Opinions on Hypex Plate (FusionAMP) Amplifiers?

[MisterOZ]

The odd (re)sampling are unavoidable, because the ADC works at that 93.75kHz too.

And I think that could be the advantage to feed the amp analog: Converting an analog signal to digital 93,75 kHz and then back to analog could in the end sound better than reclocking for example the digital 44,1 kHz input to 93,75 and then back, even if there is one more AD-DA conversion in the whole chain.

I don’t know how reclocking works to be honest (there must be interpolation, right?). But would be interesting, if someone could explain that.

 

[YSDR]

I don’t know how reclocking works to be honest (there must be interpolation, right?). But would be interesting, if someone could explain that.

Yeah, an explanation would be great. I heard that for perfect resampling, a lot of processing power is needed (if the source and the destination sample rates are not integer multiples of each other), so most digital-to-digital resample are not perfect. Anyway, according to some internet sources, the FA digital input section uses one of the best SRC (sample rate converter) on the market, a Texas Instrument SRC4382.

 

[Hypexsales]

The sampling rate is set to 93.75kHz instead of one of the more traditional audio rates. This is specifically done to improve the performance of the SRC4382.
An uncommon clock frequency reduces the odds that mix products between the incoming clock and the internal clock fall inside the PLL loop bandwidth of the SRC.

this topic has already been discussed on ASR before:

Why 93.75 kHz sampling rate?

Kii Three apparently use 93.75kHz internal sampling rate . Why such an unusual choice?

www.audiosciencereview.com

 

[MisterOZ]

Thank you! Sorry, but just a further question to have it clear: If I feed the Fusion Amp analog, is the SRC4382 active or not?

My assumption would be “no”, because there is no need to convert a samplerate, the 93.75 kHz comes directly out of the ADC (please correct me if I’m wrong). So the question would still be: Is the impact on the sound of a nearly perfect ADC (without SRC) bigger than the impact of the SDC at the digital input (with no ADC)? From a technical point of view, of course…

 

[YSDR]

What if every data shows the digital input superiority over the analogue but you still like the latter better subjectively?
The S/N ratio and the harmonic distortion is better with digital input (check the FA manual) and the analogue input values doesn't even contains the added distortion and noise of an external DAC for example.
Of course the Topping D70 have very low distortion and noise but the output is still analogue and thus limited by the analogue circuitry/parts.

But of course it is possible that the analogue input is superior to the digital input for the human ear.

 

[voodooless]

What if every data shows the digital input superiority over the analogue but you still like the latter better subjectively?

Let's first establish that you can actually hear the difference at all. If so, you can have a preference. What then? Nothing

 

[MisterOZ]

You are both right, we are discussing hairs here, if not stardust

But nevertheless I find it interesting, what happens inside the box. At the end it is a comparison between the specs of the SRC and the ADC chip (which SRC wins, according to the technical data sheet).

I will give the AES another try.

 

[Hypexsales]

The analogue inputs go directly in the ADC and into the DSP. The SRC is only for the digital inputs.

 

[voodooless]

The analogue inputs go directly in the ADC and into the DSP. The SRC is only for the digital inputs.

Before anyone asks, no the ADC is inferior to the SRC. The SRC has a 125 SINAD. There isn’t an ADC in the world that has these specs that isn’t at least as expensive as the whole Fusion box combined (or several).

 

[McFly]

Anyone users have any complaints re: fans on the FA502 / FA503 units? I'm brainstorming an active 3-way build and fan noise could be a deal breaker.

Second, any updates on a more powerful DSP module with FIR capabilities yet? I can live without this it's just a nice to have later on thing...

 

[617]

Anyone users have any complaints re: fans on the FA502 / FA503 units? I'm brainstorming an active 3-way build and fan noise could be a deal breaker.

Second, any updates on a more powerful DSP module with FIR capabilities yet? I can live without this it's just a nice to have later on thing...

Wish I could help more, but in general I've never been troubled by fan noise as long as it only spins up in use.

 

[AlphaSquared]

Perhaps beyond the scope of this thread, but I thought it worth asking.

Background

I have a pair of FA123s that I no longer use. One of them has an issue I can have Hypex address, but I have another thought.

I'd like to repurpose the components of the FA123s in support of extending my home theater audio system (see attached image).

I have two stereo NCore amps that I use with a miniDSP device to integrate DML panels and woofers that serve as left and right front speakers.
I have additionally turned my LG OLED TV into a center channel speaker by attaching an exciter to it.
I have smaller DML speakers to serve as rear left & right channel speakers.

I have an A/V pre-processor that has the capacity to do the room equalization I may need.

I need amplifiers for the smaller DML rear left & right speakers and the center channel speaker.

I can use the working FA123 for the center channel, but this seems too much of a device for the purpose.
Additionally, as I would use RCA analogue out from the A/V pre-processor to the FA123, the FA123 would first do an ADC (analogue to digital conversion) make the digital available for DSP, then apply its DAC to return analogue output to the center channel speaker.

The FA123 does much more than I need.

This said, the FA123s's NCore amps - on their own - could prove a great match for my application.

Question

Could I repurpose any of the components of these FA123s?

