Dact stepped attenuator distortion?

[hellokitty123]

I need to make a high precision low reactance variable resistor divider and normal potentiometers do not have ultra low tolerance between channels so I am looking at stepped attenuators instead.
Only one seller seems to be making a PCB stepped attenuators which is something I'd like to use in order to reduce lead length.
DACT audio attenuators
The curious thing I found is that the quoted distortion is 0.0001% which should be about -120db. That seems rather high for a resistor. Anyone know what that's about?

 

[planet10]

quoted distortion is 0.0001% which should be about -120db

Low enuff to be who cares?

dave

 

[hellokitty123]

I care. If I'm not mistaken resistors are usually many DBs lower distortion than this? I'm trying to understand what distortion quality resistors should typically have. I'm assuming Z-foils would be unmeasurable for example?

 

[rayma]

the quoted distortion is 0.0001% which should be about -120db.
That seems rather high for a resistor.

Carbon film can be even higher in distortion. Thermal and/or voltage distortion
does happen in resistors.

 

[planet10]

You are caring about something that does not matter. It is too low and THD says very little about how something sounds.

dave

 

[scottjoplin]

There is also distortion due to the contacts

 

[HeyBill]

Hello,

I have a DACT 10k. It uses SMD resistors. That may be part of the reason for the good specs. HeyBilll

 

[soekris]

Probably not something they can measure, but as a manufacturer they have to spec something so they just picked a number....

 

[gabdx]

120 db...

If your signal is 2 Volts, the distortion is 0.000002 V

To have a comparison... moving coils signals are among the smallest possible in audio and are around 0.5 mv, here your distortion would be 0.002 mV or 1/1000000 of the signal voltage.

 

[K.A.B]

You are caring about something that does not matter. It is too low and THD says very little about how something sounds.

dave

+1

 

[mchambin]

Probably not something they can measure, but as a manufacturer they have to spec something so they just picked a number....

+ 1
The spec is juste there for a professional look.