NEW BRZHifi PAD-30 : Dual TPA3255 +PFFB @ $99

[ICIETDIYEUR]

People hi

A bit more air (under the case)?

It can't do the amplifier any harm, and personally, I find it quite aesthetically pleasing.

Have a pleasant day, everyone

 

[Ruediger]

Even when there are no openings at the bottom and all air is coming (and going) from the sides - these can't hurt.

Personally I like the 10mm high pyramides or small alu feet better. But these also look good.

 

[SampleSizeOne]

People hi

A bit more air (under the case)?

View attachment 547280

View attachment 547281

View attachment 547282

It can't do the amplifier any harm, and personally, I find it quite aesthetically pleasing.

Have a pleasant day, everyone

I'm planning to design custom feet for my amp and print them out of TPU. A little space for extra airflow can't hurt.

 

[ICIETDIYEUR]

People hi

With this in mind, I discussed with a friend—the head of O-NOORUS—how it was a shame that Class D amplifier manufacturers didn't consider the design of the PCB and its surrounding enclosure (right from the initial planning stage) by applying 'Venturi effect' principles (see here -> https://www.lenntech.com/venturi.htm) to improve cooling without relying on mechanical ventilation.

I would therefore like to use this post to encourage device designers to pursue this approach; it strikes me as a compelling avenue to explore, in addition to being an eco-friendly one
With a bit of 'luck', my message might be read or passed on by a company driven by the spirit of constant evolution—isn't that what we call SCIENCE?
Best of luck with your projects, everyone

PS: @SampleSizeOne, rather than the 'PLU', I would recommend the 'PC' version, which should be better suited to your project; with the BRZHIFI PAD-30, the chassis—which comes into direct contact with the feet—plays a role in dissipating heat.

 

[SampleSizeOne]

@ICIETDIYEUR Hi, I don't know what PLU is, and I assume with PC you mean polycarbonate? I have all filaments so basically the options are limitless.

TPU starts to deform around 60°C so I'm assuming it's safe as most amp cases don't reach 60°C. In case it's a problem I can switch to PC. I own a toolchanger printer so I could also combine materials, for example a rigid material which contacts the amp and a rubber material which contacts my desk.

I must add that I bought a FIIO Level 1 and didn't opt for the amp this topic is about. But I saw the feet you ordered and wanted to share I'm going to DIY mine.

If the design is a success, I'll share the files in a new topic so others can use it as well

 

[Ruediger]

TPU at 60 and polyactide at 65 deg. wouldn't be my choice for surface attachment with these devices.

PC is much better (140 deg.) but also much more difficult to print.

I think the stock feet and many aftermarket are simple TPU though. And there is no problem with them. Sometimes they come off because the glue gets too liquid, but that's a different issue.

 

[SampleSizeOne]

Like I said I can print any filament I want/need, why do people keep mentioning inferior PLA or PLU or whatever? I'm in the 3D printing bizz since 2012, I know what I'm doing

 

[ICIETDIYEUR]

People hi

My message today follows up on my post #169 (and those that followed) regarding the total capacitance installed on the original PCB for the 'PVDD' voltage.

I verified that the NTC (3D-20) would be suitable for these changes, and it is.

Here is the original NTC:

Here are the datasheets:

I therefore proceeded to replace the capacitors to achieve a total capacitance value as close as possible to the Texas Instruments specifications.

Here are my photos ->

Original capacitors:

Removal of the lower part of the housing (to access the welds):

The original capacitors removed:

PCB marking (capacitor values):

'Strangely enough,' I had correctly guessed that the choice of factory-installed capacitor values was a matter of economies of scale (understandable given the device's price), but even the originally specified value falls short of meeting Texas Instruments' recommendations.

The new capacitors I selected (IMPORTANT -> 10 mm dia. – 20 mm length):

The new capacitors installed:

Applying new thermal paste (Alphacool APEX) before reattaching the bottom part of the case:

The new op-amps (OPA1642) I selected:

The final result: the amplifier works perfectly with the new capacitors—which meet Texas Instruments' specifications—and the op-amps I selected based on the observations and conclusions I outlined earlier regarding the BRZHIFI PAD-30.

One final point: you are under no obligation—nor is it even necessarily recommended—to replicate the modifications I made to my amplifier, as the unit works correctly (apparently) in its stock configuration (provided this is confirmed by measurements from Amirm or another member, of course).

