rickcr42
Fully Modded
Rest in peace my good friend.
Posts: 4,514
|
Post by rickcr42 on Mar 9, 2008 16:56:36 GMT
means nothing to the playback end since it is a rare system (and even rarer room) that can get down to 10hz and you can't HEAR 100k though you CAN sense it as the research has shown and part of the reason why som,e are sensitive to "digitalis". Add to that an anti-aliasing filter is a SHARP cutoff which comes with all manner of audible and inaudible problems or you end up with digital artifacts (even more audible) and the fact that a single pole passive device produces a gentle rolloff and you get a situation where the upper end just gradually rolls off rather than come to an abrupt end at best and where you add another pole of rolloff at worst.What you gain is far more pleasing in the musical sense thgan any losses unless again you are the type that needs to SEE how good something SOUNDS rather than just listen and enjoy the lack of background grunge from breaking the digital ground with all the RF artifacts in the signal. Pretty damn close.Maybe not in the same league as a precision resistor but far better than than you need IF you use a quality part.As for price limites you spend the same building an active stage when you add in the cost of powering it and in many cases FAR LESS than an audiophile interconnect which is more con than it isa system improvement in many cases actually I do and even if not am pretty much stuck with it being the way of things.what pisses ME off is I will listen to a CD or a digital stream and enjoy the music for what it is,much like when I listen to the radio and enjoy the song rather than pick apart the format,but then I spin a disc and dammit ! It sounds RIGHT and i look back at the digital and think to myself "WTF ! There GOTTA be a way to make the one sound like the other and so is where I target my DIY attempts.How to get the digital from "analytical perfection" to "damn !Let me strip naked and dance on the table" Seems we humans can accept some kinds of distortion and it is no big deal while other types piss us off,make us wince or over time just get listening fatique. Analog may be noisier on paper but the reality is those forms of noise are really no big deal when it comes to enjoying music. At the lower end we have the inherent noise level of the format (disc or tape) that we reach a level at which the noise level and the information are a wash-equal in intensity.But by the time we get there more often than not you can't hear the damn note anyway ! It is below the actual room ambient noise level so for instance a car going by will be higher in level (yet we are not bothered by it) or someone down the road yelling may be louder than the music or a plane going overhead,etc,.and yet we accept it as being a natural even t thus no intrusion.Analog falls back gradually until it dissapears into that noise.Digital runs out of bits and becomes "woody" and to me that is more aggravating than any slight hiss between cuts or surrounding some low level solo instruments. As for T-amps,no.I have little or no use for anything not Class-A so even AB is off my personal list though I know there is a place for all the above (more power,less heat,less size,less loot) The DAC chip itself has both a digital ground and an analog ground so that is the place to connect the two AT A SINGLE POINT but before that ? I am more of a "ground groups" type so I guess you would call it "global quasi-star-grounding" so each function in the DAC block will have its own "mini-system" with its own star then all the "stars" rought to a single buss.Way easier than it sounds andf is in fact very intuitive to implement when you do the layout on paper (with a pencil for those inevitable screwups ) Smart man.Hope for you yet dude
|
|
pagan
<100
How do I activate my account?
Posts: 81
|
Post by pagan on Mar 10, 2008 8:09:40 GMT
Alex and the others were amused with all the wires from various pionts on the cd67 going to small pcb then to earth.
|
|
jonclancy
Been here a while!
Mr. Ripple Eater
Amateur EAGLEist
Posts: 1,131
|
Post by jonclancy on Mar 10, 2008 21:39:07 GMT
Hi Leo, Take two, just lost a whole load of posting due to one bloody click!! OK, to summarise, I've checked the datasheets and the eval board one I have lists the loop filter on the 8416 as 470R and 0.068uF. I must have an older version, but it would be a doable change, for sure. Lukasz Fikus has some interesting views here: www.lampizator.eu/LAMPIZATOR/World_CD_DAC_championship.html and I also note that he gives Lawrence's contact details as well!!! Doh, all there if I happened to look hard enough!! Anyway, we know that the output stage is a bit weak!! ;D So it makes sense that the method Lukasz used was to bypass it altogether. While I'm not suggesting a full on Lampization www.lampizator.eu/LAMPIZATOR/LAMPUCERA/CD%20DAC%20Lampucera%20lampizator.html including the Mega version www.lampizator.eu/LAMPIZATOR/MEGALAMPIZATOR/mega%20lampizator.html , a discrete output stage would be great, I reckon. So, what about noise cancelling? Apparently the chip is quite before any filtering etc, so it could be worth a try to just take off to a discrete stage from the board at a suitable point. It will hopefully still meet the CHEAPO requirement, and improve the SQ. I haven't run the +-12V through a JLH yet, though. Happily, Mrs C seems to have got bored of punching my kidneys while I've been asleep and putting ex-lax in my breakfast cereal, so might see a little more progress on the DIY front now!! I'm currently running a pair of Class A OPA627s on a Brown Dog adapter, but I'll drop the LM4562 back in tomorrow for another listen. Still, for the dough, it's great!!! Cheers Jon Hey Jon, check out the PPL filter on the CS8416, they look the wrong values to me (C22,C23,R2) Also notice that surface mount HCF4053 chip on the bottom of the board? its on the output of the op-amps, I can' quite work out what its supposed to be doing yet The caps on the CMOUT pin are going to be worth playing about with too C25
|
|
leo
Been here a while!
