DIY Audio Projects Forum
 NEW  Matt presents bias and operation data for the 6V6 tube in SE operation - 6V6 Single-Ended (SE) Ultra Linear (UL) Bias Optimization.

DIY Audio Projects Forum

Welcome to the DIY Audio Projects Message Forum. Use these forums to discuss Hi-Fi audio and to share your DIY Audio Projects. Registration is free and required to post messages and view the file attachments. Registration will only take a minute and registered users do not see any advertisements. After you have completed the online registration process, check your email (including spam/junk folder) for the verification email to activate your account. New members are under moderation - so your posts will not be visible until approved by a moderator. See the Read Me 1st, Forum RULES and Forum FAQ to get started on the forum.

It is currently 19 Sep 2019, 15:01

All times are UTC - 6 hours [ DST ]




Post new topic Reply to topic  [ 5 posts ] 
Author Message
 Post subject: Capacitor grounding
PostPosted: 27 Oct 2018, 14:50 
Offline

Joined: 23 Oct 2018, 06:51
Posts: 10
I didn't get any replies to my post Request for help fixing Nobsound Class D amp :(

So I wonder if I can narrow down my questions on this solution I'm trying to implement:

"The two capacitors marked yellow should be disconnected from local ground and connected to the ground of preamp
or as marked on the photo to the ground of potentiometer."


Q1 - Does it matter which capacitor leg I ground?
Q2 - How do I disconnect from local ground (if on a board...)
Q3 - Where would I find the ground on a potentiometer?

Apologies for the Noob questions, I'm just trying to fix something...

Thanks
Steve


This post has a file attachment. Please login or register to access it. Only Registered Members may view attached files.



Top
 Profile  
 
 Post subject: Re: Capacitor grounding
PostPosted: 27 Oct 2018, 17:17 
Offline
Project Author
User avatar

Joined: 04 Jun 2008, 20:59
Posts: 4023
Location: Arizona, USA
Hi, Since I didn't see the other posting...what exactly are you trying to fix? Looking at the photo the way to undo a capacitor is to unsolder one lead and lift that end free from the PCB. Which end I can't tell from the photo as it is unclear which end is the one needing to be changed. Then I would use wire (about 20 gauge or so) and solder it to the freed ends of the capacitors and run it to the location you need to connect to. If you are good with tools ....I personally would probably use a Dremel and cut the trace where the capacitors are soldered into the board and attach a new wire from there. Being very sure that they are really disconnected as some pcbs have multiple levels and being really sure that you didn't cut something else out of the circuit at the same time.

Good listening
Bruce

_________________
Some of my DIY Tube Amplifier Projects:


Top
 Profile  
 
 Post subject: Re: Capacitor grounding
PostPosted: 28 Oct 2018, 10:03 
Offline

Joined: 23 Oct 2018, 06:51
Posts: 10
Thanks Bruce, I'm trying to fix a bluetooth noise issue. (Seems to be a design flaw and I'm trying to implement a suggested fix)
I got some replies to my other post so now I just need to figure out which lug on the pot I need to connect to.
I'm guessing the middle, but emphasis on the guessing!


Top
 Profile  
 
 Post subject: Re: Capacitor grounding
PostPosted: 29 Oct 2018, 01:28 
Offline

Joined: 26 Dec 2016, 03:46
Posts: 194
Location: Bayarea
brimley wrote:
Thanks Bruce, I'm trying to fix a bluetooth noise issue. (Seems to be a design flaw and I'm trying to implement a suggested fix)
I got some replies to my other post so now I just need to figure out which lug on the pot I need to connect to.
I'm guessing the middle, but emphasis on the guessing!


Like I said, the best is to try to make the seller pay for return shipping. But if you really want to fix it, you have to take it apart and take pictures of the back side of the pcb to know where the return of the pot. Once you do that, you void all warranty and return.


Top
 Profile  
 
 Post subject: Re: Capacitor grounding
PostPosted: 27 Feb 2019, 17:55 
Offline

Joined: 21 Sep 2014, 12:07
Posts: 25
I just wanted to ad to this thread, as I have found a device that really reduces BT noise. I discovered that the "tweedling" noise actually feeds back through the source voltage supplying the BT module. A company named Mornsun makes a little chip that works well. The part number for the one I'm using is B505S-1W. My BT receiver operates on 5V, and they also make them for different voltages. I just put this in line between the supply and the module and it removed 90% of the noise. The datasheet states that you can also add LC filters before and/or after the chip to further reduce the noise so I'm going to tinker some more and see if the noise can be eliminated or reduced below a perceivable level.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 5 posts ] 

All times are UTC - 6 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 10 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  
DIY Tube Projects :: DIY Tube Amp Kits :: DIY Speaker Projects :: DIY Solid State Projects :: DIY IC / Op-amp Projects :: DIY Phono Projects :: DIY Cable Projects :: Hi-Fi Audio Schematics
© diyAudioProjects.com - Terms of Service - Privacy Policy