Note: I will not share my own subjective impressions (even though they were positive), as they lack the measurements needed to draw any objective conclusions.

However, since I carried out these modifications based solely on Texas Instruments' recommendations, I highly doubt they would degrade the device's performance—quite the opposite, in fact...

Have a great day, everyone

 

[mhardy6647]

PS: Sorry, but starting from "...'Strangely enough,' I had correctly guessed...", I was unable to remove the text highlighting, which makes reading it rather confusing.

So, here's what you do. If it's not too late, edit your post and turn off the bb code click on the "brackets" at top right.

Then seek and destroy the [ U ] and [ / U ] codes.
Easy-peasy, lemon-squeezy.

People hi

My message today follows up on my post #169 (and those that followed) regarding the total capacitance installed on the original PCB for the 'PVDD' voltage.

I verified that the NTC (3D-20) would be suitable for these changes, and it is.
Here is the original NTC:
View attachment 547781

Here are the datasheets:

View attachment 547780

I therefore proceeded to replace the capacitors to achieve a total capacitance value as close as possible to the Texas Instruments specifications.

Here are my photos ->

Original capacitors:
View attachment 547782

Removal of the lower part of the housing (to access the welds):

View attachment 547783

The original capacitors removed:

View attachment 547784

PCB marking (capacitor values):

View attachment 547785


'Strangely enough,' I had correctly guessed that the choice of factory-installed capacitor values was a matter of economies of scale (understandable given the device's price), but even the originally specified value falls short of meeting Texas Instruments' recommendations.

The new capacitors I selected (IMPORTANT -> 10 mm dia. – 20 mm length):

View attachment 547794

The new capacitors installed:

View attachment 547795

Applying new thermal paste (Alphacool APEX) before reattaching the bottom part of the case:

View attachment 547796

The new op-amps (OPA1642) I selected:

View attachment 547797

The final result: the amplifier works perfectly with the new capacitors—which meet Texas Instruments' specifications—and the op-amps I selected based on the observations and conclusions I outlined earlier regarding the BRZHIFI PAD-30.

One final point: you are under no obligation—nor is it even necessarily recommended—to replicate the modifications I made to my amplifier, as the unit works correctly (apparently) in its stock configuration (provided this is confirmed by measurements from Amirm or another member, of course).

Note: I will not share my own subjective impressions (even though they were positive), as they lack the measurements needed to draw any objective conclusions.

However, since I carried out these modifications based solely on Texas Instruments' recommendations, I highly doubt they would degrade the device's performance—quite the opposite, in fact...

Have a great day, everyone

PS: Sorry, but starting from "...'Strangely enough,' I had correctly guessed...", I was unable to remove the text highlighting, which makes reading it rather confusing.

 

[mhardy6647]

You can toggle the BB codes back "on" when you're finished.

 

[EJ3]

You can toggle the BB codes back "on" when you're finished.

OK, his trouble is fixed.
My trouble would start when I bought something that did not have the correct rated capacitors to begin with.
Then I have to calculate my time and labor (based on my pay at retirment) for getting the new correct caps and installing them and add it to the price of the item.
If that is less than buying one already done correctly, then maybe I made a good deal.
If not, I certainly screwed myself by making a bad deal.

 

[ICIETDIYEUR]

Hello all

A big thank you to @mhardy6647; I hadn't noticed that feature (what a fool I am... ).
My text is now in the right format (the one I had intended).

@EJ3
Your reasoning is correct.
However, in my opinion, a few clarifications are needed.
Most of the time, people buying Hi-Fi equipment make their choices based purely on subjective impressions (the device's aesthetics, or sound reproduction quality—often judged by reviews read online or opinions from retailers).
Thanks to Amirm, ASR allows us to take things to the "next level" by using measurements to verify whether a device lives up to the manufacturer's claims, and whether its performance is acceptable or free of issues—an approach that is entirely objective.
The thoughts shared in this post—along with the points you raised based on your own experience—operate on a different level, as they require a certain depth of knowledge in electronics, specifically regarding audio reproduction circuitry; this is far from the case for the average person, whereas the observations made by Amirm are more easily understood by everyone.

