Active with Linns or Chord DAC64

Basically my question is to go active bi-amped or get an off-board DAC?

I recently got some Linn Keilidh floorstanders, which I'm enjoying very much. The detail and soundstage are very enjoyable. Combined with an Auralex acustically treated room, an SVS active sub and some huge bass traps, it's a clarity I've rarely heard before.

The Linn Index's used up front before were quite a bit more lively, but nowhere nowhere near as detailed, nor as tunefull in the mid-bass.

I'm hearing so much more off my old CD's than I thought possible, and being me, I want more!

I'm running these off a pc with an Audiophile2496 soundcard, currently outputting 24-bit at either 44.1KHz or 96KHz s/pdif digital straight in to a £1300 Denon A10SE av amp.

What I have noticed is that now the room and speakers are much lower distorsion that I'm tempted to listen 3-4dB louder than before, which is now rather loud and I fear for long-term hearing damage. I'm talking the amp showing -10dB (below reference THX level for films), minus about 5dB by ReplayGain = CD's equivalent to -15dB off a normal CD player.
[edit: added specifics on dBA in new post]

The Denon is well regarded for it's musicality. Indeed outputting straight in to a THX Ultra Denon POA-T10 power-amp straight from the soundcard's analog outputs was less enjoyable than digital spdif via the A10SE.

This tells me that either the Audiophile2496 analog output is poor (although it's very well reviewed as a pro card) or it shot some EMF/RFI that the amp didn't cope well with, and that the A10SE pre-amp section and DAC's aren't bad, I think they are 24/96 types, but more than that I'm not sure.

I'm considering what I'd like to aim for as my next upgrade for 2-channel music.

a) Two s/h Linn power-amps and ACTIV crossover cards. Sell the Denon POA-T10 to partially fund this. £500

b) Tag DAC20, analog in to the A10SE. It apparently also includes a convenientdigital bypass to send DD5.1 or DTS straight to the AV processor without playing white noise through the analog outs. £400

c) JISCO or other in-line jitter improver. £500

d) Chord DAC64. Supposedly puts CD SPDIF replay in to a different league, reportedly mostly transport independent. £1900

Any suggestions or comments appreciated.
regards,
Rob.

 

I can only comment on the active Keilidhs (which I have) and I find them very good. You don't have to have linn amplifiers to do it, but it's probably easier that way (they mount the cards inside the power amps). It all makes a very nice noise.

 

I havent tried the optical connection with a DAC64, only balanced and regular RCA connections.

With these connectors, I could clearly and audibly hear differences between transports on a DAC64.... It was at a ''bake off'' - so HenryT, Julian2002, Robbo, Wadiameister and others heard the transport change too...

Having said that, I consider the DAC64 excellent, and would expect a real benefit.. but who knows if it will make the biggest bang for buck difference in your kit? worth an audition for sure.

Whether this would be better than going active on your Keileghs, I cant say..

good luck with it
Chris

 

Hang on a moment, this looks like a wind up How come you have bass traps, an acoustically treated room and then ask a question about whether you should go active or buy a new DAC?!!!

Surely, if you've setup your room correctly, you know the gigantic differences speakers and rooms make - and the (mostly) immeasureable (and therefore unhearable) differences that DAC's or "active operation" make.

Huh? Are you using your PC as your transport (ie you put CD's into it?) or have you ripped your CD's to eg. MP3?

Huh? THX reference level is 85dB measured using an SPL meter at the listening position. The amp has nothing to do with it. BTW 85dB ain't that loud..

That makes some sense if the ANALOG (volume) section of your sound card isn't up to much..

Just how quiet is your PC? That is usually the most noticable difference compared to a dedicated CD player.

I assume that you are aware that AV processors can (and should) do significant massaging of the signal, and this might account for the differences if you have misconfigured your processor.

With your subwoofer you are locked into 2.1 at least.

Well, if you sell your AV processor, you have a problem with "bass management". The good thing about a processor is that it will massage the main channels and remove much of the bass, making the fronts job easier as they don't have to deal with full range bass.

If you go down this path, you'll be on the linn upgrade treadmill.

Linn (and naim) do active all the wrong way: if your designing an active speaker you should do so from the ground up and the amps should be built in and optimized for the driver they are connected to.

If you want active speakers you should look at ATC

But you loose bass management - your AV processor can delay the FRONTS, whereas the controls on your subwoofer cannot... Moreover, there is the question of whether you should roll off your fronts "naturally" or whether you shoudl filter the signal to them.

The jitter (if any) is after the processor in the AV unit so fiddling with its incoming spdif will do no good.

That's a very expensive DAC to use in conjunction with the analog pass-through (digital bypass) of an AV processor.

