1966
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Ultimate Audio Playback / Your thoughts about the Sound Quality / Re: Quad Arc Prediction
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on: December 21, 2009, 05:11:01 pm
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It might well be that as I am upgrading my SPDIF interface to allow for 176.4 I will come to different conclusions as apparentlt for 176.4 and 192.2 no further interpolation would be done in the DAC. My understanding is that the BADA uses delta-sigma chips, which, by design, need to oversample... even at 176.4/192KHz. (Feel free to correct me if the BADA does not use delta-sigma chips.) It'll be iinteresting to hear your experiences nevertheless - others on this forum are reporting good results using QAP with delta-sigma DACs... Mani.
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1967
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Ultimate Audio Playback / Chatter and forum related stuff / Re: Sorry Peter, but I've beaten you... I think
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on: December 17, 2009, 10:06:47 am
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... where does a subject like this comes from ? Haha, I've noticed a couple of times that you've stated in other posts, here and on other sites, that you think you were the first to use a FF800 purely as an interface. I remember thinking whenever I read these posts, "No way, matey" . But it looks like you actually may have been the first... by a day or two... Btw 7/6 is my birthday. So, your FF800 was a birthday present? To yourself? On behalf of someone else? I do this all the time. Last year, I bought an old Berning Siegfried 300B amp, as a birthday present to myself, on behalf of my wife. She doesn't even know (or care) about the difference between a valve and a light bulb, let alone understand why I would want to spend a fortune on a 5W amp! Mani.
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1968
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Ultimate Audio Playback / Chatter and forum related stuff / Sorry Peter, but I've beaten you... I think
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on: December 16, 2009, 11:56:09 pm
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I've been doing 'Computer Audio' since 2003!
I've just been looking through some old paperwork that I have. I bought my MOTU 896HD on 28/12/03, for the sole reason of connecting my DAC to my PC. This was great - I had low jitter (by slaving MOTU to Esoteric D70 via BNC) and bit-perfect output up to 24/96K using Foobar and ASIO. And this was 2003! Some people struggle to get this even today!
On 7/6/05, I 'upgraded' to an RME FF800. I could never detect any difference in SQ between the MOTU and the FF800, both acting solely as interfaces, but the FF800 was certainly more user friendly (auto SR switching, etc).
So Peter, do I take your crown?
Mani.
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1969
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Ultimate Audio Playback / Your thoughts about the Sound Quality / Re: Quad Arc Prediction
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on: December 16, 2009, 11:12:13 pm
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No, the Model Two works internally at 24/176.4K (or 24/192K) But even if it worked at 24/352.8K internally, there would be no way of piping data into it at this rate - it only has single- or dual-wire AES/EBU inputs. I would strongly urge anyone thinking of buying a new DAC to hold off until the NOS1 arrives. I will buy one as soon as one becomes available, and will post my findings - NOS1 vs. Model Two (considered by 'those in the know' to be the best A/D/A converter ever built) - right here. Mani.
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1970
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Ultimate Audio Playback / Your thoughts about the Sound Quality / Quad Arc Prediction
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on: December 16, 2009, 09:06:22 pm
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I’ve just gotten around to doing something that I’ve been meaning to do for a while – comparing the effects of QAP on my Esoteric D70 vs. my Pacific Microsonics Model Two.
The D70 uses PCM1704 converters (in dual-differential mode) and still oversamples at 176.4KHz (I believe it’s 2x oversampling, using its FIR filter). The Model Two uses custom, discrete, full-ladder converters and is non-oversampling at 176.4KHz (I believe).
The D70 results first. With no QAP (i.e. straight 16/44.1), XXHE through the D70 sounds great. It’s a beautifully laid back presentation and about as un-digital as you could imagine. If this was the last DAC I ever had, I’d be pretty satisfied with this sound. However... engaging QAP simply kills the sound. The bass loses its tunefulness – it becomes fat and lumbering. The ambience and twinkle in the top-end is gone. If anything, it sounds like QAP increases smearing. Overall, it reminds me of why, in the past, I’ve never liked the effects of any upsampling.
On to the PM Model Two. The first thing that hits you is the shear visceral impact of the sound – this thing has an output impedance of only 20 Ohms [EDIT: 10 Ohms per leg] and will drive a bloody tank! (If you ever get a chance to hear one of these things... do it!) With 16/44.1 material, the sound is stunning. But... with QAP, it simply gets better! Everything becomes more focused. And the dynamics... well you’d better have equipment that can handle what’s thrown at it.
QAP through the Model Two is the second best sound I can get from digital. The first is from original 24/176.4 files recorded on the Model Two itself (e.g. the 24/176.4 RR files). Interestingly, these 24/176.4 files don’t sound very good on the D70, suffering the same sort of effects as 16/44.1 files with QAP.
