Experience with this DIY DAC ? - Page 10 - diyAudio
Go Back   Home > Forums > Source & Line > Digital Line Level

Digital Line Level DACs, Digital Crossovers, Equalizers, etc.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 11th March 2009, 10:59 PM   #91
Segran is offline Segran  Sweden
diyAudio Member
 
Join Date: Sep 2008
Default New filter components

Hi John,

I have successfully implemented all the changes to the filters, both the LPF and the C22, C23 and R2 filter. The sound is IMHO excellent, the somewhat aggressive high that I experienced without the 1nF filter caps is gone, as well as the, as you say, lightweight mids. I found the sound now to be very well balanced and really pleasant to listen to! The difference compared to my CD and DVD players is beyond my wildest expectations, specially concerning the "sound staging".

Since the PCB is multi layer (4 layers?) its is not very easy to remove the old components. Neither Solder Wick nor my desoldering "piston pump" made a good job of it, the holes are a bit too small leaving a too little gap between the pins asn the through plated hold. I had to heat one leg at the time while usingh a pair of pliers to retract the components one leg at a time from the component side. Some solder joints are really hard since they are connected to the power plane, thereby hard to heat sufficiently even if I use 50W Weller solder iron. But with a lot of patience I got them all out without damaging the PCB. Cleaning the holed was a process in it seld, I had to take smaller diameter copper wire and re-solder them in to the holes, only to use Solder Wich to remove the solder again. While heating the wire and slolder joint ai h´mamanged to get 8 of to holed cleared enough for mounting the new components.Some of the holes where impossible to get porperly cleane,capacitiors w
  Reply With Quote
Old 11th March 2009, 11:56 PM   #92
johnm is offline johnm  United Kingdom
diyAudio Member
 
johnm's Avatar
 
Join Date: Sep 2003
Location: Hampshire
Hi Segran!

Thanks for your information and opinion on the sound of this DAC now you've implemented the changes. Sounds great!

So if I have this correctly - and to help others here - here are the changes needed so far:

R8, R9, R14, R15, R16, R17, R18, R19 = 13k7
R10, R11, R12, R13 = 3k32
C36,C37, C38, C39 = 1nF
C32, C33, C34, C35 = 220pF
C22 , C23 = ?
R2 = ?

LPF = ?

C27, C28, C30, C31 = Remove and insert wire link in place

Run wire diectly from output legs of op-amp to phono sockets.

If anyone could fill in the '?' and add any extra changes that would be fantastic.

Many thanks,

- John
  Reply With Quote
Old 12th March 2009, 12:34 AM   #93
Segran is offline Segran  Sweden
diyAudio Member
 
Join Date: Sep 2008
Default LPF components

I understand you are preparing some images that will make the mods clear to anyone.

The first 4 lines listing components/values are quíte correct.

Quote:
C22 , C23 = ?
C22 = 22nF, C23 = 1nF

Quote:
R2 = ?
R2 = 3k

LPF is just short for Low Pass Filter which constitutes all the other R's and C's we've changed.

C6 and C54 may also be replaced by links/jumpers wires if you are really haunted by the "cap's-cause-distortion-bug" and confident that whatever amp you connect the DAC to has DC blocking on it's input. In fact, all the electrolytic cap's (C26, 27, 28, 29 ,30, 31 and C6, C54 form a high pass filter with a -3dB roll-off att 5 Hz. Removing these will extend the bass into infra sound regions. In my system though, it doesn't change the bass sonically.

I haven't removed the second OP yet since I'm contemplating the best way to do it. I want the mute relay still to work.

Right now I think I will remove the IC, R37,C55, R40, R4, C44 and R39 and solder wires from R23 and R38 to pin 1 and 7 of the IC socket on the solder side of the PCB.
  Reply With Quote
Old 12th March 2009, 09:51 AM   #94
diyAudio Member
 
Join Date: Oct 2007
My parts to make these mods arrived yesterday so I will make the mods tonight hopefully, taking some pictures along the way - I promise.

Kevin
  Reply With Quote
Old 12th March 2009, 04:45 PM   #95
legarem is offline legarem  Canada
diyAudio Member
 
legarem's Avatar
 
Join Date: Jan 2005
Location: Quebec city
Hi

I'm the guy who published the direct coupling LM4562 in the lampizator web site.

The dac as is isn't flat with it's special equalization done by different RC combinaisons around the first op amp.

