As An Experiment I Stuck A Few Things Under My Pre-Amp And Am Now On A Quest


My system is built out, got the pieces I want in place, and struggled a bit with how it sounds. With certain recordings it was sublime and with others it could be a bit sterile or mechanical sounding. These are all solid state components in a Salamander cabinet, and up to this point I have never been a fan of isolation devices with SS gear. Now with tube components I did use spike type devices under amps and preamps, so I have had a bit of experience.

Last night I rounded up a few wayward isolation devices I had from previous systems and thought I would experiment a bit. The pre-amp contains the DAC also, so I thought I would start here. Put in some Wagner type pads, and got a different sound with some improved focus but the bass was lean and a bit odd. But things changed. I tried some magnetic pods I had, no change with them.

Then as a whim I cut two sections of foam pool noodle I had laying around and put it under the front and back of the preamp. I oriented them lengthwise. Something fantastic happened here! I got spooky precise focus to instruments, the bass response became impactful, the sound is more relaxed...perhaps a bit too smooth but I will take this over that mechanical presentation any day. This is sounding very nice.

So, after dinner I decide to cut a third one and perhaps the bass gets better. I put it in and all the gains are gone, it sounds worse than the first set of Wagner pads I put in. The bass literally vanishes and the soundstage collapses. Pull it out and things are good again. I listen to disc after disc last night and am pleased with the sound. I am spinning vinyl this morning and still feel the same way.

So now I have a plan of action. On one hand I am content to leave the noodles in place and roll with that for awhile. It would be nice to have a permanent solution though. It seems like I am looking for a compliant solution. I remember Brightstar used to build a little shelf that housed a bike inner tube in it, and I think Townshend Audio also had a bladder type platform.

It would be interesting to know what products folks have used that functioned in a similar manner.

Thanks for sharing any thoughts or experiences.

neonknight

Isolation devices are not often so good ...

Springs are complex to tune and better used with damping load and way better when we use two set of springs one set UNDER and one set above the speaker under damping load ... the damping load may be tune with a few grams approximation by ears ...I did it ...

Coupling and decoupling work very well but ONLY with a sandwich mix of plates , I use oak, granite,sorbothane,bamboo, cork plates , all together with astounding results ... Cost : peanuts ...

Sorbothane alone, springs alone or metal feet alone are not so good at all ...These PARTIAL solutions are deceptive and hide the problem ...

Most people as it is the case with the acoustic control of a room or with the electrical high noise floor of a house , or with EMI interference , most people had no idea how vibrations/resonance plague all audio system because they never adress the problem really and at best bought some feet made of a singular material composition ...It is not enough and deceptive solution ...

When vibration are under control the impact is huge not small at all , including timbre experience, imaging and even soundstage in my experience ...

I’ve got the often mentioned Nobsound springs under the feet of a cheapie Pangea rack which has proven to be very effective a decoupling from my super resonant hardwood floor. Also placed my preamp (solid state SPL) over a set of the same springs. Thinking about doing this for the amp as well. Sorbothane picks under the dac - which is also on the same rack. But sm considering trying some different materials or some tuned pucks along he lines of some mentioned here. Since my rack is horrifically basic and resonant, I’m even considering getting a sheet of dynamat and attaching it under one of the shelves to see what that could do. 

If you have one grab a mini level out of your tool kit...that thing with the 3 tubes filled with liquid and an air bubble. Mine was about 10 inches long. Lay it across your dac or whatever and watch for vibrations in the bubble. 

Poor mans visual vibration inspector 

This weekend I located a set of the Chinese style mag lev footers, and placed them under the pre-amp. The Trinov has a sophisticated DSP program, and one function it has is a very precise EQ option. I decided to experiment with it. I did in depth reading from websites dedicated to studio/sound engineering work to get an understanding of what I wanted to achieve. 

 

I started with a 1.1 dB cut from 1K to 5K. I then added a 1dB boost from 200 to 400 Hz. As I understand it you should cut first and boost as a last resort. But I am a newbie, and in this case it worked for me. 

I then started listening to several reference discs and began to reduce my settings. The sound was a bit too smooth and a touch too warm or vague. I can reduce by .2 dB. My first cut was from 1 to 5K and I went to -.6dB from -1.1 dB. Then I started cutting by -.2 increments. I also worked in the 200 to 400 hz range with the -.2 dB amounts. 

My final settings are 

+.4 at 200 Hz

+.4 at 250 Hz

+.6 at 315 Hz

+1.0 at 500 Hz

-.4 at 1KHz to 4Khz

I zeroed out the 5KHz setting, so no correction there. 

 

My objective was to get to the point where the sound became harder and forward, and back off one click and see what I thought. I am listening to these settings now and appreciate the clarity and detail and have not heard any aggressive tendencies. 

So far this is an enjoyable presentation. What I find fascinating is that a .2dB change in equalization is clearly audible. 1dB is significant, and to think how easy it is to influence the sound should give a person pause when selecting associated equipment, cabling, room placement, and what goes on the walls. This hobby is amazing, and it fascinates me how the little details matter.