudio, Thanks for sharing the actual idle/standby power consumptions. 10.5 watts for 2k is pretty good. I had assumed somewhere around 12 watts based on the Hypex 1200 and 3000 SMPS idle watts

@Buckeye Amps, My question was more around power consumption when the amp is on, but not working very hard (current wattage requirements are low). I am assuming that an amp with a lower idle wattage would run cooler in that scenario than one with a higher idle wattage. I don't know if that would make a meaningful difference between the Buckeye 3 channel ET400A/NCx models, which is why I posed the question. I also think updating the design to allow true standby operation is a great update, which is a plus over the Purifi models (I assume that isn't incorporated currently). If possible I think you should try to add that feature to all of your models. Lastly, the firmware upgrade to allow standby control, can that be done by the end user or would it need to be returned to you? Do you expect that feature to be implemented by the time the next 2k MA SMPS arrive for the 2024 orders?

 

[Buckeye Amps]

@ryanosaur, Thanks for sharing your experience with the red leds on your Hypex amps.

@MicroAudio, Thanks for sharing the actual idle/standby power consumptions. 10.5 watts for 2k is pretty good. I had assumed somewhere around 12 watts based on the Hypex 1200 and 3000 SMPS idle watts

@Buckeye Amps, My question was more around power consumption when the amp is on, but not working very hard (current wattage requirements are low). I am assuming that an amp with a lower idle wattage would run cooler in that scenario than one with a higher idle wattage. I don't know if that would make a meaningful difference between the Buckeye 3 channel ET400A/NCx models, which is why I posed the question. I also think updating the design to allow true standby operation is a great update, which is a plus over the Purifi models (I assume that isn't incorporated currently). If possible I think you should try to add that feature to all of your models. Lastly, the firmware upgrade to allow standby control, can that be done by the end user or would it need to be returned to you? Do you expect that feature to be implemented by the time the next 2k MA SMPS arrive for the 2024 orders?

The feature should definitely be working for all future (and pending 2024) orders. In terms of hardware the ability is there on the SMPS and our input board. Just need to tweak the firmware.

 

[Buckeye Amps]

Sold

 

[NegativeEntropy]

I currently have a Buckeye 3 channel NCx500 on order and am contemplating changing it to a ET400A model. I have a few questions hopefully some Buckeye three channel ET400A or NCx500 owners can answer.

• There have been multiple accounts of the purifi ET400A amps running cool and the Hypex NC502MP models running much hotter. Anyone that a 3 channel NCoreX owner can comment on their experience with case heat? How hot does it get? My theater/music area is in a room over a garage and gets quite hot during the Louisiana summer afternoons and I am looking to minimize extra heat generation inside the room where I can.
  • The idle load of the 3 channel NCx500 model is reported by one user to be 38 watts while the idle loads of the ET400A 3-channel are likely to be around half that. That will help with heat generation and the low idle watts of the ET400A modules are likely why they run so cool.
  • From the Hypex/Purifi datasheets: SMPS1200 has 9 watts idle loss and the ET400A idle loss is 1.7 watts/channel so the Buckeye three channel ET400A model should have a loss of 14 idle watts.
  • Per the Hypex datasheet, NCx500 have an idle loss of 5.3 watts/channel which sums to 16 watts. Since the idle loss reported is currently 38 watts then the 2k Microaudio SMPS has idle losses of 22 watts (its datasheet from what I could tell is not publically available). That does seem a bit high as the Hypex 3k SMPS has idle losses of 15 watts and the Microaudio 2k in theory should be somewhere in between that and the 9 watts of the SMPS1200.
  • As a point of reference the 4 channel NC502MP per the Hypex datasheet has an idle loss of 53 watts (17 watts per SMPS (2) and 4.8 watts per channel (4))

• I have seen prior pictures of the NCx500 module red LED lights shining through the case. For anyone that uses a Buckeye NCx500 amp, is this noticeable in a dark room when watching movies? I’ll probably have 5-7 inches of room between the top of the amp and the shelf above so I believe any light will be visible coming out of the vent and be a distraction.

