I don't actually use RCA spdif cables in my setup (I use dual-wire AES for signal and BNC for wordclock, between the Weiss and PMII). However, I came across this thread quite a while ago that intrigued me: http://goodsoundclub.com/Forums/ShowPost.aspx?postID=5565#5565.

From the thread, apparently the old Belkin Synapse Platinum Digital cables (the blue ones from the 1990s) are the 'dog's bollocks', as we say here in the UK. You may notice that there is a poster called 'miab' who is offering these cables for $65 each plus shipping. I've just ordered a couple of these from him, and they should be in the post to me right now. I'm hoping to be able to convert one to BNC and use it for my wordclock. Assuming I don't screw it up and need the other one, I may have one spare. I'd be happy to sell it for the price I paid for it (even if I'm hit with customs duty, the price shouldn't be more than £60 plus shipping). Alternatively, you might want to contact miab directly to ask if he has more...

If you're thinking of another solution, one thing to bear in mind is that cable length is important. Some people believe that too short is no good! See http://www.positive-feedback.com/Issue14/spdif.htm.

Mani.

This is absolutely fine by me - I would be amazed if my settings sounded good with a setup such as yours.


Well, no matter what Peter thinks, there is a definite implication here... and a somewhat arrogant one at that.

Nuff said...

Mani.

Not sure what you're implying here. That my system is bright, with metallic harsh highs??? You must be kidding.

I think I've always been at pains to state that any results that I'm getting are valid for my system only. When you start using QAP with a NOS 24/176.4 DAC, you may find that your current system is actually flat and lifeless...

Mani.

"The Normal Mode shows that everything should be allright, and no skips or distortions should be audible; anyway, technically all is "measured" correct.
Not so with the Special Mode, which actually denotes things are NOT RIGHT. However, it was found that just in the case this is "near the limits" things can be allright just the same, but everything "behaves" differently. Look for different sound here !"

Peter, what else can you tell us about this, without divulging too much IC? If 'special mode' is going to become another USP for XXHE (along with AP), it'd be nice to know a little more about what's happening that might be changing the sound.

Mani.

Well, I for one am very, very happy to do this


This would be great... provided it works for as many cards as possible.

Mani.

PS. My Q settings add up to 42, which must be the optimum setting (for all you Hitchhiker's Guide to the Galaxy fans)

I can get 'special mode' ...

... but it's all distorted

It's now 1:30am and I think I've found the optimum setting (for my system). Are you ready for this? It's: Q1/Q2/Q3/Q4/Q5 = 3/9/15/5/10!!!

Don't even ask how many permutations I've been through to get here...

The caveat it that with this setting, sometimes I get 'special mode'... and the requisite distortion...

BUT... sometimes I get 'normal mode'... and such, such sweet music

I'm happy... and very tired... but not too tired for just one more tune!

Ciao,
Mani.

Please ignore any references to gaps in playback in the above post. This has been easily solved by changing my firewire driver.

0.9y-5-06 now works perfectly down to Q1=-1. For Q1=-2 to -4, I get still get 'normal mode' showing in the log file... but it sounds anything but normal - distortion plus half-speed effect. No 'special mode' for me

Mani.

I was still talking about 0.9y-5-04, which is the only stable version of KS on my system. Sorry for any confusion.

But FWIW, here are the CPU graphs for both 5-04 and 5-06. On '506 Q1_-1 with gap', you can see two peaks in CPU usage around the middle of a track. The first is a periodic peak which doesn't interrupt playback. The second peak does interrupt playback for a 2-3 seconds, after which time playback resumes as normal until the peak happens again a few minutes later.

[EDIT: All graphs except '506 Q1_-1 with gap' are taken at the very beginning of the music - do not include pre-processing.]

Apart from a peak at the very beginning of playback, latency (not shown) remains totally flat at the 50μs level throughout.

Mani.

OK, I've got it now!

Peter, I'm having problems with 0.9y-5-06 (and 5-05). I've got gaps appearing intermittently in the music. Also, Unattended seems less 'responsive' than before. It takes ages for the wallpaper to come up and for the Alt-X command to work.

None of this happens with 5-04. But the 5-04 log file is interesting. I seem to be running out of buffer just as the music starts - there is a spike in latency exactly at this point also. But nothing is really audible - there may be a tiny, tiny hiccup heard sometimes, but nothing to worry about. Once the music has started, it continues without any gaps. I still get the odd very, very faint crack or pop coming through from time to time though...

On a final note, there is a big difference in CPU usage between Q1=0 and Q1=-1. The former is quite constant, the latter is full of periodic peaks and troughs...

Mani.

Hi Dan,

When you talk about 'oversampling', are you refering to what BAD call 'interpolation'?

Mani.

There seems to be an inconsistency:

Highest buffer setting - exactly when the distortion sets in, I stop getting a 'YES' (Q1=+2).

Lowest buffer setting - when the distortion sets in, I still get a 'YES' (Q1=-2).

I thought perhaps it wasn't working right. But if it's not important, that's

Mani.

PS. Still pleased with Engine#4

Peter, I get a 'YES' all the way down to Q1=-4. However, I get distortion (the exact same that I described before) at Q1=-2. I therefore have Q1 set to -1.

(I started at Q1=+14, then +5, 0, -1, -2, -3 and -4. Should I have come down from +14 in single increments?)

Mani.

Rightly or wrongly, I look at it like this: if we can't even get digital playback right, what chance do we have of getting digital x-over right?

How can bit-perfect players sound different? How can the same player sound different with different means of bit-perfect output? Maybe digital x-overs will get better and better as we learn more about what's actually happening in the digital domain. But make no mistake, right now we don't seem to have a clue...

But ultimately, it's about compromises right? And as Peter says, maybe the net result of using digital x-over is better for some people than using other means. But for me, it wasn't.

Mani.

PS. @Telstar, the Pass XVR1s are line-level active x-overs

Welcome sr1329!

I totally agree that much care needs to be taken with x-overs (not just passive).

FWIW, a few years back, I 'dipped my toe' into the world of digital x-overs, but really didn't like the results I was getting. There just seemed to be something fundamentally wrong with them (certainly back then, but I suspect still today). After playing around for a while, I stuck with my analogue Pass Labs XVR1 x-overs set to 6dB/octave...

Sorry I can't be of more help.

Mani.

A good track to try is track #5 on the 'Beethoven Piano Concertos 3, 4 & 5' recording (Linn CKD 336). Of course, the music itself may not rock everyone's boat, although I have to say that Beethoven is my favourite composer.

You can download a number of different versions of this track (all FLAC):
1) 16/44.1 (HDCD-encoded)
2) 24/96
3) 24/192

Let's, for the sake of argument, assume that 1) and 2) are derived directly from 3) by decimation. If this is the case, then Linn must have used a PM Model Two to create 1)... because it's HDCD-encoded. This gives me a bit of confidence that the job's been done right.

1) with QAP comes closer to 3) than any other configuration in XXHE. However, it's still not as good. Although I think the tonal balance is very similar, it's just a tad flatter, with a bit less life. Could this be due to the decimation process? Maybe. But whatever is lost is not regained by AP.

Mani.