Apollon 1ET6525SA ST Amplifier Review

[dukeside]

I prefer the case and minimal branding of the Buckeye version. The cottage aspect is a feature, not a bug.

 

[Jukka]

View attachment 503654
one click away. I don't need a new amp. I don't need a new amp

Hey if you don't need it, I've got a good delivery address that you can use!

 

[Jukka]

An ASR member had presented the audibility thresholds for amplifier and DAC measurements. If we stick to the information shared below, we should be almost certain of making the right choice at the right price.
Understand that the closer you get to the so-called "strict" threshold, the better the performance will be.

Thresholds :

Lenient
Dynamic range, linearity: 96 dB
THD, IMD: -66 dBFS / 0.05%
Noise: -85 dBFS / 0.005%
SINAD: 85 dB
Crosstalk: -60 dBFS
Jitter: -110 dBFS, -100 dBFS around the main tone
Frequency response: ±0.5 dB
Channel balance: 1 dB
Output impedance: 2 ohms

Strict
Dynamic range, linearity, SINAD: 120 dB
THD, IMD, noise, crosstalk, jitter: -120 dBFS / 0.0001%
Frequency response, channel balance: ±0.1 dB
Output impedance: 0.16 ohms

I must add that if one is building active speakers without resistance (resistors or coils) in between amp and driver (subwoofers, woofers and maybe midrange drivers), one will want even lower noise level, because the driver sensitivity is roughly 10-20 dB more than in a passive-xo speaker and the hiss is real. This is one reason why I'm not using PA electronics for home.

 

[David_M]

I must add that if one is building active speakers without resistance (resistors or coils) in between amp and driver (subwoofers, woofers and maybe midrange drivers), one will want even lower noise level, because the driver sensitivity is roughly 10-20 dB more than in a passive-xo speaker and the hiss is real. This is one reason why I'm not using PA electronics for home.

But why would the location of the amplification circuitry matter, if it's in the amp with passive xovers in the speaker or within the speaker with active DSP filters/xovers? Noise of said amplification would still be just as annoying or utterly inaudible.

 

[Badunn]

find out what loudness you listen to with a UMIK-1, put the numbers into a calculator for your speakers and then find out how much power you'll need.

In general, people dont listen above 90 db. Some people are a bit goofy and push it but i personally, for example, listen at 70-82 db on average. 88 db is where i push everything to the max and then get scared of the output.

Also, it depends on the recording as well, are you listening to modern recordings with squished dynamics or highly dynamic tracks? What sort of dynamic peaks do you like, how loud do you want em?

I'd personally say anything above 80 db sinad is transparent but sinad itself isnt enough, an amp could have 100 sinad and be load dependent or something, you need to check everything else.

This guide is good as a rule of thumb. Honestly, if you get a reasonably good and NON-broken modern dac/amp, and assuming no other thing is a problematic variable like low bitrate bluetooth, some eq turned on by accident or something, you wont hear that much of a difference. Even if you do, it'd be 97-99% similar and in a blind test, the difference would be so minute you'd just not care enough. The speakers and how they perform are still the bigger factors. FR is the most easy to identify one. We don't really know what level of speaker distortion is genuinely problematic cus it depends on the frequency, we're less sensitive to lower frequencies for example.

Loads of variables in transparency but the key is to just get something good enough, because our body is smart and we can adapt to small oddities, even if they show up on graphs those wont affect you much in the real world.

That's a good response - thank you.

 

[Tangram]

Regarding pricing for exports to the USA:
There is no price doubling for shipments to the United States. The base (net) product price remains the same. However, shipping costs to the USA are higher than within Europe, which is expected due to overseas air transport. In addition, the United States has introduced a 15% import tariff, which is a government-imposed charge outside of our control. Even with this tariff included, U.S. customers typically pay less in total than EU customers, who are subject to 20–22% VAT on top of the net price.
Regarding product images:
Updated product photographs are currently in preparation and will be added to our website very soon.

Could you advise if you offer a trial period, say 30 days. Thank you.

 

[Jukka]

But why would the location of the amplification circuitry matter, if it's in the amp with passive xovers in the speaker or within the speaker with active DSP filters/xovers? Noise of said amplification would still be just as annoying or utterly inaudible.

