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
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
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
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
Gentlemen my apologies for not responding so quickly, work and this problem has kept me pretty busy these past couple of days.

Narrod, Thank You for you comments and yes I’m very pleased with the results I’ve achieved with this system.

Mr. McCormack I will be contacting you sometime soon, I’ve come to the conclusion that I want to get the TLC-1 upgraded I just have a few questions to ask about things I would like to do to it (not sure if they can be done).

Now for the rest of the story. I came home early yesterday and started working on this. After thinking about what Mr. McCormack had to say about the tracking of the volume, I decided to try a 3 meter Kimber Hero between the Sony and the Micro, I was able to get a small amount of volume control to where I could use it at a lower volume but wasn't happy with the sound. My next shot was to replace the Micro with the TLC and use the 1.5 mtr KS1020. Well I now have the volume control I was looking for but not quite the resolution as with the Micro. So I’ve decide to go with the lesser of two evils and wait till I can get the TLC upgraded, I like my hearing better.
For those of you wondering what the differences are, I liken it to looking out a glass window. The Micro with Gold upgrades is a freshly cleaned window with no smudges or smears and the TLC DLX is the same window just dusty. The Micro has more depth and clarity where as the TLC is slightly veiled. But without hearing the two together I wouldn’t have known the difference. So time to make Steve and even busier man than he already is. Unless someone has any better ideas.
Thank You for your help and Happy Listening.