Mikechw
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I had a rme adi pro fs before I switched to d90.
I quite like the rotary encoder and the display.
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Topping D70s MQA Review (DAC)
- Thread starter amirm
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I quite like the rotary encoder and the display.
Maybe there is an argument for a dumb DAC. I suspect that economies of scale and production would mean that there is no actual price difference, but that is a different argument. None of these things are preamps anyway. Nor does Topping make a preamp. Preamps are for phono stages or microphones. We are only taking about switching line level signal and attenuating those signals. The DACs already have input switching, and they expose the input selection on the front panel and on the remote control. From the point of view of the user, unless that user has additional analog inputs, the existing functionality of most of these DACs is indistinguishable from a traditional analog preamp. Many of the DAC chips incorporate digital volume control, and the DACs present a user interface with switches and maybe a knob. Adding volume control is a simply a software option.
DACs with Blutooth blur the line even more. The ability to effect volume control over USB audio link even more so. I end up controlling the volume in all manner of places, often in a very unsatisfactory manner. Gain staging matters with digital. I suspect that the vast majority of Toppings DACs go into modern very cost effective audio systems. The majority I would bet connect straight to a power amplifier, and only have a control amplifier in the way because it is integrated into a legacy power amplifier. We have not yet reached the optimal integration of systems. The continual flux of, as yet not fully satisfactory, digital sources remains.
I don't know, my current amp, likes more than 4V. I'm not against volume control on DAC, I personally don't use it. yes digital attenuation is cheap and you can't be against more flexibility, my point was more about asking for motorized analog pots, to me when you expect your affordable DAC to do this it's unfair, you are asking for a product in a different segment.
Not to mention a quality reduction. We have here a 120 dB SINAD unit. Adding a preamp between it an a power amplifier can only reduce that quality, I expect.
But as soon you are not listening at 0DBFS, you are reducing your effective SINAD.
Doesn't matter how you reduce your levels. Top end DACs are limited by noise, not distortion, and that tiny amount of noise is in the intrinsic nature of the electronics. Reduce your levels in a traditional preamp and your SINAD will likely suffer even more, and certainly no less. Gain staging is critical no matter which domain you are in.
Yes, I should have added "also" at the end of my sentence for clarity.
A power amplifier has around 26 dB gain, which means noise at the speaker terminals will be around -94 dB of the full power. At that point your body will be generating more noise than the speakers.
-94 dBs compared to what (what kind of dBs), and it translates to how many dB SPL at which sensitivity?
the motorised pot thing was referencing to John's comment about why an encoder is not always good and opt for the buttons. for me I personally is fine even the dac have no volume control at all (my current Holo Spring 2 don't) and I just add my passive preamp to be used with headphone amp and the Genelecs where the volume control at front disappeared.
if one design wanted a remote friendly option one could use the motorized pot, but if not I am sure a good pot or stepped attenuator would provide more value maybe to be used with more and more common active speakers or amps with fixed gain to make the pot range in the amp more usable. either way I prefer a basically noiseless pot to digital attenuation when needed.
May I ask what make, model your power amplifier is? Even a very low sensitive unit should have at least 20 dB gain and that will deliver 300 Watts to 8 Ohm.
As per @amirm ’s chart, noise is at -118 dB relative to 2 volts in the input of the power amplifier. If power amplifier has 26 dB gain, at 2 Volts input there will be 40 volts at the speaker terminals generating 300W at 8 Ohms. A 86 dB/watt, speaker will generate around 110 dBSPL at 1 metre at that input. Noise is then is -8 DBSPL, which is much less than the 22 dBSPL, a human generates.
that is deafening level
I have ADI2 pro FS R BE. It feels really good here but from different perspective you get different answers. We see lots of complaints of poor rotary encoder for our products. And the result is actually better overall(not best for individuals) on D70 and D90 that's why it's on D70s as well. And on cheaper products we can afford people having issues and return and sending new ones or simply some people will tolerate it better for lower price. For higher price the point where the chassis, components prices shoot way up that don't leave much room for cheap components to be expensive. 16 dollars = 10+ opa1612's. That's insane TBH, although it's new and cheapER than magnetic types which are easily 30+ dollars and don't have stock. So yeah, it's an option. But honestly is it any better than relay based volume control? We are integrating it to newer products. And if you look around it's certainly what's actually being done by other manufacturers on headphone amps. We can probably leave the volume control to the next stage. I know it's not ideal in all circumstances, preamp is also expensive. But to some extent it's a good balance.
Anyways, people are spoiled. They can't have everything and having it being cheap.
PS: Does anyone know D70s actually cost more than D90 and having the same or better performance for the most part?
Double PS: Do people also know that USD dropped a lot during this year? It's sad but. That's the reality.
but from my understanding isn't at lower level the noise floor more or less remain the same with distortion? kind of like resulting at lower SINAD at normal usage voltage
Thanks for doing the calculation, my amp is about a 20 times gain too. still, I often use a gain at 2 times at the preamp. Those quick calculations are simplistic, but I agree that 4 volts is enough for most use cases. As you know, we don't normally listen at 1 m, but more importantly, peaks in music, when not overly compresses are at least 20 dB higher than the average level, sometime more. So in your example if the momentary highest transients generate 300 Watts you are really getting a listening level of 90 dB, at 1M, 84 dB at 2m, 78dB at 4 m, with some very dynamic recordings, or movies, the crest factor is even higher. And yes, I should add the 3 dBs to this for 2 speakers. Now yes, I agree that when 4 V is not enough, your gain structure is not optimal, but it's also OK to not be optimal, sometimes you want to listen very quiet as background music, sometime you push it hard, sometimes, for some weird reason, this website or this youtube video, is streaming extremely quiet, there are plenty of situation in life where you want to stop being an audiophile and not worry, but I look at my preamp volume and it's maxed out. It is what it is, headroom is always nice.
Edit: that said, I believe we are entering the "derailing thread" territory that Amir was mentioning. Merry Christmas to all.
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You are correct, you moved to discussing listening levels, or how digital streaming levels are not optimised, neither belongs to this thread. I was just proving that a 2 Volt input to a power amplifier is almost always enough. As more will clip the amplifier.
@JohnYang1997 @amirm and others, is there a DAC out there that has digital pre-gain?
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