That said, and returning to the specific amplifier discussed in this post, replacing the capacitors isn't a financial issue—the cost is negligible—though it does require solid soldering skills.
Given its high-quality, well-thought-out design (chassis, PCB) and the fact that it features two TPA3255 chips (a rarity) at such a low price point, I believe the proposed modification is a smart choice

Subsequent measurements will demonstrate that this is a truly exceptional device.

Personally, I didn't notice any audible issues (it is worth remembering that measurements often exceed the limits of human hearing).

It is also worth noting the substantial power output; you don't need measuring instruments to appreciate just how powerful it is

The unit runs remarkably cool, especially considering it houses two TPA3255 chips—meaning it has twice the heat to dissipate at idle compared to most devices that use only one. In fact, it actually runs cooler

 

[Ruediger]

My trouble would start when I bought something that did not have the correct rated capacitors to begin with.

The amp is good to use as it is. It doesn't offer balanced and the psu is the most basic option, but it's good value for the money.

 

[EJ3]

Hello all

A big thank you to @mhardy6647; I hadn't noticed that feature (what a fool I am... ).
My text is now in the right format (the one I had intended).

@EJ3
Your reasoning is correct.
However, in my opinion, a few clarifications are needed.
Most of the time, people buying Hi-Fi equipment make their choices based purely on subjective impressions (the device's aesthetics, or sound reproduction quality—often judged by reviews read online or opinions from retailers).
Thanks to Amirm, ASR allows us to take things to the "next level" by using measurements to verify whether a device lives up to the manufacturer's claims, and whether its performance is acceptable or free of issues—an approach that is entirely objective.
The thoughts shared in this post—along with the points you raised based on your own experience—operate on a different level, as they require a certain depth of knowledge in electronics, specifically regarding audio reproduction circuitry; this is far from the case for the average person, whereas the observations made by Amirm are more easily understood by everyone.

That said, and returning to the specific amplifier discussed in this post, replacing the capacitors isn't a financial issue—the cost is negligible—though it does require solid soldering skills.
Given its high-quality, well-thought-out design (chassis, PCB) and the fact that it features two TPA3255 chips (a rarity) at such a low price point, I believe the proposed modification is a smart choice

Subsequent measurements will demonstrate that this is a truly exceptional device.

Personally, I didn't notice any audible issues (it is worth remembering that measurements often exceed the limits of human hearing).

It is also worth noting the substantial power output; you don't need measuring instruments to appreciate just how powerful it is

The unit runs remarkably cool, especially considering it houses two TPA3255 chips—meaning it has twice the heat to dissipate at idle compared to most devices that use only one. In fact, it actually runs cooler

Thank you kindly for the enlightening response:
One of the things that I personally look for when I am looking into a companies gear (not just audio gear) is the additional consideration of longevity under harsh (for audio gear) conditions. Having grown up in Charleston, SC with many large storms, flooding and power outages and brownouts (also the general vicinity of where I live now), I keep all of my electrical things on UPS battery setups (lights to refrigerators).
Then, in 2003, I became a resident of Saipan and lived through many a typhoon that put where I was at out of normal electrical power (with frequent brownouts and power outages: one being an island wide power outage for 4 months in Saipan [August 8–9, 2015: Typhoon Soudelor struck Saipan with estimated sustained winds of 130 mph. 40 people were injured on the island and damage totaled $20 million. 50% of the power distribution system was destroyed]).
Since, in Guam and the rest of the Mariana islands, typhoons occur 4-6 times a year (I lived there from October 2003-May 2018), resistance to funky power and ability to operate when there is no AC and the indoor temp is 95 and the humidity and indoor humidity is 100% is a toughness criteria that I have.
Yes, I know it's abnormal for the general population, but just as I expect my car to start up, I expect my audio (and video) gear to not over heat and, well, just work. Without me having to modify it. Now, naturally, I have quiet fans that I place on gear and I'll limit my run times under these conditions, but I will expect it to give me a CD's worth of music at background levels without failure. Then it'll sit for a few hours and run again to do the same. All my gear from the 1970's, 80's, 90's (ADVENT, NAD, PROTON, SONY, Dual and Technics [TT's], Frazier and Dahlquist speakers) have stood the tests of time and usage under these conditions. Since 2014, I have been having done the type of thing that you have done, upgrading to 'better' internal components as I get a chance to.
So, at least for a few hundred thousand people, the ability to survive is a criteria (even though it may not be on during the worst of things, it is still expected to opperate when things are a bit more normal, being powered by generator power, with AC/s just working to keep the indoor temps and humidity's under 90.
Because, for us that live in places like this, things not built to their own internal spec requirements, may only last 90 days. (mostly meaning things that are built on the very inexpensive side of the spectrum).
Honestly, none of my older audio gear has ever failed due to any issue, because, after 30 years of use, it gets refurbished with newer, better internals made to usually the same (or similar) specifications and better quality than was possible than they were originally built.
For those that are wondering, the following is a synopsis of typhoons (basically the same as hurricanes) during my time living there (many relate to Guam, but Saipan is only 130 miles away and usually gets a lot of what Guam gets):

