stepped attenuators

my tom evans vibe pre-amp has one and i love the precision, and the confidence of signal at low volumes. like your burson, the only other switch on the unit is the source selector. Tom even put the power switch several feet away on the power supply.

The Ayre V1xe has one as well. I believe that the unit was discontinued because it was so complicated and expensive to build. It is hand built with silver contacts, belted, and motorized...very accurate.

I know there's more to this unit than the volume control but I feel it must have a huge influence on the sound quality.
How do you feel about them?

All switches impart a sonic signature. It has to do with diode effect. I suspect the reason you're enjoying the Burson has more to do with the circuit design and buffers than the switch.

FWIW - I like stepped attenuators too. I especially like the Seiden switches. However, my Lightspeed attenuator and Truth preamps (both using LDR technology) eliminate the switch from the equation and compared to other passive or buffered devices the difference is noticeable.

Everything has to go through the volume control, attenuator.

I switched out a defective potentiometer in my Audio Note L3 pre-amp for a Goldpoint Stepped Attenuator and am happy with the results. More open and transparent sounding. Stepped attenuators usually eliminate L and R level mismatching often found with conventional potentiometers at lower volume settings.

Everything has to go through the volume control, attenuator.

Yes obviously the signal goes through the switch. What I meant was that in an LDR design the sonic signature of the switch itself is not imparted in the signal. A Radio Shack switch works as well as the best Shallco stepped attenuator. There will be no difference. Here is a more technical explanation:

http://forum.audiogon.com/cgi-bin/fr.pl?aamps&1276356977&openflup&548&4#548
and
[url]http://forum.audiogon.com/cgi-bin/fr.pl?aamps&1276356977&openflup&549&4#549

As the OP indicated, Burson states the signal is weakest when it goes through the volume control. The only better solution than what Burson came up with is the LDR IMO.

FWIW, I'm getting one of these Burson units myself. They seem to have an excellent reputation.

Be sure that the one you select allows a sufficient range of adjustment, a friend had to change his a couple of times as the first were too sensitive and allowed him to use only the first few stops. When this happens the change between stops is magnified and it is hard to get the volume you want.

Mine and all current models have had the increase in volume steps tamed down some so as to not come on so strong at lower settings with efficient speakers. My Toninan Labs TL-D1s (95db) can tolerate 5 settings without my neighbors complaining. I know this sounds like not much of a selection but once you've heard the purity of the sound, you quickly adjust to the settings.
It was a little weird at first but I'm never going back.

Had my McCormack TLC-1 Deluxe upgraded with SMc Audio's Ultra package which has a Shallco that's built to Mr McCormack specification and assembled with Audio Note resistors. I have to agree with you on the transparency these have to offer. I would say it removes the glass from the proverbial window. Could not believe the difference. Unfortunately to use this attenuator had to forgo the passive capability of the pre, its now a buffered preamp.

Nonoise: If you're constrained to 5 settings, you can probably have the input sensitivity of your amplifier altered by the manufacturer or a good technician. This is typically very easy, and can potentially give you (almost) full usage of the volume control....

Is there anyone out there that could reduce the gain on a preamp if the manufacturer will not do it?

Rgs92, I've placed an order for a 41-step 100K Acoustic Dimensions 8-deck balanced switched ladder attenuator that will do -80db. This is -15db to -20db more attenuation than most stepped attenuators. Moreover, this unit is not much larger than the 4-deck Shallco balanced series attenuator that it will replace.

I don't care for them. I don't like the clicking. I don't like that too often the appropriate volume level seems to between the available steps.

I have had them for many years on my Jadis preamps, first the JP80 and then the JP200, and have gotten used to them. Since both of these preamps have separate volume controls for each channel (in the case of the 200, separate chassis as well), the stepped attenuators are a blessing in that I at least can tell by the clicks that I have the same volume level for each channel. I do agree with Unsound and Stanwal that, at least where I have a source that is so strong in output that I can only use the first quarter of the available volume adjustment, it does seem at times that I find the appropriate level is somewhere between the steps on the attenuator (the differences in volume are larger in the first quarter of the Jadis volume control, more fine as you go higher in volume/lower in attenuation), but this has not been a real problem for me on all but a few recordings.

I'm building a preamp using the Acoustic-Dimension 41 step attenuators. They are well built, have smooth rotation, and are quite silent. They remind me more of Seiden than Shallco. We'll see how they work in a couple weeks.

It sure seems like a scary & risky prospect, but is it crazy to find a good technician (I guess somewhere in the U.S.) who could either replace the attenuator or reduce the gain in a high-end preamp? Or is it better just to sell the unit and move on?

Rcprince,
What attenuators did you install in your JP80? Did it make a big difference?

Rgs92, which preamp?

T_bone--I didn't install anything, the stock Jadis volume controls on these units (as opposed to the JPL, for example) are in essence stepped attenuators. I believe they operate using different resistors for each step.

I wonder if they changed over time. My JP80 is ancient (s/n 008), has a single volume pot and a balance knob, neither of which are stepped.

T_bone--that really is an early one! They did change over time, not only did they become stepped attenuators, but they also replaced the balance control by using a separate attenuator for each channel, which is a better way of doing balance between channels in my view. I recall visiting Victor Goldstein when he was still the US importer of Jadis, and he showed me the version of the attenuators they used in the JP80 after the one I got, they were actually set up so you could turn both of them with just one knob (you could operate them separately by pulling out one of the knobs). It was a very large and elaborate assembly. You might check with Jadis to see if they have someone in Japan (I think that's where you live, if I recall) who could replace your volume/balance control with a current one, though the price was not cheap even when Victor was showing it to me.

Rgs92, simply order a pair of Rothwell in-line attenuators for 10dB attenuation - they come in either rca or XLR versions. I would place them between your preamp and amp - at the input to your amplifier. There are a couple of reviews you can google.

Regarding stepped attenuators, I have had several on preamps I have owned over the years and greatly prefer these discrete resistor volume controls to the rather inexpensive and not very accurate Alps volume pot. Unfortunately, even manufacturers of expensive preamps use the Alps because it is the least expensive and easiest method of implementing remote volume control. More recently, there are manufacturers offering relay activated discrete resistor volume controls that are set up for remote operation.

For those replacing a pot with a discrete resistor stepped attenuator, I would stick with the same impedance value but you could change the gain. I believe Goldpoint offers this option by adding a single resistor to their stepped attenuators. Check out the Goldpoint website or call them for more info. Also, the Bent Audio guy and others now offer motorized options for DACT and Goldpoint attenuators that might be worth checking out if you need a remote. Like G_m_c, the first to respond to this thread, I am very happy wiht the DACT attenuator in my TEAD Vibe preamp.

What Mitch2 said.

Preamp: Apex Pinnacle (a combination preamp & headphone amp).
The Rothwells didn't sound too good to me.
The Goldenjacks are somewhat better, but still are not for me. They mush images together and take away some of the (very valuable) roundedness and palpability of images that I find with high end tube preamps. They just flatten things.
I had a similar thread here and I apologize for taking up the commenters' time if they tried to help me out before.

It seems that outboard attenuators in any form affect the purity, texture, and image density found in a high end preamp with high end ICs.
(At least that's what I am finding).
No free lunch.
I have no problem with stepped attenuators as long as there are enough steps.
Thanks for everyone's help.