The amp will be used to drive Ascend Acoustics ELX towers/Horizon LCR speakers. They are advertised as 8 ohm nominal, but the impedance dips down to ~4 ohms from 90-300 Hz. I don't think are considered a very difficult load (I attached the impedance chart below) They are also rated for up to 400 watts max continuous power so they could take advantage of the extra watts of the NCx500. I generally watch movies around at around -7 to -10 dB, and listen to music around 85-95 dB so from the SPL calculations I have done either model ET400A or NCx500 should work well. The NCx500 has a decent amount more wattage into 8 ohm loads which is why I initially picked it over the ET400A, but if the heat/red light leakage are significant disadvantages then I may switch to the ET400A model.

Thanks for any experiences you can share.

View attachment 359965

@LSUGopher

I have ELX Titans (LCR). Switched from class AB Outlaw 5000 with ~150-175W peak into 8 ohm to 3 channel NCx500. Relatively large room with ~12’ listening distance. Only switched because I needed 3 more channels anyway and I did not want headroom to be a potential issue.

Got the expected extra gain. Sounds great of course. Have not done much critical listening since the install, but other than some reduced hiss close in I would only expect more headroom based on the amp measurement and no other audible change.

As you noted, efficiency of the speakers is relatively low, but they are not very difficult to drive impedance wise.

Haven’t been able to do a full recalibration as I am finishing some construction in an adjacent room and stuff is everywhere so just did pink noise level matching of previous Dirac cal.

My amp is remote mounted in a rack, so can’t help with any of your other questions. Don’t regret my purchase at all.

If you have questions I can answer I’ll keep an eye on the thread.

 

[Dr. Cyrax]

Have gotten my Buckeye 3channel Hypex ncx500, got it powering my LCR from Arendal Audio 1723 THX towers, and center.
And it is fantastic!!
No hiss, only pure enjoyment.
After several hours of "non healthy" music and movie listening it is not warmer than that I can place my hand on top, no problem.
When I am doing the rest of my surround system, its going to be Buckeye amps all the way.
Thx Dyllan, for great product and great support along the way.

 

[Heyu]

When will the amps with Dirac become available?

 

[ViperDom]

Heyu, that info would be here:

Buckeye Amps 2ch Integrated Amplifier

2ch Integrated Amplifier Specifications/Features List (w/o Add-on card): XLR Inputs (x2) RCA Inputs (x2) RCA Outputs (x2) - User specifies desired behavior at checkout - EX: User could specify Mono Sub outputs w/Low Pass Filter (24dB Octave, Analog) - EX: User could specify Stereo Sub outputs...

www.audiosciencereview.com

 

[LSUGopher]

@LSUGopher

I have ELX Titans (LCR). Switched from class AB Outlaw 5000 with ~150-175W peak into 8 ohm to 3 channel NCx500. Relatively large room with ~12’ listening distance. Only switched because I needed 3 more channels anyway and I did not want headroom to be a potential issue.

Got the expected extra gain. Sounds great of course. Have not done much critical listening since the install, but other than some reduced hiss close in I would only expect more headroom based on the amp measurement and no other audible change.

As you noted, efficiency of the speakers is relatively low, but they are not very difficult to drive impedance wise.

Haven’t been able to do a full recalibration as I am finishing some construction in an adjacent room and stuff is everywhere so just did pink noise level matching of previous Dirac cal.

My amp is remote mounted in a rack, so can’t help with any of your other questions. Don’t regret my purchase at all.

If you have questions I can answer I’ll keep an eye on the thread.

Thanks for your feedback. Always nice to see another Ascend Owner. I'm team RAAL Like you I am mainly expecting extra headroom as I am currently using an old receiver (Denon 4311, rated for 140W) as an external amp to power the LCR and have found it quite good for the past 7+ years, but am looking to retire that and hopefully the NCx will run a bit cooler than the receiver. I do like to music especially symphonies quite loud and am hoping the new amp will help with symphonic dynamics.