• June 28, 2004: Typhoon Tingting's record-breaking rainfall in Guam produced severe flooding and numerous landslides throughout the island. A total of 57 homes were destroyed and another 624 were damaged. Crop damage on the island amounted to $500,000 with most of the farmers reporting total crop losses. One person died after being swept away along a flooded road. Total property damage totaled $6 million.[73]
• August 22–25, 2004: Typhoon Chaba's effects were mostly of minor extent in Guam. Despite moderate coastal inundation, beach erosion was minimal, and the heavy rainfall did not cause significant flooding. The cost of damage in Guam reached US$25,000. Four minor injuries occurred, and no deaths took place as the storm passed near the island.[74] However, on August 25, after Chaba had begun moving away from Guam, four people were swept to sea by strong rip currents caused by the departing typhoon. Though three of the four were later recovered and treated for injuries, the other person was never found.[75]
• August 31 – September 1, 2005: Typhoon Nabi dropped 115 mm (4.5 in) of rainfall in 24 hours on the island.[76] Flooding covered roads for several hours and entered classrooms at Untalan Middle School, forcing hundreds of students to evacuate. Damage in the region was estimated US$2.5 million.[77]
• December 10, 2008: Typhoon Dolphin produced 2.05 inches of rainfall in 48 hours starting on December 10 at 0100 UTC. Guam government officials reported that there was not much significant damage, with power outages around the island being sporadic which were primarily caused by falling trees and debris. There was also some minor flooding and beach erosion caused by storm tides.[78]
• September 9-10, 2009: Typhoon Choi-wan struck the island of Alamagan with estimated maximum sustained winds of 150 mph. All six residential structures on the island were destroyed, and all the inhabitants were evacuated by the 29th of September. Damage on Agrihan to the north was relatively minor. Total damage was estimated to be $30,000.[79]

