Passive & Tubed pre-amps to power amp at same time?

If I get this right with what you want to do.

What I would do is put all your sources into the inputs of the active preamp so you can switch between them, then come out of the tape output of the active preamp into input of the passive preamp and then out of the output of it to the poweramp/s input.

Basically this way your using the active preamp as a source selector.

Cheers George

Thanks for the idea George. What I am trying to do is introduce volume control
for the CDP without any addition boost in gain while leaving other sources
unaffected that run through the tubed pre-amp. Your idea does seems like
something to explore. No tape out...but sub out. However, I am going with Al's
suggestion of attenuators. Ordered a couple of Harrison Labs -12dB RCA plugs
from Parts Express. Much less expensive than those from Rothwell and Parts
Express allows returns if they don't work out. Others on A'gon do report
satisfactory results using these. Thanks again to all for the suggestions.

Very bad idea splitters are bad quality.

Ghosthouse, if you happen to have a multimeter it would be interesting to know the values of the two resistors that are presumably used in the Harrison Labs attenuator. The values aren't particularly critical, but knowing them may provide added confidence in their suitability for the application.

You would take two resistance measurements, one between the input center pin and the output center pin, and one between the output center pin and its ground sleeve.

I've measured those values in the Rothwell 10 db attenuator as 22K and 10K respectively, which seem like reasonable numbers for most (but not all) applications. Especially, as in your case, when used between a solid state signal source (presumably having low output impedance) and the input of a tube-based component (presumably having high input impedance).

Also, thanks very much for the nice words. Best regards,
-- Al

PlanB: place the passive between the CDP and the preamp input.
Adjust to suit, but keep your cables short as passives have been shown to be quite sensitive to cables!