Bricks List: 36V & 48V Power Supplies (for Fosi, Aiyima etc.)

[TurtlePaul]

I can't help but think that the power supply is an obvious avenue for upgrade for these evolving tpa3255 amps. Has anyone looked into a dedicated switching ps like this one? Tia

Yes, you can get more power with a higher power supply. I am not sure what you mean by “dedicated switching PS” as almost all of the TPA3255 amps use external switching power bricks. That one seems relatively expensive.

Fosi V3

In the test of the Fosi V3, the Fosi 32 V power supply was able to achieve 62 watts x 2 while the 48 V supply reached 141 watts x 2 with the same 4 ohm load. Power is the major benefit - the TPA3255 has pretty good power supply noise rejection and these switching PSUs seem to generally have acceptable regulation in the audible band.

 

[SWSL]

Amateur looking for advice on power upgrade for Fosi BT30D Pro:

I bought the BT30D Pro to power a pair of JBL Studio 30 "bookshelf" speakers. I'm disappointed with the volume output. I have to turn the volume knob up to 9 to reach a modest "party" volume level.

Amateur here too. I have the BT30D pro and have run it on it's standard 32v PS and also an 8 amp 24v PS. Either way, it is party loud on the two different sets of speakers I have*. We do use the sub amplifier in it, so that's drawing part of the power and affecting the volume perception as well.

I think that turning it up to 9/10 reflects a somewhat low input. We tend to run it at about 9 o'clock (7/10?) at dance parties. But f it sounds good, I wouldn't worry about the knob position.

Still, a PS with a few more V and plenty more amps should help. And it can serve you for other amps. That's what's great about the separate PS. Buy a good one and then save money buying your next amp w/o a power supply. Ali-express will have these amps w/o and with.

Probably the best 30Dpro-compatible power supply would be a Meanwell LRS-350 36. $40. In general, I am seeing that we can get more watts per $ out of a 36V than a 48V. I guess that max V is a factor. But I kinda doubt it's worth the difference in cost and 36 is max v for the 30Dpro.


*One set is sealed 6 ohm 6" and the other is ported 6 ohm 5"

 

[Roland68]

Tiptoeing in as a long time reader/first time poster to ask: (if this is not the optimal spot for this question, feel free to redirect me. Google led me to this thread

I can't help but think that the power supply is an obvious avenue for upgrade for these evolving tpa3255 amps. Has anyone looked into a dedicated switching ps like this one? Tia

Don't be dazzled and save your money, they are completely normal, often cheap, switching power supplies in an aluminum housing.
If you want to spend money on a better switching power supply, then take something tried and tested, such as a Mean Well from the HRP series and wire it yourself. Otherwise, an electrician can do it for you. These power supplies are of industrial quality and have been tested.
In addition to the 5-year guarantee, these power supplies can deliver up to 250% power for a short period of time (max 5 seconds), making any oversizing unnecessary. A 300 watt HRP beats any cheap 450 watt power supply with a TPA3255 amplifier.

 

[asimze]

@Roland68 What abot Mean Well LRS serie? What is diference between HRP and LRS??? Is LRS serie good for upgrading PS? TIA!

 

[TurtlePaul]

@Roland68 What abot Mean Well LRS serie? What is diference between HRP and LRS??? Is LRS serie good for upgrading PS? TIA!

The LRS series seem to have tiny cooling fans. Fans are obviously not ideal for audio use.

 

[Roland68]

@Roland68 What abot Mean Well LRS serie? What is diference between HRP and LRS??? Is LRS serie good for upgrading PS? TIA!

LRS is the low profile version of the RS series. They are cheaper power supplies and far removed from the HRP series in terms of quality and performance. An LRS would have to be twice as large as an HRP to achieve the same top performance. The service life of the HRP series is also significantly longer.

@TurtlePaul
The fans in the HRP power supply series are not a problem for the audio sector. If you are drawing so much power that the fan should turn on, your music has reached a level where you can't possibly hear the fan. Not even if they are only 10cm away.

