Tuesday, February 12, 2008

finally, a stepped attenuator

i've been wanting to try out a stepped attenuator for a long time. i even got a kit from someone that is bare, with all the various resistors unsoldered.

it took some time to understand which resistor value pair goes where for that ladder stepped attenuator.

i saw a posting on echoloft selling a used DACT CT1 50k stepped attenuator and did not hesitate in getting it.

the CT1 was installed onto the 5687 preamp last night. i had to drill a larger opening for the shaft to be put in. i also had to drill a smaller hole to accommodate the small stud on the CT1 which prevents the entire attenuator from moving around.

then came the desoldering of the previous 100k Alps Blue and soldering of the connections onto the CT1.

earlier this evening, i played various cds thru the preamp via the UCD180AD class D power amp that is already hooked up to my speakers.

this was not my usual setup to evaluate changes, but with the UCD180AD as the amplifier and the rest unchanged, transparency was the first that strike me. i had the opportunity to listen to some esoteric setup over the Chinese New Year holidays. i brought along a cd for comparison.

i thought the Snow Rose 3 - Milan Rose cd was particularly close mic-ed as this was evident in my setup. i was surprised that the atmosphere was not so easily felt in other setups that i listened to during the holidays.

the CT1 kept this feel still, but i would need to compare it with my DRD amps. this would be for another day as I went through cds and cds... from Frou Frou to Madeleine Peyroux to more familiar cds such as Ryuichi Sakamoto's Cinemage.

more pics here