 

[NegativeEntropy]

Thanks for your feedback. Always nice to see another Ascend Owner. I'm team RAAL Like you I am mainly expecting extra headroom as I am currently using an old receiver (Denon 4311, rated for 140W) as an external amp to power the LCR and have found it quite good for the past 7+ years, but am looking to retire that and hopefully the NCx will run a bit cooler than the receiver. I do like to music especially symphonies quite loud and am hoping the new amp will help with symphonic dynamics.

It may, especially if you are not using subs or are crossing low. Guessing it should run cooler than what I assume to be class AB ams in the Denon.

Considered going RAAL of course but with 3 LCR to upgrade from NrT and 5 new surrounds to buy, it was not in the budget!

 

[Heyu]

Heyu, that info would be here:

Buckeye Amps 2ch Integrated Amplifier

2ch Integrated Amplifier Specifications/Features List (w/o Add-on card): XLR Inputs (x2) RCA Inputs (x2) RCA Outputs (x2) - User specifies desired behavior at checkout - EX: User could specify Mono Sub outputs w/Low Pass Filter (24dB Octave, Analog) - EX: User could specify Stereo Sub outputs...

www.audiosciencereview.com

Unless I missed it. There is no mention of dirac amps release dates.

 

[Buckeye Amps]

About 6wks or so ago, another vendor on here tried to imply that lack of certification meant there was "distrust" of Micro Audio SMPS' when Micro Audio was suggested as a proper SMPS for reaching full power output with certain amplifier modules (such as the Purifi 1ET7040SA and the upcoming Purifi 1ET9040BA). To which Micro Audio provided certifcation for the 1k SMPS currently being used for 7040 builds and promised upcoming certification for the 2kW SMPS being used in our 3ch NCx500 build.

Well, here you go!
Micro Audio 2kW SMPS Certification

I also have the full certificate on file, as well.

 

[LSUGopher]

That's a lot of questions.
If you don't want the amp to run warm after an hour get the Purifi. The watts used with the Purifi 1ET400A while idle and at lower volumes is almost half the NCx500 solution and the NCx500 amp will get warm. On the other hand, my Purifi amps stay cool no matter what. The Purifi amps offer lots of power and the best energy efficiency and heat characteristics. It's an excellent module that ages well. The Purifi will offer plenty of power for the Ascend ELX.

The Buckeye Stereo Purifi measures 14W while idle or with lower volumes in stereo. I don't have a three channel to measure. In comparison, the NCx500 stereo amp is 26W. It will heat up with 60 minutes of operation or simply leaving it on. A lot of users are going for the NCx500 design but personally the Purifi build would still be my first choice if you are looking for an exceptionally cool running amp design.

Thanks, I figured the Purifi would be more energy efficient from everything I have read. I'm concerned I will have regrets if I change to the ET400A from the NCx500. Before I ordered the NCx500 I did a lot of research and between the two before ultimately deciding to order the NCx model. I should be receiving the 3XNCX amplifier shortly after Dylan receives his next batch of MA 2k SMPS's as I ordered in early January. If I feel it runs too hot then I may purchase the ET400A version to compare. However, I can't believe that 10-15 W can make that large of a difference. I suppose I will find out when it arrives.

 

[MicroAudio]

Thanks, I figured the Purifi would be more energy efficient from everything I have read. I'm concerned I will have regrets if I change to the ET400A from the NCx500. Before I ordered the NCx500 I did a lot of research and between the two before ultimately deciding to order the NCx model. I should be receiving the 3XNCX amplifier shortly after Dylan receives his next batch of MA 2k SMPS's as I ordered in early January. If I feel it runs too hot then I may purchase the ET400A version to compare. However, I can't believe that 10-15 W can make that large of a difference. I suppose I will find out when it arrives.

I have the NCX500 3 channels amplifier running for over 3 months by now, 24/7.

It never became hot to the level that makes it hot to touch.

Can post some thermal images if needed.

Thanks

 

[Buckeye Amps]

As @MicroAudio posted, even if you left the 3ch NCx500 in idle indefinitely, it does not get that hot. In fact when I tested one of the rack builds in my own setup, the AC Infinity Aircom would never come on while sitting idle, even though the thermal probe was placed right next to the SMPS and the temp for triggering on was set to 84F.