 

[jooc]

... I bought the BT30D Pro to power a pair of JBL Studio 30 "bookshelf" speakers. I'm disappointed with the volume output. I have to turn the volume knob up to 9 to reach a modest "party" volume level.

The JBL Studio 30's are 6-Ohm and suggested power is 125W.
I'm running about 60' of 14 gauge cable to the speakers in a 14'x20' room.

Something is odd about this - are you sure there's not another node or piece of software in the chain that has the volume set low? You should have volume on everything at max until the last element of the chain where you actually adjust the volume to taste in the room, usually that's at the amp. But you have to make sure everything before that doesn't have volume turned down.

I have this stack in about a 15x30 room, and I can't get the volume up past about half way before it's far louder than anyone in the house wants it WiiM mini > smsl su-1 dac > fosi bt30d pro > triangle borea bro3

 

[doug s.]

No, your theory is incorrect. The problems with highs in these amps is attributable to the load dependency of the output filter.

Rather than a flat frequency response regardless of speakers used, these amps have droop or boost at the highest frequencies depending if the load is less than or greater than ~6 ohms in this band.

The solution is to implement post-filter feedback, which allows the amp to see the droop or boost and correct for it while also reducing any distortion from the output inductor. Texas Instruments (who makes the chips in this amp) has a white paper on how to do this, but Fosi hasn’t successfully implemented it in a shipping product yet.

ok, i have a few questions for you (and whylee, if you're reading this) - based on whylee's impressions, and what you said:

- does the v3 amp have the same issues as the bt30d, re: boost/droop at the highest frequencies?
- do you think a meanwell hrp p/s would help, per later p/s comments?
- if speaker is actually 6 ohms pretty consistently, does this become a non-issue?
- if i use a v3 amp on a fullrange driver operating only from 175hz to 7khz, is this a non-issue?
- if i use a v3 amp on a ribbon tweeter operating only from >7khz, is this a non-issue, assuming ~6 ohms, and/or ability to adjust its volume as the set-up is a fully active quad-amped setup? the ribbon gets its own amp/volume control.
- would a meanwell hrp-150, operating at at 36v (rated 150w/4.3a) be a good solution, or should i just spring for the hrp 200 or 300? (the 200 is rated 200w/5.7a at 36v; 4.3a/48v; the 300 is rated 330w/7a at 48v). and the hrp-150 is rated 6.5a at 24v; so it could work here as well - according to fosi the v3 can run at 24v. but can it run at 4.3a?

note the speakers i'm considering driving are ~100db-efficient for the full range driver, and >95db-efficient for the ribbon tweeter. so max power reqs are the least of my worries.

thanks!

doug s.

 

[Roland68]

ok, i have a few questions for you (and whylee, if you're reading this) - based on whylee's impressions, and what you said:

- does the v3 amp have the same issues as the bt30d, re: boost/droop at the highest frequencies?
- do you think a meanwell hrp p/s would help, per later p/s comments?
- if speaker is actually 6 ohms pretty consistently, does this become a non-issue?
- if i use a v3 amp on a fullrange driver operating only from 175hz to 7khz, is this a non-issue?
- if i use a v3 amp on a ribbon tweeter operating only from >7khz, is this a non-issue, assuming ~6 ohms, and/or ability to adjust its volume as the set-up is a fully active quad-amped setup? the ribbon gets its own amp/volume control.
- would a meanwell hrp-150, operating at at 36v (rated 150w/4.3a) be a good solution, or should i just spring for the hrp 200 or 300? (the 200 is rated 200w/5.7a at 36v; 4.3a/48v; the 300 is rated 330w/7a at 48v). and the hrp-150 is rated 6.5a at 24v; so it could work here as well - according to fosi the v3 can run at 24v. but can it run at 4.3a?

note the speakers i'm considering driving are ~100db-efficient for the full range driver, and >95db-efficient for the ribbon tweeter. so max power reqs are the least of my worries.

thanks!

doug s.

If an amplifier can drive 4 and 8 ohm speakers, then of course it can also drive 6 ohms. Constant impedance is not a problem, the opposite can be.
The question of the frequency range for the amplifier does not arise either. There are enough pieces of music that only contain low or high frequencies. Nobody thinks about whether to play a test tone at, for example, 12kHz or 1kHz. The amplifier has to amplify what it gets, it doesn't bother if something isn't there.