I tried to modify some parts around this op amp and ended to nothing.

You have the choice to leave it as is or completly redone the circuit arount this op amp.

The LM4562 is one of the best IF IT IS BROKEN IN. This means that it has to play at least 100 hours. The AD826 is better than a NE5534 but it has an annoying overbright high mid. The AD8066 with Browndog adaptors have slam and have terrific bass. They're not as natural sounding as LM4562. The OPA627 are too laid back.

I also tried tubes for output stage. This is good but believe me:
do you a favor:

Throw away your op amps, tubes, fets, Burson modules and use output transformers.

I used a pair of Lundahl LL1690 amorphous core and NOTHING beats this topology. It takes AT LEAST 100 + hours to be broken in but after that, you're in another league. Soundstage is huge, the image is wider, sound is mellower with better definition, it's the nirvana. It beats killer dacs.

Other things to do:

Replace the Sumlink pulse transformer for a Newava S22083 (Digi Key) They look the same but don't do the same sound.

Try a DIR9001 module to replace the CS8416 module. Replace the 3x100uF surface mount caps on the DIR9001 module with OS con Caps or good ones.

Replace the PLL parts value with the ones described here:

http://www.cirrus.com/en/pubs/errata/ER578D1.pdf

Have some fun with this marvelous dac

Here is the dac with the CS8416 receiver later changed for the
DIR9001
Attached Images
File Type: jpg dac_lundahl_187[1].jpg (45.7 KB, 2434 views)
  Reply With Quote
Old 12th March 2009, 07:05 PM   #96
diyAudio Member
 
Join Date: Mar 2009
Hey Mister M .. good to see you on another board .. If we would to implement Lundhal trans on this dac :

. any clues on how we could do this
.. do you think there would be any value is doing this instead of OPAM..

Thks
  Reply With Quote
Old 13th March 2009, 12:32 AM   #97
legarem is offline legarem  Canada
diyAudio Member
 
legarem's Avatar
 
Join Date: Jan 2005
Location: Quebec city
Here is the schem

Use top quality parts

What's your nickname on the other forum ?
Attached Images
File Type: jpg lundahl-cs4398.jpg (93.4 KB, 2282 views)
  Reply With Quote
Old 13th March 2009, 12:40 AM   #98
legarem is offline legarem  Canada
diyAudio Member
 
legarem's Avatar
 
Join Date: Jan 2005
Location: Quebec city
Because my writing on the drawing is bad, here are the parts for both channels


4 X 1K Mills non inductive wirewound
2 X 4,7 nF
2 X 40K (I used Rikens but other quality resistors can be ok)
2 X 7K Mills non inductive wirewound
2 X 400pF (mica or polypropylene but please no styroflex)

Price for the two Lundahls is $250 (US)
  Reply With Quote
Old 13th March 2009, 12:42 AM   #99
diyAudio Member
 
Join Date: Mar 2009
Edit .. this is the kit I was refering to

http://cgi.ebay.com/SAA7220-TDA1541A...QQcmdZViewItem
  Reply With Quote
Old 13th March 2009, 12:42 AM   #100
jacken is offline jacken  Sweden
diyAudio Member
 
Join Date: Feb 2007
Location: Stockholm, Sweden
Send a message via Skype™ to jacken
This measurement looks very similar to my testing of a Hong Kong DAC. But it's not the same one. That was for the smaller SMD board. You can see the modifications here http://www.jackenhack.com/blog/archi...ould/#more-748. But I also ordered the "Big" DAC, but got a version with a DIR9001 chip instead of the CS8416. This means that they only can receive 96khz. But the good thing is that the DIR9001 has lower jitter value, and as an added bonus have the 24.576MHZ crystal located on the board which makes it really easy to change to a better clock.

Quote:
this is the frequency response after taking out all that capacitors that drive HF to ground and leave only that 100 pico green capacitor that is in the opamp's feedback (in the schematic it is written that it has 56pF value but in reality it is 100pF - it might be changed also to 56pF - it is for the opamp not to oscillate)

Click the image to open in full size.
[/B]
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
A.O.S - Any experience? Keltern Multi-Way 16 26th April 2012 11:15 PM
my t-amp experience Eggzy Chip Amps 35 17th December 2005 06:29 PM


New To Site? Need Help?

All times are GMT. The time now is 08:06 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2