CI Passive Pre-amp plus electronic x-over

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Psychicanimal

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CI Passive Pre-amp plus electronic x-over
« on: 17 May 2003, 02:03 am »
I am contemplating your passive preamp but am wary of losing dynamics in my *street salsa* music, something I will not compromise.  I have no electronic training but the thought of not having a constant impedance to my Forté 4 amp makes me uncomfortable.

Dan Wright is modding my Marchand X9 electronic crossover and today he gave me the choice of installing Burr Brown's top of the line Op-amps.  This would be an extra unforseen expense, as another circuit board would have to be installed, but the thought comes to mind that they would be the ones 'driving' my power amp.  The electonic crossover would then be like a buffer between your passive pre amp and my Forté.

If it works right I think I would gain clarity and definition, getting rid of the extremely microphonic 6922 tubes my actual linestage uses.  My Phono stage is the Monolithic with its dual mono supply and my DAC you already know...

What do you think of this proposed set-up?

CIAudio

CI Passive Pre-amp plus electronic x-over
« Reply #1 on: 17 May 2003, 04:08 am »
The VPC-1 will work great in your application. As you stated, the x-over will be driving the amplifiers.

Dusty_V

Psychicanimal

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CI Passive Pre-amp plus electronic x-over
« Reply #2 on: 22 May 2003, 05:14 pm »
Well, here is what your *compadre* Dan wrote me:

"We are just about done with your crossovers.  We did
the following mods:

1) Cryo'd circuit boards.
2) Upgraded rectifiers.
3) Increased filtering caps in power supply.
4) Increased secondary decoupling at xover boards.

There are a total of 10 op-amps used and they are all
good quality Burr Browns.  I would NOT recommend the
expensive OPA-627's as they would be much too
expensive."


The more I look at this scenario (of using your passive pre w/ a modded Marchand X-9) the more sense it makes.

My only remaining concerns are equipment placement and speaker wire runs.  I would not want my gear between the speakers nor at the primary reflection points.   I have a lot of stuff, Dusty:

Two 48 lb, T4 filters (one for analog, one for digital), my Technics 1200 (w/an upcoming outboard power supply), the phono stage & DAC (each one w/ outboard power supply), the Marchand, AIWA changer, two power amps.  A modded ART Di/O is in the agenda (for transcribing my vinyl), so there's going to be more stuff coming.

This is becoming a challenge... :roll:

What would you do?


Edit:

My "subliminal" question here is just how long an interconnect run could be (using your DAC and the Monolithic phono stage ) from the passive pre to the electronic crossover?  Assume 1 m lengths from DAC and phono stage to passive pre amp.

 I want this to sound awesome...:dance:

Psychicanimal

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CI Passive Pre-amp plus electronic x-over
« Reply #3 on: 26 May 2003, 04:29 am »
Here's an update:

I called Dusty on Friday morning and we discussed the interconnect/speaker wire run scenario.  Robert of Ridge Street Audio Designs also provided some good input, given my nomadic lifestyle and the fact that I'm upgrading all my ICs to the Midnight Silver Edition's he designed.  It's looking real good... :D

I ordered the pre-amp and should be getting it by next Friday.

With the purchase of the upcoming monoblocks Dusty will include a Japanese female swimsuits calendar...:mrgreen:

Psychicanimal

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CI Passive Pre-amp plus electronic x-over
« Reply #4 on: 5 Jun 2003, 01:45 pm »
I got the pre-amp...

I used it over the weekend and ran it in a secondary rig with my Sheffield/XLO burn-in disc during nightime in order to accelerate the break-in process.  The volume pot sounds a little harsh right out of the box.

Anyway, it's been a few days now and I can tell you it's an AMAZING piece!  The volume pot is almost like dual mono, extremely revealling and neutral.  Sounstage is wide open and musical details come through effortlessly.  There is a slight loss in bass slam and a little bit in the dynamics area (maybe), but when compared to my Melos SHA-1 the tremendous gains in clarity, musicality and soundstage more than make up for its weaknesses.  Now I know that when I hook it up to the electronic crossover I'm going to get the necessary slam and acceleration.

I am really pleased with what's going on... :mrgreen:

Psychicanimal

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CI Passive Pre-amp plus electronic x-over
« Reply #5 on: 10 Jul 2003, 04:59 pm »
Last night I finally hooked up my subs and electronic crossover.  Got the 80 Hz modules this week and proceeded to connect my old Proton AA1150 dual mono amp to the NHT subs.

The results after just one hour of playback have been phenomenal!  More dynamics, clarity, soundstage, stereo separation, etc.  The subs integrate seamlessly with the Swans.  The combination of the Channel Islands passive pre and the Dan Wright modded Marchand X9 is outstanding.  Dan and Dusty must be cousins.... :lol:

The NHTs are very musical subs--far from the typical thump box, I'd say.

I heartily endorse this passive pre/electronic x-over combination for anyone seriously interested in outstanding performance on a modest budget. :D