Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Instruments and Amps Everything that makes music, Especially including instrument amps.

2-sided board for Ruby Amp
2-sided board for Ruby Amp
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 6th May 2019, 07:23 PM   #1
silasmellor is online now silasmellor  Denmark
diyAudio Member
 
Join Date: Nov 2016
Location: Denmark
2-sided board for Ruby Amp
Default 2-sided board for Ruby Amp

So I've been playing around with a Ruby as an electronics learning project, and as an excuse to cut some wood. I've made myself a small fender-ish cabinet that fits baffles for 8" and 10" speakers. To drive this, i etched a Ruby PCB using the storyboardist layout from Perf and PCB Effects Layouts. It worked great for a little while until suddenly it didn't and instead produced a mid-range pitched very intense stable tone that modulated frequency with volume and gain. After some troubleshooting i believe the fault was the J201 JFET (both D and S were close to +9V) and i have a replacement on the way.


Now, i was a little too fast when making this board and didnt cut the phenolic board large enough to allow for mounting holes. So, thought I, why not call it an excuse to draw up my own layout and have the good folks at DIYaudio school me on it! Having said all this, I hope you will provide me some feedback for this layout. Bear in mind that I am a complete beginner and know pretty much nothing except the bare basics. I am still working out the wrinkles of using KiCad for example, as is probably evident already. I have attached schematic and layout as pictures. The schematic is adapted for the bassman mod (0.1 uf coupling cap from JFET instead of 0.047 uf), and is intended to have pots and other stuff mounted off-board.


Main objective is to have fun and learn something along the way. As for design objectives i'll settle for "works", but i suppose i should say that i loosely copied the storyboardist layout, with a few changes:
- Made it a little less tight to make the component choice less critical.
- Moved 9V+ and PSU gnd inputs to bottom left side
- Double sided. The backside is PSU and a large GND plane. Front is all the signal-related stuff. I don't know if this is the right way to go, but it was easier to route this way...


One question - i notice the noisy cricket has a 220 f filter cap instead of 100. Does it make sense to increase size or is the benefit academic?


Thanks in advance for your patience and understanding... Pictures of amp cabinet to come!
Attached Images
File Type: png ruby-schem.png (8.4 KB, 129 views)
File Type: png ruby-layout.png (46.4 KB, 131 views)
  Reply With Quote
Old 6th May 2019, 07:49 PM   #2
Mark Tillotson is offline Mark Tillotson
diyAudio Member
 
Join Date: May 2018
Location: Cambridge UK
You are lacking a ground return for the input connection, without that you'll have to scrape off the solder-mask to solder the input coax screen to.

I don't see any mounting holes to fix the board to the chassis.

The routing signals one side, power & ground the other is very reasonable.
  Reply With Quote
Old 6th May 2019, 07:56 PM   #3
silasmellor is online now silasmellor  Denmark
diyAudio Member
 
Join Date: Nov 2016
Location: Denmark
2-sided board for Ruby Amp
Hey Mark, you are absolutely right, i will fix that. Mounting holes will be added once i'm happy with the overall layout. Im still figuring out how to assign stuff in kicad so holes and also silkscreen stuff is later right now.
Thanks for the feedback!
  Reply With Quote
Old 6th May 2019, 08:05 PM   #4
silasmellor is online now silasmellor  Denmark
diyAudio Member
 
Join Date: Nov 2016
Location: Denmark
2-sided board for Ruby Amp
Ok input return pad added.
Attached Images
File Type: png ruby-layout-2.png (36.9 KB, 122 views)
  Reply With Quote
Old 6th May 2019, 08:14 PM   #5
rayma is online now rayma  United States
diyAudio Member
 
Join Date: Apr 2011
Quote:
Originally Posted by silasmellor View Post
Ok input return pad added.
I would flip the pot connection so the input trace to the pot is more direct.

Last edited by rayma; 6th May 2019 at 08:17 PM.
  Reply With Quote
Old 6th May 2019, 08:25 PM   #6
silasmellor is online now silasmellor  Denmark
diyAudio Member
 
Join Date: Nov 2016
Location: Denmark
2-sided board for Ruby Amp
Thanks rayma, you have sharp eyes and i agree thats better. fixed.
  Reply With Quote
Old 6th May 2019, 08:34 PM   #7
rayma is online now rayma  United States
diyAudio Member
 
Join Date: Apr 2011
Quote:
Originally Posted by silasmellor View Post
Thanks rayma, you have sharp eyes and i agree thats better. fixed.
You may not want to do this, but you could exchange the positions of the 100uF (with battery pads),
and the pot connector. At the same time, turn the pot connector 90 degrees. Then reroute the trace
from pin #6 of the amp directly to the 100uF. Leave the trace from the 100uF to the fet where it is.

Last edited by rayma; 6th May 2019 at 09:03 PM.
  Reply With Quote
Old 7th May 2019, 08:12 AM   #8
silasmellor is online now silasmellor  Denmark
diyAudio Member
 
Join Date: Nov 2016
Location: Denmark
2-sided board for Ruby Amp
Hey rayma. I read a few places that the 100 uf cap should be as close as possible to pin 6 of the IC. Am i right that this is the intended improvement and should bring better stability against oscillation?

But in this case, the connection between volume pot and pin 2 of the IC run parallel for some part of the trace (though on opposite sides of the board. Is this acceptable routing or should i try and move one of the traces?

Edit: turned the pot 90 degrees.
Edit edit: d'oh, turning the pot conflicts with the 9v trace. back again...
Attached Images
File Type: png ruby-layout-5.png (93.9 KB, 101 views)

Last edited by silasmellor; 7th May 2019 at 08:21 AM.
  Reply With Quote
Old 7th May 2019, 12:15 PM   #9
silasmellor is online now silasmellor  Denmark
diyAudio Member
 
Join Date: Nov 2016
Location: Denmark
2-sided board for Ruby Amp
Ok a little further now, silkscreen text updated. Still room for changes of course. I am still unsure whether the parallel traces between volume pot pin 2 and IC pin 2 and V+ are OK...


I also noticed there is a protection diode between 9V+ and GND on the storyboardist layout. Am i right that this is simply to protect from accidentally reversing polarity of the power supply?
Attached Images
File Type: png ruby-layout-6.png (18.6 KB, 97 views)
  Reply With Quote
Old 7th May 2019, 03:01 PM   #10
rayma is online now rayma  United States
diyAudio Member
 
Join Date: Apr 2011
Quote:
Originally Posted by silasmellor View Post
I am still unsure whether the parallel traces between volume pot pin 2 and IC pin 2 and V+ are OK... Am i right that this is simply to protect from accidentally reversing polarity of the power supply?
The input and 9V traces should be ok.
It would work out better if the battery pads were below the 100uF.
Yes, you don't really need the diode.
  Reply With Quote

Reply


2-sided board for Ruby AmpHide 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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Double sided PCB board with continuous traces? ErikdeBest Parts 6 27th June 2016 06:29 AM
Car audio LM3886 + SMPS on single sided board rwaudio Chip Amps 43 20th February 2015 02:12 PM
Single sided lm3886 board, opinions? Adam Eng Chip Amps 5 26th March 2014 02:18 PM
Ruby Tuby at 24V? pdavis68 Tubes / Valves 0 8th December 2013 09:23 PM
should i use a double sided board and mirrior the same circuit on both sides? Shaun Perez Pass Labs 12 10th November 2002 12:17 AM


New To Site? Need Help?

All times are GMT. The time now is 04:23 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki