Any good TDA1541A DAC kit? - Page 21 - 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 20th January 2012, 01:42 AM   #201
diyAudio Member
 
abraxalito's Avatar
 
Join Date: Sep 2007
Location: Hangzhou - Marco Polo's 'most beautiful city'. 700yrs is a long time though...
Blog Entries: 101
Send a message via MSN to abraxalito Send a message via Yahoo to abraxalito Send a message via Skype™ to abraxalito
Quote:
Originally Posted by SoNic_real_one View Post
You want to convince me that TDA1541 with max 4x OS capabilities will swing faster the outputs than the BB DAC's (rated at 8 and 16x) and the Phillips datasheet is wrong when it says the settling time is 1 micro second?
I think nowadays people use TDA1541A which has a plot of distortion vs freq at 8fs (fig4). Also what's the DNL spec for your beloved BB DACs - do you have it to hand?
__________________
No matter if we meanwhile surrender every value for which we stand, we must strive to cajole the majority into imagining itself on our side - Everett Dean Martin
  Reply With Quote
Old 20th January 2012, 02:20 AM   #202
regal is offline regal  United States
diyAudio Member
 
Join Date: Jan 2004
Location: MD
Quote:
Originally Posted by SoNic_real_one View Post
Well, to give you credit for something, I become curious to test the new, fast, low noise ADA4897-1 in my PCM61 DAC. I need an adaptor single-dual now...

Would this ADA4897-a make the issue of high input impedance of opamp I/V's with the dac rise time. Ie, would its input impedance not start to rise so far into the mhz that a DAC would never see it ?
  Reply With Quote
Old 20th January 2012, 02:43 AM   #203
diyAudio Member
 
Join Date: Jan 2008
Location: Virginia
Quote:
Originally Posted by abraxalito View Post
I think nowadays people use TDA1541A which has a plot of distortion vs freq at 8fs (fig4). Also what's the DNL spec for your beloved BB DACs - do you have it to hand?
You made a funny
I was using BB DAC's as examples just because... they did build lots of r-2r dac's. BB developed many DACs in the ladder configuration - 16, 18, 20, another 20, 24 bit. Phillips developed... two r-2r: 14 and 16 bit.
And when BB was laser trimming their resistors, Phillips decided to continue their development of r-2r with TDA1543 - 16 bit with performance below 13 bit (-75dB)...
Quote:
Originally Posted by regal View Post
Would this ADA4897-a make the issue of high input impedance of opamp I/V's with the dac rise time. Ie, would its input impedance not start to rise so far into the mhz that a DAC would never see it ?
The DAC current is 1...2mA. Voltage 2V. That means 1..2 kohm resistance. I think the output impedance of the OpAmp that can drive 100 ohm at 1MHz and 80mA will be just fine. BTW it's a SiGe CMOS part...

Last edited by SoNic_real_one; 20th January 2012 at 02:56 AM.
  Reply With Quote
Old 20th January 2012, 02:57 AM   #204
diyAudio Member
 
abraxalito's Avatar
 
Join Date: Sep 2007
Location: Hangzhou - Marco Polo's 'most beautiful city'. 700yrs is a long time though...
Blog Entries: 101
Send a message via MSN to abraxalito Send a message via Yahoo to abraxalito Send a message via Skype™ to abraxalito
Quote:
Originally Posted by SoNic_real_one View Post
You made a funny
I'm always hopeful that I can entertain as well as educate

Quote:
I was using BB DAC's as examples just because... they did build lots of r-2r dac's. BB developed many DACs in the ladder configuration
Yep, but you missed out PCM53.

Quote:
Phillips developed... two r-2r: 14 and 16 bit.
To borrow a phrase from Thorsten - this is patently untrue. You're as bad as him at digesting datasheets.

Quote:
And when BB was laser trimming their resistors, Phillips decided to continue their development of r-2r with TDA1543 - 16 bit with performance below 13 bit (-75dB)...
You're talking full scale THD figures here? What's the relevance to audio? Oh and yet another patent falsehood
__________________
No matter if we meanwhile surrender every value for which we stand, we must strive to cajole the majority into imagining itself on our side - Everett Dean Martin
  Reply With Quote
Old 20th January 2012, 03:04 AM   #205
diyAudio Member
 