Team wtf is it?
Posts: 3,638
|
Post by leo on Mar 10, 2008 22:15:37 GMT
Nice one John, Well I scrounged the 3k, 1N and 22N from a scrapped sat board, it now not only locks onto the signal better theres no clicks and sounds better too IMO I'm listening to it now, your right its not too bad at all tbh, plenty to play about with
|
|
jonclancy
Been here a while!
Mr. Ripple Eater
Amateur EAGLEist
Posts: 1,131
|
Post by jonclancy on Mar 10, 2008 22:51:48 GMT
Hey Leo, Sounds like it make a difference!! Good work. And still on the "Cheapo" theme too. It'll be great if we can keep the work simple and have a list of mods on this thread so anyone can order one from eBay and have a go themselves. Cheers Jon
|
|
leo
Been here a while!
Team wtf is it?
Posts: 3,638
|
Post by leo on Mar 10, 2008 23:00:17 GMT
Agreed! just need to try this discrete stage now, should be cheap to try too, is the laser printer working ;D
|
|
jonclancy
Been here a while!
Mr. Ripple Eater
Amateur EAGLEist
Posts: 1,131
|
Post by jonclancy on Mar 11, 2008 9:52:18 GMT
Of course!!! I'll dig it out from it's specialised storage bay (back room wardrobe!!). I've even got some new crystals from Mappers as well........... I saw a discrete stage somewhere recently ;D that used boutique parts. Maybe we could do this one using standard parts and see what it's like - will still meet the CHEAPO spec that way. Cheers Jon
|
|
jonclancy
Been here a while!
Mr. Ripple Eater
Amateur EAGLEist
Posts: 1,131
|
Post by jonclancy on Mar 11, 2008 22:47:54 GMT
I just checked out the VReg on the Cheapo. It's running 3.33V, so within limits for me! Still sounding good - was listening to Pink Martini earlier, and soundstage and detail were pretty much all there. Cheers Jon
|
|
jonclancy
Been here a while!
Mr. Ripple Eater
Amateur EAGLEist
Posts: 1,131
|
Post by jonclancy on Mar 18, 2008 14:19:37 GMT
Okay, Hopefully, some news coming in from Leo about the Cheapo in the near future. However, chez moi, I've just been using the Cheapo with the LM4562 again, and dropped the Browndogged Class A OPA627s onto the CK2III. The 627s were pretty dark with the Arcam amps I'm using ( and they are known for being smooth). But, this morning, I got this through the post!! cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=230232349460&ssPageName=MERC_VIC_ReBay_Pr4_PcY_BIN_Stores_IT&refitem=350033949568&itemcount=4&refwidgetloc=closed_view_item&usedrule1=CategoryProximity&refwidgettype=cross_promot_widget&_trksid=p284.m183&_trkparms=its%3DS%252BI%252BSSOr just do an ebay search for TA2024 D-class Audio Amplifier Board For a tenner, you get an amp, connectors and cables. The accessories were all pretty low quality, so I used some Cardas binding posts I have bought for my (long coming) nice-amp project, and my 12V SLA battery. The TA2024 is a little noisy, with some hiss coming through the speakers with no source connected, but that may just be some RF as it's not cased up. But just fire it up!! Fans of the 2024 sound (TA-10, Sonic Impact etc etc) will instantly recognise the timbre and sound-stage. For a tenner!!!! Even the missus commented on the bass on my test track. Not just power, but texture. OK, so there isn't the iron grip of a 100-watter, but the sound is very satisfying out of the box. With the 627s it was very smooth and bass deep with a slightly rolled off top end. The 4562 corrected the top end, but was less powerful lower down - probably more accurate, but I'll let it bed in and see. I'm going to get another for passive bi-amping (horizontally - with one amp doing HF and the other doing the LF, no chance of the earths meeting and causing SMOKE!!!). You can't use this amp on headphones because of the common earth for a start, but as an El Cheapo music maker, this and the little DAC are hard to beat for your cash!!! Photo later. Jon
|
|
leo
Been here a while!
Team wtf is it?
Posts: 3,638
|
Post by leo on Mar 18, 2008 17:11:52 GMT
Thanks for the update Jon, theres so many cheap bargains to be had now if you browse around We need to get some of these discretes done, after knocking up a very rough one here with the elcheapo dac it was producing some very nice sounds indeed! it looks a total birds mess and I'm amazed it worked but to my ears it really lifted the performance of this thing I think if we run the discretes from the JLH's fancy parts are not needed, as you said it keeps this well cheap
|
|
jonclancy
Been here a while!
