PT/OT placement

[HeeBGB]

OK So I have a Rocket I have been building SLOWLY. I have just been lazy mainly because I hate drilling and cutting chassis. It is going to be a traditional Rocket circuit wise but layout is a bit different because it is in a 1x12 Blues Junior format.

I have very little chassis space to mount the OT due to speaker interference. I has initially laid out the chassis to have the OT next to the PT. It fits physically but I get hum when using the headphone trick. I can move it across the chassis but then the OT is directly in front of the input jack and also the pre-amp tubes. Anyone have experience with this type of layout? I would hate to build this thing and have issues with noise from poor layout.

[Firestorm]

I don't know about a Rocket, but Steve Carr builds some of his with the OT way over on the input side. He's got the laminations the other way, though. It might matter.

[xtian]

The headphone trick will help you find the orientation with the LOWEST hum, but there will always be a very small level of hum, whether you're using headphones or a scope.

[HeeBGB]

The pic with the OT close to the PT there is a fairly audible hum there. I will just have to build it with the OT near the input and see what happens.

[martin manning]

In the case where the two transformers are on the PS end, did you try rotating both 90 degrees?

[Bob S]

Couple of things I've noticed with the headphone/scope trick.
I make sure both transformer housings have good contact with the (grounded) chassis.
The best orientation is 90 degrees to each other usually.
But not always - I had one instance where it was quietest with the OT about 3 degrees off perpendicular. Didn't make sense, but it worked.
I get the hum as low as I can & call it good.
Neat layout btw.

[HeeBGB]

It is done. I put the OT at the input end of the chassis. Now I need to figure out where to mount the choke. That should only take me another 6 months and then I can start soldering.

[Colossal]

Looks good man! Don't stop now!

[Reeltarded]

It looks great!! Just put the damned thing together already!!!

[M Fowler]

It will never work those transformers are too close, will hum for sure.

[Reeltarded]

They all hum until you teach them the tunes.

Use a resistor instead!

[badtweed]

I build my own variants/versions of the AC30 circuit and have the trannies located apart.

http://thebigwhistle.blogspot.com/2012/ ... leted.html

[M Fowler]

I remember that Quad 36, very nice amps.

[JoeCon]

And Orange amps put them like this...

[njwrecks]

LookS great hEEbgb!!!