Questions on autoformer

[crazy bill the eel killer]

Hello Dave,
Just purchased an autoformer module for use in an integrated diy amp. Was using a PEC carbon pot, but I want to try the autoformer route. Which begs a couple of questions.

1). the amp will be a ( all stages triode strapped ) ef86-el84 SE. Maybe RC coupled, but probably CCS loaded on the EF86. One large chassis. Obviously, I've got a lot of iron on this thing ( PS to be CLCLC for the EL84, then RC coupled OD3 to the EF86 ), and I'm a little concerned about noise. What is the best way to shield the autoformers from induced hum. My initial thinking is to build the autoformer modules into a completely mu-metal shielded box in the front of the chassis. Single input ( vinyl only ). But I'm pretty new at this stuff, so I'm open to suggestions. Is this the best way to go, or overkill, or is there a better way. ( Actually, overkill is OK if it will get the job done ).

Appreciate any advice you can offer. If building a separate box for the autoformers is the better way to go for ultimate sonics and lowest noise, I will go that route, but I will really would like to keep a single box for the project.

Thanks in advance for any help you can offer.

Cheers, Crazy Bill

[crazy bill the eel killer]

Sorry Dave,
Must be braindead at this late hour.

Second question:

I like BIG volume control knobs. I know w/ the two pot arrangement on this module I will be limited to the size of the knobs, but my concern is about the weight of the knobs.

I will DIY the knobs as large as possible given the spacing on the modules ( ( either black walnut or birds-eye maple ( Both in house ) ), but I wonder about the switches used and whether the weight of large diameter knobs on the shaft will be problematic.

Appreciate any advice.

Cheers, Crazy Bill

[dave slagle]

weight shouldn't be a problem. just be sure to secure them with foam or something if you ever ship the unit.

dave

[crazy bill the eel killer]

Hello Dave,
Built two prototyped versions to compare.
First one is listed above, the second is an IT coupled 6922-El84 amp. I'm presently leaning towards the IT coupled version. With both I used my 100K PEG pot.
Which begs the following.
Since your autoformer modules are replacing the 100K pot, can I ditch the grid stop on the 6922. I/m hoping the bandwith limitations on the autoformer will be a sufficient to stop the 6922 from oscillating.

thanks, Bill

[dave slagle]

hey,

you can try it and see.

dave