Apollon Audio AS1200 Review (Stereo Power Amplifier)

[PierreV]

Driving 32K€ speakers with 700€ power amps... Hardcore audiophiles should get sick reading this.

The actual price I paid was much much lower than that

But yes, the current setup on that pair ( CCA digital out to Cambridge DacMagic+ to Hypex ) would give pimples to hardcore audiophiles.

 

[daftcombo]

Reading this thread again, I am now asking myself if upgrading from NC252 to NC500 (or NC400) for Aria 906 is worth it... I'm getting as crazy as you, guys.

 

[PierreV]

If you are eager to upgrade your system, what about elegant cable elevators that will convey the message you are a discerning high-end audiophile?

 

[VintageFlanker]

I am now asking myself if upgrading from NC252 to NC500 (or NC400) for Aria 906 is worth it... I'm getting as crazy as you, guys.

Probably as useless as my upgrade from ADI-2 DAC to ADI-2 DAC V2.

 

[daftcombo]

Well, actually I'm considering getting another pair of Aria 906 for myself, and am wondering if I should get another NC252 or go for a NC500. But I'm reluctant to spend more on an amp than on speakers. (Let alone on a DAC!)

 

[daftcombo]

So, I got another pair of Aria 906, running at the moment with a Class AB amp delivering only 50W before clipping under 8 ohm. As the Aria have an impedance of 30 ohm around 2 kHz, it can be a bit of a concern.
So, I'm considering either the Apollon here, or an hypex NC500MP based amp.

 

[daftcombo]

I had many class D amps from ICEpower, Ncore, Nuprime, and traditional class AB. None had this kind of noise. For what it's worth, I use a Supra Mainblock with filter. The amp is connected properly with phase on hot pin (checked with electric-test screwdriver). Also, I already heard about this noise on forums so wasn't surprised. Still not a massive issue for me as I don't hear it 2 meters from the amp.

Does the Supra Mainblocl help with your former amps?
Is the hum worse without it?

 

[chips666]

Hello
I am new on this forum, never posted before because i can only give subjective impressions
I have been swapping amps between 1200AS2, NC502MP and NC400 stereo dual mono for months now
The sonic differences are very small, dont dare to put them in words, probably not able to pick them out in proper AB blind testing
I live with all 3 of them and cannot decide what to keep
Chain: Hqplayer - RME ADI-2 dac - class D - Klipsh RP-8000F
Enjoy...

 

[VintageFlanker]

The sonic differences are very small, dont dare to put them in words, probably not able to pick them out in proper AB blind testing

Probably!

I live with all 3 of them and cannot decide what to keep
Chain: Hqplayer - RME ADI-2 dac - class D - Klipsh RP-8000F

The RP8000F are quite sensitive, so I wouldn't bother about power if I was you. Then, in that specific case, I would go for the cheapest one.

 

[tetrode]

View attachment 35895

Please forgive me if this is not the right place to ask for technical assistance. I've been planning to assemble a pair of ICEpower 1200AS1-based monoblocks having read and been motivated by this thread some time ago. I'm embarrassed to say what has me stumped is the wiring of the power button.

These amp modules come alive as soon as mains power is supplied to connector P100 which is the leftmost connector in the above image. The front panel pushbutton can put the amp in standby mode by pulling one of the connector pins high. The switch in the Apollon amp in the photo has for wires going to pins 3, 4, 5, and 6 on connector P101:

But, the question is which wires (standby enable, switch LED) go to which pin?

This is Apollon's 4-channel amp that uses two 1200AS2 modules:

I assume the two wires going to pins 4 and 6 are the ones putting the amp into standby mode but the definition of those pins doesn't make sense to me. Standby should be pulled high, not tied to ground.

Any thoughts you'd care to offer would be much appreciated. Again, sorry if this post does not belong her.

And, thank you to the original poster of this thread. It has proven very helpful.

 

[NTK]

@tetrode The amp goes on "standby" when the signal to the "Standby" input is high. Per datasheet, the input is internally pulled down, so if nothing is connected to pin 6, the input will be low and the amplifier is out of standby. (You can also see it in the timing diagram: Standby low → audio on.)

 

[tetrode]

@tetrode The amp goes on "standby" when the signal to the "Standby" input is high. Per datasheet, the input is internally pulled down, so if nothing is connected to pin 6, the input will be low and the amplifier is out of standby. (You can also see it in the timing diagram: Standby low → audio on.)
View attachment 86840

Thanks for the reply but I know the standby pin must be pulled high to put the amp in standby (I wrote: "The front panel pushbutton can put the amp in standby mode by pulling one of the connector pins high."). What has me puzzled is that the Apollon amp appears to be putting the module into standby by tying pins 4 (GNDaux) and 6 (standby) together. How would that pull "standby" high?

