Popping switch - Help! - 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 November 2001, 04:18 PM   #1
lwi is offline lwi
diyAudio Member
 
Join Date: Nov 2001
(first off, sorry for the redundancy of my posts, but I have beed advised that I could get more help in this forum)

I have a DIY guitar amp (a mesa/boogie 2:90 copy), and it has a problem.

One of the switches produces a rather large popping noise (from the speakers) when turned off.
Its not the main power switch, the switch increases or decreases the cathode voltage on a 12ax7.
I believe it's because of internal arcs inside the switch.

Installing a 10nf capacitor on the contacts did not remove the popping, and either way, the high end frequencies are compromised.
I have read here and a few other places that a contact suppressor and a vdr might help.

I invite you to read the discussion I had on the "Everything Else" forum, it contains schematics that could help you help me:

Switch with internal arcs - Help!

thanks in advance,

Lwi

[Edited by lwi on 11-23-2001 at 12:52 PM]
  Reply With Quote
Old 24th November 2001, 01:06 AM   #2
diyAudio Member
 
Join Date: Oct 2001
Go and buy a good switch. I just bought a $10 switch that looks like those used for eject buttons. Large, red, with good insulation. Those shouldn't pop at all
  Reply With Quote
Old 24th November 2001, 02:50 AM   #3
walker is offline walker  Australia
diyAudio Member
 
Join Date: Nov 2001
Location: Perth West Australia
Send a message via ICQ to walker
Downhere, the switch is causing a popping sound from the speaker when opened. This is because the cathode jumps to its new operating voltage changing the cathode plate voltage instantly, hence the pop.
Iwi, after thinking about it over night, I think you should try the 0.1uF cap and listen out for any loss of top end.
If that dosen't do the job we may have to start trying soft swicthes, similar to those used in expensive mixers, (they are actually small simple circuits).

Meanwhile I'll try to get hold of a Messa circuit or manual, maybe someone on the forum could help?

Regards WALKER
  Reply With Quote
Old 24th November 2001, 06:08 PM   #4
lwi is offline lwi
diyAudio Member
 
Join Date: Nov 2001
oh, i have the original schematics, I can e-mail them to you if you like. Your e-mail address isn't available through your profile.. email me at lwi_b@hotmail.com, and I'll send them back to you.

for the time being i'll look into soft switches..
thanks,

lwi
  Reply With Quote
Old 24th November 2001, 06:43 PM   #5
walker is offline walker  Australia
diyAudio Member
 
Join Date: Nov 2001
Location: Perth West Australia
Send a message via ICQ to walker
Iwi, I had difficulty posting the circuit. I have emailed it to you. As I can't measure some of the circuit parameters you my have too play with the values.
You could alter it and use any high voltage transistor or fet.
These circuits are very common in quality mixers, they allow you to switch in and out sources without hearing the switch click. They are also used to debounce switches.

Regards WALKER
  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
amp popping fligti91 Parts 0 10th November 2007 10:06 PM
Never try to switch 450V DC at 3A with a conventional mains switch... Eva Power Supplies 28 1st November 2006 09:24 AM
ICE popping up all over! mp006ltk Class D 0 20th October 2006 07:37 PM
Popping in my DAC 5th element Digital Source 5 10th August 2004 12:04 AM
Using a momentary switch for main power switch? FullThrottleRic Parts 9 25th June 2002 08:23 PM


New To Site? Need Help?

All times are GMT. The time now is 10:36 AM.


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