Mr. Ripple Eater
Amateur EAGLEist
Posts: 1,131
|
Post by jonclancy on Mar 18, 2008 22:39:24 GMT
In which case, I'll print off some artwork tomorrow. If anyone wants a page of artwork, then just say so by PM with your address and I'll print one off for you and pop it into the post. Leo, is there any chance of an A4 pdf with repeated images PLEEEZE? Cheers Jon
|
|
XTRProf
Fully Modded
Pssst ! Got any spare capacitors ?
Posts: 5,689
|
Post by XTRProf on Mar 19, 2008 5:21:34 GMT
Hey guys, Post some pictures, man! U have got me salivaring.
|
|
leo
Been here a while!
Team wtf is it?
Posts: 3,638
|
Post by leo on Mar 19, 2008 9:31:15 GMT
Soon as things are a bit more organised
|
|
jonclancy
Been here a while!
Mr. Ripple Eater
Amateur EAGLEist
Posts: 1,131
|
Post by jonclancy on Mar 19, 2008 12:29:29 GMT
Hey guys, Post some pictures, man! U have got me salivering. I'm sure it's the discrete stage you want to see, but in the meantime....... Cheers Jon
|
|
XTRProf
Fully Modded
Pssst ! Got any spare capacitors ?
Posts: 5,689
|
Post by XTRProf on Mar 20, 2008 9:18:34 GMT
Hey guys, Post some pictures, man! U have got me salivering. I'm sure it's the discrete stage you want to see, but in the meantime....... Cheers Jon Ma Ma Mia! Here we go again ............ Some cheap but good beauty there. Good workmanship as well. Real pro assembly.
|
|
pagan
<100
How do I activate my account?
Posts: 81
|
Post by pagan on Mar 23, 2008 13:18:52 GMT
Leo You no like the CS8416 receiver? Or is it the "I'll get there when I get there PPL clock" sooner or later?
Have you tried the balanced spdif in with Transformer yet?
allan
|
|
leo
Been here a while!
Team wtf is it?
Posts: 3,638
|
Post by leo on Mar 23, 2008 16:43:28 GMT
CS8416 isn't too bad as a receiver but feeding the dac from a low noise regulated oscillator has always given me better performance than running it from the CS8416's output
I use pulse traffo's on my other two dacs and will add one to this as soon as I can get hold of another, at the moment I'm using things I have spare like regulated clock etc
|
|
leo
Been here a while!
Team wtf is it?
Posts: 3,638
|
Post by leo on Apr 27, 2008 12:16:26 GMT
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Apr 27, 2008 12:29:47 GMT
Leo Why don't you try reducing the 100 ohm output resistor to 68 ohms ? The AD826 doesn't have problems driving capacitive loads. Check it's output stage in the data sheet schematic. Alex
|
|
leo
Been here a while!
Team wtf is it?
Posts: 3,638
|
Post by leo on Apr 27, 2008 13:13:16 GMT
Leo Why don't you try reducing the 100 ohm output resistor to 68 ohms ? The AD826 doesn't have problems driving capacitive loads. Check it's output stage in the data sheet schematic. Alex I actually use 22R as its what I had to hand
|
|
leo
Been here a while!
Team wtf is it?
Posts: 3,638
|
Post by leo on Apr 27, 2008 13:20:04 GMT
The forum is running like crap for me today!
The specs for this chip is very good, it has good settling time, high slew rate and bandwidth, PSRR isn't the best but with using low noise regulation isn't it a problem. As you already stated Alex it also has very good drive!
|
|
leo
Been here a while!
Team wtf is it?
Posts: 3,638
|
Post by leo on May 7, 2008 0:50:59 GMT
Sorry the pic is crap, I'll do a better one soon as I can. Lesson learn't, be very careful what caps you use for the PLL filter!!! my dac started sounding overly bright after about an hour, long story short it was the PPS smd caps for the PLL, I changed these to polypropylene for the 1nf and polyester for the 22nf, problem solved, well in my case I fitted an oscon for the 3.3v digital supplys, a a mixture of tants and Rubycon ZA's for the VA for the dac and tants for the opamp. PPS is still used for the active output stage AD826 is still working very well in this Elcheapo so I left it in Toslink was used for quick testing, soon as this is put in a case I'll be fitting a 75R BNC for the spdif Sound is very good for cheapo, clean and detailed The discrete output stage is still better but the gap is now smaller
|
|
leo
Been here a while!
Team wtf is it?
Posts: 3,638
|
Post by leo on May 7, 2008 0:53:01 GMT
Next thing to try is a mod for the CMOUT pin
|
|
leo
Been here a while!
Team wtf is it?
Posts: 3,638
|
Post by leo on May 17, 2008 12:32:48 GMT
For anybody that may have brought an Elcheapo heres a few easy and basic mods to try Use a similar regulated 5v supply as posted by Rick earlier in the thread For the +/-12v the standard supply should be ok, obviously it can be improved upon
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on May 17, 2008 12:47:18 GMT
Leo For the life of me, I still can't see what is so special about that 5V power supply. I must be missing something somewhere. I think Rick may have posted something about it in another thread ? Alex
|
|