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

Twisted Pear Superior quality electronic kits

Reply
 
Thread Tools Search this Thread
Old 10th June 2018, 09:53 PM   #1
MartinC700 is offline MartinC700  United States
diyAudio Member
 
Join Date: Oct 2010
Location: California
Default Troubleshooting my Cronus/B3SE-PRO

Quote:
Originally Posted by Dimdim View Post
How much bandwidth does your oscilloscope have?

Are you using your probe at the x10 setting?
It's set on the x10 setting and it's a 100Mhz scope.
  Reply With Quote
Old 10th June 2018, 10:16 PM   #2
Dimdim is online now Dimdim  Greece
diyAudio Member
 
Join Date: Sep 2008
Location: Athens
Troubleshooting my Cronus/B3SE-PRO
That's probably it. If your MCLK oscillators are a 45/49Mhz pair, what you are seeing should not resemble a square wave. You'd need an at least 200MHz scope to see an almost-square wave at these frequencies.
__________________
http://www.dimdim.gr
  Reply With Quote
Old 11th June 2018, 01:08 AM   #3
MartinC700 is offline MartinC700  United States
diyAudio Member
 
Join Date: Oct 2010
Location: California
Quote:
Originally Posted by Dimdim View Post
That's probably it. If your MCLK oscillators are a 45/49Mhz pair, what you are seeing should not resemble a square wave. You'd need an at least 200MHz scope to see an almost-square wave at these frequencies.
Thanks for the help, makes total sense. I guess I'll have to continue investigating why sync mode is problematic.

Regards
  Reply With Quote
Old 15th June 2018, 11:18 PM   #4
MartinC700 is offline MartinC700  United States
diyAudio Member
 
Join Date: Oct 2010
Location: California
I hate to keep adding to the thread but am still looking to get sync mode working with a standard stereo set up. Changed out the clock u.fl connection to a double shielded version and routed it away from the DAC chip. Seems a little improved, it plays , and if I set the filter to brickwall there is very little noise breakthrough, on other filters the noise is pretty severe. Does this point to any particular issue causing the problem?

Thanks in advance for any pointers anyone can give.
  Reply With Quote
Old 16th June 2018, 12:21 PM   #5
fred_com is offline fred_com  Russian Federation
diyAudio Member
 
Join Date: Nov 2009
Location: Belgorod
Hey Martin,

one possible thing to check is the 33 (or 20) Ohm resistors, that terminate the masterclock lanes on Cronus. The suspects in my case were R8 and R9 on a Cronus v1.3.

I've had similar problem, where the async mode worked fine, but when I started using the sync mode, it would loose the lock after a couple of minutes.

The scope showed the sawtooth pattern at the output of the clock, but when measured at the side of R9, it was all fuzzy, not the solid line. And this was happening on one of my Cronuses, the other worked fine in the same environment. So I've reflowed all the IC's, all the other components, even exchanged all the IC's with the working Cronus, but still no good.
Then I've noticed that on the faulty one the termination resistors were 20 Ohm, while on the working one they were 33. So I've removed those 20 Ohm ones, and put some 33 Ohm, and now it's working fine.

Other thing I did was to reflow the masterclock u.fl connector, maybe that helped also, but it's hard to say now.

Thanks,
Fedor
  Reply With Quote
Old 16th June 2018, 02:19 PM   #6
MartinC700 is offline MartinC700  United States
diyAudio Member
 
Join Date: Oct 2010
Location: California
Hi Fedor,

Many thanks for your suggestions, I will check the termination resistors. I am also looking at the Arduino as being a possible issue. I use it to control the firmware by pulling down the port expander GPIO pins, as well as using it to sense the frequency that the Amanero is receiving by sensing the relevant Amanero pins. This seems to work fine in async mode, but putting a scope on the Amanero pins, there is a very large amount of HF noise (in the high MHz range) so I am thinking that this noise is getting into the DAC via the GPIO pins or the grounding.


