Custom rack, isolation under platform vs component?

Thanks again for compliments.

@jumia I'm new to audio, but have some background in physics. From what I understand, vibration in the components can come through the ground from speakers, through the sound pressure waves in the air, and that internal components like transformers can also cause vibration. So even a solid state amplifier can end up vibrating due to these factors, isn't that accurate? 

Yeah I understand vibration and all that stuff, but I simply put a cheap acoustical tile panel beneath speakers to absorb most stuff.

The components I have come with nice footings , some come with a pinpoint that sits on top of a isolation disc. I put my power conditioner on an acoustical panel.

I think that's a pretty good way to approach it and is incredibly cheaper then spending a few thousand dollars on isolation platforms which I think Are absolutelyridiculous. For turntable I can see it.

I think spending money to address grounding issues and power noise makes more sense

Yes, you're probably right. I'm new to this and bought expensive speakers. Someone in an older thread I posted told me I'd learn a very expensive lesson. I do have a power conditioner but haven't gotten too much into those aspects. I'm sure I will and then there will be a new money pit. 

Looks great!
Check out Nobsound springs on Amazon for under the rack.  They’re like $35 delivered and four of them will handle up to 320 pounds!

Nicely done.  Woodworking is definitely a skill, even on something fairly straightforward as this, takes a lot of practice! 

I like the first iteration - looks and concept.  Assuming the mortise and tenon joints were just glued?  If all the joints were screwed into the vertical legs, I think you would have obtained the structural rigidity needed.  As well as using beefier dimensional lumber for those horizontal pieces.(1.5" x 2.5"). 

I'm all for isolation as well and don't let the naysayers deter you from your design.  For very little cost, you could use springs under those platforms.  You have the background to figure out total weight of the component and platform to get it down to single digit freq (3 - 8hz ~).  As long as compression is right, you're golden! 

Seeing as the platforms are now permanently fastened, you could still make use of springs under the components themselves (directly or via another smaller board), at least as a test.