Apollon Audio Class-D Amp Build Quality

[mike70]

read again

Ok, is the difference ... got it. Sorry.

 

[idleherb]

@Apollon Audio I love the compact new amps, especially that you also added the 1ET7040SA as a monoblock there. You're one of the few companies (are there others actually) that actually cares quite a bit about the visual design and provides us some alternatives to choose from, while pushing the financial barrier further down. Speaking of which, you just made it a lot harder for me to decide which model to get

 

[Papillon]

Boxem makes nice cases too.
They have fewer choices though and focuses only on Purifi modules

 

[Apollon Audio]

Interesting power rating: 675 W at 4 ohms per channel, using a single 1200 W power supply. Since you have AP to measure, I assume the power supply has more headroom than specified? It's almost using the full 700 W of each module, very nice.

As promised here are some measurements of the Apollon NCx500 ST measured @4Ohm with APX555b. This was measured at the lowest gain setting 11,5dB. Please note that the Apollon buffer is not bypassed at the lowest gain setting.

 

[Apollon Audio]

And 8Ohms...

 

[Matias]

As promised here are some measurements of the Apollon NCx500 ST measured @4Ohm with APX555b. This was measured at the lowest gain setting 11,5dB. Please note that the Apollon buffer is not bypassed at the lowest gain setting.

View attachment 281354View attachment 281355View attachment 281356

This is really impressive. I assume it measures this using the standard OPA 1612 opamp?

I also suppose no need to use 2 power supplies, one for each module, as the power increase would be almost nothing, and even sharing a single PS crosstalk should be minimum, right?

 

[Apollon Audio]

This is really impressive. I assume it measures this using the standard OPA 1612 opamp?

I also suppose no need to use 2 power supplies, one for each module, as the power increase would be almost nothing, and even sharing a single PS crosstalk should be minimum, right?

Yes it is really impressive and I would agree that it is the sweetspot. It was measured with the standard OPA1612 yes.

The power increase is minimal with two power supplies. Around 40 watts of difference @2Ohm and @4Ohm and better headroom within the power supply. Two NCx500 modules are hitting the upper peak of one SMPS1200. There is slightly better crosstalk in a dual mono design with two power supplies. But not much.

 

[mike70]

It's (very) uncommon to see purifi based amplifiers with RCA inputs ... but apollon makes it.

That's why I want to ask for ... there's some kind of shortcoming about it? I mean, apart from the known better immunity on RFI, higher gain, etc ... we're talking about a real lose in sound quality with unbalanced connections on these modules?

I have an unbalanced class AB amplifier (and everything else unbalanced) ... So I'm checking my options.

 

[Sokel]

It's (very) uncommon to see purifi based amplifiers with RCA inputs ... but apollon makes it.

That's why I want to ask for ... there's some kind of shortcoming about it? I mean, apart from the known better immunity on RFI, higher gain, etc ... we're talking about a real lose in sound quality with unbalanced connections on these modules?

I have an unbalanced class AB amplifier (and everything else unbalanced) ... So I'm checking my options.

Concerning Purifi,no difference between the two in another's brand built (Sparcos Edition).
At least to me and some others that testing it.

 

[Julf]

That's why I want to ask for ... there's some kind of shortcoming about it? I mean, apart from the known better immunity on RFI, higher gain, etc ...

Better noise reduction and avoidance of ground loops. Clear advantages, no disadvantages, so the question is "why would anyone use unbalanced?". Unbalanced made sense back in the tube/valve days, when a differential input added significant complexity.

 

[ILoveBeryllium]

Some receivers and devices sometimes only have RCA and not balanced XLR connections.

 

[Julf]

Some receivers and devices sometimes only have RCA and not balanced XLR connections.

You are fine driving a balanced input from an unbalanced source (and still get most of the benefit).

 

[mike70]

Now I have amplifier and sub unbalanced ... thinking about using a minidsp flex as preamp.

The balanced flex version needs special cables for that configuration ... That means added cost (balanced version + replacing cables) ... that's why a Purifi unbalanced version looks good to me

 

[Julf]

Now I have amplifier and sub unbalanced ... thinking about using a minidsp flex as preamp.

The balanced flex version needs special cables for that configuration ... That means added cost (balanced version + replacing cables) ... that's why a Purifi unbalanced version looks good to me

The cables shouild cost less than $20. It is just a shame to not use the differential input capability of the Purify.

 

[AkodoGilador]

Are there any differences between the "Apollon Hypex NCX500 Mini Stereo Amplifier" and the "Apollon Audio NCx500ST Stereo Amplifier" other than the smaller case and rubber feet on the latter?

Alex

 

[idleherb]

Are there any differences between the "Apollon Hypex NCX500 Mini Stereo Amplifier" and the "Apollon Audio NCx500ST Stereo Amplifier" other than the smaller case and rubber feet on the latter?

Alex

The Mini case is "built like a tank", 10mm aluminium all around. The new cases are of thinner build quality.

 

[Paffi]

You are fine driving a balanced input from an unbalanced source (and still get most of the benefit).

So you think, when using an RCA source (if there is no xlr output) and connect it via RCA-XLR adapter cable to xlr Input of the amplifier is still better than simply using the rca to rca connection? Why?

 

[Matias]

So you think, when using an RCA source (if there is no xlr output) and connect it via RCA-XLR adapter cable to xlr Input of the amplifier is still better than simply using the rca to rca connection? Why?

Since NC400 Bruno P already wrote:
"9.4 Vastly preferred balanced setup: XLR input.
Regardless of whether the remainder of your audio system has balanced connections or not, the very best way to wire the input of the NC400 is to leverage the advantage of its balanced input. You can get almost all of the quality improvement afforded by balanced connections even with an unbalanced source, provided that you have a balanced input."
- from the NC400 datasheet

 

[Julf]

So you think, when using an RCA source (if there is no xlr output) and connect it via RCA-XLR adapter cable to xlr Input of the amplifier is still better than simply using the rca to rca connection? Why?

Bruno Putzeys: The G Word, or How to Get Your Audio off the Ground

 

[mike70]

I ordered the balanced Flex