Amp for lightspeed attenuator? = $1000 used

Hi Dddrrree, your Lightspeed will work into the 10k input impedance of your present amp with no stress to any components.
However it now becomes the source cdp/dac which has to be able to drive the combined impedance of the 10kohm of your amp and the input of the Lightspeed, which equates to around 5kohm combined. This is still fine for the majority of low impedance output sources which have solid state output stages of 100ohms or less.
But it becomes a problem with tube output stage sources cdp's dac's etc, that are usually sometimes over 2kohm output impedances, then you could hear some dynamic compression, still not harmful to any components.
If you want to get the best from your Lightspeed Attenuator, then yes the poweramp input impedance should be over 47kohm which is the industry standard for solid state amps and tube power amps are well over that at 100kohm or more, which are even better.
Cheers George

Thanks for the walk through George. I'm driving the lightspeed using a musical fidelity V-DAC, which is supposed to have an output impedance between 40ohm and 80ohm, which seems to be within the range you mention. (BTW: what is the right email address to use to buy another unit? I sent several emails to the one on your site but never received a response.)

As a complicating feature, I'm using Y connectors to split the lightspeed output signal so I can feed it to a velodyne SMS-1 bass management unit (which I use to drive two subs).

Poprhetor: I should have mentioned that I don't have high efficiency speakers (recommended 100-150W @ 6ohm) so it doesn't seem that the jolida's would work. I'll troll through the huge lightspeed thread for amp recs; the problem is that its information isn't so dense :)

I'm running the Lightspeed into a Dynaco ST-70 rebuilt by Will Vincent. Bought it straight from him through A'gon for just over $1,100. It has an input impedance of 470K ohms and input sensitivity of 1V. How do those numbers sound?

"Dddrrreee As a complicating feature, I'm using Y connectors to split the lightspeed output signal so I can feed it to a velodyne SMS-1 bass management unit (which I use to drive two subs).Dddrrreee"
You can get me on "georgehifi at optusnet dot com dot au"

As with any other system active or passive these "Y connectors and active subs" brings in another added equation to the impedance matching, of system compatibility.
If you use active subs, this makes the load to the Lightspeed and the source even more difficult, then I suggest a buffer after the Lightspeed like the "Burson 100 Buffer" which unfortunately is no longer available new, you may find one second-hand or another equivalent that is a pure buffer with no volume controls or selector switching on it.

Cheers George

I use a Lightspeed clone (Lighter Note by Uriah Dailey) with a Rogue Atlas. Not sure about the exact specs but they are working GREAT together.