Initial test yesterday seemed to show that without the Arduino connected sync mode would run with only the occasional 'click'.


The other thing I am looking into is how the digital grounds are connected.


Regards
  Reply With Quote
Old 16th June 2018, 08:52 PM   #7
MartinC700 is offline MartinC700  United States
diyAudio Member
 
Join Date: Oct 2010
Location: California
More experimenting - with the DAC operating without the Arduino connected or powered on and with the switching all via SW1 and SW2, and with no USB connected into the Amanero, the noise is still there (all be it at a lower level). Since async has no issue, I need to look more closely at the Cronus. I did have a prior one with bad joints to the potato chip, I wonder if this one may have issues?

If I scope the clock outputs from the Rhea modules, they look very stable (although with my 100Mhz scope it doesn't show the square wave properly. If I then probe the MCK output on the board, it's all over the place, and full of noise - I would expect the MCK output to look stable just like the Rhea module output. Anyway time to take out the Cronus and have a really good check over.
  Reply With Quote
Old 16th June 2018, 10:20 PM   #8
MartinC700 is offline MartinC700  United States
diyAudio Member
 
Join Date: Oct 2010
Location: California
Checked the resistor values on the master clock line. On this Cronus they are 20 ohms. On my older Cronus (both v1.3) they are 33. The old one unfortunately had bad solder joints and I messed up a trace attempting to repair it.
  Reply With Quote
Old 16th June 2018, 10:38 PM   #9
Russ White is offline Russ White  United States
diyAudio Member
 
Russ White's Avatar
 
Join Date: Jan 2005
Location: Nashville, TN, USA
20 or 33ohm termination resistors are fine - actually even 0 ohm is fine because there is termination on the B3SE side.

I would carefully inspect for dry joints - it is possible.

I would especially check around the clock buffer and the FF.

Very sorry you are having issues - I moved your posts to a new thread so we can concentrate on them here.

I would also just double check your supplies during operation. I have seen supplies sag when I did not expect them too.

Also you could check the MCK signals at the input side of the clock buffer and at the DAC. I would also do that for all the other audio signal. Check them before the termination resistors - and at the DAC.

Cheers!
Russ
__________________
Less pulp more juice Twisted Pear
Audio
/Twisted Pear Audio Blog
  Reply With Quote
Old 17th June 2018, 09:29 PM   #10
MartinC700 is offline MartinC700  United States
diyAudio Member
 
Join Date: Oct 2010
Location: California
Hi Russ,

OK, a little more information (hopefully useful).

Disconnected and powered off the Arduino to take it out of the equation, so just have the Cronus / Amanero stack and the DAC. With it powered up the clock signals look nice and stable at the crystals, and up to the Potato chip. After the chip really jittery and unstable.

Then kept the same hook up but took the power off on the DAC by removing all the Tridents. - Still the same outcome, jittery clock signal all the way after the Potato chip.

Next unplugged the u.fl connector for the MCK on the DAC, with it unplugged the clock signal looks really clean and stable all through the Potato chip and the 20 ohm resistors all the way to the output on the Cronus. Seems like the master clock signal is getting affected when plugged in to the DAC.
  Reply With Quote

Reply


Troubleshooting my Cronus/B3SE-PROHide 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
Cronus - It's about time. Russ White Twisted Pear 752 21st September 2018 02:40 PM
B3SE-Pro experimental dual mono firmware. Crom Twisted Pear 37 15th August 2018 03:28 PM
FS output stage for B3SE(ES9018) with Lundahl LL1684 and Vishay S102C Foil resistors schultzsch Swap Meet 12 29th June 2018 01:40 PM
FS - Spare Cronus bern Swap Meet 2 18th May 2018 09:26 AM
DSD256 not playing - BBB Hermes, Cronus, B3SE HeadSh0T Twisted Pear 0 8th February 2017 04:04 AM


New To Site? Need Help?

All times are GMT. The time now is 10:41 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki