[Nounours]

Hi Friends,

I have to buy 2 mono stepped attenuators (25k) for my preamplifier.

I am interested by the 48 positions of the Khozmo but:

a-.I do not know how good the sound is, compared to the DACT or GoldPoint ? are they better or equal (I have read this topic:www.head-fi.org/forums/f6/how-khozmo-stepped-attenuators-440942/ but it does not clarify how good they are compared to the Dact or the Goldpoint).


b-.I have no idea on how to attach them to the front plate of my preamp: I cannot sold the pins of the attenuator onto the mainboard, so I will have to attach the attenuator to the front plate and use a cable to link the attenuator to the mainboard. The Dact and Goldpoint seem simpler to install regarding this aspect, because they offer a dedicated screw to achieve that).

c-.If the Khozmo is not chosen, what is the best one: Dact, Goldpoint or other ? (I have not enough space fo rthe Shallco).

Thank you very much for your help,
N.

 

[gdurocher]

Bought a Khozmo shunt attenuator off of ebay and sent it back since it sounded worse than stock potentiometers/gain controls on my amp.  Gave them a second chance by swapping for a ladder type with upgraded resistors but still no attenuator for over 4 months.

 

[Steve Eddy]

Bought one off of ebay from these people and would not recommend anyone go through same experience.

Bought one what? He's asking about three different attenuators.

se

 

[Steve Eddy]

c-.If the Khozmo is not chosen, what is the best one: Dact, Goldpoint or other ? (I have not enough space fo rthe Shallco).

You don't have enough space for a Shallco, but you have enough space for the Kozmo?

If you have the space, I'd recommend the 40 step attenuators from Acoustic Dimension.

http://www.acoustic-dimension.com/attenuators/attenuators-main.htm

No, they don't have a 25k version, but is there any reason why you couldn't use 10k or 100k? What sort of input is it feeding and what will you be driving it with?

Otherwise, I'd go with the Goldpoint over the DACT. They're both based on the same Elma switch, but in my experience, the springs that Goldpoint uses give them a better feel.

Good luck!

se

 

[mcandmar]

A Dact, Goldpoint, Khozmo, or eBay cheapo attenuator using the same resistors is going to sound the same, what your paying for is the quality of the switch. I'm using a vintage Goldpoint ladder in mine which has a nice tick-a-tick-a-tick action vs the cheap eBays that go clunk-clunk-clunk. I haven't had the pleasure of trying the others, though the Khozmo with its ball bearing shaft does look interesting..

 

[Steve Eddy]

The problem with the Khozmos is they're all "shunt" type attenuators, a bad idea that got started by people who had some embarrassingly erroneous notions about what constitutes the "signal path."

The attenuators sold by Acoustic Dimension I mentioned previously also have a ball bearing-based shaft and feel absolutely fantastic.

se

 

[smitty1110]

I'm fairly new to the nitty-gritty details of audio electronics, so could you please explain why shunt-type attenuators are not ideal?

 

[Steve Eddy]

I'm fairly new to the nitty-gritty details of audio electronics, so could you please explain why shunt-type attenuators are not ideal?

Namely because the input impedance of a shunt attenuator changes depending on the rotation, and that you're always left with some attenuation (due to the fixed series resistor that's always in the circuit). That's not necessarily such a BAD thing. Really my biggest problem with them is that they were "designed" by those who don't have any real understanding of what constitutes the "signal path." They erroneously believe that the "signal path" only travels horizontally, and anything that is shunted (i.e. vertically) is not in the signal path.

Based on this misunderstanding, they believed that you could use one very high quality resistor in series and then you could use a lesser quality potentiometer (or resistors in the case of a stepped attenuator) in the shunt position because they believed it was not in the signal path. But the fact is that what's in the shunt position is equally if not more important than what's in series. The voltage that you get at the output of such an attenuator is wholly the result of the current flowing through the SHUNT portion of it. So anything going wrong there is going to have an effect on the signal.

But the mythology of what constitutes the signal path persists, as do many myths that have been created and perpetuated by the so-called "high end" audio industry.

Bottom line, a "shunt" attenuator offers no real advantage over a regular attenuator.

se

 

[smitty1110]

Cool, thanks for the reply.

 

[paradoxper]

I convinced a DIY builder to start using the Acoustic Dimension 40 step attenuator per Steve's recommendation some months back and after building up
my amp using it (the first of many to come) he enjoyed it so much it has become his standard choice for all builds.
 
Very smooth and plenty of steps. As far as quality - not a problem to report. Not to dump all over Khozmo, but they've been known to be very shoddy.