DAC placement

Don't be fooled. It can be just just as important to isolate solid state as tubes. In the case of the PWT and PWD both benefit from isolation treatment. I use Herbie's Tenderfeet with 2 Supersonic Stabilizers on top of each component. For proper results of any isolation system one needs to first locate the component where it sounds beat on the shelf if you are using one. Then experiment with footer placement, then component top weights. Besides the Herbie's products, I've used VPI Bricks, MpIngo Discs, Vibrapods and Vibracones, and cones of various makes and sizes. Some components, like my ARC Ref3 don't seem to need footers as the stock feet are good enough. Also if you can move your component racks so they are situated on the middle side walls, you'll hear a difference too. Vibrating components smear the sound and you can loose the subtle sonic details that can really make your system sound outstanding. Don't forget raising your cables offs the floor as well. I've found that each of these tweaks can improve the fidelity of a system and when they are all added up the difference can be profound.

In my experience, isolating most components other than front end devices (turntables, CD transports and spinning disks) is unnecessary. As long as your input and output cables are snug and do not wiggle about (USB cables are notorious for this), you will be OK. It doesn't matter whether your gear is tube or SS, unless it's badly designed or cheaply made.

I have designed and installed audio data collection systems (including DACs and ADCs) that were installed into 4WD vans for travelling at speeds up to 70MPH over the desert (no roads). The suspension system for the equipment racks only damped vibration over 6gs. We tested up to 6gs with and without suspension - there was no recordable or audible difference as long as the cables were tight. Some of the gear used tubes (large power transmitter tubes).

Isonodes and Isopods under everything (including Isopods under my Silverline Preludes). The Isopods are so sticky they keep anything exactly where you put it...my DAC could withstand a pipe bomb. Be sure to note that too much isolation can cause components to become lonesome and depressed. Also, I play electric bass and guitar (frequently) through high quality "combo" amps (mostly)...there's your isolation paradox! My "boutique" little all tube guitar amp must be torturing itself, but since it sounds great I just look the other way.