[viivo]

I'm unable to find a single genuine review from an audio or headphone site for this amp that's been available for 5 years.

For the price - they can be had for as little as $79 - I have trouble believing the specs and features listed on the official site. It obviously doesn't have real balanced inputs.

Does anyone have experience with this amp? Is there a reason no real review site has touched it?

 

[tomb]

I see no reason why the XLR balanced input is fake. Some very highly reputable amplifier manufacturers will tell you the entire amplifier is balanced, because of this: it allows connections to a balanced source. The key is that it is not fully differential, nor can it be, with TRS outputs.

For the price, it looks like a reasonable value and probably could compete in the price range of Schiit's Magni.

The real problem is the specs. Unlike you, I can believe them, because they are not good for an amplifier - at all.
S/N at -96 dB for an amplifier is quite frankly, atrocious. The Magni, for instance, achieves 110 - 121 dB, depending on the gain setting. Those are not small differences in amplifier S/N. A difference of 14 - 24 dB in S/N for an amp is monumental. Even at that, Bellari is not quoting a reference for that S/N. (Neither does Schiit for the Magni, so we have to assume they're both doing it at 1kHz, where everything looks good.)

Further, the frequency response is guoted as +or- 3dB! 3dB is a typical frequency deviation spec for speakers! The only differences are that the ends of the spectrum are much wider on the Bellari, but that's meaningless outside the audio band, anyway. It still means that it can vary +or- 3dB from 20-20kHz, and that's horrible for an amp, at least a solid-state one. Note the Magni's frequency response spec deviation is +or- 0.02dB over 20-20kHz! That's more than a hundred-fold better performance over the audio band. (I'm not trying to sell Schiit - they certainly don't need it from me.)

When Bellari talks about "flat" vs. "enhanced," (their extra button on the front panel), it should be with tongue planted firmly in cheek. JMHO ...

 

[Elegiac]

I emailed them twice asking for specs, and they never responded.

 

[ADUHF]

Here are two reviews of the HA543, fwiw...

 

[ADUHF]

I wanted a good low-cost amp with both balanced XLR and unbalanced RCA inputs for my 250-ohm DT-770s and other headphones, and it has served that purpose very well for the two years I've owned it. I wish it came with a little better power supply, and was a bit heavier. But those are my only minor gripes so far.

I hear no audible noise with it in my setup. But wouldn't recommend it for IEMs, or some other very high sensitivity headphones. It has no gain adjustment on it, other than the basic volume control.

 

[ADUHF]

When Bellari talks about "flat" vs. "enhanced," (their extra button on the front panel), it should be with tongue planted firmly in cheek. JMHO ...

Enhance boosts the treble and bass, sort of like a loudness button on receivers. The effect is too pronounced for my headphones though. So I always leave this feature off.

If you're using headphones that are all mids, with little or no bass or treble, then perhaps Enhance might be worth a try. (?) I prefer a more linear/flat response though.

 

[ADUHF]

I see no reason why the XLR balanced input is fake. Some very highly reputable amplifier manufacturers will tell you the entire amplifier is balanced, because of this: it allows connections to a balanced source. The key is that it is not fully differential, nor can it be, with TRS outputs.

I mostly use the RCAs. But have also tried the XLRs, and they seem to work ok. The XLR inputs are balanced, but the amp is not, according to the Rolls/Bellari tech.

 

[ADUHF]

I emailed them twice asking for specs, and they never responded.

I have never tried emailing the folks at Rolls who make these. But I have talked to them on the phone a number of times, about this and other products they make. And they have always been very helpful. They only have one person who does techsup though. And his hours are somewhat limited.

 

[tomb]

Enhance boosts the treble and bass, sort of like a loudness button on receivers. The effect is too pronounced for my headphones though. So I always leave this feature off.

If you're using headphones that are all mids, with little or no bass or treble, then perhaps Enhance might be worth a try. (?) I prefer a more linear/flat response though.

I mostly use the RCAs. But have also tried the XLRs, and they seem to work ok. The XLR inputs are balanced, but the amp is not, according to the Rolls/Bellari tech.

So this thread was actually an attempt at marketing this amp, because you're basically just repeating what I've said and not addressing the real issues with their specs. Good luck with that.

 

[ADUHF]

So this thread was actually an attempt at marketing this amp, because you're basically just repeating what I've said and not addressing the real issues with their specs. Good luck with that.

The OP asked about reviews, and if anyone had experience with the amp, so I responded and gave some of my impressions of the product. Others may have different experiences though. And I'm not recommending that anyone buy it. It has done a good job for my needs, but may not fit other people's.

 

[ADUHF]

This is a low impedance solid state amp btw. I believe it is less than 1 ohm on the headphone outputs. (That info also comes from the Rolls tech.) So it will probably also not do very much to warm up the bass on open-back headphones that are more rolled off in that frequency range, just fyi. At least not with the Enhance option turned off.

I don't know if these are the sort of specs others are seeking, but here is a link to the amp's manual which has a few more details, fwiw...

https://rolls.com/doc/manuals/manual_HA543.pdf

 

[tomb]

This is a low impedance solid state amp btw. I believe it is less than 1 ohm on the headphone outputs. (That info also comes from the Rolls tech.) So it will probably also not do very much to warm up the bass on open-back headphones that are more rolled off in that frequency range, just fyi. At least not with the Enhance option turned off.