If your information about the efficiency is correct, then the HRP will be completely oversized at 150 watts for the treble and 300 watts for the bass range. These power supplies can provide over 200% power for a short time (5 seconds), others max 110-130% for a maximum of 1-2 seconds.

First just order a V3 for the bass range and test whether the noise floor for the high frequency range is ok.

 

[doug s.]

If an amplifier can drive 4 and 8 ohm speakers, then of course it can also drive 6 ohms. Constant impedance is not a problem, the opposite can be.
The question of the frequency range for the amplifier does not arise either. There are enough pieces of music that only contain low or high frequencies. Nobody thinks about playing a test tone at, for example, 12kHz or 1kHz. The amplifier has to amplify what it gets, it doesn't bother if something isn't there.

If your information about the efficiency is correct, then the HRP will be completely oversized at 150 watts for the treble and 300 watts for the bass range. These power supplies can provide over 200% power for a short time (5 seconds), others max 110-130% for a maximum of 1-2 seconds.

First just order a V3 for the bass range and test whether the noise floor for the high frequency range is ok.

i was asking about the impedance question, and at what frequency, because turtlepaul mentioned frequency response droop/rise when load is less than/greater than 6 ohms.

i understand the fact that i don't need the power provided by the hrp's i mentioned, which is why i am thinking the hrp-150 would be more than sufficient; just wanting to make sure that, for example, 36v and 4.3a would work well, or would 24v at 6.5a be better? and, along those lines, maybe even the hrp-100 would work at 24v/4.5a?

but honestly, an over-spec'd p/s is not of great concern; pricing does not vary all that much. i'm more interested in sound quality. and, while i realize the v3's are way more power than i'd ever need for my application, there's no reason i'd ever use the v3 amps in this system for low end - i have a pair of crown xls2000's driving the bass bins below 175h and the subs below 50hz. i'm just interested in determining whether these would be good enough to replace my 5wpc, but extremely energy inefficient amps, driving my full range and tweeter drivers.

thanks,

doug s.

 

[TurtlePaul]

The falloff or peak in high frequency response is caused by the interaction between the output filter in the amp (an inductor and capacitors) and the impedance of the speakers. Different power supplies have no impact.

 

[doug s.]

The falloff or peak in high frequency response is caused by the interaction between the output filter in the amp (an inductor and capacitors) and the impedance of the speakers. Different power supplies have no impact.

thanks, turtlepaul.

do you know at what frequencies this falloff or peak takes place? ie: will a driver operating from 175hz to 7khz be affected or not? or only above 7khz? and if impedance is flat, in either case, then it won't have the peak and/or falloff? from this graph, it sees like both drivers would have this issue.

and, re: power supplies, would any or all of the above mentioned supplies work? ie: hrp-100/150/200, at any or all the voltage/amp ratings i mentioned? i know the hrp-300 will work. (any advantage in sonics, unrelated to the frequency falloff or peak issue, using higher amp than the 5a that fosi suggests?)

thanks again,

doug s.

 

[amix]

I'd also like to buy a Fosi Audio ZA3. The listing on eBay is approx. 100€ without a power supply, which I could maybe substitute with one of my own but I am a bit scared, since, at the same voltage, it has a much higher current rating as the 48V supply shipped by Fosi Audio and I have very expensive speakers, that I do not want to burn.

It's a Meanwell HLG-600H-48A with two rails: one is 48V/12.5A, the other one is 5V/0.5A. Also, there's an inscription reading: "For operation LED modules only"

Here's a picture:

Can this be used? It's 600W and my speakers are rated IEC 170W with 6ohms impedance.

It seems to have a feature to lower voltage and current a little, so, probably I will also try this.

EDIT
I just realised, that the PSU has three rails. Two actual power supplies and one 5V for remote control. Which makes me pretty happy, since this way I may go dual mono on the same PSU while paying 240€ for both amps.


