Khozmo 48 position stepped attenuators

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Khozmo Ladder attenuator 48 step MBB 50kohms

Just got my first unit, I'm gonna see how she sounds. Looks pretty good so far!

I do not suggest taking the unit apart unless you are excellent at aligning mechanicals in quadruplicate alignment. There is very little room for error. The first time/attempt at re-assembly would be quite the task for the average Joe, methinks. I cannot imagine the quad ladder unit assembly headache.

In case you are wondering, there is obviously an insulator for the wiper to isolate it from the shaft and lock system. You can't quite see it from the given internal picture.
 

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wow!

I can not imagine what it takes to assemble those things!!
Whew!

I have some concerns about the wiper assembly and the thickness of the traces... but it is a magnificant effort no matter what...

What was the price for this beast?

How many DB per step - and are these "pots"?? (tapped string of resistors)

(I note the Dale resistors... I presume those are 1/4 watt??)

_-_-bear
 
They were about $189 each delivered to N-A, from Poland. My biz partner has ordered two of the surface units, and I grabbed one of the dale resistor types. They appear to be 1/8th watt, according to the website.

The thing about attenuators is that they are like isolated resistive loaded '3-d' field spaces with respect to their action and innards. Due to this, mechanical loading and mechanical control (or any other aspects) of the elements is critical as they can do get into motor effects from vibrational input. This is why people say that the knob of a volume pot can make such a sonic difference. It changes the mechanical damping of critical components. it's almost like a case of when microphone cables are overtly sensitive to mechanical noise input becoming signal. Actually, it's exactly that.

Music isn't steady state, so there are microseconds of the transient structure of the signal passing though them (volume pots) that momentarily have near infinite impedance (due to sharp delta)...so microphony rears it's head and becomes a notable problem.

With two seconds of thinking attached to that, then it becomes clear that this happens in all equipment in all areas all the time. Not just the volume pot. But the volume pot is a near special case, as it is an electrically isolated variable system. Like some loose cannon of a connected but isolated high impedance transistor noise function. Under maximum load variation, no less. With a critical circuit on either side. Think of it as a variable spring hooked up between two spring like structures. And you are attempting to get variable levels of signal modulation through all three..by varying the middle one. You'd better have a really well built middle one and it had better be under excellent control.

I'm glad to say that this unit is mechanically stable and quiet. Which, as you can read above, is critical to getting superior sonics. However, I have not tried the unit yet to check on it's electrical considerations and I many never report on that aspect, I may leave it up to the inquisitive to investigate.


Whatever the situation may turn out to be, it's a great looking unit. I wholeheartedly support the design and sale of these units, which is why I have one. We need this stuff to be out there and being developed.
 
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I was initially worried it would sound too 'silvery'. The combination of rohs compliant solder and the plating had me worried, initially.Thankfully, so far, it is not and is calming down nicely. Dynamics are improving.

It is being used in one of the most demanding situations possible - a passive preamp.

WBT nextgen RCA's, a maximally damped chassis, and er, VERY unique wiring. ;). It is 'possibly' the most resolving of passive preamps in existence at this time. ;) There are sound and solid reasons for that, which I won't get into at this time. Apologies......
 
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KBK

Many thanks for the pics and impressions.

"calming down nicely" sounds like famous last words before delegating a component to a dark drawer :) hopefully not what you mean

Any idea how it compares to a Shallco?


I wish I knew. Send me a Shallco and I'll let you know. :p

I'll need a year for both to break in, of course.


Now for the SMD (surface mount) 50k ladder MBB units that arrived yesterday.
 

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I'm liking the sound of the Dale resistor ladder unit, so far. It's been in daily use since the first day I reported on it. It is, of course, a case of randomly using different settings and hoping I'm hitting enough of them and using each long enough...that most settings (resistor pairs and associated contacts) are breaking in. The pot is 'on' and passing signal 24/7.
 
The point is literally debatable and such long and torturous debates have emerged here on this forum, so you should go and search for those threads. This thread is centered around being a discussion on the availability and sonic aspects of this particular attenuator.

Apologies.
 
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