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 17th March 2011, 10:41 AM   #811
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
I use CAT5 twisted pair or star quad and 0.6mm diameter insulated single core as twisted pair.
__________________
regards Andrew T.
  Reply With Quote
Old 17th March 2011, 11:46 AM   #812
diyAudio Member
 
Join Date: May 2009
Default audio parts

I don't want to be annoying with those questions but could I put 200k or 240k instead of 220k? 910k instead of 1M? Thanks.
  Reply With Quote
Old 17th March 2011, 11:50 AM   #813
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
240K on input if you use a 20K volume pot or less is OK. 910K on output instead of 1M, yes no problem.
  Reply With Quote
Old 17th March 2011, 11:50 AM   #814
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Quote:
Originally Posted by crazyfrog View Post
I don't want to be annoying with those questions but could I put 200k or 240k instead of 220k? 910k instead of 1M? Thanks.
yes, these small changes are not critical to operation.
__________________
regards Andrew T.
  Reply With Quote
Old 18th March 2011, 07:11 AM   #815
westend is offline westend  United States
diyAudio Member
 
Join Date: Jul 2005
Location: shorewood
Another DCB1 is born!

Click the image to open in full size.

Click the image to open in full size.

I can't comment too much on the component choices, I did not populate the board. The preamp is powered by an Antek AS-1215, 16v secondaries. Shunt voltages are -9.71v. and +9.65v.. The Fairchild MOSFETs run extremely cool with no load. I will put a signal through it,tommorw to see how all performs. If it is anything like the original Hypnotize or the original B1, I think another winner is present. Thank you, Salas!
  Reply With Quote
Old 18th March 2011, 07:54 AM   #816
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Nice construction. Check also the voltages across the fat resistors (10 Ohm?) next to the blue filter caps to be something around 1.5-2.5V, and the DC offset on audio outputs to be in the very low mV. Then you can safely hook it up and let us know how you liked it. After 48 hours play it will mellow out a bit also.
  Reply With Quote
Old 18th March 2011, 09:38 AM   #817
diyAudio Member
 
Join Date: Jan 2011
Location: sitting down
greetings all,

got my boards and various parts to start populating. read the posts and now, of course I have a couple of questions.

1) I'm going to feed a ta2020 amp with no input caps. some docs mention not to feed it dc. So I read in this thread to put output caps with a bypass cap. Is this true and if so, I read 1.5 uF and .0047 uF bypass. Are those values OK or is it a question of taste.

2) I tried to test the delay circuit on a breadboard using the pew tq2 relay (I think its an amorat or something like that) . I here the coil engage when I put 12V but the circuit does not delay. I measure the 550 center pin and V increases to about 4V so the timing cap and resistor seem to wotk fine. tried changing the 517 and still no turn-on delay. Any clues?
  Reply With Quote
Old 18th March 2011, 10:20 AM   #818
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Quote:
Originally Posted by necplusultra View Post
2) I tried to test the delay circuit on a breadboard.............. I here the coil engage when I put 12V but the circuit does not delay. I measure the 550 center pin and V increases to about 4V so the timing cap and resistor seem to work fine.
what is the turn on delay period?
If it is very short you won't be aware of it.
__________________
regards Andrew T.
  Reply With Quote
Old 18th March 2011, 10:28 AM   #819
diyAudio Member
 
Join Date: Jan 2011
Location: sitting down
there is no delay. I put a led on the 12V feed and one on the relay and both turn on simultaneously. Using the 100uF and 47kR should given at least a second delay.
  Reply With Quote
Old 18th March 2011, 11:20 AM   #820
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Post a schematic of what you make, by following your breadboard connections.
  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 02:44 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