Tube bass preamplifier power supply (Need Help) - Page 3 - diyAudio
Go Back   Home > Forums > Amplifiers > Tubes / Valves

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

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 23rd January 2011, 11:31 AM   #21
diyAudio Member
 
ruffrecords's Avatar
 
Join Date: Jun 2007
Location: Holt, Norfolk
Quote:
Originally Posted by fingerboy21 View Post
Should I worry about having channels too narrow? My grid is 50mils, so the closest points are about 30mils apart. Is that a problem?
Yes, they are far too close.

The only place you really need fat tracks is from the ac input to the diodes and from the diodes to the first filter cap. This is where the peak charge currents go and they can be 5 to 10 times the nominal load current. The rest of the circuit only needs to handle the load current. An earth plane is not necessary and only makes soldering more difficult. You really need to aim for 3mm minimum separation between the HT and 0V tracks.

Cheers

Ian
  Reply With Quote
Old 24th January 2011, 03:05 AM   #22
diyAudio Member
 
Join Date: Dec 2010
Location: New Hampshire, USA
I suppose I should spread out my parts a bit more then? 3mm is about 120 mils so I would need to move parts to get the pads far enough apart.
  Reply With Quote
Old 25th January 2011, 06:13 PM   #23
diyAudio Member
 
Join Date: Dec 2010
Location: New Hampshire, USA
Progress:
Click the image to open in full size.

That was the best I could do for track sizing. The larger tracks you see are 150 mils, and the smallest ones are 75 mils.
  Reply With Quote
Old 25th January 2011, 06:45 PM   #24
diyAudio Member
 
ruffrecords's Avatar
 
Join Date: Jun 2007
Location: Holt, Norfolk
That looks OK to me. I normally do my diodes the other way with the ac fed to the middle and the outputs above and below but that's largely a matter of taste. I alos make space for 1N5000 series diodes even if I fit 1N4000 series just to give a little extra clearance in that region. Looks like you have room to do that it you want.

Just one question, why do you have two caps in parallel just after the rectifier??

Cheers

Ian
  Reply With Quote
Old 25th January 2011, 10:21 PM   #25
diyAudio Member
 
Join Date: Dec 2010
Location: New Hampshire, USA
The largest caps that I could find that would fit my chassis and budget were 220uF, so I put them in parallel for a total of 440uF. I like your idea on having the AC fed to the center. I will try that. Thank you sir for your time and expertise.
  Reply With Quote
Old 26th January 2011, 01:42 AM   #26
diyAudio Member
 
Join Date: Dec 2010
Location: New Hampshire, USA
It's getting a bit frustrating trying to get my layout just the way I want it. I know that's not going to happen on a single layer board with no jumpers, but I have also read that legally mains voltage tracks needs to have around a 300mil separation. How the heck would I be able to do that?

For my diodes, simple turn each of them 180 degrees?
  Reply With Quote
Old 26th January 2011, 02:30 AM   #27
diyAudio Member
 
Join Date: Jun 2004
Location: Indiana
Sorry if I missed it, but for such a simple circuit why all the headache and bother of a PCB? Why not just knock it up point to point?
__________________
If We The People refuse to hear the truth we will be ruled by liars.
  Reply With Quote
Old 26th January 2011, 03:00 AM   #28
diyAudio Member
 
Join Date: Dec 2010
Location: New Hampshire, USA
It needs to look professional since it's a college senior project. I'm going to leave the PCB as it is and I will test it with precaution. Live and learn. If it's not optimal, so what? It's my first shot at it.

I want to thank you all for your incredible help.
  Reply With Quote
Old 26th January 2011, 06:41 PM   #29
diyAudio Member
 
Join Date: Dec 2010
Location: New Hampshire, USA
Final:
Click the image to open in full size.
  Reply With Quote
Old 26th January 2011, 06:57 PM   #30
diyAudio Member
 
mastodon's Avatar
 
Join Date: Jan 2011
Quote:
I know that's not going to happen on a single layer board with no jumpers
In case it helps (I dunno if it's good practice, but anyway): you could always 'stretch' a resistor and thereby implement a jumper of sorts. I.e., you could artificially make the resistor longer in your pcb design and effectively make use of the leads it comes with. Maybe it's superfluous and you've already tackled it; in that case, nevermind

But take the R3-C4 node at R3's end; it seems that B+ is a bit close to ground at that point. You could move C4 a bit more to the edge of the board (i.e. to the right), and place the node I mention between C3 and C4, thereby moving it away from the ground trace. Which looks a bit thin, btw, but this 'workaround' allows you to make that trace thicker as well.

Just trying to think along; I have no particular competence in PCB layout.
  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
Preamplifier Power Supply Problems FlyAndy Solid State 2 24th November 2010 07:54 PM
Power Supply for Preamplifier skogs Solid State 15 15th June 2007 02:16 PM
Which is the better power supply for a preamplifier? fotios Solid State 16 2nd March 2007 08:35 PM
FS : Battery Supply Tube Preamplifier (12V SMPS to 275V) ANALOG GUY Swap Meet 0 30th October 2006 09:38 AM
Tube preamplifier & Solid State power amplifier for guitar Dusk Solid State 2 13th October 2004 10:48 AM


New To Site? Need Help?

All times are GMT. The time now is 08:15 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