In conclusion, I believe QAP needs a 24/176.4 NOS DAC to do its magic...
Mani.
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1973
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Ultimate Audio Playback / XXHighEnd Support / Re: Unreliable
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on: December 05, 2009, 11:12:02 am
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And laptops ? ... well ... Careful, I might get really upset I've been using a old Sony laptop (T2300 with 2GB RAM) since I started using XXHE... a while ago now. It's worked perfectly (with XP, Vista and now W7), even with the Weiss AFI1 set on the lowest latency. What I like about laptops is that they're generally pretty quiet, chuck less RFI around... and oh, you can run them off a battery - no grundge going back into your mains. Don't knock 'em 'til you've tried 'em... Mani.
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1975
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Ultimate Audio Playback / Your thoughts about the Sound Quality / Re: 0.9y-4 - w00t
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on: November 23, 2009, 01:22:19 pm
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Actually, perhaps getting the clock from the DAC to the interface 'intact' is not as trivial as it seems. Certainly, I can't see how the breakout cables that the Lynx card uses could maintain the required 75 Ohm impedance for receiving the clock 'intact'...
Mani.
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1976
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Ultimate Audio Playback / Your thoughts about the Sound Quality / Re: 0.9y-4 - w00t
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on: November 23, 2009, 12:54:35 pm
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Have you had any experience with the Merging Pyramix Mykerinos software/hardware offering? No I haven't... but I am intrigued. One thing that I've wondered for a while is how the interface can still affect the sound if it's being slaved to the DAC. It seems likely that different power supplies, etc, could certainly affect the situation if the clock resides in the interface... but when the clock doesn't sit in the interface but in the DAC instead and the interface is bit-perfect, what else is there that can affect the sound of the interface? I've been threatening to compare the 3 'interfaces' that I have (AFI1, FF800 and MOTU) in slave mode for a while now. Hopefully, I'll get a chance to do this in the next few weeks. Mani
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1977
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Ultimate Audio Playback / Your thoughts about the Sound Quality / Re: 0.9y-4 - w00t
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on: November 23, 2009, 11:20:03 am
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I think things might be a little more complicated. Loads of CD players and DACs use the PMD-100 and PMD-200 filters. Indeed, anything with HDCD replay must use these filters (other than the BADA that is, which I think uses an equivalent - superior? - filter).
For 16/44.1, I can well believe that the BADA's Filter 2 is the same as the filter that the Model Two uses... at these SRs.
But the Model Two uses true multi-bit converters, as opposed to delta-sigma, and I think does not oversample at rates >=176.4. But as you've found, it can be hard getting any definite answers from anyone.
To be honest, I'm still stumped as to why QAP still sounds 'good' with delta-sigma DACs, which by definition, need to use heavy oversampling to work. But many people are reporting that it simply does. At some point, I'll try to find some time to experiment with my FF800...
(Your friend has a BADA and a Model Two? Lucky guy...)
Mani
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1978
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Ultimate Audio Playback / Your thoughts about the Sound Quality / Re: 0.9y-4 - w00t
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on: November 22, 2009, 10:55:45 pm
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Mani, as I mentioned before the BADA has 4 filters (actually 8 as there are 16 and 24 bit versions of each of the 4 filters). Filter 2 is the same filter as used in your Model 2. Earflappin, The following has been posted on the Goodsoundclub forum: "The Berkeley Audio DAC reportedly uses the Delta-Sigma Analog Devices’ DAC AD1955A." Could you pass this by the Berkeley guys and find out for sure? If this is indeed the case, then I can't see how the filters can be the same - the Model Two uses custom, discrete full-ladder converters. BTW, a 5-6dB increase in volume with QAP is huge! I wonder what's going on... Mani.
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1979
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Ultimate Audio Playback / Your thoughts about the Sound Quality / Re: 0.9y-4 - w00t
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on: November 20, 2009, 07:50:29 pm
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Unfortunately, I'm not currently in the UK to test whether QAP sounds louder, but I really don't remember thinking that it did. If it weren't for my peak level meters, I'm not sure I would have noticed any difference in output level whatsoever.
On a totally different note, I'd like to share my experience comparing Quad-with-no-upsampling and QAP. Initially, QNU sounds 'clearer'. Everything seems to 'shimmer'. But this gets grating very quickly... almost painful! On many occasions, as I was switching between No-Quad and Quad, I would forget to tick the AP checkbox [EDIT - sorry, I meant to say "select AP from the drop down list"]. After a while, I could tell within a few seconds that AP was not on.
Mani.
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