Starke Sound AD4.320 Review (Multichannel Amplifier)

[nstzya]

The Fiera 4 specifications are red flagging skeptics (like me).

Here is why:


- Power specifications do indicate frequency range, which should include 20Hz to 20kHz and bandwidth limiting applied.
- 1% distortion is too high
- SINAD at 1 watt and less, where most of us listen, is not specified.
- SNR is only given at maximum power, where most amps do best, not in typical listening

It looks like another case of specification cherry picking.
Actually, less informative than many AVRs.

- Rich

Rich, did you mean to write, “power specifications do NOT indicate frequency range…”? I have to agree with you about cherry picking. It would seem that they continue to have chosen to not abide by FCC regulations (or convention) and that these power ratings once again most likely represent purposeful exaggerations.

Also low gain/sensitivity remains - no increases there. So if you want to drive directly (without preamp) from DAC/Streamer/Disc players (and some AVR’s) you’ll not even get anywhere close to the rated (would “claimed” be a better adjective?) power.

 

[tomchr]

- Power specifications do NOT indicate frequency range, which should include 20Hz to 20kHz and bandwidth limiting applied.

Power specs usually don't. The power is measured mid-band (usually at 1 kHz).

- 1% distortion is too high

Is it? Many Class D amp guys measure the max power at 10 % THD. Some of us measure at 0.1% THD or below.

- SINAD at 1 watt and less, where most of us listen, is not specified.

I would argue that SINAD at 1 W isn't particularly useful. THD at 1 W would be more meaningful or better yet show me a harmonic spectrum for 1 W output. But few do that.

- SNR is only given at maximum power, where most amps do best, not in typical listening

Yeah. A measurement of the noise floor would be better. But that's not commonly done. Also, had they measured SNR with an 8 Ω load they could possibly have gotten an even higher number as the amp is likely able to produce slightly higher voltage into a lighter load.

It looks like another case of specification cherry picking.

How so? To me it looks like "we need a spec table but we don't want to put in any effort" with a bit of marketing blather (fan noise, true balance (sic) circuit) added.

Output current: 16.5A/33A (bridge) and higher output power into 2 Ω (BTL) make no sense. I suspect the "BTL" mode isn't actually bridged but rather two channels operating in parallel.

Tom

 

[tomchr]

Also low gain/sensitivity remains - no increases there. So if you want to drive directly (without preamp) from DAC/Streamer/Disc players (and some AVR’s) you’ll not even get anywhere close to the rated (would “claimed” be a better adjective?) power.

Possibly true. Though if you have a pro source you'd have no issue driving the amp to clipping. Either way. Does it matter that you can't drive the amp to clipping as long as you can make it play loud enough? Lower gain in the power amp results in a better gain structure and lower overall system noise. That's a good thing in my view.

Tom

 

[audio_lover]

Just got their newsletter in my inbox that links to some measurements as well:

SoundStageNetwork.com | SoundStage.com - Starke Sound Fiera4 Amplifier Measurements

www.soundstagenetwork.com

https://hometheaterhifi.com/reviews...-four-channel-class-d-power-amplifier-review/

 

[Martynet]

Hey guys,
New model just released... Will you look into it? Maybe they fixed all the issues above

Fiera4 - 4 Channel Amplifier

The Starke Sound Fiera4 Our ongoing pursuit of better sound quality led to the 2nd-generation, Class D, Fiera4 with proprietary power and amplifier modules. It is a unique 4-channel amp that can be bridged for 2 or 3-channel operation using simple switches on the rear panel. Upgrade the sound of...

shop.starkesound.com

 

[nstzya]

Possibly true. Though if you have a pro source you'd have no issue driving the amp to clipping. Either way. Does it matter that you can't drive the amp to clipping as long as you can make it play loud enough? Lower gain in the power amp results in a better gain structure and lower overall system noise. That's a good thing in my view.

Tom

Fair enough, Tom. I did not realize the gain of 21.5 is for the balanced (XLR) input (forgiveable given the spotty specifications table).

In fact, the measurements by Soundstage seem to be quite a bit more consistent with the claimed specifications this go round - a positive outcome.

I’d be interested in any expert analysis or comment on the measurements.

 

[tomchr]

Scrolling down the list of measurements by Soundstage I'm still not seeing anything to indicate that the manufacturer is cooking the books or otherwise hiding something. In fact, the amp meets the published specs just fine. So any ambiguity in the specs or lack of specs is probably because the spec table was thrown together last minute.

That said, I'm not overly impressed by this amp. The THD+N vs output power curve has a really odd shape. I wonder if there's a change in operating mode at around 100-200 mW. The IMD is pretty high too. I'm concerned by the peaking in the frequency response curves for the higher impedance loads, though that's pretty common for Class D amps. 150 µV RMS output noise is pretty high. That said, some amps with five-figure price tags perform worse.

I'd be interested in why Amir only measured about half the rated output power, though. Measurement error?

Tom

 

[voodooless]

I'd be interested in why Amir only measured about half the rated output power, though. Measurement error?

I think it’s time for you to read the whole thread Have fun

 

[tomchr]

Entirely possible. But who has time for that?

