Multi-channel line stage

Archived from groups: rec.audio.high-end (More info?)

I am having a multi-channel passive line stage designed and built by
Guy Hammel of Placette Audio. Even though the genesis is his two
channel passive line stage, this will be a custom job for my specific
system (including matching amp impedances). While we are in the
planning stages this is the time to add features or make design
changes (to a limited degree). Is there anything I have left out that
can help performance or improve ease of use? The features are
described below. Thank you.



Email from Guy Hammel to me:


Robert:

I have your email and specs.

We can add an extra output for the R/L front channels to bi-amp you
bass modules.

The Linestage will have a total of five selectable inputs with two of
them being six channel and three of them being two channel. It will
have six outputs plus the extra outputs for the R/L front subs. The
R/L amps and speakers are always connected to the same R/L front
outputs. When you select one of the two multichannel sources, the R/L
front speakers will play just the R/L front material. But when you
select one of the three stereo inputs, then the R/L front speakers
will play the R/L stereo program and the other channels will be muted.

All six channels will use the same Vishay volume control you are used
to in your two channel unit.

Although channel levels are set in the source, the Linestage will
still have a F/R fader to fine tune the program while listening.
Keeping the rear low enough so that it's almost inaudible has been
about the best setting I've tried. Even though it is just barely
audible, when you mute the rear the entire presentation will collapse
dramatically to the front.

The Lansing cases are about 4" high, 17" wide and 18' deep. These are
very high quality boxes that are anodized, not painted. Some color
choice is available if you are interested in something besides black.
Let me know and I can get back to you with the added cost.

Archived from groups: rec.audio.high-end (More info?)

Thanks Harry. It looks like the center channel trimmer can be added. I
don't believe I have seen this feature on other multi-channel line
stages I have looked at. Is this a common feature that I just missed?

Guy Hammel of Placette Audio Email to me follows:

Robert:

This (need for center channel trimming) is something that came up with
a unit that we just built that did not use matched amplifiers. I was
able to add a third processor that allows for trimming the center
channel along with the F/R fade. The design is still being tested for
reliability and no sure figure for cost yet but it won't be all that
much.

I'll let you know before we get started on your unit how it's working
out.

Thanks, Guy


Robert C. Lang



"Harry Lavo" <harry.lavo@rcn.com> wrote in message news:<cfua2p01418@news3.newsguy.com>...
> "Robert C. Lang" <langvid@pacbell.net> wrote in message
> news:cfu32b0se7@news4.newsguy.com...
>
> >snip to relevant section<
>
> >
> > Although channel levels are set in the source, the Linestage will
> > still have a F/R fader to fine tune the program while listening.
> > Keeping the rear low enough so that it's almost inaudible has been
> > about the best setting I've tried. Even though it is just barely
> > audible, when you mute the rear the entire presentation will collapse
> > dramatically to the front.
> >
>
> I'd also suggest you add a center vs. L-R trimmer to make easy disc by disc
> adjustment...different mixes use the fronts and centers differently and this
> often calls for volume trimming. The F vs R adjustment is absolutely
> essential.

Archived from groups: rec.audio.high-end (More info?)

"Robert C. Lang" <langvid@pacbell.net> wrote in message
news:cgdtpu02vd0@news1.newsguy.com...
> Thanks Harry. It looks like the center channel trimmer can be added. I
> don't believe I have seen this feature on other multi-channel line
> stages I have looked at. Is this a common feature that I just missed?
>

No, this is a commonly needed feature that most manufacturers have missed.
It may be less critical with movie sound, where there are some standards.
But in MCH audio, anything seems to go at this time.

> Guy Hammel of Placette Audio Email to me follows:
>
> Robert:
>
> This (need for center channel trimming) is something that came up with
> a unit that we just built that did not use matched amplifiers. I was
> able to add a third processor that allows for trimming the center
> channel along with the F/R fade. The design is still being tested for
> reliability and no sure figure for cost yet but it won't be all that
> much.
>
> I'll let you know before we get started on your unit how it's working
> out.
>
> Thanks, Guy
>
>
> Robert C. Lang
>
>
>
> "Harry Lavo" <harry.lavo@rcn.com> wrote in message
news:<cfua2p01418@news3.newsguy.com>...
> > "Robert C. Lang" <langvid@pacbell.net> wrote in message
> > news:cfu32b0se7@news4.newsguy.com...
> >
> > >snip to relevant section<
> >
> > >
> > > Although channel levels are set in the source, the Linestage will
> > > still have a F/R fader to fine tune the program while listening.
> > > Keeping the rear low enough so that it's almost inaudible has been
> > > about the best setting I've tried. Even though it is just barely
> > > audible, when you mute the rear the entire presentation will collapse
> > > dramatically to the front.
> > >
> >
> > I'd also suggest you add a center vs. L-R trimmer to make easy disc by
disc
> > adjustment...different mixes use the fronts and centers differently and
this
> > often calls for volume trimming. The F vs R adjustment is absolutely
> > essential.