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Passive preamp users help with McCormack Passive’s

Let me apologize if this gets long winded, but I need help with my setup. Currently I have a Sony DVP 9000es with Modwright Signature Truth Mods, a McCormack Micro Line Drive w/Gold upgrades, a pair of McCormack DNA-1 DLX Gold’s vertically driving a pair of Vandersteen 3A Signatures. I use Kimber Select 1020 I/C’s 1.5 meter from the Sony and a 2.0 meter pair to the amps. The problem I have is no volume control, by the time I turn the volume down low enough to listen the volume control starts to loose balance control, turning it up to regain the correct balance control and it’s too loud to listen. What I mean by this is all the sound starts to shift to the right side of the sound stage. At first I thought it was one of my amps starting to go but after swapping sides with the amps the problems remains. I was using a McCormack TLC 1 DLX but after trying the Line Drive with the Gold upgrades I couldn’t go back to the TLC. As far as the numbers go the Sony’s output is around 3 volts with 600ohms impedance and the I/C’s have 19 to 20 pF/meter Capacitance. Anybody have any helpful advice?
ig316b
narrod
1,064 posts
 
Contact Steve. He can give you the most helpful information on his product. Your system sounds like a wonderfully synergistic combination and should sound great.

I know you swapped the amps. Did you swap the speakers? If you have the would indicate a problem with the McCormack or the Sony.

Good luck,

Wendell
stevemcx
166 posts
 
Wendell is correct - you should contact me directly to discuss this. For one thing, it seems likely that you are connected to the active outputs - not the passive. Be sure you are connected to the passive outputs if that is how you would like to run the system. In addition, the gain of the active portion of the MLD is adjustable, so you could set it at unity or +6dB, and this might solve the problem. What you are hearing is the less-than-perfect tracking of the volume control down at the very start of rotation (a common issue with stereo potentiometers). If you reduce the MLD's active gain or switch to passive operation, the problem should go away (unless the Modwright-Sony has unusually high output voltage).

Call me at 760-732-0352 and I will be happy to go over this with you.

Steve McCormack
SMc Audio
electroid
283 posts
 
Well, that can happen with a pot. Consider a resistor ladder like CJ and McCormack now uses in a Placette passive, Also try horizontal bi-amp. I found it better than vertical in my bi-amp setup.

ET
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