Tom

 

[amirm]

Entirely possible. But who has time for that?

Tom

Company admitted the shortfall in power claiming some units were shipped with wrong transformer. I tested another sample with the same problem. Meanwhile Audioholics was sitting on a sample with the same issue. Once the news of that came out company pulled the amp from their offerings.

 

[tomchr]

Whoops!

Tom

 

[voodooless]

Company admitted the shortfall in power claiming some units were shipped with wrong transformer. I tested another sample with the same problem. Meanwhile Audioholics was sitting on a sample with the same issue. Once the news of that came out company pulled the amp from their offerings.

You missed out entirely on the juice bits of them claiming you don’t know how to do measurements and some other shenanigans

 

[tomchr]

A note at the top of Post 1 explaining that the company shipped a defective sample with a link to updated measurements of a good sample would be nice. Mistakes do happen even though this particular mistake certainly doesn't put the manufacturer in any sort of good light.

Tom

 

[voodooless]

A note at the top of Post 1 explaining that the company shipped a defective sample with a link to updated measurements of a good sample would be nice. Mistakes do happen even though this particular mistake certainly doesn't put the manufacturer in any sort of good light.

There never was a good sample though

 

[tomchr]

No? The one measured by Soundstage seems to be just fine. We can argue that its performance isn't stellar, but at least it meets the published specs.

Tom

 

[amirm]

No? The one measured by Soundstage seems to be just fine. We can argue that its performance isn't stellar, but at least it meets the published specs.

Tom

That is a new product and not the one I reviewed.

 

[nstzya]

No? The one measured by Soundstage seems to be just fine. We can argue that its performance isn't stellar, but at least it meets the published specs.

Tom

Tom,

I don’t think that you realize that this is an entirely different amp model than the original with different power supply, etc.

 

[tomchr]

Ah. My bad. I did indeed get lost in the numerology.

Missing the specified power by a factor of two (even on the second – and supposedly fixed – sample) is hard to explain. This is one of many reasons we need valid measurements to be part of every review.

Tom

 

[nstzya]

That said, I'm not overly impressed by this amp. The THD+N vs output power curve has a really odd shape. I wonder if there's a change in operating mode at around 100-200 mW. The IMD is pretty high too. I'm concerned by the peaking in the frequency response curves for the higher impedance loads, though that's pretty common for Class D amps. 150 µV RMS output noise is pretty high. That said, some amps with five-figure price tags perform worse.

Tom

You might be interested in the review at:

Starke Sound Fiera4 Four-channel Class D Power Amplifier Review - HomeTheaterHifi.com

Class D audio is becoming more common, with many new receivers having their multiple channels powered with Class D amplifiers. Starke...

hometheaterhifi.com

Quite complete discussion of the design. And goals. And compromises. And how it was designed by sound and not necessarily by measurements. With the ability to subjectively sound “smooth” and “take the edge off” digital sources. Not exactly fidelity in the ASR sense, but the reviewer likes it. And provides extensive discussion supported by loads of measurements/graphs.

 

[tomchr]

No argument there. But the Fiera4 does meet its specifications in the HomeTheaterHifi review - at least from what I can tell from a quick glance. It still shows a wonky THD+N vs output power profile and rather high IMD ... just as in the Soundstage review. I also noticed that HomeTheaterHifi uses an AP SYS2xxx-series analyzer, which has higher THD+N than the current APx555B. So if the measurements by HomeTheaterHifi are worse than those by Soundstage (or Amir if he gets his hands on a Fiera4) that's likely why.

I will openly admit that I didn't read much of the text. I usually don't because the text usually doesn't add any information I can't glean faster from a graph. I did notice that the SMPS supposedly puts out "pure DC without ripple" (which is impossible). The reviewer then explains how a Class D amp works, which I already knew. Again, no information added. "Smooth, takes the edge off"... Yeah. Whatever. I'd rather that the amplifier would just amplify but that's me.

I'm still not seeing a Grande Conspiracy. I see a manufacturer who has put out a product that meets the published specs. It's just not a very good amp by modern standards. Oh no! Somebody call the cops!!

I usually don't read the comments either, but did happen to notice that the first comment was from someone here who raged about how the company had previously committed fraud. That's a pretty serious accusation that doesn't exactly put ASR in a good light.

I agree that the manufacturer could have handled the AD4.320 "half-power" disaster much better in many different ways. I also agree that how that disaster was handled says something about the company and influences my desire to buy from them. But do we need to play Bash the Manufacturer?

The reason I got sucked into this thread was that someone perceived some underhanded action in the way the specs were presented. That's something I've come across before and I really struggle to understand it. If a manufacturer shows their product from its best angle, they're cooking the books. If they're not publishing my pet spec, they must be hiding something and they always hide something for nefarious reasons. It is impossible that the manufacturer didn't publish data for my pet spec because they consider that spec to be irrelevant or ill-defined (take headroom for example). If the reviewed sample performs better than spec, the manufacturer must have shipped a golden unit for the review. How am I as a manufacturer supposed to work within this environment?

Tom