[BillB]

I would imagine that the deciding factor will be the resistors as the switches are just multi-point selector switches.

Gold point uses .1% SMD resistors...this seems a tad overkill IMO as 1% metal films would probably be more than adequate.

For an interesting multi-step pot on the cheap check out the TCJ attenuator from Broskie. There is a new "old" version that doesn't use the fancy ELMA switches and is only $39 with resistors (your choice metal or carbon).

They are unique in that the center control is a stereo unit with course control and has a seperate left and right fine control.

Here's the link:

http://glass-ware.stores.yahoo.net/netcjstat.html

[richidoo]

Step just means that the attenuator is not infinitely variable. Pots and LDR are infinitely variable, but a network of individual resistors is not. Each are capable of outperforming the others according to the implementation. That's what matters.

Check out Bent Audio and Intact Audio for magnetic. In resistive, check out Placette Audio and Goldpoint Audio. There are others too.

georgehifi over on diyaudio builds finished lightspeed attenuator using LDRs for about $500, and helps people to build their own from info on that thread. YMMV... I don't know of any other commercially available passive attenuator using LDRs. Apparently Melos made one at one point, and DartZeel still uses them for source switching and attenuation in their preamp. Silonex makes low distortion LDRs, they have some technical articles online.

In this hobby there is no "best," only what's best for your situation, and even that changes over time.

[dweekie]

georgehifi over on diyaudio builds finished lightspeed attenuator using LDRs for about $500

$400 shipped actually (for now, good exchange rates), which is a faily good deal in my opinion for a fully completed product from Australia.  When you have guys like Nelson Pass and Paul Hynes chiming in on the performance and viariations of their own, it certeinly is worth looking into.  I'm enjoying mine a lot.  If you need George's email, send me a pm. 

[BradJudy]

$400 shipped actually (for now, good exchange rates), which is a faily good deal in my opinion for a fully completed product from Australia.  When you have guys like Nelson Pass and Paul Hynes chiming in on the performance and viariations of their own, it certeinly is worth looking into.  I'm enjoying mine a lot.  If you need George's email, send me a pm. 

HAL mentioned that you had one, but I figured it was one you built from his design.  So you bought one of his finished products?  Any pictures?

[mgalusha]

Or you could go over the top and get some Shallco 45 or 60 step switches with silver contacts and outfit them with something like Vishay S102 or VTA 55 resistors.

The Colorado Audio Society had a meeting at Ayre Acoustics last week and they have what look to be 60 or 64 step Shallco's with ultra low tempco flip chip resistors on them. There are four of those in the preamp, one per phase/channel, gotta be just horribly expensive but they were certainly nice as was all the engineering they showed us. 

[maxwalrath]

Or you could go over the top and get some Shallco 45 or 60 step switches with silver contacts and outfit them with something like Vishay S102 or VTA 55 resistors.

The Colorado Audio Society had a meeting at Ayre Acoustics last week and they have what look to be 60 or 64 step Shallco's with ultra low tempco flip chip resistors on them. There are four of those in the preamp, one per phase/channel, gotta be just horribly expensive but they were certainly nice as was all the engineering they showed us. 

Damn...

[cujobob]

I did a lot of reading on this back when I ordered my Mapletree preamp (a DACT stepped Attenuator was an option I considered)...from what I had been reading online, it seems inconclusive as to whether the stepped attentuators really made much of a difference.  Its a difficult piece to compare...Alps Blue Velvet isn't bad and is much cheaper, IIRC.

[dweekie]

$400 shipped actually (for now, good exchange rates), which is a faily good deal in my opinion for a fully completed product from Australia.  When you have guys like Nelson Pass and Paul Hynes chiming in on the performance and viariations of their own, it certeinly is worth looking into.  I'm enjoying mine a lot.  If you need George's email, send me a pm. 

HAL mentioned that you had one, but I figured it was one you built from his design.  So you bought one of his finished products?  Any pictures?

I only have the standard set of pictures.  I haven't opened it up, but I don't think it's too exciting inside considering the LDRs are covered in wax I believe.  It performs very, very well.  I have some fairly insensitive speakers and a low power amp that allows me to compare the effects of various pots.  It's a testing method that works well enough with some caveats, but the Lightspeed does do a great job. 

[Telstar]

I DO think that the LDR are the best attenuation method, provided that your source and amp impedance match.