DAC designs

Dedicated to the silver disk spinner
SimonC
Old Hand
Posts: 545
Joined: Mon Sep 24, 2007 11:34 am
Location: West Yorkshire

#1 DAC designs

Post by SimonC »

There's been talk over the last few weeks about various DAC designs, and maybe even having a go a designing one ourselves :help:

So here goes, everyone throw your idea's & opinions into the pot and lets see where it takes us.

There's some very strong opinions on the web around which DAC chip, over & non oversampling, up-sampling, buffers, re-clocking, jitter, I2S vs. SPDIF etc. Between us all we probably have heard a fair selection of the different options, plus the SB mods that have been floating around.

What do people want from a DAC?

Simon C
User avatar
pre65
Amstrad Tower of Power
Posts: 21373
Joined: Wed Aug 22, 2007 11:13 pm
Location: North Essex/Suffolk border.

#2

Post by pre65 »

Hi-how about a shoot out at some time to see what differences can be heard from various types ?
The only thing necessary for the triumph of evil is for good men to do nothing.

Edmund Burke

G-Popz THE easy listening connoisseur. (Philip)
User avatar
colin.hepburn
Shed dweller
Posts: 2294
Joined: Sat Jun 02, 2007 1:24 am
Location: Scotland Aberdeenshire

#3

Post by colin.hepburn »

Hi all
Well as I am looking in too upgrading my older CD player the marantz CD 67 with valve output and clock chip plus other parts internal Dac on this player is SM5872A/B my other Player is the Marants CD52mkII SE internal Dac SAA7350 this is the player I was think of adding an external dac kit too But what do I know About Dacs???? :? The what/why /how /who of a DAC well don’t know but the TDA 1543 chip seems popular as this one DAC DIY Kit DAC-AH CS8414 24bit 96KHz
And a DAC DIY Kit DAC-38T PCM1704 96KHz 24Bit
http://store.analogmetric.com/category.php?id=21
but would valve output be better and would these Dacs work well with the Marantz players how do you find out with out spending a load of cash on trial/and error what do you think :o
:? :?
Colin
The Blues man ImageImage
User avatar
Nick
Site Admin
Posts: 15707
Joined: Sun May 06, 2007 10:20 am
Location: West Yorkshire

#4

Post by Nick »

If you asked me theis a month ago, I would have been less than enthusiastic, and thought it wasn't something I was bothered about. However after hearing the TDA1541 (four pf them) based Cambridge audio DAC of Ians, I reaslise that there is a lot of imrovement to be gained over the current CD sound I am getting.

Before that, I was using the modified Toshiba DVD player (better op-amp and black gates in the signal path). Then aving got a Berisford DAC, this confirmed that the Toshiba was doing a god job, as while there was a sall difference between the DVD and the DAC, I would be hard presseed to say what was better. Then hearing Mos modified SB3 confirmed that, again there was a difference, but not one that would have made me spend money.

Then this old, low tech 1541 DAC blew this all into the water. It wasnt just me, the difference was heard by the people at SimonCs get together.

What was interesting to me though, was the Cambridge was much better than the Berisford, but sounded very similar to Colins (Topsies) CD player, so whatever I liked in the Cambridge, that was doing it as well.

I have looked at the AnalogMetric kits, and they seem worth a try for the money. I have aloso looked at the NOS design Thorston produced, that looks interesting, and the idea of transformer I/V conversion appeals to my valve head, and I found that Sowter had a range of TXs for that purpose, so it clearly was a option that several had used.

There is a interstign thread on DIYAudio (I think) about taking the i2s stream, and using a bunch of shift registers and producing time shifted copies of the stream, feeding them to individual 1541s and then summing the output, to give a linear interpolation of the signal. But having not heard the result, I can help agree with the comments about the distortion introduced to the signal by drawing a simple line between the 44k points.

The 1543 looks interesting as well, because of its small form factor and lower cost, and there is a interesting review of a dac with 16 of them in this months HiFi world. The measurement section is full of reasons why it will sound bad, and muddled, and the review is enthusing over how transparent and clear it sounds, possible the best they have heard.

I must admit the review of that DAC does match a lot of what I heard listening to the Cambridge DAC.

I think it would be interesting to compare DACs some time, but I don't know how many different ones we could get access to, and I wish we could find a less confrontational term than "Shoot out" :-( (but thats just me)
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
User avatar
al newall
Needs to get out more
Posts: 1737
Joined: Mon Aug 06, 2007 7:55 pm
Location: Chester

#5

Post by al newall »

Well Owston ain't far off now.

I'll have a CS8416/4397 DAC ready very soon, with or without tube output section.
Add this to your list. :)
Much to learn there is.
User avatar
pre65
Amstrad Tower of Power
Posts: 21373
Joined: Wed Aug 22, 2007 11:13 pm
Location: North Essex/Suffolk border.

