Kel84 hisssssssssss

[Nuff3rs]

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.

[John Caswell]

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

[Nuff3rs]

Originally Posted by John Caswell

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.

[Nuff3rs]

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.

[vinylspinner]

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

[Nuff3rs]

Originally Posted by vinylspinner

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.

[vinylspinner]

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

[Nuff3rs]

Originally Posted by vinylspinner

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.

[John Caswell]

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

[vinylspinner]

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