I don't know if these are the sort of specs others are seeking, but here is a link to the amp's manual which has a few more details, fwiw...

https://rolls.com/doc/manuals/manual_HA543.pdf

Yes - those are the same specs I referenced that were bad - 96 dB S/N (with no reference), and +or-3 dB on the frequency response, which as I said, is how most companies spec speaker response (+or-3 dB).

It's not as low impedance on the output as you suggest. The fact that the power output is specified at 62 ohms means it has a much high output impedance than 1 ohm or less. Otherwise, it would produce more power with loads lower than 62 ohms.

That said, if the price is really that cheap (the MSRP is not), then there's nothing wrong with trying it out. A lot more money is wasted around here on equipment that's worse.

 

[ADUHF]

Howdy again, tomb.

Here's a photo of my HA543 and Beyer DT-770, shot with my flip phone, so you and others here will know I'm being truthful when I say that I have one of these. I can't remember exactly when I bought it, but think it was in the Fall of 2020, during the pandemic. Which probably means I've been using it for more than 2 years.

I have used other inexpensive 4-way headphone amps from places like Guitar Center and Sam Ash. But they were higher in impedance, and did not produce as good sound quality as the HA543. So I believe this is the best headphone amp I've owned so far... And it is my only one at the moment.

Before I bought the HA543, I was using a compact mixer (a Mackie Mix8) as my headphone amp, and my EQ.

 

[ADUHF]

Yes - those are the same specs I referenced that were bad - 96 dB S/N (with no reference), and +or-3 dB on the frequency response, which as I said, is how most companies spec speaker response (+or-3 dB).

It's not as low impedance on the output as you suggest. The fact that the power output is specified at 62 ohms means it has a much high output impedance than 1 ohm or less. Otherwise, it would produce more power with loads lower than 62 ohms.

That said, if the price is really that cheap (the MSRP is not), then there's nothing wrong with trying it out. A lot more money is wasted around here on equipment that's worse.

I appreciate some of your insights on this, tomb. And understand that some of the specs on this unit are a bit confusing... And I'm not sure I can sort them all out for you.

If you have questions about the HA543 specs, probably the best thing to do is to contact the tech support guy at Rolls. And maybe he can clarify some of them a bit better.

My understanding from speaking to him though is that the HA543 is 1 ohm (or less) on the headphone outputs. And the power rating of 326 mW/side, 652 mW/channel in the manual is based on a 62 ohm load.

I have no way of verifying any of this. But I also have no reason to doubt it either, based on my experience with the unit. Because it seems to have more than enough juice to drive my lower sensitivity 250 ohm DT-770's. And the electrical damping and distortion seems better than some of the cheaper, higher impedance amps and mixers (with built-in headamps) I've used in the past. And because sub-ohm SS amps aren't really that exotic or hard to come by anymore.

I don't know if the 92 dB SNR spec in the manual is correct. But if it is, then it could be an issue for some IEMs and higher sensitivity headphones, as I mentioned previously.

According to the manual (and the tech), the amp can work with a fairly wide range of headphone impedances. But it seems to be designed more for home or studio use, rather than for higher sensitivity IEMs, and other portable headphones, which are more prone to noise. So I would be more hesitant to use it with those... As I mentioned before, it has no gain switch. Only the single volume control.

A low SNR would not be a factor in my setup though because of the headphones I'm using. There is no audible noise from the HA543 with my lower sensitivity 250-ohm DT-770's. It is dead silent to my ears with these headphones, even in a quiet room.

Re frequency response... the HA543 sounds pretty flat to me, with the Enhance feature turned off. But I also have no way of measuring or verifying that. I use EAPO to EQ the FR on my headphones though. And if necessary, it can also be used to fixed the nonlinearities in an amp. So whether the amp is perfectly flat or not is not a huge concern to me. Both the manual and the Rolls tech say it's flat with the Enhance feature turned off though, fwtw.

Happy New Year btw!

 

[tomb]

Happy New Year to you, too.

Sorry to harp on a few things here, but it's important that people reading this don't get misconceptions embedded in their audio equipment thinking processes. This is not just about the Bellari.

The meaning of the word "flat" depends on frequency response, not whether a mfr says so or not. The amplifier is the one device in the entire string of an audio equipment setup that has the governance over a flat frequency response. It is the single device that can be made with the flattest frequency response - not sources, not speakers, not headphones. If it's not flat, you don't have a prayer of correcting with the rest of the system.

Noise also doesn't have to mean noise that you can readily "hear." There is an entire band of noise that is sub-audible in terms of hearing it separately, but it has a very real effect on the rest of what you do hear. Bass with noise issues can be muddy, light, or simply non-existent. Or in the case of 60 Hz hum, bass can be over-emphasized. All of this can be because of noise, even if you don't hear the noise itself. *

To be fair, I said the Bellari is inexpensive enough that trying it out is probably worth the purchase. It sounds like it works well for you. It can probably work well for many others, too.


* A simple example: Imagine that an amp produces 60 Hz hum at about -100 dB, but the rest of the S/N ratio is down at -120dB. You can't hear that hum (or anything else) when it's below ~ -90dB. While listening to your music, it hits a drum beat with a 60 Hz spike of 50 dB over background sound. However, the problem will be that your amp will produce 50 dB + 20 dB, or 70 dB at 60 Hz, relative to the rest of the frequency response of the amp. You will definitely hear that. It also won't sound as good, because that's noise added to the drum hit, not a bigger drum hit.