i use a lynx aurora n as my dac and to my ears i much prefer the sound without input buffer
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2nd generation EIGENTAKT PURIFI 1ET6525SA (successor to the 1ET400A)
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@pma I did ask march audio about the thd+ V snr on their forum. Alan confirmed that at the 5 watts point, their is no significant difference between the two.
They also have released 3 1et6525 based amps. Appear to have the best measurements for this module that I have seen so far.New P482 Stereo Power Amplifier
Hey Alan On ASR there was a question regarding the validity of your corrected SINAD figure. The poster said it wasn't valid because the noise floor increases with increasing power output. Therefore just taking the shorted input noise figure doesn't account for the increased noise at higher...forum.marchaudio.com
March Audio – Purifi Audio Amplifiers and Speakers
marchaudio.com
The power specs quoted on the March Audio site are the manufacturer specs. You will want to take them with a grain of salt.
If you live in the USA the problem with March Audio is price. Not only does March charge more for the amp, but shipping is more than double what Boxem charges. March charges $122 for shipping a Purifi amp to the USA. Boxem is about $48 in comparison and Buckeye is free.
If you put all three brands on an AB switch and move between them in a blind test you won't be able to reliably distinguish which one is playing. So it comes down to looks, which to be honest at 8' to 11' away is not that different. Maybe if it sits 2' in front of you while listening you may prefer the Boxem or March case?
Bottom line, choose your Purifi amp from the source you TRUST to service you after the sale. How expensive is it to have it repaired out of warranty? How easy is it to get a response from the company? When you do get a response does it fully answer your question? Do they ship in a timely fashion? Do they post measurements on their site that were verified with their build? Or is it just the Purifi module spec? How flexible are they with special requests? You get the idea. Looking for .0001 better posted measurements from the builder will likely be a mirage and in the unlikely event it's true will never be heard.
As long as people understand what it means, good for them.exept for audiophonics version where the input stage can be bypassed
Some initial temperatures of the boXem A 4216/E4 using a an infrared thermometer with laser pointer. 4-channel Purifi 1E6525SA module based amplifier.
1. No load and turned on idle for >1 hour.
2. Ambient air temp around 76F (24.4C) with low humidity.
3. The top of the chassis is 89F (31.6C).
4. The outer two modules are cooler than the two inner ones. Outer two are around 102F (38.9C).
5. Inner modules are >106F (40.5C)
6. The Hypex SMPS3K power supply transformer is >118F (47.7C)
7. The power supply's large capacitors are at 91F (32.7C)
The heat sink plates look large, but heat venting is at bottom of chassis. The modules are mounted upside down which is an interesting design choice, but I assume this was done to avoid dust accumulation and accidentally spilling liquids in to the unit by mistake. Mine will be in a cabinet, so I will have to raise the feet by 1 inch (2.5 cm) and ensure adequate air flow.
These temperatures of the modules and PS are higher than my 3-channel Buckeye NCx500 amplifier with the Microaudio SMPS2K power supply. It too has good sinks.
1. No load and turned on idle for >1 hour.
2. Ambient air temp around 76F (24.4C) with low humidity.
3. The top of the chassis is 89F (31.6C).
4. The outer two modules are cooler than the two inner ones. Outer two are around 102F (38.9C).
5. Inner modules are >106F (40.5C)
6. The Hypex SMPS3K power supply transformer is >118F (47.7C)
7. The power supply's large capacitors are at 91F (32.7C)
The heat sink plates look large, but heat venting is at bottom of chassis. The modules are mounted upside down which is an interesting design choice, but I assume this was done to avoid dust accumulation and accidentally spilling liquids in to the unit by mistake. Mine will be in a cabinet, so I will have to raise the feet by 1 inch (2.5 cm) and ensure adequate air flow.
These temperatures of the modules and PS are higher than my 3-channel Buckeye NCx500 amplifier with the Microaudio SMPS2K power supply. It too has good sinks.
Thanks for publishing these measurements
That's indeed the most important data: these are bulk caps on the mains voltage side. That makes them safety critical components whose ambiant temp must stay below the power supply rated ambiant temperature (50 °C).
Cold air intake is at the bottom of the chassis, hot air is leaving the box through the front and back vents (approx. 34 cm2). The idea of the upside down mounting came from experiments with an NC252MP whose power supply FETS are mounted below the bulk capacitors. Keeping these caps at reasonable temperatures with traditional flat mounting is quite ambitious but once you install the module upside down, heat-sinking almost becomes optional. And yes, I just hate dust in electronics, so grills on top of the chassis are a no go for boXem.