2010s​

Typhoon Dolphin near Guam on May 15, 2015

• May 22–23, 2012: Tropical Storm Sanvu brought tropical storm force wind gusts and rainfall between 38–51 mm (1.5–2 in) to parts of Guam and the Northern Mariana Islands. However the only damage reported was on Guam where falling tree limbs caused an estimated $20,000 of damage to power lines.[80]
• October 16–19, 2013: Typhoon Francisco passed south of Guam and the Northern Marianas Islands. Gusts on Guam reached 84 km/h (52 mph) at Andersen Air Force Base. Wind gusts were not as strong when the typhoon approached the Mariana Islands for a second time. The typhoon also dropped heavy rainfall on Guam, peaking at 201 mm (7.9 in) at Inarajan. Damage in the region totaled $150,000 (2013 USD), and was largely limited to fallen trees.[81] There was a power outage on Guam during the storm, but the Guam Power Authority was able to quickly restore service; this was due to the first usage of newly installed meters that showed exactly where the cuts had occurred.[82]
• March 4, 2014: Typhoon Faxai's wind and an enhanced wind flow to the north of the typhoon generated large swells, which claimed the life of a woman.[83]
• July 11, 2014: Typhoon Rammasun only made landfall on Guam as a tropical depression, with winds much weaker than earlier anticipated.[84] However, under the system, the island received a substantial amount of rainfall, making that day the wettest in around 3 months. The United States territory received 25 to 50 mm (0.98 to 1.97 in) of rain.[85]
• March 15, 2015: Tropical Storm Bavi's circulation subsequently passed over Guam during March 15, with winds on the island barely reaching gale force on the island.[86] Within Guam, sporadic power outages and minor tree damage were reported, while waves on the uninhabited northeastern coast of Guam reached 20–30 ft (5–10 m) and were the highest waves recorded on the island in a decade.[87][86]
• May 14–16, 2015: Typhoon Dolphin produced the first typhoon-force winds on the island since 2002 during Typhoon Pongsona.[88] It passed between Guam and Rota, producing gusts of 171 km/h (106 mph) at Andersen Air Force Base on northern Guam. The winds left 40% of the island without power and left at least 3,300 people without water. The storm also dropped heavy rainfall, flooding Guam Memorial Hospital.[89] Dolphin damaged 390 houses, including nine that were destroyed, leaving 1,055 people homeless. With damage estimated at $10 million, the island was declared a disaster area.[90]
• July 5, 2015: Typhoon Chan-hom's wind gusts were recorded at 117 km/h (73 mph). Rainfall on the island totaled over 300 mm (12 in), based on radar estimates from the University of Guam,[91] and possibly as high as 410 mm (16 in).[92] On Guam, the storm caused minor power outages and flooding.[93]
• July 9, 2015: Typhoon Nangka passed over the island Alamagan with 145 mph (233 km/h) winds.[94] Rough surf and coastal flooding caused property damage estimated at $1 million in Guam.[95]
• August 8–9, 2015: Typhoon Soudelor struck Saipan with estimated sustained winds of 130 mph. 40 people were injured on the island and damage totaled $20 million. 50% of the power distribution system was destroyed.[96] Two people drowned near Guam in separate incidents due to rip currents produced by the storm.[97]
• August 15–17, 2015: Typhoon Goni impacted the territory with recorded sustained winds of 80 km/h (50 mph) and gusts up to 93 km/h (58 mph).[98] The storm's slow movement enabled heavy rain to fall over Guam, totaling 345 mm (13.58 in) at the NWS office near the center of the island;[99] this was enough rainfall to cause flooding, particularly on the western side of Guam.[100] The concurrence of heavy rainfall and gusty winds caused isolated power outages on the island, with floods temporarily shutting down the Tumon power sub-station. Increased water flow along the Ugum River shut down the Ugum Water Treatment Plant, leaving some residents without water access.[99]
• April 3, 2018: Typhoon Jelawat's remnants produced rip currents and strong surfs that drowned a woman, before she was rescued along with two other swimmers.[101][102]

 

[Ruediger]

With power outages and challenged electronics it's generally a good thing to have external psu. With luck only that brick dies.

But against things like fast spikes and dips in main voltage only a UPS helps.

I have my expensive stuff behind good UPS. But can't do that for everything. Surge protection and disconnect from the net must do for a power hungry home theatre f.e.
Everyone has choices (and plugs to pull when things get wild outside).

 

[EJ3]

With power outages and challenged electronics it's generally a good thing to have external psu. With luck only that brick dies.

But against things like fast spikes and dips in main voltage only a UPS helps.

I have my expensive stuff behind good UPS. But can't do that for everything. Surge protection and disconnect from the net must do for a power hungry home theatre f.e.
Everyone has choices (and plugs to pull when things get wild outside).

I had a line transformer blow on a telephone pole outside my home on James Island, SC and it took out the speaker relay and right channel (all was repairable) in one of my NAD 2200s that was plugged into the 1500+ watt UPS (which also was taken out). The other 2200 and other smaller stuff that was plugged into it were fine. As were the other UPS's and their plugged in gear. The event created a flash inside the house that I saw in a 4 step lower room about 50 ft. away. So, yeah, there is no guarantee that your stuff will be saved but you can pretty much guarantee that it won't be saved without one.
On the other hand, on Guam, when we had a 12-14 hour power outage that my wife and I had not noticed (I was on the computer and my wife was taking out the trash at 3 AM [our normal routine before going to bed between 4 & 5 AM at the time]). When my wife came back from the dumpster, she said "How come there are no streetlights, no one else has lights but we do?" I said: "You know those black boxes I have in every room that you hate? They are why we have power when no one else does." She answered "Oh, so now I understand what a great idea they are!". Over the next few days she found ways to actually make then look better in how they were situated and created ways to distract from their appearance so as to make them less noticable.

