Shelf Material

I can report on experiments 131a and 131b. A friend who likes acrylic shelves told me they were best, not on spikes, but on a hardish damping sheet - some of which he lent to me. So if you recall I found the Corian to be OK on spikes if one used a soft footer or bladder product - experiment 131. So I tried the damping pads in place of the spikes and removed the soft footers and bladders - 131a. The result was better in this configuration 131a - and I was beginning to feel that this was a pretty good result. It was around about midnight, but I said "what the heck" and began experiment 131b. This time I used 300lb strain guage nylon (the 100lb stuff definitely stetched too much and the nylon coated steel rang like a steel string on a guitar) to suspend the Corian. Now it was getting late, and I was a bit tired, but first impressions were very favourable indeed. Experiment 131b rules at this point and the 300lb nylon cable showed absolutely no visible signs of stretch even when subjecting it to loads over 50lbs (after all I am suspending each shelf with four threads and so they can theoretically go up to 1200lbs). Resonance effects on the sound are now very low indeed, and I have some ideas of how to reduce them further. In conclusion, I think the suspension idea has considerable merit and that very thick nylon is better than steel. The Corian is a two edged sword however. It does ping, and I am sure there are still small vestiges of this in configuration 131b, but it otherwise has an excellent top end and bottom end, and the dynamics are very natural indeed. It may still very well be that if I find an ideal shelf material, that sitting on spikes may get closer to the results with suspension. This would get over the problem of the transport swaying after the CD has loaded, for example. But right now, suspension is sounding great - and believe it or not, my beautiful wife Sonia thinks it is "cute". For those of you that really love soundstaging - you have got to try this suspension thing - the depth of field is stunning.

Thanks for your kind thoughts on beaming me the slab Dekay. But 100lbs would normally cost about $US400 to get here, and that assumes they don't sting me for the awkward shape. I do actually have a cheaper way which is to get a NZ freight company to pick it up in the US. I am checking out the maple idea and seeing where the best prices are, but I am keen also to try the Neuance shelf which Caterham 1700 is kindly helping me with.

Caterham 1700. I have posted it off to you and it will get to you early next week - in fact the plane it is on arrives in the US today Saturday. The Caterham motors were lovely creatures. You may or may not know that when Lotus aborted the Lotus 7 Mark IV, it licensed it to various companies, including one here in New Zealand - Christchurch to be precise. With its light fibreglass body it was at the time the fifth fastest production car ever made for 0 to 60mph. Above that its poor aerodynamics slowed its acceleration and the front wheel arches - they were really just protruding pieces of plastic - waved alarmingly. They were not as graceful looking as the Europas, Elites, Elans and Esprits that I played around with, but they were one heck of an exciting (and occasionally wet) way to get to work in the morning.

Hi Redkiwi; Are you calling me Garfield? Recently, to audition a tube amp, I pulled my McCormack DNA-2DX amp out of its usual position on the bottom shelf of my large, heavy, all welded steel stereo stand. It has Melamine MDF shelves. After finishing with the tube amp, I put the DNA-2 back in, and over the next couple of days was generally disappointed with music quality which was vaguely irritating-- bass was sort of muddy, mids congested, and upper mids and low treble were slightly bright and even wirey-- but hey, I had been listening to a tube amp for several days (I was also breaking in a fairly new AC cord). It finally dawned on me that one thing I had neglected to do was re-set the DNA-2s vibration grounding spike. The DNA-2 amps have six sorbothane decoupling feet and a coupling grounding spike at the bottom, center, rear of the amp. This spike is threaded directly into the bottom plate of the amp. It's purpose is to couple the amp to the material it sits on. Yes, I know this sounds contradictory,ie to have both decoupling and coupling mechanisms built into the same component, but it REALLY works. After I screwed the "spike" down to the point where the two rear amp feet were just off the shelf (this is what McCormack recommends) I played some music and VIOLA' the music came back-- bass became deep, tight and solid, mids became more clear and well defined, and best of all the brightness/wireness of upper mids and treble went away. BTW, years ago when Stereophile reviewed the DNA-1 amp, the reviewer commented that the soft feet AND the "spike" were a contradiction and the reviewer didn't think they should "work together", but according to Steve McCormack-- not so, ie they DO complement each other; and hey, S. McCormack invented the famous Tip Toes. I have two points here: (1) this dual approach system really does work on the DNA amps, and (2) So why wouldn't it also work with other components-- at least those that don't have to be perfectly level such as DACs and pre-amps. It would be easy enough to check out, all that would be needed is two Sorbothane feet such as Audioquests Big Feet (or Little Feet), and a sharp metal cone foot (for a tripod arrangement). I don't have either yet, but think I'll round some up to try. Steve McCormack certainly has to be one of the masters of vibration control in stereo components. He is at www.smcaudio.com should you want to contact him. And he is a very nice guy. The above ramble is not about shelf materials, but I think it is certainly germane to your subject. Cheers. Craig.

Caterham: Both shelves (whole and with a hole) were cut from the same piece of MDF, there were no other shelf materials involved. I did not power down the system or move my source, so the comparison was quick and easy. Their was no noticeable difference between the two, though both sounded bad. The shelves were used on my amp only and not the source. The next time I will try 1" MDF with and without the hole. The 3/4" MDF is definitely too thin for the 24" stretch. I have Musical Fidelity X gear (the funny shaped stuff) which limits what I can do. I am really dependent on the platform as I cannot change the feet on the components. I also do not have enough clearance left in the cabinet to add more than 1/2" to the sandwich. I had to power down this morning to add my new dual mono power amp (which has a bad hum in both of the channels past 9 O'clock on the gain) so I will wait a few weeks to try the 1" shelf. I already requested a call tag for the amp and hopefully it can be repaired as it is the only one available. I already tried switching polarity, isolating cords and the power supply, etc., so it is something internal most likely in the separate power supply as both channels are humming. Anyway, the reduced mass theory is sound - the materials in their application were just not up to par for a decent evaluation. Aside from function I have been thinking of how rewarding it would be to design the form of equipment racks as I have yet to see a stock one that I would want in my living room. We have very diversified tastes that range from a late 1800s black lacquered bent wood settee to the original umbrella chair, but none of the racks cut it as far as I am concerned.