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

Showing 2 responses by restock

restock
831 posts
 
I have similar problems: A tube preamp with 23 db gain, a fairly high output CDP with 2.3V, a very sensitive amp. Overall this results in about 10db too much gain.

As for solutions:I also read about mixed results with the Rothwell attenuators and therefore ended up looking at the following attenuators:

- Endlers variable stepped attenuators
- EVS fixed volume attenuators

Overall the EVS seem like the best solution. Another alternative of course is to go completely passive.

Rene
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
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