Salas hotrodded blue DCB1 build - Page 177 - diyAudio
Go Back   Home > Forums > Source & Line > Analog Line Level

Analog Line Level Preamplifiers , Passive Pre-amps, Crossovers, 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 18th March 2012, 09:18 PM   #1761
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Quote:
Originally Posted by piero7 View Post
Hi Salas, what the value of the impedance with 600mA output current and 2A?
340uOhm & 220uOhm. Diminishing returns in other words after 1A.
  Reply With Quote
Old 18th March 2012, 09:46 PM   #1762
piero7 is offline piero7  Italy
diyAudio Member
 
piero7's Avatar
 
Join Date: Apr 2009
Location: Matera
Quote:
Originally Posted by Salas View Post
340uOhm & 220uOhm. Diminishing returns in other words after 1A.
Thanks Salas!
  Reply With Quote
Old 31st March 2012, 01:54 PM   #1763
diyAudio Member
 
Join Date: Aug 2005
My Tea-bag kit is up and running since a good few days, and I have to say it is sounding very good. There is a lot more 3d and stable imaging going on compared to the normal b1. The difference is so big, its more then a full step up.

Thanks allot Mr Pass, Salas and Tea-bag, my stereo sounds fantatisc now.
  Reply With Quote
Old 31st March 2012, 02:02 PM   #1764
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Congrats! But you know what we say here? With no pix it did not happen.
Just joking. If you got some pictures of it in your system members are always happy to look at.
  Reply With Quote
Old 31st March 2012, 02:08 PM   #1765
VT67 is offline VT67  Belgium
diyAudio Member
 
VT67's Avatar
 
Join Date: Jun 2004
Location: Belgium
Quote:
Originally Posted by Salas View Post
Congrats! But you know what we say here? With no pix it did not happen.
Just joking. If you got some pictures of it in your system members are always happy to look at.
+1

Regards
  Reply With Quote
Old 31st March 2012, 03:17 PM   #1766
diyAudio Member
 
ggetzoff's Avatar
 
Join Date: Nov 2004
Location: Southwest
Quote:
Originally Posted by rikkert1978 View Post
My Tea-bag kit is up and running since a good few days, and I have to say it is sounding very good. There is a lot more 3d and stable imaging going on compared to the normal b1. The difference is so big, its more then a full step up.

Thanks allot Mr Pass, Salas and Tea-bag, my stereo sounds fantatisc now.
High-end audio without the price. Brings a tear to my eye

Here's my build so far. I went with Caddocks and TX2575s on the IN/OUT branch.

I just need to match the LEDs for Vref and CCS. I'll do that today and get some woodworking done tomorrow.
Attached Images
File Type: jpg securedownload.jpg (517.6 KB, 287 views)
__________________
Airline Pilot-If it's not Boeing I'm not going.
"Brain as big as a planet..." {sic} Nelson Pass
  Reply With Quote
Old 31st March 2012, 03:26 PM   #1767
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
A ''pointy'' build and a ''to the point'' realization.
  Reply With Quote
Old 31st March 2012, 11:56 PM   #1768
diyAudio Member
 
ggetzoff's Avatar
 
Join Date: Nov 2004
Location: Southwest
Okay, flipped the switch and voltages are 10.06vdc and 10.11vdc.

T-B, thanks for the extra LEDs, I was able to get good matches for each source section.

Current wise, I'll be going for some dissipation ; the 10R is only pressed in place to test voltages.
Attached Images
File Type: jpg dcb1.jpg (412.7 KB, 263 views)
__________________
Airline Pilot-If it's not Boeing I'm not going.
"Brain as big as a planet..." {sic} Nelson Pass
  Reply With Quote
Old 2nd April 2012, 05:48 AM   #1769
Dukja is offline Dukja  United States
diyAudio Member
 
Join Date: Sep 2011
Location: Oklahoma, US
Hi,

I just finished the kit from T-B. All LEDs up. The Vdrop on R1 was about 2.0V at V+ side, but it was only 1.7V at V- side. And they would drop to about 1.95 and 1.66 after a few minutes. One side Vdrop seems to be border line (2 +/- 0.3V).

Also, the V+ measured to be about 10.05 and V- to be -10.14 so that V- was actually slightly higher than V+. Output DC offset was about 2mV and 3mV at L&R channel. The fact that |V-| > |V+| worries me. I am not sure if there is something that need to be fixed?

When I matched the LEDs, I only use the diode mode on a Fluke 179 and read the voltage. Was that not the "good enough" way to match LEDs?

Thanks a lot for your help!

Last edited by Dukja; 2nd April 2012 at 06:13 AM.
  Reply With Quote
Old 2nd April 2012, 09:17 AM   #1770
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
The Fluke 179 luckily has a 2.5V diode test spec and gives results for LEDS also, but the meter to save its battery never gives more than essential current to turn them on. Hence it won't give a reference measurement at the current range they see in any specific circuitry. BUT your PSU results are no problem for the DCB1 tolerances. Your DC offset is not spectacular but in spec too. For mostly aesthetic reasons you can try to near the running currents in both CCS. The -V side drop is weaker due to different Vgs of your POS and NEG Mosfets. Use ~25% less setting resistor value on the negative CCS. I.e. 10R on POS and 8.2R on NEG as it is set now, or 5.6R and 4.7R for a hotter running system @ ~350mA if you feel your sinks cool enough now. It usually becomes even nicer when running higher. Do those things in leisure, your DCB1 is good for use as it is.
  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
dcb1 buffer with shunt reg. merlin2069er Swap Meet 0 3rd August 2010 05:25 PM
F2 and DCB1 parts selection - please advice! DQ Pass Labs 6 25th November 2009 03:20 PM
Y B Blue - how blue LED improves the CD playback Peter Daniel Digital Source 176 25th September 2003 07:40 AM


New To Site? Need Help?

All times are GMT. The time now is 08:24 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