Guys Help!

Am I talking about the right thing? I want a shunt accross the on
switch so I don't get a "thump" and I want the tube rectifier to
warm-up gently. I put one in and it helps.. but it needs to be
larger. The B+ fuse I've got still blows.

Sheldon stokes said he was using 1/2 or 1/2 amp fuse. Mine is 1 amp
and still toasts them every few months. Must need a larger value or
more time length.

Maybe someone with a digitkey or Moser catalog handy could give a
suggestion?

It's a EL84 amp if your not familiar!

Thanks,

Michael

SAMIAM wrote:
Guys Help!

Am I talking about the right thing? I want a shunt accross the on
switch so I don't get a "thump" and I want the tube rectifier to
warm-up gently. I put one in and it helps.. but it needs to be
larger. The B+ fuse I've got still blows.

Sheldon stokes said he was using 1/2 or 1/2 amp fuse. Mine is 1 amp
and still toasts them every few months. Must need a larger value or
more time length.

Maybe someone with a digitkey or Moser catalog handy could give a
suggestion?

It's a EL84 amp if your not familiar!

Thanks,

Michael

You're blowing 1 amp fuses on the B+ line? There's something very wrong
here. I do not like, it, Sam-I-Am. Rather than implementing a patch-work
fix, I'd suggest finding out what's causing the problem.

You could have electrolytic capacitors beginning to fail, or a rectifier
tube that's going bad (do you ever see arcs in the rectifier during
warmup?).

Or perhaps the output tubes are arcing. (Do you ever hear loud, sharp
snaps in your speakers?)

Are you using AGC (fast-blow) or MDL (slow-blow) fuses? I was using a
0.5A AGC on my home-brew 6L6GC push-pull stereo amp, and the fuse blew
only after about a month of operation (and that's with a solid-state
rectifier!) so I changed to MDL and it hasn't blown again in over two years.

HTH,
Fred
--
+--------------------------------------------+
| Music: http://www3.telus.net/dogstarmusic/ |
| Projects: http://dogstar.dantimax.dk |
+--------------------------------------------+

Hi Samiam ,

The first things that came to mind are :
1) check the elco's in the PSU .
2) check the bias .
3) check the power tranny for shorts .

Ronald .


"SAMIAM" schreef in bericht
om...
Guys Help!

Am I talking about the right thing? I want a shunt accross the on
switch so I don't get a "thump" and I want the tube rectifier to
warm-up gently. I put one in and it helps.. but it needs to be
larger. The B+ fuse I've got still blows.

Sheldon stokes said he was using 1/2 or 1/2 amp fuse. Mine is 1 amp
and still toasts them every few months. Must need a larger value or
more time length.

Maybe someone with a digitkey or Moser catalog handy could give a
suggestion?

It's a EL84 amp if your not familiar!

Thanks,

Michael

"Ronald" wrote in message ...
Hi Samiam ,

The first things that came to mind are :
1) check the elco's in the PSU .
2) check the bias .
3) check the power tranny for shorts .

Ronald .


"SAMIAM" schreef in bericht
om...
Guys Help!

Am I talking about the right thing? I want a shunt accross the on
switch so I don't get a "thump" and I want the tube rectifier to
warm-up gently. I put one in and it helps.. but it needs to be
larger. The B+ fuse I've got still blows.

Sheldon stokes said he was using 1/2 or 1/2 amp fuse. Mine is 1 amp
and still toasts them every few months. Must need a larger value or
more time length.

Maybe someone with a digitkey or Moser catalog handy could give a
suggestion?

It's a EL84 amp if your not familiar!

Thanks,

Michael


And once you get the fuse-blowing figured out,you can put a .01uf
1KV cap across the switch.Thats's my usual fix for the turn-on
"thumps".

"Ronald" wrote in message ...
Hi Samiam ,

The first things that came to mind are :
1) check the elco's in the PSU .

?? what are the elco's. I forgot to mention the amps have been
completely rebuilt- new caps/sheldon stokes power cap board/resisters
etc..

2) check the bias .

I don't think UA-1's and UA-2 have a bias adjustment.

3) check the power tranny for shorts .

Yep- I should pull the fuse and check them with the VTM against the
frame.


Michael

Ronald .


"SAMIAM" schreef in bericht
om...
Guys Help!

Am I talking about the right thing? I want a shunt accross the on
switch so I don't get a "thump" and I want the tube rectifier to
warm-up gently. I put one in and it helps.. but it needs to be
larger. The B+ fuse I've got still blows.

Sheldon stokes said he was using 1/2 or 1/2 amp fuse. Mine is 1 amp
and still toasts them every few months. Must need a larger value or
more time length.

Maybe someone with a digitkey or Moser catalog handy could give a
suggestion?

It's a EL84 amp if your not familiar!

Thanks,

Michael

Hi Michael ,

?? what are the elco's. I forgot to mention the amps have been
completely rebuilt- new caps/sheldon stokes power cap board/resisters
etc..

Maybe "elco" is a lokal name for lythics here .... But since you have a new
cap board I think there will be no problem .... But once I had a new cap
running hot so there might be a production error .......

2) check the bias .

I don't think UA-1's and UA-2 have a bias adjustment.

So check the cathode-R's ...... (or cathode voltage)

3) check the power tranny for shorts .

Yep- I should pull the fuse and check them with the VTM against the
frame.

There might also be an internal short between windings if it was running hot
in the past .....

Good luck ,

Ronald .




Michael

Ronald .


"SAMIAM" schreef in bericht
om...
Guys Help!

Am I talking about the right thing? I want a shunt accross the on
switch so I don't get a "thump" and I want the tube rectifier to
warm-up gently. I put one in and it helps.. but it needs to be
larger. The B+ fuse I've got still blows.

Sheldon stokes said he was using 1/2 or 1/2 amp fuse. Mine is 1 amp
and still toasts them every few months. Must need a larger value or
more time length.

Maybe someone with a digitkey or Moser catalog handy could give a
suggestion?

It's a EL84 amp if your not familiar!

Thanks,

Michael