Peavey 5150 Effets loop problems

[MBKorn]

Hi there
I have reading a lot about the effets loop problems with the hum on the internet.

The case is that i have a hum-problem when i use the effets loop. Its not loud but its there!

When i plug a cabel between send and return without any pedals between the hum is still there, when i activate the loop on my controlpedal. when i pull out the cabel in return, the hum is going away. The hum gets louder when the cabel laying over the amp, in the near where the transformer is.

Would it be an ideer to move the hole effets loop, couse to me it seems that the problem is that the loop is to close to the transformer-thing?

Any one else have s suggestion what to do?

thanks, michael

 

[blackie13]

don't use the loop...
all tube buffered loops suck tone...

 

[satannica]

Best upgrade I ever did to my 6505s.

 

[MBKorn]

What exactly does this trick with the ns2?
Does it remove the hum or?
Cause when i use my MXR Smart Gate in the effects loop, the low hum is still there. I think its genereted after the effects as the problem seems to be in the return-part.

thanks for your answere

 

[BC Audio]

don't use the loop...
all tube buffered loops suck tone...

The simpler the signal path, the purer the tone. However, a well designed loop will suck very little tone on its own, and should not add any hum.

I am surprised at the badreputation of loops in general. Are they really all that poorly designed? I can't believe there are so many bad loops out there. I guess there are, or there would be no Dumblator and clones.

 

[satannica]

What exactly does this trick with the ns2?
Does it remove the hum or?
Cause when i use my MXR Smart Gate in the effects loop, the low hum is still there. I think its genereted after the effects as the problem seems to be in the return-part.

thanks for your answere

The 6505 is a noisy amp by its nature. It does need taming both front-end and in the loop.

This 4CM with the NS2 puts the preamp of the 6505 into the NS2s isolated circuit. I use one on my NS2 and it's whisper quiet when I'm not playing. And I've noticed zero tone-suck with it.

 

[MBKorn]

Noone who can help me? :-(

 

[JerryP]

Hi there
I have reading a lot about the effets loop problems with the hum on the internet
Yesterday i picked up my 5150 from a repair-guy who had a look at it.

The case is that i have a hum-problem when i use the effets loop. Its not loud but its there!
when i plug a cabel between send and return without any pedals between the hum is still there, when i activate the loop on my controlpedal. when i pull out the cabel in return, the hum is going away. The hum gets louder when the cabel laying over the amp, in the near where the transformer is.

Would it be an ideer to move the hole effets loop, couse to me it seems that the problem is that the loop is to close to the transformer-thing?

Any one else have s suggestion what to do?

thanks, michael

The loop circuitry on the 5150/6505 amps is on all the time, the only thing that switches out when you use the footswitch is the jacks and anything in them.
You can't have cables or pedals on top of the amp or near transformers or you will get noise.
Signal cables should not be near A/C power cables or speaker cables.
If your loop is on with nothing plugged in nd has no noise and you plug a cable in and get noise my first guess is you have a shitty cable.
Check what brand 12AX7 you have in spot V3, the loop spot. If it's a New Sensor manufactured tube change it. That would be Sovtek, Mullard, EH, Gold Lion, or Tungsol.
I have info on my forum. http://www.fjamods.com/phpBB3/index.php
Jerry

 

[MBKorn]

 

[MBKorn]

Hi there
I have reading a lot about the effets loop problems with the hum on the internet
Yesterday i picked up my 5150 from a repair-guy who had a look at it.

The case is that i have a hum-problem when i use the effets loop. Its not loud but its there!
when i plug a cabel between send and return without any pedals between the hum is still there, when i activate the loop on my controlpedal. when i pull out the cabel in return, the hum is going away. The hum gets louder when the cabel laying over the amp, in the near where the transformer is.

Would it be an ideer to move the hole effets loop, couse to me it seems that the problem is that the loop is to close to the transformer-thing?

Any one else have s suggestion what to do?

thanks, michael

The loop circuitry on the 5150/6505 amps is on all the time, the only thing that switches out when you use the footswitch is the jacks and anything in them.
You can't have cables or pedals on top of the amp or near transformers or you will get noise.
Signal cables should not be near A/C power cables or speaker cables.
If your loop is on with nothing plugged in nd has no noise and you plug a cable in and get noise my first guess is you have a shitty cable.
Check what brand 12AX7 you have in spot V3, the loop spot. If it's a New Sensor manufactured tube change it. That would be Sovtek, Mullard, EH, Gold Lion, or Tungsol.
I have info on my forum. http://www.fjamods.com/phpBB3/index.php
Jerry

Hey Jerry and thanks for your answere
I have been reading a lot on your page - always a plesure.

When i have a cabel direct between send and return it make a hum (50-60 hz). Its not loud but its there. When i unplug the cabel in retur it stops. I have tryed with severel differet cabels.