That said, there is always room for improvement and from mid December, a new heatsink allowing better bottom to top airflow around modules and PS will be used.
I'll get around to actually installing it at the end of this week or when I get some time as I have to travel out of town on business. The amp itself looks like a good solid build, the only negatives I can give on initial observation is that there is no LED on the front panel indicating the unit is on and there is no master on/off switch. This wouldn't be a problem if the venting were at the top where I could observe the Purifi module LEDs come on.
Can I purchase the new heatsink from you when you've cleared out your initial orders and install it myself and is there an on-line users manual for the A 4216 units?
Both Fred at boXem and Dylan at Buckeye Amps have been pleasure to deal with and have answered all questions. I wouldn't hesitate to purchase from either of them.
Can I purchase the new heatsink from you when you've cleared out your initial orders and install it myself and is there an on-line users manual for the A 4216 units?
Both Fred at boXem and Dylan at Buckeye Amps have been pleasure to deal with and have answered all questions. I wouldn't hesitate to purchase from either of them.
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The sweet spot for minimal heat is two Purifi modules (Stereo) and a standard Hypex SMPS1200 power supply. Once you start using the same case to house four modules and a SMPS3K the challenge to maintain a cool operation is significantly magnified. Purifi stereo amp configurations run cooler by design.
No front LED is a design choice. Manual is in the ToDo list. Maybe we can take this conversation in the boXem A seies thread
.I don't think it's a difficult design challenge. It comes down to case size, heat sink capacity and proper ventilation. I saw one DIY amp here on ASR that had 3/8" thick copper plates on each of 8 modules, two case fans, two PSs and a large chassis. It looked like a really nice build.
Well, I am hoping that you guys are not considering the temps measured by @rsg as "too high". Because they are frankly reasonable.
Engineering is meeting or exceeding a set of performance targets while meeting or being under a target cost. Getting the best performance at whatever cost is called a hobby. Nothing against it, but that is not how a company is run.
Heat spreader had to be modified due to manufacturing issues and solving these issues improved air flow as a nice side effect.
Engineering is meeting or exceeding a set of performance targets while meeting or being under a target cost. Getting the best performance at whatever cost is called a hobby. Nothing against it, but that is not how a company is run.
Heat spreader had to be modified due to manufacturing issues and solving these issues improved air flow as a nice side effect.
The temperatures are very reasonable. I want to stress again the measurements are on the surface of each module & PS. The case itself is quite cool. In comparison, the case of multi-channel HT audio-video processors get hotter. The reason for my measurements are not to denigrate any manufacturer, but to plan putting equipment into an enclosed cabinet with adequate airflow.
Having used high powered class AB amps for the last 25 years, I’m quite pleased with both the Purifi & Hypex modules.
Having used high powered class AB amps for the last 25 years, I’m quite pleased with both the Purifi & Hypex modules.
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That's a bit of an oxymoron.
It's difficult to supply "adequate airflow" without an opening in the cabinet and maybe a quiet fan of some type.
No other electronics in a cabinet helps but it's unusual as people end up stacking components with little room for circulation.
Closed spaces by their very nature imped airflow and allow heat build.
We spray foamed the attic this year with 6.5" of foam on all Truss/rafters and down side walls. Next, we removed the 10" of insulation above the ceiling. The attic space is now within 3 degrees of the temperature in the house.
It's 48F outside and 77F inside right now with no heating equipment in use.
We open windows during the day to enjoy fresh air.
A sealed enclosure will be much like that but on a smaller scale and the amp provides a heat source.
Fans will be used and an opening is available. The cabinet is a Salamander Synergy Systems with ventilated front door. Generally I allow for 6-8” above amps & processors. Fans are from AC Infinity.
Audiophonics has the quad channel 1ET6525SA on preorder, they promise availability on Dec 20, 2024: https://www.audiophonics.fr/en/power-amplifiers/audiophonics-hpa-q450et-p-20248.html
This is like a multiway-diy-dsp-crossover dream.
This is like a multiway-diy-dsp-crossover dream.
Also available at boXem's, if I'm not mistaken - add to this a dual-mono NCx500 and your stereo 3-way DIYs should have all the clean horsepower needed
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