Preamp tour for Ncore owners

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James Romeyn

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Preamp tour for Ncore owners
« on: 26 Sep 2012, 05:44 pm »
Estimate time frame to start this tour is early November. 

Circa 2010 is a long thread I started stating audible superiority of the pure analog line stage preamp (eight channels) within Pioneer's 2003-2004 model VSX-D912 HT receiver.  Even in stock form the 912 line stage sounded indistinguishable to unbalanced input/output of a particular $7500 preamp by one of the high-end's most celebrated amplifier designers (inventor of the full dual-differential full-complementary circuit, I owned the preamp at the time).       

A friend purchased two such receivers, one for backup.  I'm offering, for fun and edification, to send one 912 on tour for users to compare in their own Ncore-based systems.

If there is interest, tour starts after I perform the following mods:

Install IEC receptacle
Remove fixed mains cord
Insert shorting plugs in every unused RCA input
Include high-quality IEC mains cable (Stan Warren recipe)
Damp top cover, top/chassis mating surface, and loose parts such as antenna spring terminals
Unplug/defeat noisy power amp cooling fan (users must agree not to use/test power amp section...fan activates with source-input voltage and with volume set beyond a certain threshold.  Using preamp only and no power amps: with gain set beyond a certain threshold, when music stops you hear ugly fan buzz, then 912 senses no input voltage, then 1.5 seconds later the fan shuts off)

Comparisons might be entertaining, eye-opening, and shake common SS/tube perceptions.  I'm familiar with the musical presentation of preamps up to about $20k and doubt the 912 will be embarrassed regardless what it is compared to. 

Over many decades I noticed how easily I identified preamp signatures/thumbprints, then noticed the indelible mark on every source, and quickly tired of it.  After several years I still perceive no 912 line preamp signature/thumbprint of any kind.   

Net weight is 23 lbs, add for packing, so consider shipping cost to the next person and eventual return to me.

For my Trinaural-based system, eight line channels is particularly useful: inserted between the Trinaural processor and three Ncore mono blocks, the 912 allows remote on-the-fly level adjustment (1.0 dB steps) for bass (80 Hz active Trinaural crossover) and center channel (all channels algebraically processed including center, center is not L+R summed mono). 

Stereo users will of course use only L/R unbalanced inputs/outputs, ignoring the six remaining line channels.

Do most Ncore users with unbalanced sources employ Bruno's ideal quasi-balanced interconnect?   


 
   
 
« Last Edit: 27 Sep 2012, 01:39 am by James Romeyn »

Atlplasma

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Re: Preamp tour for Ncore owners
« Reply #1 on: 26 Sep 2012, 06:52 pm »
I think this is a great idea. While I don't want to sign up for the tour, I will connect my Yamaha RXV2700 to the Ncores for giggles. It will be interesting to see how it compares to my Dodd preamp.

Ric Schultz

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Re: Preamp tour for Ncore owners
« Reply #2 on: 26 Sep 2012, 07:39 pm »
I don't see the point of listening to an unobtanium obsolete modified receiver as a line stage.  So, it sounds better than whatever.  How does that help anyone?  If you cannot own one then all it shows you is that something else is better than what you have.  Even if you found one and had James modify it for you......do you really want a huge receiver on your shelf as a preamp?  And no balanced outs to run the Ncores in their best way or run bridged? 

How about sending around a serious balanced buffered LRD attenuator that can be built by someone.  Or how about two modified stereo Grounded Grid preamps (modified so you could use them either unbalanced or balanced).  This would be helpful because people could actually build their own superior line stage. 

James Romeyn

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Re: Preamp tour for Ncore owners
« Reply #3 on: 26 Sep 2012, 08:14 pm »
My friend just found and purchased two on Ebay, and refused a 3rd.  Practically any one can do the mods, I'm a solder klutz. 

If there was better feng-shui with equal or better performance in a 4-channel pure analog line preamp with remote separate channel tuning, I'd buy one.     

James Romeyn

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Re: Preamp tour for Ncore owners
« Reply #4 on: 26 Sep 2012, 08:17 pm »
I think this is a great idea. While I don't want to sign up for the tour, I will connect my Yamaha RXV2700 to the Ncores for giggles. It will be interesting to see how it compares to my Dodd preamp.

Honestly, I'd not wast the time. 

The man who first brought the 912 to our attention is a PhD. (forgot the field, physics?) with proprietary amplifier test procedures, which the 912 passed with flying colors.  The 912 is a freak among receivers.   

I'd presume awful results from any ordinary receiver. 

Rclark

Re: Preamp tour for Ncore owners
« Reply #5 on: 26 Sep 2012, 09:41 pm »
I would love to try it.

Atlplasma

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Re: Preamp tour for Ncore owners
« Reply #6 on: 26 Sep 2012, 09:43 pm »
Honestly, I'd not wast the time. 

The man who first brought the 912 to our attention is a PhD. (forgot the field, physics?) with proprietary amplifier test procedures, which the 912 passed with flying colors.  The 912 is a freak among receivers.   

I'd presume awful results from any ordinary receiver.

I take your point. I also read on your other thread that the receiver works best with 8 ohm speakers. Would you suggest that members with harder-to-drive speakers skip the tour?

Ric Schultz

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Re: Preamp tour for Ncore owners
« Reply #7 on: 26 Sep 2012, 10:08 pm »
He is talking about using the receiver as a preamp only.  Nothing to do with speaker loads.  You would use it to drive the Ncores.

James Romeyn

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Re: Preamp tour for Ncore owners
« Reply #8 on: 27 Sep 2012, 01:34 am »
I take your point. I also read on your other thread that the receiver works best with 8 ohm speakers. Would you suggest that members with harder-to-drive speakers skip the tour?

From OP:
Quote
(users must agree not to use/test power amp section

The earlier thread subject started out as the receiver including its power amp stage, and ended being more about the line stage only.

I fully understand the reaction that taking seriously any function of any receiver for audiophile purposes might indicate early onset of dementia or worse in someone my age.