If you beleive in acoustic treatment, I shouldn't have to say this , but... Make sure your sub/main integration is right using a proper tool like ETF (http://www.etfacoustic.com/) this will cost you $500, but will last forever and will help you with placement of your sub, traps and acoustic treatment. It could well be the best $500 you'll ever spend. You should also spend $35 on F Alton Everests "Master Handbook of Acoustics" if you don't already have a copy.

If you want active speakers then go shopping for ATC.. Linn and naim are just pretending to be active because it gets their users onto the "upgrade crack" to their excessively expensive amplifiers.

Don't waste your money on expensive DAC's until your sure that you understand bass management and how to setup subwoofers. Think through whether you want to delay the signal from the main speakers to coordinate the arrival of the sound from the sub and the mains - this is far from trivial. Look over Floyd Toole's papers at Harman:

http://www.harman.com/wp/index.jsp?articleId=120

http://www.harman.com/wp/index.jsp?articleId=121

http://www.harman.com/wp/index.jsp?articleId=122

Good Luck!

 

Thanks Guys.

Room treatment was a huge improvement in sound, that's why I did it before considering getting a bit esoteric with the replay chain.

THX reference level is CALIBRATED at 75 or 85dB, it maxes out at about 105dB IIRC at 0dB volume. It's hard to compare film and CD volume levels as CD's use dynamic range compression, are often way up on level and have no actual level standard. I know the ReplayGain feature aims for 89dB, but I'm not sure if that's average level or peak level. No actually that loud? Gosh! I'll have to measure SPL's, as that would be a cheap option:- don't be a wimp and turn it up!

If I went the Linn ACTIV route, it would be the Denon POA-T10 2-channel power-amp I'd sell, not the Denon A10SE AV amp. I do know that once I've got the Linn ACTIV cards for my speakers that fit the Linn amps I choose I'd be pretty much dead end. But then again I don't see me upgrading again for a very long time. I have read quite a few comments that agres with tones' experience, in that getting rid of those passive crossovers in any speakers are a big upgrade, much more so than changing to a slightly better amp or two.

I auditioned some M&K and BlueSky 6.5 Active monitors and was very impressed with those, although I think the Linn Keilidhs are very similar in neutrality and lack of listening fatigue. I went to the audition thinking if they were amazing, I could sell the Keilidh's and the POA-T10 power-amp and that would fund a pair of them at least. I came away thinking how nice they were at £750 a pair including amplification, but also how nice what I have is. It is another option.

I hear what you are saying about sub integration. That's one of the things I really like about the A10SE, it seems to do it well without effecting the front channels much. I'm familiar with response measurements and phase changes.

I do understand the caution around any 'AV' product, many of which sound horrible for music.

I don't actually use a DVD/CD-drive for playback. I rip my CD's to lossless .APE format and have a large library of music playing off the quiet pc, you know cpu fan speed adjustment, large cpu heatsink, fanless graphics, Zalman 'silent' power-supply, fdb hard disk, etc. This way I have easy access to my music and don't have CD media to arrange or risk scratching, as they can be put away. After running a couple of hours, the pc isn't totally silent, but still way quieter than my PS2, X-Box or TIVO.

I disagree that jitter is after the processing in the av amp. From what I've read, this slaves off the SPDIF source, which will have jitter defined by the accuracy of the crystal on the soundcard.

The A10SE AV amp has a Direct mode that avoids digital processing, but as dac19 pointed out, I'd then lose my high-pass filter for my main speakers, surprisingly the sub low-pass output is still available, which apparently is an analog low-pass implementation. To be honest, I couldnt say I can hear a huge difference between the Direct and Stereo modes, even though in theory there's more sub/mains overlap and the mains then are put through a 24-bit DSP, before then either mode goes through DACs for any digital SPDIF source.

I am a convert to blind ABX'ing. I have been surprised what I thought I could clearly hear the difference between, but in a blind comparison, I couldn't reliably tell them apart.

Yes, putting a DAC64 in front of even one of the best AV amps might also be overkill and not get the best out of it. I just don't know, although I'd certainly be looking at a home trial before parting with almost £2K!

What's the difference in performance of a DAC20 compared to DAC64, as there's an over 4x price difference at the moment. Trouble is the DAC20 is a direct price, so no home trial.

My question is really how to work out what to do.

Will giving a really clean, tunefull analog source be any point?

regards,
Rob.

 

if i understand you correctly then the dac64 would be a waste of money i nyour system.
you'd be taking the digital signal out of the transport converting it to analog in the dac 64 and passing it to your dennon a/v amp which would then convert it back to digital, filter it and then convert it back to analog for amplification. surely any benefits the dac 64 would bring would be eliminated by the subsequent adc / dac that your a/v amp would do. this of course would not be the case if you used the analog bypass but then you'd lose the filtering as has been pointed out.

this is one of my main gripes with a/v / stereo integration done this way.

cheers


julian

 

What a good point Julian, which I had totally missed. Unless running Direct mode, the AV amp will be ADC and DAC'ing any analog input even if the DSP is transparent.

