2. amps-preamps
  3. 1137965724

CD output voltage too high for preamp: what to do?

I have an Audible Illusions preamp which is designed for a 1.5v input signal. I am told that this is standard. My Ayre CX-7e puts out 2.25v. They play beautifully together but I have too little control over volume: I cannot use the preamp vol controls beyond 9 o'clock because it is way too loud. Likewise it is hard to get just the right volume in the limited range available. This is worse with some CDs for reasons I do not know.
Audible Illusions will change the preamp attenuation board for $275, but before I do so I wonder how others have dealt with the problem of newer CD players with higher outputs than their preamps were designed for.
gmargo
restock
831 posts
 
Hifi57audio, I was wondering about exactly the same point concerning imput impedances, when inserting external shunt type attenuators:

Why do the EVS or Endler attenuators typically use a much lower impedance attenuator?

For example from the Endler website:

These are 4k or 20k shunt type attenuators which place only one resistor in series with the signal. Series resitance values of 1k, 2k, 4k and 20k were evaluated with 4k sounding the best. I use a proprietary technique on the switched side of the circuit to eliminate the possibility of an open circuit in case the contacts bounce. This helps keep things ultra quiet even in the presence of dc.

And from the EVS site:

Attenuators are available in a low impedance (1K) and a high impedance (10K) version.

Hifi57audio, any clarification on these low impedances for external stepped attenuator would great!

Thanks,

Rene
clio09
3,355 posts
 
I ordered the Endler attenuators in the 4k 24 step version. I am going to use them on the amp with my preamp in the chain feeding them. I did read in the PF review that used alone with a source feeding it, while the attenuators were very musical and transparent, there was a tradeoff in reduced soundtage and imaging (more 2 dimensional sound is what the end result was). Has anyone experienced this? Might this be different using the preamp in the chain?

My preamp is a Joule Electra LA-100 MkIII, with input impedance of 20k ohms and output impedance of 300 ohms. Currently it is set at 11db of gain.
hifi57audio
15 posts
 
Restock- Beats me, unless they are designed for pro use. Sound reinforcement/studio equipment often employ a matched impedance interface to optimize power transfer. If thats the case it would almost certainly be offered with a balanced connection only.
livewire18
6 posts
 
My AI 3A has a jumper that reduces the gain. Is this an option or am I missing something?
clio09
3,355 posts
 
Depends on how much the gain is reduced. My preamp has switches with plus or minus 3db increments. Even at the lowest level of 11db I am experiencing too much gain.
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