Apollon 1ET6525SA ST Amplifier Review

[Descartes]

Can anyone explain all the different options that they offer in regards to the amplifiers

What is OPA?
- OPA 1656
- Sonic Imagery 994 (+100.00€)
- Sparkos Labs SS2590 PRO (+200.00€)

Also is the difference in pricing just the box when comparing Purifi 1ET9040BA?

 

[amper42]

OPA 1656 is what I have. I think it sounds fantastic and usually is offered with no extra fee. It's also the OPA Bruno Putzeys recommended for Purifi use in the past during on-line discussions.

 

[MarTec]

I plugged a consumption meter onto the power cord. This amp, my unit, consumes about 16.5 W when idle. It needs to get very loud, hearing damage levels of loud before the base consumption is exceeded with my subwoofers. For comparison I measured 28.6 Watts from two NC400 mono blocks.

Out of curiosity: could you also share the consumption in “standby” mode (when the amp is in sleep mode)?
Would like to know if this is different to the idle value.

 

[Sokel]

Out of curiosity: could you also share the consumption in “standby” mode (when the amp is in sleep mode)?
Would like to know if this is different to the idle value.

If it's a true standby mode it must consume less than 0.5W by law in EU.
Nothing to worry about.

 

[MarTec]

Well..that’s what I try to find out.

I did the checks for my Wiim Ultra and 3eaudio A7.
A7 is between 0,6-1,0w in standby and 12,6-12,9w in idle.
But the Ultra stays at 5,0-5,2 in standby (idle is also around 5,1-5,2w).

Hence the 0,5w EU law may not be applicable to all devices.

 

[Sokel]

Well..that’s what I try to find out.

I did the checks for my Wiim Ultra and 3eaudio A7.
A7 is between 0,6-1,0w in standby and 12,6-12,9w in idle.
But the Ultra stays at 5,0-5,2 in standby (idle is also around 5,1-5,2w).

Hence the 0,5w EU law might not applicable to all devices.

It's a little higher for network gear, 0.7W if I remember well?
But Wiim's 5W is way too much, it can't be a standby mode, maybe they mislabeled it.

 

[MarTec]

Not sure if Wiim officially posted the standby values anywhere.

In the Wiim settings you can change the time to enter the „standby“ mode hence i assume they are aware of the difference ( idle vs standby).

On the other hand, higher volume seems to have (almost) no impact on the Wiim. Listening via Spotify with a volume set at 35, the Wiim‘s consumption is between 5,3-5,4w.

 

[amper42]

Well..that’s what I try to find out.

I did the checks for my Wiim Ultra and 3eaudio A7.
A7 is between 0,6-1,0w in standby and 12,6-12,9w in idle.
But the Ultra stays at 5,0-5,2 in standby (idle is also around 5,1-5,2w).

Hence the 0,5w EU law may not be applicable to all devices.

This is absolutely true. Many class D amps energy usage does not drop significantly when idle. Boxem does after about 10 minutes of no music playing but my other amps are not that energy miserly. I use a Tripp Lite ISOBAR6ULTRA and simply switch the amp off when the music session is over. It protects the amp from surge and reduces phantom power draw.

 

[Jukka]

Out of curiosity: could you also share the consumption in “standby” mode (when the amp is in sleep mode)?
Would like to know if this is different to the idle value.

Idle as in fully on, but receiving silence on the input. When plugged to a wall socket, but not switched on by the power button, this unit seems to draw 1.0 W. I don't know how precise this meter is. It's a cheap meter, so I wouldn't trust it to .1 accuracy, but this is quite basic measurement so it shouldn't be far off.

 

[Apollon Audio]

Leaving your 16.5 W amplifier on 24/7 in Finland costs approximately
€1.05 to €1.40 less per month than leaving the two
28.6 W NC400 mono blocks
on.
The calculation is based on the following breakdown:

1. Energy Consumption Comparison (Monthly)

• Your Amplifier (16.5 W):
  • Daily:
    View attachment 515589
    16.5W×24hours=396Wh (0.396 kWh)
  • Monthly (30 days):
    View attachment 515588
    0.396kWh×30=11.88kWh
• NC400 Mono Blocks
  (28.6 W):
  • Daily:
    View attachment 515590
    28.6W×24hours=686.4Wh (0.686 kWh)
  • Monthly (30 days):
    View attachment 515592
    0.686kWh×30=20.58kWh
• Difference:
  View attachment 515593
  8.7kWh
  per month.