#6

Post by pre65 »

Hi-i can bring my Shek NOS DAC with the "uprated" DIY power supply.
The only thing necessary for the triumph of evil is for good men to do nothing.

Edmund Burke

G-Popz THE easy listening connoisseur. (Philip)
simon
Thermionic Monk Status
Posts: 5600
Joined: Thu May 24, 2007 11:22 am
Location: People's Republic of South Yorkshire

#7

Post by simon »

Nick wrote:and I wish we could find a less confrontational term than "Shoot out" :-( (but thats just me)
Nope, it's not just you Nick. Shoot out is an emotive term and implies "there can be only one" to quote Highlander. There are several ways of doing anything in life, and IMHO the term goes against everything we believe in as experimenters and DIYers. Can't we just call it a comparison? Okay, got that off my chest, sorry for the rant.

Some interesting points Nick, and I suspect that as pretty much all of us listen to digital music to some degree we are all interested in a good DAC. For my part I can't offer a great deal as I don't really understand the workings of DACs but for sure I'm interested.
User avatar
pre65
Amstrad Tower of Power
Posts: 21373
Joined: Wed Aug 22, 2007 11:13 pm
Location: North Essex/Suffolk border.

#8

Post by pre65 »

Hi-i understand the comments re "shoot out" but surely,its just a word (or two) to describe what we all know IS just a comparison.

Perhaps i should have said DAC evaluation session ! :lol:
The only thing necessary for the triumph of evil is for good men to do nothing.

Edmund Burke

G-Popz THE easy listening connoisseur. (Philip)
User avatar
shane
Social outcast
Posts: 3403
Joined: Sun Sep 16, 2007 12:09 pm
Location: Kept in a cool dry place.

#9

Post by shane »

Just call it a DACfest...
User avatar
Nick
Site Admin
Posts: 15707
Joined: Sun May 06, 2007 10:20 am
Location: West Yorkshire

#10

Post by Nick »

Hi-i understand the comments re "shoot out" but surely,its just a word (or two) to describe what we all know IS just a comparison.
I know its off topic, but I don't think you can underestimate the way that simple words can affect how people interpret and behave.
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
User avatar
Nick
Site Admin
Posts: 15707
Joined: Sun May 06, 2007 10:20 am
Location: West Yorkshire

#11

Post by Nick »

Just call it a DACfest...
More of a SourceFest, as DTB has already suggested a Phono Stage retrospective would be of interest to him.

But we should remember that Steve is organising Owlson, so whilst I know he takes the "its up to the folk who go to decide" view on the events, we need to remember that its not only a few peeps from this forum going, so it might be polite not make too many plans about the weekend.
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
User avatar
Dave the bass
Amstrad Tower of Power
Posts: 12273
Joined: Tue May 22, 2007 4:36 pm
Location: NW Kent, Darn Sarf innit.

#12

Post by Dave the bass »

shane wrote:Just call it a DACfest...
"DACattack"?

"DACwars"?

"Dac wun sounds nice"?

:)

DTB
"The fat bourgeois and his doppelganger"
User avatar
Dave the bass
Amstrad Tower of Power
Posts: 12273
Joined: Tue May 22, 2007 4:36 pm
Location: NW Kent, Darn Sarf innit.

#13

Post by Dave the bass »

Nick wrote: More of a SourceFest, as DTB has already suggested a Phono Stage retrospective would be of interest to him.
.
Yep please, I'm very excited at the prospect of listeing to others Phono stages and more to the point being able to hear what mine is/isn't doing alongside them. Brute honesty should be employed but I like the phrase compare/contrast too.

To make it fair on Steve maybe we could arrange summink like this on a sunday when I think it's (according to past event postings) a bit less busy.

DTB
"The fat bourgeois and his doppelganger"
User avatar
pre65
Amstrad Tower of Power
Posts: 21373
Joined: Wed Aug 22, 2007 11:13 pm
Location: North Essex/Suffolk border.

#14

Post by pre65 »

Hi-i was thinking (dangerous at my age !) of a way to compare my CD output with/without the DAC.

If i leave the DAC wired in as it is to the pre amp CD input and then wire up the CD player phono outs to the pre amp tuner input i can then do an instant comparison by simply moving the input selector one click.

Any reasons why it won't work ?

Today is a preparing the Metisse for racing on Sunday day so i will try the comparison later.
The only thing necessary for the triumph of evil is for good men to do nothing.

Edmund Burke

G-Popz THE easy listening connoisseur. (Philip)
User avatar
Nick
Site Admin
Posts: 15707
Joined: Sun May 06, 2007 10:20 am
Location: West Yorkshire

#15

Post by Nick »

If i leave the DAC wired in as it is to the pre amp CD input and then wire up the CD player phono outs to the pre amp tuner input i can then do an instant comparison by simply moving the input selector one click.
No, thats exactly what I did to compare the Berisford and CDP.

Yes, I know I complain about the merits of AB comparisons. :-(
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
Post Reply