Fosi Audio CA30 4-ch power amp WITH HPF & LPF

[john61ct]

Stumbled on this, been out a while, IMO deserves more investigation, I may sponsor having one sent to @amirm to verify their specs.

Infineon IR4322 Class-D chip - why not TPA3255 ?

Yes designed as a car amp, runs off 12V my primary use case is off-grid partly "nomadic" so would set up power conversion to use in normal S&B homes as well

Problems with using car stereo amp in a house.

I have a pair of low power sub amps and a car stereo amp that I would like to use to make a practice amp for guitar/bass for a student musician. Anybody have any thoughts how I should proceed? (If at all?)

www.audiosciencereview.com

4 channels per small unit, roughly 100W per channel into 4Ω at 1% THD, 140+W into 2Ω

"up to" 320W x2 bridged into 4Ω

so lots of value and flexibility for subs, multi-channel, 2–8Ω speakers and 4Ω subwoofers bridged

crossover control on all channels, 50 – 250 Hz either LPF or HPF or FR bypass

high-level (speaker) and low-level RCA inputs

claimed noise level of ≤200 μV, THD "as low as" 0.008% @5W, SNR > 100 dB SINAD ≥80 dB

input sensitivity 0.75 – 8 V !

damping ≥140 (100 Hz @ 10 W)

I saw "4-channel, 3-channel, or 2-channel bridged modes" !! but the manual only shows 2- channel, if anyone can explain how to do 3/4-channel please do!

https://cdn.shopify.com/s/files/1/2251/7913/files/CA30_User_Manual.pdf?v=1770711447

Introducing CA30: HiFi Sound, Now on the Road

Launching on February 9, the CA30 will mark our first step into the world of car amplifiers. CA30 is designed to bring HiFi-grade tuning, compact design, and efficient performance into the automotive space. With CA30, we aim to deliver clean, powerful sound on the road—without unnecessary...

fosiaudio.com

...

 

[xanalog]

Thanks for the post and links, @john61ct,

I bought a FOSI CA30 when introduced, just to motivate me to replace the old 6.5" OEM speakers in one of our cars.
The 2 subs, in the rear-deck, have their own dedicated amp. The front-door speakers are coaxials, as are the rear-side speakers.
There did not seem to be much interest to test them here, when I asked this February.

OT: After doing more than a few hours of research into what crutchfield offered for <2.35" speaker depth; against what aliexpress offered.
I wagered on coaxials for $100/pair, from aliexpress.
I hope I don't end up being a bozo, for gambling!

 

[lewdish]

I'm glad to see car audio finally getting Class D Amp tech from hifi w/ transparency on their designs. I'm sure theres a few that already meet similar spec butr the pricing is outstanding for this, I'd def love to see Amir review it, and I hope Fosi will make more premium models as well.

 

[xanalog]

I hope Fosi will make more premium models as well.

Not many cars today have just 4 speakers, anymore.
It'd be nice to have a 6-channel version. Possibly, in a larger form-factor with similar user-controls (even w/a small fan).

 

[Head_Unit]

I saw "4-channel, 3-channel, or 2-channel bridged modes" !! but the manual only shows 2- channel, if anyone can explain how to do 3/4-channel please do!

Well usually channels 1&2 bridge, which would then make a 3-channel amp. Further bridging channels 3&4 would then make a 2-channel amp.

As for the amp, the dollars per watt seems better than competitors at Crutchfield, though not astoundingly so. I also wonder how this would fare in a car, especially hammered into hard clipping, compared to a big brand like Rockford or Alpine who do an awful lot of testing which I rather doubt Fosi does.

 

[xanalog]

3-channel = CH1@Left + CH2@Right + CH3/4@Bridged.

 

[john61ct]

Well usually channels 1&2 bridge, which would then make a 3-channel amp. Further bridging channels 3&4 would then make a 2-channel amp.

As for the amp, the dollars per watt seems better than competitors at Crutchfield, though not astoundingly so. I also wonder how this would fare in a car, especially hammered into hard clipping, compared to a big brand like Rockford or Alpine who do an awful lot of testing which I rather doubt Fosi does.

I have no interest in "car audio" as such.


I am not trying for lowest dollars per watt but if you know of more powerful units with just as flexible built-in crossover controls - or bandpass even better

at high-SQ and such good value, I'm all ears.

DC power input is important to me, so long as under 60V.

 

[john61ct]

Not many cars today have just 4 speakers, anymore.
It'd be nice to have a 6-channel version. Possibly, in a larger form-factor with similar user-controls (even w/a small fan).

I prefer the small size and modular approach. Definitely want fanless.

Mine is not an automotive use case, lots more channels, and I will just get multiple units to get to the # of channels I end up with.

 

[xanalog]

Definitely want fanless.

In a car -unlike a home- environment, absence of a fan is not essential.
A vehicle's cabin temperatures can exceed 130F (~155C). In such a mobile environment, enemy #1 becomes heat.
Being able to conduct/dissipate internal heat uniformly to exterior surfaces is but the first half of thermal management.

FOSI advises:

...For optimal cooling, please install the amplifier with the fins facing upward, maintain 5–10 cm of clearance, and do not cover the fins during operation.

But FOSI fails to note that the CA30 should not be mounted over carpeting.

Since an(y) mobile amp will be stowed away (possibly under a seat) where air-flow may not exist; an internal fan becomes a win-win-win-win
(direct air flow, lower temperatures, longer hardware life and muffled fan noise).

 

[xanalog]

DC power input is important to me, so long as under 60V.

