JL ELectronics Sylph-D200 Amplifier Module Review

[johan]

abdo123 , it all depends on what you are designing for. Yes for companies like Hypex and such it makes sense to have higher gains .

If , however , we design an amp for good sound , 10db of gain is more than enough to listen (xlr input) rather loud in almost any room .

 

[abdo123]

we design an amp for good sound

So Hypex is designing amplifiers for bad sound?

This is not about good sound, this is about getting a higher spot on the ranking to get more $$$.

 

[johan]

Hypex design is for everyone and every flavor . Beyond getting a higher spot (I do understand this argument) I think there is a real need for lower gains . Who listens at 200W in a normal home ?

Most listening sessions are around 20-50W .

 

[abdo123]

Who listens at 200W in a normal home ?

Most listening sessions are around 20-50W .

what does this have to do with gain?

 

[johan]

A low gain will give you best SNR at precisely those listening levels...

 

[ceausuc]

Hypex design is for everyone and every flavor . Beyond getting a higher spot (I do understand this argument) I think there is a real need for lower gains . Who listens at 200W in a normal home ?

Most listening sessions are around 20-50W .

Years ago... I met a friend to compare our amps.
He had a 50w/8ohm audiophile amp (~1500$) I had a diy Tripath based amp : ~150w/8ohm.
We tested a pair of small bookshelf speakers (don't remember the name) and when we went from his to mine: 50w->150W we just couldn't believe that we were listening to the same speakers - they completely 'woke up' (from treble to bass) just from getting all that power.

Of course when we tested Triangle speakers (which are efficient), there was a different story - and Tripath power was unnecessary. Actually annoying because I couldn't touch the volume pot on the Tripath to get a normal listening volume

So.. do we need high power of not?
What is certain is that we need high sinad to increase our sales

 

[johan]

Thats possible...but its not evidence amp needs 150W
In a proper designed amp , low gain vs hi gain , low gain wins in SNR

In the end , I think that you need multiple gains...and yes low gain is important to have.

 

[Antônio Souza]

Hi,
I have just received the Aiyima tpa3255 with internal SMPS and Jrc5532d*2 op amp. I saw it inside and the board is very well made and the case is very good, much bigger than the 07 (the one with external Psu) , but it has tone controls, so no hi end here. I have not tested it yet, and I have no technical experience in amps. I will use it in my third system, so no high expectations here. But for Usd$150 shipping included I thought is was a good buy.

 

[abdo123]

A low gain will give you best SNR at precisely those listening levels...

lower gain will give better SNR at all listening levels.

output noise doesn't increase/decrease as the signal gets louder or quieter, the ratio between noise and signal increases as the signal gets higher though, because noise remains the same.

 

[johan]

lower gain will give better SNR at all listening levels.

output noise doesn't increase/decrease as the signal gets louder or quieter, the ratio between noise and signal increases as the signal gets higher though, because noise remains the same.

Higer gain will always add extra noise/distortion on top of original signal .

 

[restorer-john]

lower gain will give better SNR at all listening levels.

output noise doesn't increase/decrease as the signal gets louder or quieter, the ratio between noise and signal increases as the signal gets higher though, because noise remains the same.

What you are missing is low gain power amplifers simply shift the responsibility of noise (residual in uV) to the stage before. It's blatant buck passing. Whether that stage be a D/A converter, a phono preamplifier or mostly, the preamplifier itself.

At the end of the day, if you want to swing a high enough voltage at the speaker terminals to encompass the full range of even 16 bit, you need residual noise levels all the way through the chain in the low single microvolt range, through to low tens in the power amplifier stage.

 

[abdo123]

What you are missing is low gain power amplifers simply shift the responsibility of noise (residual in uV) to the stage before. It's blatant buck passing. Whether that stage be a D/A converter, a phono preamplifier or mostly, the preamplifier itself.

At the end of the day, if you want to swing a high enough voltage at the speaker terminals to encompass the full range of even 16 bit, you need residual noise levels all the way through the chain in the low single microvolt range, through to low tens in the power amplifier stage.

I was just replying to the point Johan made, saying that lower gain 'works better' with lower wattage amplifiers.

lower gain increases S/N in general regardless of wattage/output.

 

[SylphAudio]

What you are missing is low gain power amplifers simply shift the responsibility of noise (residual in uV) to the stage before. It's blatant buck passing. Whether that stage be a D/A converter, a phono preamplifier or mostly, the preamplifier itself.

At the end of the day, if you want to swing a high enough voltage at the speaker terminals to encompass the full range of even 16 bit, you need residual noise levels all the way through the chain in the low single microvolt range, through to low tens in the power amplifier stage.

For me it's ok as long as it's within range of most DAC's output. I could have used a lower gain configuration for this amplifier that we've sent to Amir, which can easily touch >95dB SINAD, some DACs can reach 5Vrms balanced out.

Instead we opted for 2V/4V input and 10K ohms input impedance.

 

[johan]

I was just replying to the point Johan made, saying that lower gain 'works better' with lower wattage amplifiers.

lower gain increases S/N in general regardless of wattage/output.

Lower gain (or any gain ) cannot increase original SNR. The advantage of lower gain is that your best SNR is at full signal (4Vrms from DAC) and you get around 40W of power in speakers (most listening session )

At 27db gain/40W( speaker) your DAC will (need) output less signal (not full signal) and thus your SNR will be less.

 

[eddantes]

To showcase the SINAD rating hehe

At least were being honest. And frankly, so long as were all being open and transparent about it - I don't have a problem with that.

 

[abdo123]

Lower gain (or any gain ) cannot increase original SNR.

Original S/N of what? the amplifier? or the DAC?

Lower amplifier gain will increase the S/N of the DAC (if the DAC can keep up) and will reduce the DAC's contribution to the overall noise output, but it will not reduce the output noise of the amplifier.

SINAD ranking that Amir uses for amplifier measurements does not isolate the noise of the DAC/Analyzer, so low gain amplifiers will score higher than high gain amplifiers, even if the output noise of both amplifiers is the same.

This the point I have been trying to make, I apologize if I was unclear before.

Now could you please explain to me why low gain is better for low wattage designs? without the voodoo.

 

[johan]

Abdo123 ,

You are mistaken to believe that low gain on amp can increase SNR of input signal.
In a perfect world 14 db or 27 db of gain will give you same result. Equal SNR to input signal .Thats the best you can hope , equal to input. Gain means that both signal and noise will be amplified by the same number. (so signal to noise ratio will never change)
Real world is slightly...imperfect.


As mentioned by restorer john...the ampifier has residual noise (x gain). Generally speaking its best to amplify before AMP since the noise of the AMP is always higher than residual noise of opamp stage (preamp)

 

[abdo123]

You are mistaken to believe that low gain on amp can increase SNR of input signal.

ofcourse it will, you even said it yourself.

At 27db gain/40W( speaker) your DAC will (need) output less signal (not full signal) and thus your SNR will be less.

 

[johan]

Nothing can increase SNR , you can only decrease by more...or less

 

[fordiebianco]

ofcourse it will, you even said it yourself.