Should I isolate my amplifier.

[Meloski]

How important is it to isolate the amplifier? What are the benefits? I have very little headroom on the rack (1/2") I was thinking SDS isofeet would fit.



Let me know your thoughts.

Cheers,

[brian2957]

Hi Michael , I would certainly give SDS Isofeet a try . You may be pleasantly surprised . Beautiful amp BTW

[Meloski]

I have a IsoPlatMat and love it. But What are the benefits of isolating the amplifier?

[brian2957]

I found that the Isofeet provide improvements in areas such as clarity and soundstage . Bass is deeper and cleaner and voices in particular seem to have more ' emotion ' . I'm not saying the Isofeet will work with all equipment , however , if they do work with your amp I think you will be very pleasantly surprised . I've just ordered another set for my Rega Brio R . I currently use the first set I purchased under my server and I'm well pleased with the results .

[Ammonite Audio]

Rather than isolate the amplifier, I would experiment with placing some fat squidgy sorbothane feet under the stone slab, and then use oak or plastic cones to couple the amplifier to the slab, which can then dissipate vibration. In other words, provide somewhere for vibration energy within the amp to go. The sorbothane feet will provide a good degree of general broadband isolation from whatever the slab is sitting on.

[zanash]

as all valves are microphonic ..stopping any ground carried vibration reaching your amp will improve the overall sound. buy a cheap stethoscope [medical or engineering types work] and listen to the amp case as you tap the floor , and then the stand. Then add your cones or isoplat stuff and listen again.

[struth]

Special care should be taken with all the cables too keeping them well away from each other will help

[Wakefield Turntables]

What are you trying to isolate your amplifier from exactly? What about EMI / RFI ?

[Arkless Electronics]

If it's line level then there will be little or no improvement from vibration isolation (depending on gain and how microphonic the valves are). Try gently tapping the valves whilst the amp is at normal listening level and no music is playing to get an idea of microphonics level of your amp. Remember this is applying vastly more shock and vibration than will be experienced by the valves when you are playing music! A plastic toothbrush handle makes a good tapper

As an example of microphonics level, I once was playing the saxophone along to a record that I was taping to cassette (yes it was years ago) using a valve phono stage and valve head amp. The sax could be heard faintly in the background on the recording..... However, remember that this was with a valve head amp and therefore the worst situation re microphonics as could ever happen! We are talking x1000 or so amplification before the line stage here and a very loud indeed live sax about 2 yards from the hifi. The amount of microphonics will of course vary hugely with the type and actual sample of valve used and the circuitry around it.
Some will tell you it's critical and will even recommend isolation for solid state power amps.... A total waste of effort and money IMHO

As an aside to this, which may be of interest to valve diy'ers, if you ever get ridiculous levels of microphonics from a valve amp then suspect RF oscillation
If the valve is oscillating, at lets say 30MHz, due to parasitics, then any movement of the valve elements will frequency (and often amplitude) modulate the oscillation which will often end up being demodulated. You won't hear the 30MHz of course but you will certainly hear the RF condenser microphone (google it) you have inadvertently built!