Feedback through turntable

Going from 4 springs to 3 springs won’t buy you much. Neither 4 springs nor 3 springs provide much, if any, horizontal isolation since springs are inherently stiff in the lateral direction. There is some isolation in two rotational directions IF the springs are actually matched to the load and the ISO SYSTEM is not too stiff. The ISO SYSTEM resonant frequency will be lower for lower number of springs.

All things being equal I usually recommend preloading the springs with mass such as granite or marble, if needed for matching the (relatively light) load to the spring rate of the springs.

There is also the issue of leveling...especially for a tt. You can find the "sweet spot" if you don't have a base structure that has the ability to adjust level.

I use different sizes/weights of bags filled with lead shot to match the load when needed.

I’m not crazy about lead. It's a non audiophile-friendly material. Messes up the bass. Don’t take lead for granite. It resonates throughout the system. Try substituting a different material just for grins and I think you’ll see what I mean.

geoffkait,

I understand where you're coming from. I know that lead can deaden the sound if not used thoughtfully. I should have then said, the shelf that supports the component I need the additional weight in my system to get the proper loading, I use a BDR shelf that doesn't react to the addition of lead like other materials. I have several weights of brass with points that work well in other areas.

My main point was, for a tt, where level is critical, I find in my system, I like to have a support structure that has a built in leveling adjustment. I find if one has a tt with adjustable feet, it's best with them screwed all the way in and do the leveling elsewhere. In some cases where finances are a major factor, this may be a way to go at some later point. Another positive is that you can then play with better (feet options) on your tt that will better address the sound quality while still using the springs under a tt's DIY shelf.

Having said that, the addition of marble shelves or any other shelves, while adjusting for load, will not help with the leveling. The bags of lead shot or brass feet strategically placed is an option that can kill two birds with one stone, so to speak.

The important thing is to get started and all of the many options available to you will be a good upgrade in the future.