?
FOSI states:

"Power and ground cables must be AWG #4"

 

[john61ct]

Sorry I have no idea why you would be surprised by that last.

Nor what you don't understand about 60V - I was ofc talking about a requirement for other, "even better" reco'd model amps.

 

[john61ct]

In a car -unlike a home- environment, absence of a fan is not essential.

As I have stated many times now, mine is not a car use case, I just was stating MY preference. Not a deal breaker though, so long as I can't hear it from arm's length in silence.

I have plenty of ventilation, everything is mounted on shelves in an open 19" rack.

I haven't had carpeting anywhere since childhood (yuck)

 

[john61ct]

Is Fosi usually willing to send @amirm an eval unit?

If not and he is interested, anyone willing to sponsor a drop ship? I would, but funds are tight ATM

 

[Ropeburn]

Oh, this looks interesting indeed. Mobile/off grid use? Looks perfect if it delivers. Even viable at home if you have a 12V solar system anyway (I do), can run it directly from the battery. Price is nice too:

?
FOSI states:

Of course they'll state that. If this thing draws say 400W, that's like 28A at 14V. Hefty power cables are a must.

 

[Redacted]

I'm glad to see car audio finally getting Class D Amp tech from hifi w/ transparency on their designs. I'm sure theres a few that already meet similar spec butr the pricing is outstanding for this, I'd def love to see Amir review it, and I hope Fosi will make more premium models as well.

Class-D has been the staple of car stereos for many years - or are you saying the designs they use are really getting better?

 

[Redacted]

I think high-power car amps use internal DC-DC converters to get the power, but really, I'd be surprised if the measured performance-per-dollar made car audio worthwhile in a domestic setting - there's a lot of excellent, big value amps available now....

 

[john61ct]

I think high-power car amps use internal DC-DC converters to get the power, but really, I'd be surprised if the measured performance-per-dollar made car audio worthwhile in a domestic setting - there's a lot of excellent, big value amps available now....

The low cost is a factor, but being DC powered is required in my case.

Please link to better alternatives if you know any

 

[Redacted]

There were various ones reviewed on here, such as Fosi, Aiyima, Topping etc al. and dozens on Amazon. I'm not going to do the research on this, but I know many do use DC power supplies via a wall-plug PSU, which will be DC out.

By performance, I meant SINAD, not wattage, so if you want high power these domestic amps may not have the power of car amps but be careful with the specs. If say, 200W RMS at 1% distortion or more is OK (it is in cars) then fine, but otherwise compare power outputs at the same distortion level - apples for apples.

Maybe you want to use a 12v battery for said amps? If so, I'd look at inverters than can drive amps needing mains. I have spent a lot of time living off 12v leisure batteries through an inverter and my stereo & guitar amp & TV ran fine!

Also, since many home amps need 48v, there is always the possibly of using your own DC-DC to get 48v from a 12v battery:

https://www.ebay.co.uk/itm/127708775745?var=0&mkevt=1&mkcid=1&mkrid=710-53481-19255-0&campid=5338268676&toolid=10044&_trkparms=ispr=1&amdata=enc:1oTaeNlP-QLGOrT6qjZctOQ33&ff=11&loc_physical_ms=1006983&adtype=pla&customid=Cj0KCQjw2YDQBhD_ARIsAE1qeSdDY0FTONekTud6KQ2iTjaW1R1O4iKychaEYjdn7I6u-T3i6jzclk8aAgFQEALw_wcB&gclid=Cj0KCQjw2YDQBhD_ARIsAE1qeSdDY0FTONekTud6KQ2iTjaW1R1O4iKychaEYjdn7I6u-T3i6jzclk8aAgFQEALw_wcB

 

[Mark185]

I bought one for a 12 volt portable stereo rig in a Harbor Freight Apache 3800 case. I wanted something better than the many builds out there using Wuhzi Audio amps based on TPA3116 and TPA7498 chips. The Infineon chip used in the CA30 is at least as good as the TPA3255. Infineon is a European company and they purchased International Rectifier and all of their intellectual property regarding mosfet Class D amp designs. IR was the company that originally solved the big problems with Class D amplifier output stages and the high distortion they were originally known for a decade ago. Nothing wrong with choosing an Infineon chip here. Helix also has an amp based on this chip.

So for the portable build, I used Morel MW144 drivers for the low end and am trying different drivers for the range 500 Hz and up. The Morels are very good midbass drivers and a distinct step up from most of the builds out there. I started with CDT Audio wideband drivers in small metal pods mounted to the sides of the case. I am also going to try One Audio 3" wideband drivers and expect I will like them more. Initially, I am using the Fosi built in filters which only go up to 250 Hz. I am also programming a TinySine DSP board for active crossover and PEQ for the final solution.

Initial impressions. The Fosi delivers. The sound quality is very good and the amp drives the inefficient Morel drivers very well. The CDT Audio widebands are a bit bright on the top end and need EQ but that is not the fault of the Fosi amp. I should add that I have a collection of high performance SQ 12 volt amplifiers dating back to the original Nelson Pass designed Soundstream D200 and including good amps from Alpine and ARC Audio. The Fosi holds its own against those far more expensive amps and works well in my battery powered application. I use 2 12 volt 16 amp hour LiFePO4 batteries in parallel and they run this rig for about 8 hours. I am using a Teyes CC3 android head unit with optical SPDIF output going to an SMSL DAC.

i should add that with this application, most of my listening has been nearfield without all the background noise present in an automobile application. Problems with noise and/or distortion will be far more apparent in this use case and the amp is clean.

 

[Redacted]

Are you in a hideout in the woods?