I might be tempted to run Direct, without the sub for music, although in my current system it just gives the edge on things like kick-drum weight and control compared to the Keilidh's alone. Although I haven't tried without a sub since getting all the room treatment up.

I happended again last night, I went in the room a watch a film and ended up listening to more of my back CD titles. What a shocking waste of an AV system!

cheers,
Rob.

 

Why? It shows you have manage to set up a very good system that let you enjoy your music collection very much. Is that not what you wish for to start with? Unlike a conventional stereo system it also has another built in ability.

 

Thanks wolfgang, yes I was being ironic, but it doesn't pass over too well on the internet.

regards,
Rob.

 

FluffUser,
My mistake. That is the weakness of reading too quickly. If I read your earlier post correctly not only you are a blind ABX believer but practioner as well. Hope you find the solution you are looking for.

 

I checked in to listening levels. The Foobar2000 CD player's ReplayGain auto-level setting implementation aims for 89dB (equal loudness weighting, like A-weighting but more accurate) average for 95% of each album. ref: http://replaygain.org/ (note: ignore the talk of just MP3's, this is way out of date with players, like foobar2000.org)

I think I also read somewhere that most people find 83dB average levels about the threshold of being uncomfortable (assuming reasonably minimal distorsion). This would be a -6dB setting on the amp, which I find slightly too loud.

Q: What average (a-weighted, slow) meter levels do you folks listen at?

Listening at a -10dB amp setting from this source gives average levels measuring about 79dBA-34dBA, which ties in with the above, with peaks at about 93dBA max (102dBC-weighted) registered on my analog meter on fast, I happened to be listening to a few Eurythmics Savage and U2 Rattle and Hum tracks when I measured.

ReplayGain is set to do this per whole album, so some tracks may be louder than the album average, some quiter as the artist intended.

Classical would be more dynamic so peaks possibly higher, where whereas modern dynamically compressed pop would have slightly lower peak levels when se by average album loudness automatically in this way.

Your thoughts appreciated.
regards,
Rob.

 

89dB compared to what? dB is a relative scale.

Normally, the implicit base for sound pressure level's is 20 micro-pascals.

Again, -6dB on the amp is meaningless without knowing what SPL it generates.

Roughly:
120dB SPL is the point of pain..
80dB SPL is a noisy office, traffic noise.
40dB SPL is a "quiet residence".

80+dB. I'm listening to Gomez, Drench - the words "come and fight back" are hitting about 82 A-weighted/slow.

Turn that feature off and take your measurements without it..

I haven't heard the effect ReplayGain has, but I'd be inclined to turn it off all the time

 

Where would you say the middle of the A/slow needle sweeps are?
i.e. If the needle sweeps between 78 and 82, then the average is roughly 80dB?

I'm not sure why you are discounting dB, as it seems we have common measurement to use here.

ReplayGain is a great way to pre-calculate the ideal listening level for each album or track. All adjusted in the source digitally at over 24-bit precision before dithering down to 24-bit for the DACs.

It means no tracks sound way too loud or quiet. Too loud is fatiguing, too quiet means on not hearing as much dynamics as I could. I'd really miss what it gives me.

cheers,
Rob.

 

The "slow" setting is doing time interval power averaging, so it is already displaying the average.. Simply averaging 78 and 82 doesn't take account of the relative intervals of the sound intensity.

I'm not. I am cautioning you against comparing dB's from different domains... eg. dB's in replayGain don't have anything to do with Sound Pressure Levels...

No, it doesn't pre-calculate the ideal listening level. It normalizes the level of the signal through time-power averaging (if the matlab files are anything to go by).

Once you set the volume control for one album, the others will have similiar SPL averages on a *long* time constant..

If it sounds any different to you setting the volume control for each album, then it is doing something it shouldn't be doing - varying the average sound level over a short period. If anything it is reducing your dynamic range by making quiet passages artificially louder..

 

Nope, settings are per-track or per-album, pre-calculated by analysing the whole album in advance. No dynamic range compression, that's for sure.

regards,
Rob.

 

Agree with most of your points.
From my understanding dB scale is not that difficult to explain.

The scale start at 0 dB which is understood to be as the quietest perceivable sound by healthy normal HUMAN being at the age of teenage. Therefore anything above is more many times louder it is relative to this.

Google search find a site as define as 0.00002 Pascal of sound pressure or 0.000000000001 Sound Intensity watts/m.

When you try to measure it with a SPL meter you buy and then read more about it is when it becomes more interesting. It is a bit like how deep the rabbit hole you wish to go.

http://www.safetyline.wa.gov.au/institute/level2/course18/lecture54/l54_03.asp