I could have all the following wrong (see attached image) ...
The 100w amp appears to sit on a discreet board and receives power from the power supply mounted on the board holding the two 125w amps.
I don't need the DSP | DAC functionality.

Would the following work for the center channel amp?

• RCA analogue inputs.
• Binding posts for speaker wire.
• Add an appropriate power supply for the 100w amp.
• Supply mains connection.
• Put in in a box.

The question then becomes whether I can do something similar for the rear right & left channel, but using the 125w amps and bypassing DSP | DAC.

I know I can purchase 2 or there UcD180HG with HxR from Hypex and put something together, but I really don't need 180 watts per channel.

These FA123s have served me very well across a number of different systems, I'd love to give them another life.

Any thoughts appreciated.

 

[YSDR]

I could have all the following wrong (see attached image) ...
The 100w amp appears to sit on a discreet board and receives power from the power supply mounted on the board holding the two 125w amps.
I don't need the DSP | DAC functionality.

Would the following work for the center channel amp?

• RCA analogue inputs.
• Binding posts for speaker wire.
• Add an appropriate power supply for the 100w amp.
• Supply mains connection.
• Put in in a box.

Do you need all the 3 amp channel of the FA123 for the center speaker? If so because you want to tri-amp the center speaker, then I would leave the FA123 as is and remove the passive crossover from the center speaker and do the crossover with the FA123 DSP. Sending the signal through the ADC is better than a passive crossover if you ask me.
Otherwise you can do your listed mods if you want, but you don't need a separate power supply for the HF100, just connect to the main NC-MP122 board as the FA123 or remove it completely if you don't need. Don't forget that the HF100 is for 500Hz and up, it's a dedicated high-frequency amp.
The FA DSP+DAC unit is the board that have the analogue inputs.

 

[Juhazi]

Let's first establish that you can actually hear the difference at all. If so, you can have a preference. What then? Nothing

Before anyone asks, no the ADC is inferior to the SRC. The SRC has a 125 SINAD. There isn’t an ADC in the world that has these specs that isn’t at least as expensive as the whole Fusion box combined (or several).

SINAD etc. difference is irrelevant, we don't have source signal in music/video with that kind of S/N ratio. I use analog inputs without any problems, digital (usb) only for DSP/HFD settings and testing. I even have volume adjust by analog signal level from preamp/AVR. This is not an ideological but a practical choice for me.

I have two pairs of FA123, first ones since May 2018. No problems. They have been switched off a couple of times so far.

 

[AlphaSquared]

Do you need all the 3 amp channel of the FA123 for the center speaker? If so because you want to tri-amp the center speaker, then I would leave the FA123 as is and remove the passive crossover from the center speaker and do the crossover with the FA123 DSP. Sending the signal through the ADC is better than a passive crossover if you ask me.
Otherwise you can do your listed mods if you want, but you don't need a separate power supply for the HF100, just connect to the main NC-MP122 board as the FA123 or remove it completely if you don't need. Don't forget that the HF100 is for 500Hz and up, it's a dedicated high-frequency amp.
The FA DSP+DAC unit is the board that have the analogue inputs.

Thanks for the input and clearing up the location of the FA DSP+DAC.

I only need a single amp to drive the center speaker, which consists of a single DML panel (the LD OLED TV itself) driven by a single exciter - no passive crossover.
In tests, I've used the HF100 to drive the center channel and it does fine in my application.

Ideally I'd like to place the:

- HF100 it own chassis with a power supply and analogue inputs & outputs and
- NC-MP122 board in a separate chassis with its own analogue inputs & outputs.

Sounds like it will work.
Confirmation appreciated.

 

[bexi]

Anyone users have any complaints re: fans on the FA502 / FA503 units? I'm brainstorming an active 3-way build and fan noise could be a deal breaker.

The fan is quite noisy. You can hear it at listening spot when music is not playing. Fan spins about in half hour intervals few minutes at the time. Of course it is temperature controlled.
I have FA502 in subwoofer enclosure in tight space. I learned that you should give amp some breathing room and holes next to amp.
I do not know if you could replace fan easily. It did not seem so.. I would like to replace it with Noctua some day.

Had some problems with standby also. Would not go into standby. Problem was leaking current in mains. Using RCA cable, no grounding and main plugs in different distribution block. Fixed now connecting to same distribution block as rest of the system.

One unit was fine upgrading firmware. Other one failed and had to do power off.. after that firmware was flashed in recovery mode fine. That was not one time fluke as I had to do second firmware upgrade like this. Maybe some problem with USB chipset? Using Lenovo x230.

 

[Gremlins]

Hello community

The fa503 xlr input is at 6.15v to max power, what kind of preamps do you use?

I use a dac that outputs 4v max on xlr

Most dacs/preamps have 4v output max to my knowledge

 

[bexi]

Hello community

The fa503 xlr input is at 6.15v to max power, what kind of preamps do you use?

I use a dac that outputs 4v max on xlr

Most dacs/preamps have 4v output max to my knowledge

You can set gain and sensitivity on control panel. Filter design app gives another volume setting.

 

[Gremlins]

Thank you. I see volume control that can be set, but o dont see gain.

You have a screenshot to share?

 

[bexi]

Not connected right now. Google image search with hypex fusion amp device settings