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Topic: External DAC with Pianoteq?

Would using a high quality external DAC noticeably reduce latency or improve the sound of Pianoteq?

I am running Pianoteq 6 on a  13” early 2015 MacBook Pro, 2.9 GHz i5-5287U CPU, 8GB RAM. Powered studio monitors are connected directly to the headphone port. Internal and host sample rates are set at 48KHz, and the buffer size is 512 samples, which yields a displayed latency of 10.7ms. However, I sometimes run both sample rates at 88.2 KHz with the buffer set at 512 (OK for the Model B) at which the displayed latency is 5.8ms. Max polyphony is set at 128.

One DAC I am considering is the Grace Design m9xx/m900 (384 KHz max sample rate—overkill?). Other options I might try include a Roland Quad Capture, a Geffen High Res USB Decoder, or a Yamaha MG10XU mixer. All three of these options operate at 24 bits/192 KHz max. I don’t have the equipment needed to measure latency, distortion, etc., so I’d be relying on my ears, and most people’s ears are in better condition than mine.

Is the built-in D/A converter in a MacBook Pro good enough in most instances? Would you likely hear the difference? I will appreciate any advice provided.

A Pianoteq reviewer recommended the Grace DAC. It has impressive specs, but would most musicians hear the difference?
https://441k.com/review-modartt-pianote … 204264de17

What D/A device do you use?

Last edited by SHartger (23-10-2017 16:16)

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Re: External DAC with Pianoteq?

The DAC and line stage in the MacBook Pros often are quite good but they are built to a price and size.

- A high-quality "DAC" and its analogue circuitry might (or might not) improve sound quality and might provide a better headphone amp. The Grace boxes are high-quality and expensive. The high sample rate capability of the Grace does not matter as long as it can produce sample rates output by PianoTeq & your Mac (e.g. 44.1khz & 48.0khz). Not sure this is a good investment to be frank.

- Higher-end "Audio interfaces" might provide a few options. Better DAC & output circuitry. Maybe a better headphone amp. If you are using MIDI cables from your keyboard, you might be able to reduce latency significanly & improve sound quality. If you are using USB cables from your keyboard I don't think an interface will help latency so much or at all, but am not sure. There are several higher-end ThunderBolt2 & USB interfaces that will work with your system; cheap ones will generally have cheaper DACs/output stages, weaker latency performance, unstable drivers. You MacBook has ThunderBolt2 ports so should work directly with 2017 ThunderBolt2 interfaces without a dongle so that could provide the very best latency performance. But everyone's system is different so you might spend $600 to find unchanged latency and similar sound quality.

The reported latency you are quoting doesn't mean much as it only represents some of the latency. Round-trip latency is the full time it takes to press the key to the time sound hits your ear drum; that is what matters.

I think PianoTeq stage and standard produce data up to 48khz. If you want to use that rate, set the MAC / DAC at the same rate (eg don't use 88.1khz because your computer slows down doing useless sample rate conversion maths).  PianoTeq Pro offers up to 192khz but I don't think that will matter on a laptop for personal use.

Your computer should be able to get lower latency than 48khz @ 512 samples. That would reduce latency. Can you try reducing buffer to 256, 128, 64 samples? Sometimes PianoTeq will complain about lower buffers with a pop-up; I think you can kill the pop up (options-perf-unclick "CPU overload"); try lowering the buffer until you hear crackles and pops, which indicates the "highest sample rate & lowest buffer combo" your computer can use. Experiment with different sample rates and buffer sizes as you might find better performance at 44.1khz.

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Re: External DAC with Pianoteq?

Thanks, music-guy! I’ll try changing the parameters.

My keyboard connection is a USB cable. The DP is a Roland FP-30.

Wonder if one can roughly measure round-trip latency with a DAW, comparing the signal generated by the keyboard’s built-in tone generator with the audio from Pianoteq. Would need to have the ability to zoom-in on the waveforms, and adjust for the built-in generator’s latency.