Simply because active speakers, especially in DIY, quite often have nothing but wire between amplifier output and speaker driver input, and that gets you the full efficiency of the driver and that efficiency is so much greater than passive xo that combined dac+amp noise will be audible. I can hear noise from all of my speakers that are connected to amplifiers this way. My tried amps: NC400, NC122MP, NC100HF, TPA3255. Drivers vary: 1" CD+horn (110 db/W/m), 10" midrange (99 db/W/m), 15" woofer (97 dB/W/m), 18" subwoofer (95 dB/W/m). All DACs are 100+ SINAD. Only balanced interconnects. The hiss is there.

With passive crossovers, the crossover sits in between amplifier output and speaker driver input. Passive crossovers usually introduce resistance into the signal path (crucially after power amplifier, which is the last step that actively produces more noise) and that decreases noise, among other things. That's why passive speakers have lower sensitivity than their drivers alone. They usually range from 85 to 91 db/W/m, which is a lot less than what's above. The resistance in passives for high frequency drivers is usually from level matching resistors and for midrange and all woofers it's usually a result of lowpass filter coils and some equalization filters. DSP-Active speakers can and should have some passive xo components and one reason is to reduce hiss.

 

[lordhumungous]

I guess with this kind of performance (and other purifi and hypex based modules) it’s end game, like we have it for DACs.
What more do we want? Let’s focus on speakers to reduce their distortion!

Well said.

 

[theREALdotnet]

Why no golfing panther for this amp?

 

[Fledermaus]

Soccer panther is the golfing one's European counterpart

 

[David_M]

Simply because active speakers, especially in DIY, quite often have nothing but wire between amplifier output and speaker driver input, and that gets you the full efficiency of the driver and that efficiency is so much greater than passive xo that combined dac+amp noise will be audible. I can hear noise from all of my speakers that are connected to amplifiers this way. My tried amps: NC400, NC122MP, NC100HF, TPA3255. Drivers vary: 1" CD+horn (110 db/W/m), 10" midrange (99 db/W/m), 15" woofer (97 dB/W/m), 18" subwoofer (95 dB/W/m). All DACs are 100+ SINAD. Only balanced interconnects. The hiss is there.

With passive crossovers, the crossover sits in between amplifier output and speaker driver input. Passive crossovers usually introduce resistance into the signal path (crucially after power amplifier, which is the last step that actively produces more noise) and that decreases noise, among other things. That's why passive speakers have lower sensitivity than their drivers alone. They usually range from 85 to 91 db/W/m, which is a lot less than what's above. The resistance in passives for high frequency drivers is usually from level matching resistors and for midrange and all woofers it's usually a result of lowpass filter coils and some equalization filters. DSP-Active speakers can and should have some passive xo components and one reason is to reduce hiss.

But that doesn't make sense, with all due respect. A 10' - 30' speaker cable from an amp to the passive speaker will pick up far more noise and interference (as I can attest) than a short, less than 1-foot cable from the internal amp to the respective driver. The active speaker amps take a balanced signal from an XLR cable from an external preamp. As you know, this cable can be hundreds of feet long, without picking up noise and damaging the signal. All necessary filtering for each internal driver is done by DSPs inside the active speaker. Whatever noise is governed by the SNR of the internal amps, and making low-noise amps is no longer an issue nowadays (within reason).

Also, it should be noted that your speakers are ultra-sensitive speakers, so its easier to hear noise than one would on less sensitive speakers, as expected. Having an internal passive crossover will not mitigate that problem.

 

[Sokel]

But that doesn't make sense, with all due respect. A 10' - 30' speaker cable from an amp to the passive speaker will pick up far more noise and interference (as I can attest) than a short, less than 1-foot cable from the internal amp to the respective driver. The active speaker amps take a balanced signal from an XLR cable from an external preamp. As you know, this cable can be hundreds of feet long, without picking up noise and damaging the signal. All necessary filtering for each internal driver is done by DSPs inside the active speaker. Whatever noise is governed by the SNR of the internal amps, and making low-noise amps is no longer an issue nowadays (within reason).

We can't blanket all actives, a lot of them have external amps, like mains monitors for example like 8381A

(and lots of others, it would be a pain to unmount from a wall for service, let alone no ventilation in there, thermals would go nuclear with their multi-kW amps)

Sane practices apply to them as well.

 

[Matias]

Why no golfing panther for this amp?