Thanks!
Andreas

 

[asimze]

I also decided to purchase a new Mean Well LRS-350-48 power supply. Next week I expect the power supply to arrive, so I will report my experiences. Basically, class D amplifiers must have a stronger power supply, to have power reserves, and that's why I decided on 350 W and not 240 W. How many amps the system draws depends on the amplifier, the power supply is only available there until it overheats!!! Of course, there are other protections on the power supply.

 

[amix]

How many amps the system draws depends on the amplifier

That's what I expected but there is still the slight fear, that something might go bonkers on the amp's side and it happily sucks out those 600W from the PSU just so it can offload them into my poor speakers. But probably the amp would rather burn before the speakers. Still, I am scared ;-).

I also wonder why there is a warning to only use it with LED modules.

 

[joqueval]

That's what I expected but there is still the slight fear, that something might go bonkers on the amp's side and it happily sucks out those 600W from the PSU just so it can offload them into my poor speakers. But probably the amp would rather burn before the speakers. Still, I am scared ;-).

I also wonder why there is a warning to only use it with LED modules.

Hello.
About Mean Well, I can only say positive things.
I use the 24V versions for LEDs and 24V motor power.
In that environment they are reliable and thousands have been installed in recent years.
I had pending testing with the 24v 320W model.
This week I will contact the area distributor to gather information.
I think the warning will be because the LEDs are very stable in terms of consumption, with audio there may be a variation in demand

 

[amix]

About Mean Well, I can only say positive things. [...] This week I will contact the area distributor to gather information.

Absolutely! Meanwell is a high quality manufacturer, throughout all price ranges. May I kindly ask you to come back with his reply regarding of the use of an LED PSU for audio applications, that would be awesome .

I think the warning will be because the LEDs are very stable in terms of consumption, with audio there may be a variation in demand

Interesting. I wonder why the warning, though, since delivering constant power seems more stressful, but then, electronics are full of ifs and thens. ;-)

 

[joqueval]

Absolutely! Meanwell is a high quality manufacturer, throughout all price ranges. May I kindly ask you to come back with his reply regarding of the use of an LED PSU for audio applications, that would be awesome .

Interesting. I wonder why the warning, though, since delivering constant power seems more stressful, but then, electronics are full of ifs and thens. ;-)

Hello.
This morning I made a couple of calls discussing the case.
I have also sent the query directly to Mean Well, to have direct information.
As I discussed with one of the distributors, the differences could be found in the waveform of the output signal.
Although linear sources are more recommended for audio, switched type sources have prevailed.
These sources are designed to operate 24 hours a day and offer a constant output voltage to avoid variations in the light offered.
As soon as I have news I will inform you.

 

[doug s.]

Hello.
This morning I made a couple of calls discussing the case.
I have also sent the query directly to Mean Well, to have direct information.
As I discussed with one of the distributors, the differences could be found in the waveform of the output signal.
Although linear sources are more recommended for audio, switched type sources have prevailed.
These sources are designed to operate 24 hours a day and offer a constant output voltage to avoid variations in the light offered.
As soon as I have news I will inform you.

i investigated meanwell; i think the hrp series would be the one to get. i looked into the HRP-300-48. i could have gotten a pair shipped for $110, which i think is a good deal. (i'd have to add in a few dollars for appropriate connectors.) but for my use, i think it's a bit overkill. if you have inefficient speakers that dip to low impedance, it might be worth the added coin. i was happy to get a pair of the aiyima 48v 5a (6.3a peak) power supplies for the a07a max amps for $60 shipped.

ymmv,

doug s.

 

[joqueval]

Hello.
I have received a response to the query about sources
As we imagined, there is no problem in using it for audio, although they recommend some specific models.
In some cases you can choose not to use models with IP protection, since if they are used indoors it is not necessary.

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Hi Jose,

Yes, you could use HLG/ELG models as well.

However, please note that safety certifications are for LED driver.

You could also consider other PSU such as below for audio application.

Please contact with local distributor.

HEP-320-MEAN WELL EUROPE Switching Power Supply

GST280A-MEAN WELL EUROPE Switching Power Supply
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