• These commercial threads are for private transactions. diyAudio.com provides these forums for the convenience of our members, but makes no warranty nor assumes any responsibility. We do not vet any members, use of this facility is at your own risk. Customers can post any issues in those threads as long as it is done in a civil manner. All diyAudio rules about conduct apply and will be enforced.

ZOUDIO AIO4CH: 4-channel amplifier with DSP and Bluetooth

@zerokelvin99
1) Basic limiting (digital range compander) should be available from the next update of the config tool

2) Harmonic bass alignment is only available for large orders unfortunately. The chip supports it, but its too difficult to integrate in my software.

@Joe
Wow, nice! It is indeed amazing how many features it combines in one.
 
with chinese 12v 6A for "hifi" psu the treble gets a little scratchy compared to very smooth with 15V Mascot 10A, mean to try MeanWell 24V some time soon.

I bought a cheap "garbage" $20 shipped Chinese 24V switching PSU off ebay and found the "scratchy" (for lack of better term) sound on my high pass as well. I've been using a Liteon 19V laptop brick which definitely sounds better than this more recent purchase... So I quit the 24V unit.

I can only guess this has something to do with control loop stability of the LED strip intended PSU, or the switching frequency. I'd say PSUs from a more reputable manufacturer (who may care more about optimizing control loop stability) will give better SQ performance.

Next, I ordered a linear PSU @ 24V, 6A from ebay to try. I paid <$30 for it, shipped, which was competitive with the cost of a pair of 12V, 7Ah batteries. Obviously the batteries have no control loop to offer a less than ideal source impedance over frequency to this amp. I would think they'd make an ideal power supply.

Hopefully, the linear will perform best. For anyone interested, here's the one I picked Acme Electric DC Power Supply Unit, SPS Model 120-24/28, Used, Warranty | eBay - I'll report back on SQ with the 6A linear sometime after it arrives...

I've no idea if the voltage difference (19 vs 25) had anything to do with the SQ perceived difference between the two switching PSUs - but I'm glad to have the 19V Liteon connected back up. The thoughtful inclusion of the reverse polarity protection diode at the PSU input is appreciated! :razz:

Bottom line - choose carefully the PSU you're going to run this amp with; dont dismiss it SQ wise without having first run it using a good quality PSU! If there's a sweet spot voltage input wise regarding SQ, I'll gladly set the linear there so long as its pass transistor / heat sink can take it -
 
Last edited:
I have a plan to get this thing up & running sometime this week.
Looking forward to finally trying it out, was waiting for some DC - DC converters of various make. Got a couple of them in-hand right now, and a Meanwell 15v lots of amps PSU and a small array of batteries just in case.
Not sure what I'll do about a box for it, that's the current holdup. Want to do this at least semi-right.

Nevertheless, if you make some TAS3251 boards like this, I'll take at least 4 if the price is not too bad.
 
My point with PSU that are under powered under the recomended max 24v 7A are you got early distortion if you crank it up.
Yes I hear it.
Why don't max it and get headroom?
As I read the ripple is lower in SMPS when you don't have to max it.
What sounds better linear or SMPS?
Maybe more bottom with my 19v 5A linear PSU compared to my cheap 24v 6A who shutts down after 4A I read.
But I don't have golden ears so no offend.
A boost converter good be a good thing if it sounds better or get more power but it's alwayes at a coast.
Not to blame all of you who hearing things that I don't but if you are the few people that have golden ears and hear things that normal people don't hear you maybe choosed another amp?
 
I don't understand who you're intending the comment for. I can use voltage regulators to step down to 24-25v from a higher voltage PSU, batteries, linear or SMPS got lots of various voltages... Was just thinking this is a good opportunity to try voltage boosters to use a decent quality 15v SMPS I have that should be a good match. If I want to keep it simple I'll just use a single 12v SLA or if all else fails just two in SLA series with a standard vreg down to the same 25v.

I am going to aim for ca 25v regulated and about 8-10A either way, no point for me to settle with lower voltages.

What's better between linear and SMPS: Depends on design and implementation.
Both have the potential to be fantastic, mediocre or rubbish. And everything in between.
 
That's over $200 just for the power supply? I thought the amp was supposed to be the expensive part...

We'll see if I can hear any difference with the $30 linear I have coming from ebay.

