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Connecting CD directly to Poweramp

I have an Ah! Tjoeb 99 and recently decided to plug it straight into my (decent) poweramp (audiolab 8000p) and bypass my (mediocre) preamp (NAD 118). This limits me to using the volume control on the CD player. However, the voltage output on the CD is too high for the amp, so I have to turn the volume way down in order to use it. Since it is a digital volume control I am losing a lot of information doing it this way. But the character of the sound is much better, since I am hearing the tube sound of the CD player much more.

I am told that I have two choices (assuming I don't want to spend 2000 bucks on a decent preamp): buy a passive attenuator (e.g. Creek OBH 12) or adjust the voltage output on the CD player (allowing me to set the CD volume at a higher level and so preserve information that currently I am losing).

Can anyone tell me what the pros and cons of these two approaches are? I am worried that using a "passive" unit in the signal path will take away some of that tube sound, but at the same time I don't know what decreasing the voltage output will do, since it is set at the "optimal" level at the factory. On the other hand, with a passive unit I can plug two inputs into it, which gives me more flexibility in the system.

Any ideas, comments?
andrewa
jdombrow
371 posts
 
Depending on your budget, you might consider a transformer volume control (TVC). Bent Audio makes an outstanding unit.

jd
elevick
2,636 posts
 
If I'm correct, the Tjoeb is based on the Marantz CD. The volume control stinks but the sound is nice. I wouldn't bother modifying the unit for a lower voltage. The volume is still very cheaply done and won't allow for "infinite" control-simply too few steps.

A Creek will do the job beatifully. However, there is a major problem with the remote on a creek. It is affected by the signals from the cd player. Every time you push up, down, ff or rw on the cd, it will adjust the volume on the creek!

You can always find another passive volume control or for similar money, buy an older high end pre-amp (SUMO or similar).
listener57
730 posts
 
You might want to contact tweakaudio.com which is home to the $350 retail price Ultimate Attenuators which attach directly onto the amp input RCA terminals making a separate interconnect unnecessary. Avoiding another interconnect reduces the cost of adding this minimalist equivalent to a passive preamp. The designer, Ric, has different models for tube or transistor amp. This will optimize your performance if you do not need remote control, and listen exclusively to one source, CD's in your example. I have been a fan of this approach after hearing excellent improvement over any moderate price conventional active preamp.
gordus
118 posts
 
Channel Islands is another maker of excellent and inexpensive passives
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