use D1 I/V with voltage output dac
 User Name Stay logged in? Password
 Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read Search

 Pass Labs This forum is dedicated to Pass Labs discussion.

 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
 11th June 2006, 02:36 AM #1 poolorpond   diyAudio Member   Join Date: Aug 2005 use D1 I/V with voltage output dac Go easy with me on this as I am relatively new to all of this. The question is how to use the D1 output stage with a pcm1751, voltage out dac. I know that a transistor is a current amp. I know that adding a resistor before the first transistor can convert v to I (and vice versa). The dac puts out 2.5v To calculate the resistor: V=IR, so R = V/I If we set the desired current to 2ma, then R= 2.5/.002 = 1250 ohms Does this seem salient? Is there anything else I should do, like couple with a cap as well? Thanks
 11th June 2006, 03:46 AM #2 relder   diyAudio Member     Join Date: Jan 2002 Location: Tucson, AZ Why do you want to do this? The D1 is a I -> V stage, you already have a voltage out, why convert the voltage to a current and then back to a voltage again? What you need is a buffer and/or some filtering. Look into one of the Pass preamps if you are really set on a Pass design.
 11th June 2006, 05:16 AM #4 relder   diyAudio Member     Join Date: Jan 2002 Location: Tucson, AZ Yes, the math is OK, have fun.
 11th June 2006, 09:23 AM #5 CheffDeGaar   diyAudio Member     Join Date: Feb 2003 Location: Safe and sound Haven't seen it clearly from your post, but use the resistor in series between the Dac Output and the Mosfet Source. No need of a coupling cap. __________________ /Cheff - Falling feels like flying, until you hit the ground
 11th June 2006, 02:12 PM #6 poolorpond   diyAudio Member   Join Date: Aug 2005 Thanks.
 11th June 2006, 07:47 PM #7 poolorpond   diyAudio Member   Join Date: Aug 2005 I had 1.5k resistors on hand and it is working fine and sounds great. Question, though, the data sheet recommends using a 10uf polarized cap at the voltage output of the dac. I tried inserting the D1 circuit before the cap but it did not work (bad noises) unless after the cap. The data sheet does not describe the reason, only that it is needed and that the dac is ac coupled. Is this blocking DC? Any thoughts? Is there a reason that it would sound as good as it does with some budget cap in the signal path?

 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 Forum Rules
 Forum Jump User Control Panel Private Messages Subscriptions Who's Online Search Forums Forums Home Site     Site Announcements     Forum Problems Amplifiers     Solid State     Pass Labs     Tubes / Valves     Chip Amps     Class D     Power Supplies     Headphone Systems Source & Line     Analogue Source     Analog Line Level     Digital Source     Digital Line Level     PC Based Loudspeakers     Multi-Way     Full Range     Subwoofers     Planars & Exotics Live Sound     PA Systems     Instruments and Amps Design & Build     Parts     Equipment & Tools     Construction Tips     Software Tools General Interest     Car Audio     diyAudio.com Articles     Music     Everything Else Member Areas     Introductions     The Lounge     Clubs & Events     In Memoriam The Moving Image Commercial Sector     Swap Meet     Group Buys     The diyAudio Store     Vendor Forums         Vendor's Bazaar         Sonic Craft         Apex Jr         Audio Sector         Acoustic Fun         Chipamp         DIY HiFi Supply         Elekit         Elektor         Mains Cables R Us         Parts Connexion         Planet 10 hifi         Quanghao Audio Design         Siliconray Online Electronics Store         Tubelab     Manufacturers         AKSA         Audio Poutine         Musicaltech         Holton Precision Audio         CSS         Dx Classic Amplifiers         exaDevices         Feastrex         GedLee         Head 'n' HiFi - Walter         Heatsink USA         miniDSP         SITO Audio         Twin Audio         Twisted Pear         Wild Burro Audio

 Similar Threads Thread Thread Starter Forum Replies Last Post baxtr Parts 7 16th January 2009 10:37 PM kelticwizard Everything Else 11 25th March 2007 05:17 AM marko Car Audio 6 2nd January 2007 12:19 AM durxter Chip Amps 20 6th March 2005 06:25 PM rayban68 Solid State 0 6th October 2004 06:19 PM

 New To Site? Need Help?

All times are GMT. The time now is 02:10 PM.