Random Loud Spurting Sound coming from my amp - diyAudio
Go Back   Home > Forums > Live Sound > Instruments and Amps

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

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 7th August 2011, 06:53 PM   #1
diyAudio Member
 
Join Date: Aug 2011
Default Random Loud Spurting Sound coming from my amp

hey all,
I am in search for an answer to a problem, and was hoping you all would know more about amps then me to aid me in a answer. I currently own a 60 watt crate tube amp, V series made in America (st.louis). I also use a boss me-30 for effects, and memory boy. I havent replaced the tubes for 2 years. but they seem fine.

For the most part the am has been flawless, sounds great and has given me the tone I really want. However recently after the amp has been playing for about 20 minutes the amp lets out this awful extremely loud spurting crackling noise, it lasts for about 3 or 4 seconds a burst, but will get more and more frequent as I continue to jam.
I have cleaned out the pots, and input jacks, checked the tubes. and so far no real luck. except whenever I put the amp on stand by for a while and turn it back on, the sound will not show again for at least 15 minutes.
I have basic electronics skills, and tube skills, I know how to solder. I also know how tube amps work, I have read multiple books on them but lack field experience. thanks for taking the time to read this!
-Aaron
  Reply With Quote
Old 7th August 2011, 07:19 PM   #2
Pano is offline Pano  United States
diyAudio Moderator
 
Pano's Avatar
 
Join Date: Oct 2004
Location: Kona, Hawaii
Blog Entries: 4
Moved to Instruments and Amps
  Reply With Quote
Old 8th August 2011, 03:44 AM   #3
diyAudio Member
 
Join Date: Aug 2011
UPDATE, it almost sounds like a spring, almost like something is bursting inside the amp, but for a short really loud burst. It did come with a reverb spring box, but i have already removed that. also just FYI, The reverb tube, purely functional, blew awhile ago I think, because the reverb stopped working a while ago.:/ I am almost feeling like getting a new amp...
  Reply With Quote
Old 8th August 2011, 01:53 PM   #4
diyAudio Member
 
Join Date: Jul 2005
Location: North Derbyshire
Back in the 70's we used to use two Carlsboro 200W valve mixer/amps for PA (just using them as power amps).

They both used to make internmittent 200W 'farting noises', perhaps similar to the problem you're having?.

But they were so intermittent I was never able to find what caused it (they only ever did it at gigs, never during testing). So we got rid of them and replaced them with a tiny 100W + 100W Citronic slave amp, which not only was a fraction of the size and weight, but was also considerably louder and better quality.

I don't know how you've tested the valves?, but the only real way would be to swap them over from an identical good working amp.

As long as it's reliably faulty (if you see what I mean?), it shouldn't be too hard to find the problem - first off do you have a circuit?, and what effect do the various controls have?.
__________________
Nigel Goodwin
  Reply With Quote
Old 8th August 2011, 04:07 PM   #5
diyAudio Member
 
Join Date: Aug 2011
I am tempted to just buy new tubes, just because I need them, and it might solve the problem.

Actaully the controls for the most part are always turned off on the actual amp. Except for the clean chanel. (Mid, Treble, Reverb, Gain) and I control everything from my boss me-20 (correction, not 30)
Also, when I am using just gain station on my amp, the sound still has yet to surface. This is what gives me suspicion to believe that its mabe just the tubes.

I guess what I am trying to ask is, what are the common characteristics of a blown tube?

Last edited by scottishlad5; 8th August 2011 at 04:18 PM. Reason: additional question
  Reply With Quote
Old 8th August 2011, 04:53 PM   #6
diyAudio Member
 
Join Date: Jan 2010
With a recently produced tube amp, the tubes are the first thing to suspect. Your second sentence makes me wonder about your preamp tubes - if you never get the problem with the preamp turned down and just using the power stages with an outboard preamp that would isolate it to that area.
  Reply With Quote
Old 8th August 2011, 06:45 PM   #7
diyAudio Member
 
Join Date: Aug 2011
Exactly, and it not existing in built in overdrive on my amp, it makes me think the tube built for the clean channel is blown, I think thats the first or second tube.

UPDATE: It does crackle on clean channel too, :/. However if I play softly i never hear the sound, but if I reach a certain pitch on my fret board with a louder volume the crackle will surface again. Also right before the crackling session begins, you can hear a slight quieter version of the crackling.

Last edited by scottishlad5; 8th August 2011 at 07:10 PM. Reason: addtional evidence
  Reply With Quote
Old 8th August 2011, 07:27 PM   #8
Cassiel is offline Cassiel  Libya
diyAudio Member
 
Cassiel's Avatar
 
Join Date: Sep 2004
Location: Madrid
It could also be a resistor - measures good but after warming up starts to misbehave.
  Reply With Quote
Old 8th August 2011, 07:56 PM   #9
diyAudio Member
 
Join Date: Aug 2011
Quote:
Originally Posted by Cassiel View Post
It could also be a resistor - measures good but after warming up starts to misbehave.
I just visually checked the resistors; they appear to be fine, no budging as far as I can tell or black marks around any resistor. Is there anything I should be looking for specifically?
  Reply With Quote
Old 9th August 2011, 04:48 PM   #10
Cassiel is offline Cassiel  Libya
diyAudio Member
 
Cassiel's Avatar
 
Join Date: Sep 2004
Location: Madrid
When troubleshooting this you've got to go step by step. Pots, tubes, resistors, etc. An intermittent resistor doesn't really need to look burnout. Anyway, it would help if you post the schematic.
  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
Spurting noises in Theta TLC (jitter attenuator) arupg Digital Source 1 17th October 2010 07:47 PM
Weird sound coming out from my speakers. motbuddy Solid State 4 21st June 2010 10:13 AM
no sound coming out of amp tony711 Car Audio 4 9th June 2010 06:47 AM
Zenith K731 AM/FM radio audio random cracking sound in FM mode AC439 Tubes / Valves 15 20th February 2009 10:06 PM
Pioneer SX-838 -- random no sound output, clicking relay VTbimmer Solid State 11 26th February 2004 01:12 AM


New To Site? Need Help?

All times are GMT. The time now is 05:53 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