Poweramp Spacing

[meemawuk]

So who leaves a 1u+ space between their poweramp and anything else for heat/hum reasons?. I'm running a 2:90 with a Gmajor above it and a Triaxis above that in a 4u rack. Will I have any ventialtion/hum problems if the front and back of the rack case are off, at high volume?

Experience and suggestions welcomed!

 

[ToneAddictJon]

You shouldn't have a problem, the tubes are at the back of the 2:90 with a fan blowing from the side, so the heat should dissipate to the back and out, not straight up into other units. I have a space above my power amp in my rack only because I haven't finished my rack yet.

 

[Muris_Varajic]

I had 2:90 right above Rocktron Prophesy,heat wasn't problem
but I did have some hum.
They I moved 2:90 one space higher making a spacing between
and hum was gone.
Not sure if this is rule but that happened to me.

Odd thing,before that I had 2:90 bellow Prophesy and
I didn't have any hum problems,
so hum started as I switched positions of units.

 

[RJ2213]

I had 2:90 right above Rocktron Prophesy,heat wasn't problem
but I did have some hum.
They I moved 2:90 one space higher making a spacing between
and hum was gone.
Not sure if this is rule but that happened to me.

Odd thing,before that I had 2:90 bellow Prophesy and
I didn't have any hum problems,
so hum started as I switched positions of units.

i'll venture to say that cable routing couldve been the cause of that also, but now that will remain a mystery forever.



i have a bit of hum in my system i'm noticing, i may try to seperate my triaxis and 2:90, but its mainly just on my high gain settings so i doubt it will help. either way i'm just about to buy a vented blank plate for my rack so this will be the perfect time to try it.

 

[Muris_Varajic]

i'll venture to say that cable routing couldve been the cause of that also, but now that will remain a mystery forever.

Cable routing,you mean if cables are touching each other or something? :?

 

[FC Spoiler]

You should keep signal cables away from power cables, that's where hum can appear.
I left 1 HE open between the poweramps and +/- 3He between power amp and preamp, with extra fans between the poweramps and between the poweramp/preamp. Just to be sure.
The rig is dead quiet (when not played :mrgreen

 

[6L6C]

I had this setup years ago also, (heat was never a problem even with a unit right over the 2:90) although the cabling does make a huge difference!! Try to keep anything audio away from the 2:90 and yes one space will cut it. The reason the 2:90 has some rather large transformers that sit up front.

I’m also a big believer in Humfrees, won’t help with your question but you might also have some grounding issues
http://www.musiciansfriend.com/product/Humfrees-Rack-Isolation-Tabs?sku=544710
Put together a rack years ago that was small and was forced to put the processor right above the 2:90 but after addressing all the grounding issues as far as noise it really was not that bad at all

You can see the Humfrees on this setup, Wish I took a pic of the back but didn’t. But all the cables are cut to length the audio favored one side of the rack and the AC the other. If audio and AC have to pass one another try to do it in a way so you make 90 degree angles as opposed to the cables running parallel.

Check out one of JP’s rigs, so time was put into the cabling
http://www.johnpetrucci.com/images/gear/IMG_0816.jpg