Join Date: Jan 2008
Location: Virginia
Sure, has no relevance when it stings
I guess you did read the fable with fox and the grapes?
  Reply With Quote
Old 20th January 2012, 03:08 AM   #206
diyAudio Member
 
abraxalito's Avatar
 
Join Date: Sep 2007
Location: Hangzhou - Marco Polo's 'most beautiful city'. 700yrs is a long time though...
Blog Entries: 101
Send a message via MSN to abraxalito Send a message via Yahoo to abraxalito Send a message via Skype™ to abraxalito
Yep I've read it - did you notice incidentally that my chosen I/V converter has worse specs than -75dB at full scale? Regal's given me some stick about that
__________________
No matter if we meanwhile surrender every value for which we stand, we must strive to cajole the majority into imagining itself on our side - Everett Dean Martin
  Reply With Quote
Old 20th January 2012, 03:29 AM   #207
Previously: Kuei Yang Wang
 
Join Date: Nov 2002
Hi,

Quote:
Originally Posted by SoNic_real_one View Post
You want to convince me that TDA1541 with max 4x OS capabilities will swing faster the outputs than the BB DAC's (rated at 8 and 16x) and the Phillips datasheet is wrong when it says the settling time is 1 micro second?
I never claimed that the Philips Chip settles faster than the BB ones. Nor have I indeed made any of the other claims you attribute to me.

The BB chip is rated to settle to +/-0.0006% of full scale, which is +/- 2LSB for 16 Bit and +/- 4LSB for 18 Bit. As for 1uS, this is TDA1541, I was referring to the later and by far more common TDA1541A which is specified to settle TO +/- 1LSB (+/-0.0003%) in under 500nS. It is anyones guess what the settling time to +/-4LSb would be like...

Past that, settling time TO +/-1LSB is much longer than the RISE TIME. And the rise time is what may cause a feedback amp to slew. It is also important to note that almost all I/V circuits are integrators, placing additional demands on the op-Amp to charge/discharge the integrator capacitor.

Quote:
Originally Posted by SoNic_real_one View Post
Well, to give you credit for something, I become curious to test the new, fast, low noise ADA4897-1 in my PCM61 DAC. I need an adaptor single-dual now...
Why?

According to you (post 186) 12V/uS slew rate is all that is needed. Maybe you should try a TL072 instead?

Ciao T
  Reply With Quote
Old 20th January 2012, 03:40 AM   #208
Previously: Kuei Yang Wang
 
Join Date: Nov 2002
Hi,

Quote:
Originally Posted by SoNic_real_one View Post
Phillips developed... two r-2r: 14 and 16 bit.
Philips never build R2R DAC's.Philips DAC's have always used active switched current sources and multi-emitter transistor dividers.

Ciao T
  Reply With Quote
Old 20th January 2012, 03:44 AM   #209
Previously: Kuei Yang Wang
 
Join Date: Nov 2002
Hi,

Quote:
Originally Posted by abraxalito View Post
You're as bad as him at digesting datasheets.
What part of which datasheet did I get wrong? My quip about the Fet switches in you favourite VGA? If they do not use switches, what do they use, do you have any reference that shows what is used?

Ciao T
  Reply With Quote
Old 20th January 2012, 04:00 AM   #210
diyAudio Member
 
abraxalito's Avatar
 
Join Date: Sep 2007
Location: Hangzhou - Marco Polo's 'most beautiful city'. 700yrs is a long time though...
Blog Entries: 101
Send a message via MSN to abraxalito Send a message via Yahoo to abraxalito Send a message via Skype™ to abraxalito
Quote:
Originally Posted by ThorstenL View Post
What part of which datasheet did I get wrong? My quip about the Fet switches in you favourite VGA?
Yep. Incidentally it was a little more than a 'quip' but we'll let that slide for now

Quote:
If they do not use switches, what do they use, do you have any reference that shows what is used?
Why would you believe what I say when you don't believe what ADI says? I'd only be quoting from that - that DS and the related parts using the same architecture plus ADI's design support materials are my only source.

Even if you didn't read the explanations the fact that the attenuation vs control voltage plots are smooth without step jumps might tell you something which undermines your FET switch opinion.
__________________
No matter if we meanwhile surrender every value for which we stand, we must strive to cajole the majority into imagining itself on our side - Everett Dean Martin

Last edited by abraxalito; 20th January 2012 at 04:02 AM.
  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
Raindrop Hui TDA1541A DAC Kit wushuliu Swap Meet 25 21st November 2013 10:07 AM
which clock for analogmetric tda1541A dac kit Chilli6565 Digital Source 4 6th May 2010 12:41 PM
FS: AYA DAC Rev 2.0b TDA1541A Non-Oversampling DAC kit or complete krishu Swap Meet 0 17th December 2009 09:33 AM
Recommend a DIY tda1541a dac kit? boidos Digital Line Level 2 6th August 2009 01:43 PM
TDA1541A Chineese DAC KIT UV101 Digital Source 8 10th February 2009 10:46 AM


New To Site? Need Help?

All times are GMT. The time now is 11:12 PM.


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