2. Estimated Cost in Finland
Electricity prices in Finland fluctuate, but for 2025–2026, a typical total price for household consumers (including energy, transmission, and taxes) is roughly 12 to 16 euro cents per kWh.
View attachment 515595Statista +1

• At 12 c/kWh:
  View attachment 515591
  8.7kWh×0.12=€1.04
  saved per month.
• At 16 c/kWh:
  View attachment 515594
  8.7kWh×0.16=€1.39
  saved per month.

3. Yearly Impact
If left on continuously, switching to the 16.5 W idle unit saves you roughly €12.50 to €16.70 per year.

I would like to share my opinion on this topic. Switching the amplifiers off after use will significantly extend the lifespan of the internal components compared to leaving them powered on continuously.

At the same time, frequently powering the amplifier on and off is also not ideal. Using an auto-sense function that repeatedly turns the amplifier off during silence and then back on again when music resumes can introduce many power cycles. These repeated start-up cycles place additional stress on components such as power supplies, relays, and capacitors.

For this reason, the most balanced approach is typically to switch the amplifier on when you start listening and turn it off once you are done, rather than leaving it powered continuously or relying on frequent automatic on/off cycles.

 

[DavidEdwinAston]

I would like to share my opinion on this topic. Switching the amplifiers off after use will significantly extend the lifespan of the internal components compared to leaving them powered on continuously.

At the same time, frequently powering the amplifier on and off is also not ideal. Using an auto-sense function that repeatedly turns the amplifier off during silence and then back on again when music resumes can introduce many power cycles. These repeated start-up cycles place additional stress on components such as power supplies, relays, and capacitors.

For this reason, the most balanced approach is typically to switch the amplifier on when you start listening and turn it off once you are done, rather than leaving it powered continuously or relying on frequent automatic on/off cycles.

Do you also suscribe to the view. Power amp. last item to be turned on in the chain, and first to be turned off?

 

[delta76]

That's why I always go back to the AB class amps.

Almost every active sub in the market now is using class D amp. What do you mean?

 

[dcolak]

Almost every active sub in the market now is using class D amp. What do you mean?

and they suck

 

[delta76]

and they suck

Ah Ok

 

[boXem]

I would like to share my opinion on this topic. Switching the amplifiers off after use will significantly extend the lifespan of the internal components compared to leaving them powered on continuously.

At the same time, frequently powering the amplifier on and off is also not ideal. Using an auto-sense function that repeatedly turns the amplifier off during silence and then back on again when music resumes can introduce many power cycles. These repeated start-up cycles place additional stress on components such as power supplies, relays, and capacitors.

For this reason, the most balanced approach is typically to switch the amplifier on when you start listening and turn it off once you are done, rather than leaving it powered continuously or relying on frequent automatic on/off cycles.

Abiding the EU law for a company operating in EU is not a question of opinion, be it about power modes or displaying prices VAT included. Just sayin.

 

[J84]

HI which binding posts?

 

[J84]

Going on five years with my DIY Purifi. All it does is sit there, cool as a cucumber, and do its job. Flawlessly. I'm sure this one will do the same with a few added features like the gain variability and the 12v triggers. Very nice.

Btw, op amp rolling, especially op amp rolling with things like the Sparkos, actually tend to degrade measured performance. We've seen where Amir reviewed the original Eigentact with the stock Eval 1 buffer then reviewed the same 1ET400A based amp only with a premium buffer using the Sparkos as in a Nord amp, for example, only to see SINAD drop by 4-5 db. It's a tweak highly recommended by the like of Positive Feedback writers to impart a sense of "tubelike smoothness" to the overall sound. Nuff ced.

Thank you, Amir. You've really been prolific this week.

Hi do the tweak really introduce "tubelike smoothness*?

 

[Descartes]

Would love to buy Apollon as their case look superb but paying $1000 just for the enclosure is not worth it!

 

[harkpabst]

Abiding the EU law for a company operating in EU is not a question of opinion, be it about power modes ...

Recommending your customers to not rely on standby mode but power devices on and off as per actual need is certainly not against the EU law.

... or displaying prices VAT included.

Yes, and the actual VAT rate is unknown until the customer selects the EU (or other) country to ship the product to.

 

[Apollon Audio]

Abiding the EU law for a company operating in EU is not a question of opinion, be it about power modes or displaying prices VAT included. Just sayin.

When selling across the EU, VAT is not a single fixed rate. It varies depending on the customer’s country (19%, 20%, 22%, 25%, etc.).

Under the EU OSS system, VAT must be applied according to the buyer’s location, which means the correct VAT rate can only be determined at checkout once the country is known.

For customers outside the EU, VAT is not applied at all. Because of this, displaying a single VAT-included price would actually be inaccurate for a large portion of customers.

This is why many international webshops calculate VAT during checkout rather than showing one fixed VAT-included price.