2. amps-preamps
  3. 150745-121

can someone answer me this.....

i have done some extensive research and talked to quite a few people who own or have had this preamp.  I recently came into a conrad Johnson et 3 se, nt much clarity,the bass is muddy and the presentation is dark, ive read where some claim the system is to bright.  ive also read where its good to get a specific type of tube.  I don't want to do that just yet because im trying to learn the units characteristic.  I wonder if its not quite broken in yet.  maybe the impedance thing that Im just learning.  steve mccormck suggested that I try some after market power cord, that I ordered.  
assoc. equipment
McCormack dna 500
oppo 203
alon IV's
acoustic zen interconnects
I make my own speaker cables …..
no wires are touching, none are on the carpet or floor.....
kennesawjet

Showing 2 responses by almarg

almarg's avatar
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almarg
9,670 posts
 
almarg speak English, my head started hurting, followed by flashbacks of science class.....lol.
The point I was making in my previous post was simply that while the impedance situation in the connection between the preamp and the power amp is not ideal, and does not conform to the recommendation stated in the manual for the preamp, I’m pretty certain that it is not what is causing the symptoms you have described. And I expressed agreement with Ralph (Atmasphere) that a tube is the most probable culprit.

The reason I went into further detail in that post is that you had referred in your initial post to "the impedance thing that Im just learning."

almarg, don’t know a thing about the imped factor. and do you still have that 17ls. or what preamp goes best with the dna 500....

It was another poster who referred to the 17ls, not me.

Regards,
-- Al



almarg's avatar
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almarg
9,670 posts
 
Regarding impedance compatibility, the DNA-500 has a specified input impedance of only 10K, and the manual for the ET3 recommends a minimum load impedance of 20K. Based on some interior photos I found on the web it appears that both the ET3 and the ET3SE utilize 4 uF coupling capacitors at their outputs, so the 20K recommendation presumably applies to the ET3SE as well as to the ET3.

However, given that the impedance of a 4 uF capacitor at 20 Hz is 1990 ohms, and given that the output impedance of the preamp at frequencies above the deep bass region is undoubtedly far lower than that (the specified nominal output impedance is 100 ohms), while the resulting mismatch will produce a slight rolloff and a bit of phase shift in the bottom octave, that is unlikely to be the major contributor to the problem. More likely the single tube that is used in the unit (assuming the optional phono stage is not included) is the major culprit, as Ralph (Atmasphere) suggested. And if the optional phono stage is included, given that you are using a line-level source the single tube that is used in the preamp’s line section is what should be focused on.

Regards,
-- Al

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