World-Designs-Forum  

Go Back   World-Designs-Forum > World Designs > Problems
Register FAQ Members List Calendar Gallery Today's Posts Search Today's Posts Mark Forums Read

Problems For questions and answers re World Designs Projects

Reply
 
Thread Tools Display Modes
  #1  
Old 28th December 2016, 05:50 PM
Nuff3rs Nuff3rs is offline
Junior Member
 
Join Date: Oct 2015
Location: Bristol
Posts: 17
Default Kel84 hisssssssssss

Hi all. My first post here and also my first amp.

I've now had the amp roughly 3-4 months. My problem is as soon as I switch the amp on I get hissing and the occasional pops coming through the speakers. It isn't very loud and you cant hear it when playing music.
Being inquisitive I removed the bottom and had a look about.
It seems whoever made the amp either didn't tighten up the screws or left a black wire off for some reason. I tried to trace it back and found its the black wire running straight across the black - outputs at the back of the amp.
Here's a few pictures of the internals, I've circled in red the loose wire.
I'm not sure the connection blocks are standard? I've been looking on line and no one seems to have this in there's!?

Oh PS: I must let you all know that my electronics skill is zero so any advice for a first timer would be greatly appreciated.



Reply With Quote
  #2  
Old 28th December 2016, 11:41 PM
John Caswell John Caswell is offline
Super Moderator
 
Join Date: Dec 2005
Location: Wokingham, Berkshire
Posts: 1,397
Default Re: Kel84 hisssssssssss

Hi Nathan,
and welcome to the WAD/WD forum.
Well the first thing to ask is does this hiss occur on both channels?
Secondly does it vary with altering the volume control?
Once answered back here we shall see what can be done about it.
Resist the temptation to change anything until told/asked to do so.

John
Reply With Quote
  #3  
Old 29th December 2016, 12:04 AM
Nuff3rs Nuff3rs is offline
Junior Member
 
Join Date: Oct 2015
Location: Bristol
Posts: 17
Default Re: Kel84 hisssssssssss

Quote:
Originally Posted by John Caswell View Post
Hi Nathan,
and welcome to the WAD/WD forum.
Well the first thing to ask is does this hiss occur on both channels?
Secondly does it vary with altering the volume control?
Once answered back here we shall see what can be done about it.
Resist the temptation to change anything until told/asked to do so.

John
Hi John,
Thanks for the welcome!

I think it's the same on both channels and yes I'm sure it gets worse with the volume control.
I'm not 100% about this as I'm not home and cannot confirm this. I will try and report back tomorrow morning.

Thank you again,
Nathan.
Reply With Quote
  #4  
Old 29th December 2016, 08:36 AM
Nuff3rs Nuff3rs is offline
Junior Member
 
Join Date: Oct 2015
Location: Bristol
Posts: 17
Default Re: Kel84 hisssssssssss

Morning John,

I've just tried the amp and it seems as if it's from both speakers and doesn't get louder with the volume knob.

Cheers,
Nathan.
Reply With Quote
  #5  
Old 29th December 2016, 10:47 AM
vinylspinner vinylspinner is offline
Member
 
Join Date: Jun 2006
Location: devizes in wiltshire
Posts: 65
Default Re: Kel84 hisssssssssss

Hello Nathan and welcome to the forum,

Is the hiss on all inputs and do you have any spare ecf80 valves that you can substitute?

These are a nice little amp imho, regret selling mine.

Nigel
Reply With Quote
  #6  
Old 29th December 2016, 01:44 PM
Nuff3rs Nuff3rs is offline
Junior Member
 
Join Date: Oct 2015
Location: Bristol
Posts: 17
Default Re: Kel84 hisssssssssss

Quote:
Originally Posted by vinylspinner View Post
Hello Nathan and welcome to the forum,

Is the hiss on all inputs and do you have any spare ecf80 valves that you can substitute?

These are a nice little amp imho, regret selling mine.

Nigel
Hi Nigel, hope you had a good Christmas mate.

The hiss is on all inputs yes. It's not overly loud mind you but it's starting to bug me a little when I get up to change the record.
I've not got any spare valves no, I was thinking about maybe looking for some as spare anyway so I suppose that would be my first starting point.
Have you any recommendations? At the moment I have JJ EL84 and Mullard ECF80
Nathan.
Reply With Quote
  #7  
Old 29th December 2016, 01:57 PM
vinylspinner vinylspinner is offline
Member
 
Join Date: Jun 2006
Location: devizes in wiltshire
Posts: 65
Default Re: Kel84 hisssssssssss

Hi Nathan,

Having a nice quiet Christmas break tbh, not doing a great deal, how about yourself?

I can let you have some ECF80 and ECC83 valves to try if you wish, foc and there is a chap on AOS selling a quad of EL84 JJ power valves for 30 posted, might be useful for a spare set.

Also, looking at your pictures, the cap at c1 looks to be damaged, may be worth getting it looked at (looks to be the top of the casing only)

Nigel
Reply With Quote
  #8  
Old 29th December 2016, 02:50 PM
Nuff3rs Nuff3rs is offline
Junior Member
 
Join Date: Oct 2015
Location: Bristol
Posts: 17
Default Re: Kel84 hisssssssssss

Quote:
Originally Posted by vinylspinner View Post
Hi Nathan,

Having a nice quiet Christmas break tbh, not doing a great deal, how about yourself?

I can let you have some ECF80 and ECC83 valves to try if you wish, foc and there is a chap on AOS selling a quad of EL84 JJ power valves for 30 posted, might be useful for a spare set.

Also, looking at your pictures, the cap at c1 looks to be damaged, may be worth getting it looked at (looks to be the top of the casing only)

Nigel
Oh yes I think you maybe right! I didn't spot that when I had the bottom off. I'll take another look when I get time mate.
Thanks for the offer if the valves! That would be great, would be handy to have a few spare thank you!
I'm having a working Christmas I'm afraid I've got the weekend off though so that's a bonus.
I found some on eBay too but I think it's the same seller. I'll PM him and ask about them.

Cheers Nigel
Nathan.
Reply With Quote
  #9  
Old 29th December 2016, 05:10 PM
John Caswell John Caswell is offline
Super Moderator
 
Join Date: Dec 2005
Location: Wokingham, Berkshire
Posts: 1,397
Default Re: Kel84 hisssssssssss

Hi Nathan
I am a bit puzzled by this black wire that is not connected, but the other thought is that the feedback wires are not connected obviously giving you higher gain than normal. The other thing that I do not like is the proliferation of chocolate block connectors and long signal/feedback wires close together, a recipe for trouble
Being a rank starter does complicate the issue somewhat as telling you what to do could be fraught with problems.
Is there any way you could get it to me so i can see what is going on?

John
Reply With Quote
  #10  
Old 29th December 2016, 05:28 PM
vinylspinner vinylspinner is offline
Member
 
Join Date: Jun 2006
Location: devizes in wiltshire
Posts: 65
Default Re: Kel84 hisssssssssss

Hi John,

I could bring it down with me in January if Nathan wants to get it to me at some point, is that ok with you?

Nigel
Reply With Quote
Reply

Thread Tools
Display Modes

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


All times are GMT +1. The time now is 11:57 AM.


Powered by vBulletin® Version 3.7.3
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright World Designs