About the thing that the cabel should not be in the near of A/C power cables or speaker cables. How do i make this? I mean ... the effects loop is sitting direct between the A/C power and the speaker cabel?

I have also tryed to thange the tube in position 3 without any luck. *On all the tubes there stand JJ ECC 83s

Any adwice?

Thanks a lot, Michael

 

[just42dave]

new tube in v3 is my guess and not one thats been lying around you can't remember where it came from,, new and unused tube. Old tube could cause the "yuccckiness".. Or... you have a ground loop in which you need to isolate the ac from the pedals better which is why I only use voodoo labs pedal power,, wasted alot of money before i figured out ground loops, never happened since

 

[JerryP]

Hey Jerry and thanks for your answere
I have been reading a lot on your page - always a plesure.

When i have a cabel direct between send and return it make a hum (50-60 hz). Its not loud but its there. When i unplug the cabel in retur it stops. I have tryed with severel differet cabels.

About the thing that the cabel should not be in the near of A/C power cables or speaker cables. How do i make this? I mean ... the effects loop is sitting direct between the A/C power and the speaker cabel?

I have also tryed to thange the tube in position 3 without any luck. *On all the tubes there stand JJ ECC 83s

Any adwice?

Thanks a lot, Michael

Just took another look at the schematic, have your tech take a look at the solder joints on the effects loop jack circuit board and the wiring to that board from the main board. You might have a ground connection problem for the jacks.
JJ tubes should work fine.
You don't want the signal cables wire tied in a bundle with the A/C wiring or speaker cables.
Jerry

 

[MBKorn]

Hey Jerry and thanks for your answere
I have been reading a lot on your page - always a plesure.

When i have a cabel direct between send and return it make a hum (50-60 hz). Its not loud but its there. When i unplug the cabel in retur it stops. I have tryed with severel differet cabels.

About the thing that the cabel should not be in the near of A/C power cables or speaker cables. How do i make this? I mean ... the effects loop is sitting direct between the A/C power and the speaker cabel?

I have also tryed to thange the tube in position 3 without any luck. *On all the tubes there stand JJ ECC 83s

Any adwice?

Thanks a lot, Michael

Just took another look at the schematic, have your tech take a look at the solder joints on the effects loop jack circuit board and the wiring to that board from the main board. You might have a ground connection problem for the jacks.
JJ tubes should work fine.
You don't want the signal cables wire tied in a bundle with the A/C wiring or speaker cables.
Jerry

Hi Jerry

As far i know he have resolderet a lot on the effects loop circuit board. He talk about it could be something with the transformer, there is not good enough isolatet (the one, there is making the noise-problem, when the cabel is laying over the amp). He say a idea would be, to pack the transformer in some aluminium. But when i read what you are writing, it does not sound like thats the problem or?

Thanks again for your time, Michael

 

[JerryP]

Nothing wrong with your transformer, find a new tech!
Jerry

 

[MBKorn]

Hey Jerry and thanks for your answere
I have been reading a lot on your page - always a plesure.

When i have a cabel direct between send and return it make a hum (50-60 hz). Its not loud but its there. When i unplug the cabel in retur it stops. I have tryed with severel differet cabels.

About the thing that the cabel should not be in the near of A/C power cables or speaker cables. How do i make this? I mean ... the effects loop is sitting direct between the A/C power and the speaker cabel?

I have also tryed to thange the tube in position 3 without any luck. *On all the tubes there stand JJ ECC 83s

Any adwice?

Thanks a lot, Michael

Just took another look at the schematic, have your tech take a look at the solder joints on the effects loop jack circuit board and the wiring to that board from the main board. You might have a ground connection problem for the jacks.
JJ tubes should work fine.
You don't want the signal cables wire tied in a bundle with the A/C wiring or speaker cables.
Jerry

Hi again Jerry

i have now been in contact with the tech and he tells that he have doen all what you have writen. Do you have another suggeston what can be wrong. Is it bad jacks ect? Or should i maybe move the loop, so its placed somewhere else, where the A/C power is not so strong?

Thanks again, michael

 

[MBKorn]

Hi again

I have been in contact with the tech and he tells that he have doen all what Jerry have writen. Someone have another suggeston what can be wrong?. Is it bad jack-inputs? Should i move the loop, so its placed somewhere else, where the A/C power is not so strong?

Thanks again

 

[MBKorn]

Can i really be, that no one have a solution on my problem?

 

[faisalbaig]

solution: send ur amp to jerry.

 

[D-Rock]

My 6505 head does this too and I've changed the preamp tubes so many times.
Doesn't bother me though cause I don't use the loop. Decimator up front and that's it.

 

[guitarman967]

Not to overstate the obvious but did you or your tech try simply cleaning the send and return jacks?