I hate it when this happens. I should be working right now - finalising the content of my new website. BUT... I can't stop listening to music!

I've been using my 'reference' rig - PMII directly into Berning OTL 300B driving AKG K-1000 headphones. I know it sounds trite, but I've never heard a digital source sound so analogue. Listening to 'So What' from 'Kind of Blue', even the tape hiss at the beginning of the track sounds different. I know it's impossible, but I can almost hear the digital sampling with Engine#3 - the hiss has a granular texture. With Engine#4, this is gone. It's smooth tape hiss. I could swear that I'm listening to an open reel machine.

The music is just lovely. Not necessarily more 'life-like' (whatever that means)... but lovely. Nothing shouting out at you. Keith Jarrett's piano now sounds like a big and expensive piece of kit, rather than a small stand up made of MDF.

There is one caveat with all of this though. Although I haven't tested it, I suspect that Engine#4 needs QAP... on my system at least. I can imagine that without this, it will simply sound too smooth. But KS together with QAP is like peanut butter and chocolate - great on their own, but sublime together.

I'll put my neck out and say that for me, with my DAC (NOS at >=176.4K) Engine#4 may prove to be a greater step in SQ than even QAP. If indeed Engine#4 is adding some distortion and/or noise, then all I can say is that I like it!

Mani.

IT WORKS!!!!!

Thanks for getting this sorted out Peter - really appreciate that.

The lowest Q1 setting seems to be dependent on the buffer being used. With a buffer of 3072, I can take Q1 down to +3. Lower than this, and I get distortion... and the music plays at half-speed weirdly enough. With the buffer at 128 (as low as I can go at 176.4KHz), I can take Q1 down to -1 no problem. Below this, I get the same distortion as before.

So, with the buffer at 128 and Q1=0, I played a few minutes (only a few!) of music - just one track actually. I tend to start with an HRx 176.4KHz track to assure myself that everything is bit-perfect at 176.4... and indeed it is.

How to describe Engine#3 vs. Engine#4? Well, with Engine#3, you see the trees - hell, you see the branches and the leaves and the insects crawling around eating each other! With Engine#4, you see the forrest in it's entirity. It's a more 'organic' sound. It's less 'shrilly' and 'shouty'. It seems to have a nicer tonal balance - the harmonic texture of violins seem fuller and more pleasing. But whether this is more accurate or not, I don't know right now.

Just my very early thoughts.

Mani.

You know Peter, you just shouldn't let such people through the door...

FWIW, whenever I've compared a Linn hirez (24/88.2, 24/96 and 24/192) or an HRx 24/176.4 to the equivalent 16/44.1 with QAP, I've preferred the hirez. (The Linn 24/88.2 and HRx 24/176.4 files were mastered on the same machine that I'm listening to them on - I'm not sure about the Linn 24/96 and 24/192 files.)

With my DAC, QAP definitely sounds more detailed than with no upsampling - I wouldn't call it more analogue... there's just more life in the music, if that makes sense. It certainly brings 16/44.1 files closer to their hirez Linn and HRx equivalents. Any other form of upsampling that I've tried takes 16/44.1 files further away from their hirez equivalents... just killing the sound and making it dull to listen to, with no life whatsoever.

Mani.

Still 

Hey Peter, I thought the BD-Design CrazyAs that you're using were chip amps, based on the LM3886. If they aren't, then I apologise profusely...

In any event, I've been meaning to do a write up of my experience coming over to your place. Unfortunately, work is just too busy right now (I'm currently in Barcelona, preparing to speak to 600 top guys from Philips on Tuesday!). But I will say that I loved the sound of your setup...

Mani.

You'd better change your power amps then 

Mani.

Peter, what are, or will be, the implications of this (if any) for the rest of us?

Mani.

My battery life is plenty long enough to hear my 13 seconds of KS glory... before I run out of buffer

Actually, my audio laptop is ancient and the battery is terrible (15-20 minutes). But I've ordered a new battery, and hope to get 1-2 hours out of it at a go. This is enough for my 'serious' listening sessions.

I wonder... what are you 'desktop boys' doing to filter the inevitable noise from your SMPS to your MB?

Mani.