Also imagining that one might be able to evaluate pops & clicks objectively by playing a MIDI file through known good & experimental DAC configurations sequentially, and then syncing the outputs in a DAW and comparing them. I’m not likely to get that ambitious.

Anyway, thanks for your help!

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Re: External DAC with Pianoteq?

I found an interesting thread on this subject at the Piano World forum. This thread discusses the DACs in smartphones, but I would guess that the DACs in MacBook Pros are at least as good.

Source: http://forum.pianoworld.com/ubbthreads. … hread.html

Paul: Actually the DACs (and audio chips) used in phones are extremely high quality. I should know - me and some of my colleagues have been involved in their pre-silicon verification. The transmission medium for digital makes no difference - it's the final DAC and reconstruction filter that matters. So long as you have an accurate and low-jitter clock, all is usually good. I did a test on my devices and got them all to play a digital 440Hz test tone - there was no audible beating between any of them over a time period of a minute or so. This means the frequency accuracy of the clock supplying the DACs was excellent.

[Critic]: I dont believe that DACs in phones are high quality. Seems to me it would be a waste of money as nobody is expecting very high quality here. There may be many reasons to not hear beating. I suppose the beating you get with a standard 100ppm crystal is very hard to hear anyway, as the beating would be in the order of 1 cycle per 23 seconds worst case.

Paul: You might not believe it, but it is true. Cost is related to volume and the volume is exceedingly high for the audio processing IPs that are used in the SOCs on phones. The DACs are usually 1-bit coupled to class-D amplifiers. Just take a look at the specs of the chips Cirrus Logic sells for some examples of what is currently in production. I and my colleagues have worked on both Cirrus Logic and Wolfson Audio audio IPs that end up in phones and the quality is so good that you would be pressed to hear any distortions unless you have an exceptional listening environment and transducers.

If 100ppm tolerance gives 1 beat in 23 seconds at 440Hz, then, to all intents and purposes, it's bang-on and any kind of calibration will likely not improve this any further. No-one can tune to that level of accuracy anyway.

From another thread: http://forum.pianoworld.com/ubbthreads. … hread.html

Peter: On the other side, DACs are nowadays very good, even the cheap ones. These are usually Sigma delta converters that have exceptional linearity by design and a output filter to remove the quantization artifacts. Compared to ADC's these are not complicated and expensive.

Last edited by SHartger (24-10-2017 15:42)

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Re: External DAC with Pianoteq?

For listening with headphones, it seems much more important to invest in the quality of the headphones than the price of the DAC.
Personally I use to play kennerton odin audio headphones with for DAC a simple Behringer u-phoria UMC204HD (85 €), and when I re-listen to the recordings of Pianoteq 6 with my second dac Aune X1S coupled to a tube amplifier Audio Value RKV MARK2 (with this Kennerton headphones, or one of my other 2 Stax SR007 or Audez LCD-3 headphones (unfortunately too fragile to play).) There is only a slight difference in the finesse of Acoustic sounds a little less natural with Behringer, but much better than with a Sennheiser HD650 or HD800 headphones that I used before.
(I'm not talking here about the sound I got from my pianist recordings, but from Pianoteq's reproduction with the Minnesota International Piano-e-Competition's midi files), but not all the cheap DACs are good. I was a little disappointed with the DAC Steinberg UR22 MKII which is actually especially interesting in providing free DAW Cubase.
For the integrated DAC of a smarphone, I got great results with my phone Huawei Mate 8 for example.  You should simply avoid using headphones with an impedance greater than 100 ohms, or limit the sound level to avoid distortion.

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Re: External DAC with Pianoteq?

SHartger wrote:

I am running Pianoteq 6 on a  13” early 2015 MacBook Pro, 2.9 GHz i5-5287U CPU, 8GB RAM. Powered studio monitors are connected directly to the headphone port.

I have almost the same set-up except a different Macbook. Powered monitors directly connected to the headphone port of my Macbook AIR... and my sound is just lose. No power, feels nothing like a Grand, the lows even have no juice although I do have two 8 inch woofer powered speakers.... on another post I opened people recommended an interface for me. I'm waiting for it to arrive...