I would like to add a tube headphone amp to my 990; that I have replaced with another in my two channel tube set up in my den. I would prefer to use a 990 direct output, and not the 990's Dolby headphone out jack. Has anyone done this? And if so, would you please share your setup configuration? I certainly would appreciate any advice.

I haven't done this, but I agree that it would make the most sense to not use the 990's headphone jack to feed a separate headphone amp. Two options come to mind: use the left/right pre-amp outputs or use the second zone outputs. A third option would be one of the line-level record outputs, assuming that the headphone amp has volume control, but I don't think it's likely to be as good an approach.

I might lean toward the left/right pre-amp outputs if you are presently using the balanced left/right pre-amp outputs for your main system, although there are some control problems that we'll get to in a moment. If you are using the unbalanced pre-amp outputs already, you would need to add a well-made splitter and re-calibrate the system to adjust for the split. One drawback to this scenario is that both the headphone amp and the main amp are going to get the same signal with the same volume control. You'd have to manually turn off the main amp if you wanted to listen to the headphones only. You'd also have to make sure you are using a stereo mode when listening to headphones - don't want the signal being spread across all five or seven speakers when you are only using two of them. As we've said, the 990's volume control would also act on the signal, so if the headphone amp has a volume you'd probably want to find a good spot to set it to.

The second zone would probably be the most convenient thanks to the independent volume control and input selection. The second zone only works with stereo analog sources, though, which means you might have to run additional stereo analog connections to the 990's inputs and shifting the D/A burden from the 990 to those sources for sources that would otherwise be connected digitally. This is the direction that I'd probably lean toward. As with the pre-amp outputs, this approach includes a volume control at the 990.

A third option is to use the Tape or Video1 output to feed the headphone amp. I don't recall at the moment if the record outputs work with digital inputs or not - if they don't, you'd have the same input considerations as you have for the second zone. This approach would not have any volume control at the 990 (not sure what mute would do). It would also be tied to the main pre-amp outputs for input selection. It's probably the least convenient of the three scenarios.

Thank you for the advice Gonk. I currently do have the amp hooked up through the record out. Thus, leaving the volume control to the amp as you pointed out. As well, the main pre-amp for the input selections. Digital sources do not work through the record out.
It sounds very nice though spinning vinyl using the AKG 701 cans through the tube amp. A huge improvement over the 990's headphone out, but at a considerable cost that I would not have done if I was not upgrading this headphone amp. The 990's headphone output is not bad, just not as good as a much more expensive tube amp.

Can you mute the system and still get sound from the record out?

Yes Gonk, it does continue to produce sound. I wish that I could use a pre-amp output without all the complications.

gonk in response to jbhunt1 wrote:

The second zone would probably be the most convenient thanks to the independent volume control and input selection. The second zone only works with stereo analog sources, though, which means you might have to run additional stereo analog connections to the 990's inputs and shifting the D/A burden from the 990 to those sources for sources that would otherwise be connected digitally. This is the direction that I'd probably lean toward. As with the pre-amp outputs, this approach includes a volume control at the 990.

I like using the ZONE 2 method for "preamping" my separate headphone amp. This is because it is totally separate from whatever program there might be in "ZONE 1" or "main". Additionally the remote control of the zone 2 volume is another nice feature. For example relaxing in your easy chair listening to a nice soft John Coltrane [or whatever] CD and controlling its volume while the wife or kids watch TV

Gonk is correct about running separate analog cable since zone 2 is only analog. Not a big deal.

Furthermore I split zone 2s stereo. One leg goes to the headphone amp. The other goes to one of the inputs on a DVD recorder with the video from the zone 2. So while watching on the main TV I can not only listen to headphones, but also do a DVD recording from satellite, laserdisc copying or VHS tape copying.

In short the zone 2 option is very handy. Good luck and good listening