Sorry, totally


Pedal, this is really interesting.

I can understand why a DAC connected via adaptive-USB to a laptop would be influenced by a cr*ppy laptop power supply - with adaptive-USB, the clock resides in the laptop, and massive jitter reduction therefore needs to be undertaken in the DAC, usually through ASRC.

This should not be the case in my situation. Daniel Weiss is totally adamant that his firewire products use an isochronous protocol, where the clock sits in the DAC/interface. In my case, I take things further by having the interface slaved to my DAC.

Theoretically, I can't see how packets of data from the laptop to the interface could carry jitter. But it seems it really is there and is clearly audible (if indeed what I'm hearing is caused by jitter).

Mani.

jkeny,

Thanks for the suggestions - I will try the first, and continue with the second if that fails.

But just to be clear, I cannot hear any obvious noise with AC power, i.e. no buzzing or increased static/hiss. What I do hear though is an added 'shrill' or 'edginess' to virtually everything. It makes it difficult to listen to - almost bringing too much attention to the sound.

FWIW, I really can't imagine how KS could improve upon what I already have (when I'm running from battery). If what I have now was the end-game, I'd be happy!

[EDIT: Is there such a thing as an 'end-game' in this hobby-cum-obsession of ours?]

Mani.

I thought bernharddiner (with a DAC2) was experiencing the same problem as me, no?

In any event, I've tried all the clock variations, to no avail. I'm pretty certain it's the DICE firewire driver that's to 'blame'. Hopefully, you'll find a solution...

Mani.

Things are a bit stranger than I originally thought.

I'm measuring -1dB for the 0dB signal! This is true for XXHE no upsample and with QAA. (Just to make sure, I checked with Foobar, and am getting the same result.)

So, three possibilities:
1. the test tone is not 0dB (I doubt it)
2. there's some attenuation happening in my computer (I doubt it - HDCD would not be recognized by my DAC if this were the case)
3. the meters on my PM Model Two need re-setting/re-calibrating

In any event, for the 1KHz 0dB sine wave; with AA, I'm getting -1dB; with AP, I'm getting -3dB.

With music, the difference is greater. Taking something like Whitney Houston's 'Your Love is My Love'; with AA I'm getting 'overs' from the first note; with AP, I'm never getting above -2dB.

What I think we can surmise is that the attenuation is greater than it needs to be. I would say by 2dB.

I can change the sensitivity of my 'over' meters to measure between 0 and 7 successive full scale data words. I'm happy to play around with this if you were to decrease the attenuation.

Mani.

Hey Peter, as always, your efforts are much appreciated.

But quite honestly, I love the sound I'm currently getting from 0.9y-5 with Engine#3. However, this is only the case when I'm running my laptop on battery power. The difference between batttery and AC is just huge... the former I love, the latter I just can't listen to. The master clock is in the DAC, the firewire interface has it's own power and yet how the laptop is powered still matters...

On another point, I think you may have over-done the attenuation with AP. Playing a 0dB FS 1KHz sine wave, I'm getting a reading of -3dB on my machine. I know this won't have any reconstucted peaks, but I'm not getting above -3dB with any type of music either. Of course, maybe my meters aren't 'sensitive' enough to register a limited number of samples above -3dB...

Are you sure you're attenuating by 1.5dB and not 3dB?

In any event, QAP sounds phenomenal, so my worries about digital attenuation in this case seem to have proved wrong.

Mani.

Peter, the USB boys can wait... focus on getting the Weiss firewire interfaces working first

Mani.

Peter, yes I normally have it set to 24 bits. However, setting it to 32 doesn't seem to make any difference, as far as Engine#4 is concerned. As you said, Engine#3 is happy either way, so I stick with 24.

As you know, I tend to use a laptop (actually both the computers I've tried Engine#4 on so far have been laptops). At some point, I'll try it with the Weiss connected to the TI firewire 400/800 PCI card in my desktop. I think the Weiss is just very particular about the firewire chip - certainly, it doesn't work with some/many of them.

But do you know what might be causing my buffer issues with Engine#4... and why I don't have any with Engine#3?

Mani.

I'm constantly running out of buffer...

... something my wife's known for ages 

Mani