ASR Panthers

Headless Panther The fear of audio companies - this headless panther signifies a poorly engineered product. Measurements of the product typically show bottom-of-the-pile performance and/or false claims by the product vendor. Sometimes the product is broken in a way that lends it unusable or...

www.audiosciencereview.com

 

[amirm]

But that doesn't make sense, with all due respect. A 10' - 30' speaker cable from an amp to the passive speaker will pick up far more noise and interference (as I can attest) than a short, less than 1-foot cable from the internal amp to the respective driver.

That is not what he is talking about. He is correctly saying that any noise that the amplifier has, will become far more audible in an active configuration where the speaker drives the driver directly. Whereas in passive speakers, there is a crossover network which causes losses which result in noise being less audible. Length of wire and such is not material in this context.

 

[Sokel]

Truth be told, another thing to point out in favor of Apollon's buffer is its very healthy (stated) 100 kOhm input impedance.
This kind of immunity is rare these days.

 

[PristineSound]

@Apollon Audio any news on a possible NCx1000 offering, preferably in the Lux case.

 

[Joe Smith]

Beautiful unit! Again, more power than anything I need, but I appreciate the engineering and the styling of the amp. Inner layout is a thing of beauty.

 

[SKNG]

Prices on www.apollonaudio.com are excluding VAT and shipping. On the other hand - at least until a couple of days ago - Apollon offered a 10% discount.
But even at around 1.275 € (plus shipping) this Stereo amp remains great value for money.

Just before Christmas, I ordered 9040 amps from Apollon's premium line.

To be perfectly honest, I doubt that
a) my deaf ears would hear any difference with this stereo amp
b) I will ever be able to use the power reserves of the 9040s

I was aware of all this beforehand, but I still opted for a slightly more expensive 9040 solution (which nevertheless replaces significantly more expensive amplifiers).

Never say never, but with these 9040 Purifi module amps, I won't be thinking about upgrading my amplifier in the foreseeable future...

And that's the great news:

- With the Purifi (and actually also Hypex) modules, there are undoubtedly sublime Class D amplifier modules with incredible performance at such affordable prices that were absolutely unimaginable just a few years ago.
- Manufacturers such as Apollon and Buckeye are turning the Purifi/Hypex modules into affordable and excellent amplifiers with excellend building quality.
- End users/buyers can choose from a wide range of enclosures (from spartan to very high quality) depending on their personal preferences.

It will be interesting to see whether these affordable Class D amplifiers will ultimately compete with suppliers of extremely expensive ‘high-end’ amplifiers like the recently introduced Linn Klimax Solo 800 which is being sold for abt 90.000 Euro a pair...
Even if I choose an extremely high-quality enclosure – such as Apollon in their premium line and check all the upgrade boxes – I can hardly manage to spend more than 5% of the Linn Klimax Solo 800 price
But of course, that's not how the target group for such high-priced monster amplifiers thinks...

I'm with u, always wanted a premium line Apollon Audio amp but I want an amp that can do almost double down from 8>4>2 ohm with authority so when fund allowed ordered them n got them delivered last April, except this 1ET6525SA I have all the other Purifi amplifier module monoblocks by Apollon Audio.
Top are premium 1ET9040BA monoblocks,bottom left 1ET7040SA monoblocks n bottom right 1ET400A monoblocks as u can see I have to use blue tape to darken the power on light on the bottom 2 pairs that's why I said it's value adding for add in the brightness adjustment switch to the more budget friendly line of amplifier.

 

[David_M]

We can't blanket all actives, a lot of them have external amps, like mains monitors for example like 8381A

(and lots of others, it would be a pain to unmount from a wall for service, let alone no ventilation in there, thermals would go nuclear with their multi-kW amps)

Sane practices apply to them as well.

I bet this speaker would easily accommodate a few Purifi modules without incurring an unreasonable power penalty cost. One does not require multi-kilowatt power dissipation for multi-kilowatt amplifiers.

 

[David_M]

That is not what he is talking about. He is correctly saying that any noise that the amplifier has, will become far more audible in an active configuration where the speaker drives the driver directly. Whereas in passive speakers, there is a crossover network which causes losses which result in noise being less audible. Length of wire and such is not material in this context.

Are you saying that an amp may provide 100W of power, for example, but the xovers dissipate 20W due to internal losses, so the drivers receive 80W, hence the noise is less audible?