 

[EJ3]

With power outages and challenged electronics it's generally a good thing to have external psu. With luck only that brick dies.

But against things like fast spikes and dips in main voltage only a UPS helps.

I have my expensive stuff behind good UPS. But can't do that for everything. Surge protection and disconnect from the net must do for a power hungry home theatre f.e.
Everyone has choices (and plugs to pull when things get wild outside).

I haven't done home theatre since 2001, strictly 2.2 or 4.2 since then. My city home (on it's own lot) has all 20 amp outlets, with 2 on the wall where the stereo gear. At one of the other homes on this continent we have, well, when you only have 30 amp service, you're a bit limited.

 

[Ruediger]

I had a line transformer blow on a telephone pole outside my home on James Island, SC and it took out the speaker relay and right channel (all was repairable) in one of my NAD 2200s that was plugged into the 1500+ watt UPS (which also was taken out). The other 2200 and other smaller stuff that was plugged into it were fine. As were the other UPS's and their plugged in gear. The event created a flash inside the house that I saw in a 4 step lower room about 50 ft. away. So, yeah, there is no guarantee that your stuff will be saved but you can pretty much guarantee that it won't be saved without one.

I have some good/better experience with higher grade sinewave UPS that have the outlet on their generated power all the time. Versus more simple online or offline UPS, that more or less just represent a "fast switch".

Rare incidents and catastrophic weather can't be foreseen. But the general power problems in an area would have a certain flavor. Where one or the other level of UPS is called for.

On the other hand, on Guam, when we had a 12-14 hour power outage that my wife and I had not noticed (I was on the computer and my wife was taking out the trash at 3 AM [our normal routine before going to bed between 4 & 5 AM at the time]). When my wife came back from the dumpster, she said "How come there are no streetlights, no one else has lights but we do?" I said: "You know those black boxes I have in every room that you hate? They are why we have power when no one else does." She answered "Oh, so now I understand what a great idea they are!". Over the next few days she found ways to actually make then look better in how they were situated and created ways to distract from their appearance so as to make them less noticable.

I remember some time back (way before class D got popular) in the middle east, at noon the generator shuts off for 1 hour for cooldown and oil change. Just off, nothing special about it. No equipment whatsoever had a problem with that occuring every day. Not the TV, AC, the 40kg Kenwood amp or the fridge size Kenwood speakers. Nothing ever died from that.

But today at work we are plagued with high/low voltage and especially the fast changes through these conditions. We need an army of UPS to save our basic computers. And an array of high grade separated, buffered power to save our server racks and backbone. Really annoying.

Anyway, today a basic 1500w online UPS is so cheap. I recommend to get something like it for private hifi of value. It's not 100% secure, but way better than just surge protection. And I heard these fantasy insurances that come with some brands, they really paid out in clear cases.

 

[EJ3]

I have some good/better experience with higher grade sinewave UPS that have the outlet on their generated power all the time. Versus more simple online or offline UPS, that more or less just represent a "fast switch".

Rare incidents and catastrophic weather can't be foreseen. But the general power problems in an area would have a certain flavor. Where one or the other level of UPS is called for.



I remember some time back (way before class D got popular) in the middle east, at noon the generator shuts off for 1 hour for cooldown and oil change. Just off, nothing special about it. No equipment whatsoever had a problem with that occuring every day. Not the TV, AC, the 40kg Kenwood amp or the fridge size Kenwood speakers. Nothing ever died from that.

But today at work we are plagued with high/low voltage and especially the fast changes through these conditions. We need an army of UPS to save our basic computers. And an array of high grade separated, buffered power to save our server racks and backbone. Really annoying.

Anyway, today a basic 1500w online UPS is so cheap. I recommend to get something like it for private hifi of value. It's not 100% secure, but way better than just surge protection. And I heard these fantasy insurances that come with some brands, they really paid out in clear cases.

In Saipan they had a daily schedule for a rolling power blackout. Mine happened to be from noon to 2 PM (which the A/C would not get the temp back down until the next morning if it is down for 2 hours at that time of the day).
But, fortunately, the apartment I had was on the third floor of a bank. And their generator would kick on instantly (the A/C never even flinched) every day, whether the bank was open or not. So 2 hours of free power daily! I did not know of this benefit when I rented the place.

 

[Ruediger]

Generator backup - what a luxury.