 

[NTK]

Thanks for the reply but I know the standby pin must be pulled high to put the amp in standby (I wrote: "The front panel pushbutton can put the amp in standby mode by pulling one of the connector pins high."). What has me puzzled is that the Apollon amp appears to be putting the module into standby by tying pins 4 (GNDaux) and 6 (standby) together. How would that pull "standby" high?

That will depend on the switch position. When the switch is closed, the amp goes into standby; when the switch is opened (because the pin is internally pulled low), the amp is active.

[Edit:] Are you sure the other side of the switch is not connected to DDVDstby (may be through the other module, since one standby switch controls both modules)?

 

[tetrode]

That will depend on the switch position. When the switch is closed, the amp goes into standby; when the switch is opened (because the pin is internally pulled low), the amp is active.

[Edit:] Are you sure the other side of the switch is not connected to DDVDstby (may be through the other module, since one standby switch controls both modules)?

Hmmmm. Now that's an interesting thought! No, I'm not sure DDVDstby isn't being passed through. So, perhaps inserting a normally-closed switch between pin 3 (DDVDstdby) and pin 6 (standby) is what puts the module into standby mode. That would definitely make more sense since:

And:

If the switch LED were connected between pin 4 (GNDaux) and pin 5 (AVDD) the LED would be off when the switch is in the normally closed position and illuminated when the pushbutton is engaged. I think

Very excellent thinking on your part! THANK YOU!

 

[Panelhead]

i confirm that those white blobs are made of silicone for damping vibrations and noise from the unit itself, similar solutions are used on PC PSU for the same purpose.

the hum/buzz you hear is probably coil whine o vibrations for the coils, you can try dampening but it's something "natural" with some kind of electronic products

I have used a 2k - 3K 25 watt resistor to damp singing chokes. A Swamping resistor. Did not affect the audio, only stopped the buzzing.

 

[Chippyboy]

@VintageFlanker

You mentioned "Once you turn the unit on, you will hear some kind of buzz/hum noise out of the amplifier."

I can inform people categorically that the culprit here not the power amp. The icepower amps are not at fault and I would not want people to be put off them for a fault which they do not have!

EDIT: Details deleted.
I had forgotten that I have been asked not to discuss the details in public, so I will PM you.

 

[VintageFlanker]

@VintageFlanker

You mentioned "Once you turn the unit on, you will hear some kind of buzz/hum noise out of the amplifier."

I can inform people categorically that the culprit here not the power amp. The icepower amps are not at fault and I would not want people to be put off them for a fault which they do not have!

EDIT: Details deleted.
I had forgotten that I have been asked not to discuss the details in public, so I will PM you.

Excuse me?
Ok, I red your PM. The hum/buzz noise remains. whatever it is connected to the RME or not. The RME is not related to it in any way.

would not want people to be put off them for a fault which they do not have!

Why so? Are you working for Icepower ?

 

[Apollon Audio]

@VintageFlanker

You mentioned "Once you turn the unit on, you will hear some kind of buzz/hum noise out of the amplifier."

I can inform people categorically that the culprit here not the power amp. The icepower amps are not at fault and I would not want people to be put off them for a fault which they do not have!

EDIT: Details deleted.
I had forgotten that I have been asked not to discuss the details in public, so I will PM you.

The buzzing/hum from the transformer is not a fault but a bad choice of a loud transformer being used. The more the module is driven the louder the hum gets from the transformer. We installed around 200 Icepower 1200as2 amplifier modules and all have this hum noise coming from the transofrmer. Don’t get me wrong the hum is not coming from the speakers. I also noticed that the hum noise coming from the transformer is quite reduced in the last few batches of modules that we received.

 

[Chippyboy]

Seems to be some hostility on your part, which I have to say is rather disappointing after the lengthy PM I sent you, trying to be helpful.

Anyway maybe we are at cross-purposes, but you mentioned hum coming from the speakers:

"Unless you turn the amp on BEFORE your preamp/DAC. In that case, you will hear that same noise put to audible levels straight in your tweeters. All turns back dead silent while I switched on my ADI-2 DAC"

I told you why in the PM.

 

[VintageFlanker]

Anyway maybe we are at cross-purposes, but you mentioned hum coming from the speakers:
"Unless you turn the amp on BEFORE your preamp/DAC. In that case, you will hear that same noise put to audible levels straight in your tweeters. All turns back dead silent while I switched on my ADI-2 DAC"

I told you why in the PM.

You're actually right about that part. But your initial post wasn't about this issue. The hum exists, as @Apollon Audio just confirmed. Period.

Sorry for being rude, but your original post, out of context, was kind of weird.