Chassis type/shape importance?

[ShoemanGB]

Question for you...  I'm building another stand-alone preamp and am wondering how important using a traditional box type chassis is?  It will never see road use so max durability is not a worry, it'll live either in a rack or on a speaker cab or shelf.  I'm using three of Merlin's boards for the audio circuitry, and will have a PT and SS recto/filtering probably on tag strips.  I have an aluminum sheet that is physically a good size to fit that all on, and will make a separate face plate for the jacks and controls.  All will probably end up in a wooden case of some sort so you can't stick your fingers in it accidentally -- zap!. 
 Will there be a higher chance of electrical interference just using a flat plate instead of the usual cake pan shaped (for lack of a better description)  box?   I could buy a Hammond of course but is it really needed?

[acheld]

I think it really depends . . .

If in a rack, then yes, you should go for enclosed shielding.

If the unit is removed from other RF generators, then probably not a big deal.   If you live in a "noisy" environment, then shielding is a good thing.  The problem is, how do you know before completion whether it is needed?   

I guess with his component boards, it would not be a deal breaker to install them in a box after you have tested your build.

I'd be real interested in how you're going to use Merlin's boards.   I have a set lying around (they tell me they are just "relaxing") that I want to put to work -- but haven't had the time to generate a workable idea for them.  Please post on your project.

[ShoemanGB]

True that the boards make it easy to rehouse them is needed.  This is my 2nd project using them. For the first I built his High-gain preamp in his book with a James stack added.  I've been tweaking it for many months. I've come to the realization that it's too "high gain" for my tastes no matter how I mod it.  If you like pointy guitars and spandex and watched MTV in the '80's you'd like it.  I was there, but I don't.  I'm maybe more a bell bottoms, long hair classic rock kinda guy with a lot of jam bands added in too.  I'll get some pix and post them here so you can see.  Super easy to use boards.  I gutted my Firefly chassis and added them, using the existing PS.   This new project will house both 5F6 Bassman and Marshall 1987 based preamps, one triode input stage board for each running to a single one of his gain stage/CF/tonestack boards (switchable from F to M stack specs) then an output level pot/jack that will then go to my Torpedo Cab-mixer-monitors/headphones.   I know that I'll never get the real deal tones from just the preamps but it will be fun and I'll learn a lot too.

[PRR]

> how important using a traditional box type chassis is?

You can build electronics in a geetar-shape enclosure.

https://www.amazon.com/ammoon-PockRock-Multi-effects-Processor-Function/dp/B01N34J7K0

However if it isn't nearly completely enclosed in conducting stuff, it may work in my back woods, buzz bad near my power pole, and scream "Breaker Breaker Good Buddy" over by the truck stop.

I assume that PockRock has sprayed metal inside the plastic. (Or the actual "audio" is thumbnail size with shielded cable to the jacks.)

[DummyLoad]

http://www.par-metal.com/product-rmc-14series.php


--pete

[mresistor]

I suppose you could line the wood inside with RF shielding film. https://www.amazon.com/Faraday-Fabric-Protection-Shielding-Nickel/dp/B087FB6BJS

{EDIT: tracking portion of Amazon URL removed -- PRR}

[Mike_J]

All the amps I have made have been enclosed in a wood enclosure and one side of the chassis has been open. In order to shield that opening I have attached what I think is a form of tape used on ducts to make them airtight. I seem to recall the tape is aluminum. Just tape the wood that is going to cover the opening in the chassis and from my experience no problems. Similar to lining the cavity of a guitar which I also did with the same tape. 

[ShoemanGB]

 
I'd be real interested in how you're going to use Merlin's boards.   I have a set lying around (they tell me they are just "relaxing") that I want to put to work -- but haven't had the time to generate a workable idea for them.  Please post on your project.

Here ya go: