Hi,

I'm faced with a bit of a dillema. I was told I could use the 990's headphone amp, as a pre-amp, for my new, external headphone amp. Now, instead, the fellow that built it is telling me I should use the analogue outs of the 990, instead of the headphone amp out, to drive the external headphone amp. If I choose this second route, will I still have Dolby influence over the external headphone amp? Or, in other words, which is the more practical and/or better approach?

Also, how many analogue outs does the 990 have, given I'd need two (three, if I connect my tape deck)?

HELP!

thanks,

John

I don't know enough about high-end headphone amps to speak to the different ways to connect one (headphone jack output vs. stereo analog outputs). I can say that I'm 99.5% certain that there's no way to get access to the Dolby Headphone processing without using the headphone jack. Dolby Headphone is only engaged when the headphone jack is active, which in turn disables the pre-amp outputs. I've never tested the Video1 or Tape record outputs to see if they are still active when in this mode - if they were and the input was digital, I guess there's a chance that they would be getting that Dolby Headphone stereo output, but that goes back to my 99.5% comment since I'm pretty sure that both of those don't happen together.

The 990 has four stereo analog outputs: Video1 record output, tape record output, aux record output, and the second zone. The first three are fixed level outputs (no volume control) while the second zone has its own volume control and input control. If I remember correctly, the 990 will convert digital inputs to stereo analog for the record outputs, but the second zone is essentially a stereo analog pre-amp tucked inside the 990. As such, to use the second zone you need to connect any sources that you plan to listen to through it via analog stereo cables even if you are using digital normally.

Thanks Gonk.

I maintain ... all this stuff is way too complicated! lol

I appreciate the explanation.

Again, thanks.

John

John,

Having used external headphone amps in the past, this is the first I have heard that you can use the headphone jack from the 990. The ones I have used only had the L/R RCA inputs receiving its source from a tape loop from the preamp. With that said, I suspect that you can use the headphone jack of the 990 and receive the Dolby effects through your ext. headphone amp and only this way. This way you can also use the remote of the 990 to remotely adjust the volume. I haven't seen an external headphone amp that I have used that has a remote. The ones I used required you to turn the volume knob on the unit. Probably the builder of your external headphone amp suggests you to use the tape loop because it is a fixed output signal and is not "processed" like the signal will be via the headphone jack potentially degrading the sound. I would suggest trying it both ways and see which sounds best for you. Currently, I am satisfied with the sound out of the 990's headphone jack via my Sennheiser headphones. Like Gonk said, once you engage the headphone jack, there will not be a signal found in the other outputs.

Thanks, slbenz,

for the explanation. Yes, I understand about the added processing of the headphone out, which, you are correct, is the concern of the fellow that built the headphone amp. I guess the ideal would be to have both types of connections, as you suggest, retaining the use of the remote, when I'm lazy, watching TV and/or switching to analogue out, when desiring a quality listen.

Why does added power mean more complication. My old 64 327 had over 300 hp and was as simple as it gets! lol

Anyway, thanks for your responses.

John

You can always go with the second zone scheme - it doesn't give you Dolby Headphone, but you have a simple signal path through the 990 (analog stereo pre-amp, basically) and remote volume control along with independent source control.

This subject was discussed extensively in this thread:
Thread discussing headphone etc.

In it I had several posts discussing the issue.

I am aware that DR_JB has a teriffic headphone amp.
My suggestion is that this can be fed via zone 2. I use zone 2 for this and other functions.

My suggestion is that for headphone listening just use the analog function of zone 2. The added benefit of this (over other analog outputs) is that this has an independent volume control by the secondary remote.

Mama or grandkid watches and listens to TV while yours truly can listen to music via headphones.
Anyone wanting more info send me a PM.

PS.........Dr_JB...enjoy
PPS........everybody...enjoy

nfaguys,

thank you. I'm looking for analogue cables now.

Next problem, video switching setup. HELP!

I've come to the conclusion that my technical skills are all gone ... I'm lost! lol

Again, thank you all.

John

Keep an eye out for a post in your video switching thread shortly...