One consideration is I leave the power supply part energized 24/7 and just use the push-on rotary control on the Zoudio. So the power supply needs to be OK with quite close to Zero load current. The laptop power supply is all set to be able to do that, so it's pretty convenient that way. The linear is this industrial thing, probably meant to run 24/7 also and probably has zero issue with no load. Or is that no issue with zero load.

KaffiMann - I used a case like this; Enclosure Electronics Project Case Instrument Circuit Shell 200 x 175 x 70mm Box | eBay

Pretty much just used the stick-on feet that came with the amp, made holes for the power LED, Volume/Function knob and the 3.5 mm stereo input. There's plenty of room to mount speaker connectors in the back, but I wired the 4 cables directly to the amp. The light plastic enclosure with the light amp in it moves when you press on the knob to turn it on! Better than nothing.
 
That's over $200 just for the power supply? I thought the amp was supposed to be the expensive part...

We'll see if I can hear any difference with the $30 linear I have coming from ebay.

One consideration is I leave the power supply part energized 24/7 and just use the push-on rotary control on the Zoudio. So the power supply needs to be OK with quite close to Zero load current. The laptop power supply is all set to be able to do that, so it's pretty convenient that way. The linear is this industrial thing, probably meant to run 24/7 also and probably has zero issue with no load. Or is that no issue with zero load.

KaffiMann - I used a case like this; Enclosure Electronics Project Case Instrument Circuit Shell 200 x 175 x 70mm Box | eBay

Pretty much just used the stick-on feet that came with the amp, made holes for the power LED, Volume/Function knob and the 3.5 mm stereo input. There's plenty of room to mount speaker connectors in the back, but I wired the 4 cables directly to the amp. The light plastic enclosure with the light amp in it moves when you press on the knob to turn it on! Better than nothing.
Thats my point, an $200 PSU is not worth it, I bought it 2012 when reading all people raving about difference in PSU and sure I got better bottom than my cheap power adapter but my cheap 24v 6A $30 SMPS sounds the same.
 
Not sure if I understand what you're complaining about. You're saying that you achieved sub-par performance using a sub-par psu, and that using a psu that has good rail stability under load is very important...?

I'm sorry, but that is merely stating the painfully obvious. The recommended minimum spec for a 24v psu is 7 amps. It's a given that you'd run into issues on transients when using a 24v 4a capable brick. I would expect that if you want this 4ch amplifier to perform properly on peaks with a mixed 8ohm + 4ohm load (2*30w 8ohm + 2*60w 4ohm), you need an at the very least 200w capable psu at 24v. Not including losses.
 
The PSU that seems to me like a natural fit for this board is the meanwell RSP-200-24

I could get one from ebay for $50. I already have a Meanwell 24V, it's like 40A (depends on ambient temperature) - but it has two, screamin' little 40mm fans in it that run full speed as soon as you plug it in. Worked great to test the electric lawn mower I picked up at a yard sale...

The "junk" one was supposed to be a knock off of the Meanwell, and I tagged the seller because the unit received did not match the listing photo - it had a fan:mad: The unit is supposed to provide 10A continuous. I'm certain, most assuredly, that I was probably drawing <1A when I decided I didnt like the sound. The bass sounded fine, but the treble was "scratchy" as another thread contributor has noted. I ended up paying $10 for it - to ultimately cartwheel into my power supply junk box...

Just talkin', ya know? Sometimes I read something here, while obvious to most, that helps me out - like the quoted post provided the Meanwell part number - and this occurs without the OP having any knowledge of that happening for someone. It may be so going forward.
 
Last edited:
Understanding the highest voltage gives the best headroom for transients, I do read in this thread folks are running this amp at other than the highest voltage it can take as input.

I've also read that this amp "knows" what the input voltage is and adjusts itself accordingly to provide the best SQ performance. A "how it works" feature I suppose only known to the TI engineers who designed it - or - I could be completely wrong and such optimizations need to be done externally. In any case the I believe the register containing a word-representation of the sensed input voltage value is there and readable over I2C...

So, I'm interested if there's a "sweet spot" regarding input voltage where this amp sounds best. Not just the intuitive "It's going to sound best at max input voltage". Maybe, maybe not - who knows what's going on if the amp really does comp for input voltage all on its own. A selling feature that makes sense to have been designed into it - the amp sounds the same (or better?) as battery voltage supply naturally declines with use.
 
Last edited: