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D150 How closely matched

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Posted on October 18, 2014 at 14:29:08
Cpwill
Audiophile

Posts: 1096
Location: DC
Joined: December 22, 2003
Contributor
  Since: October 24, 2008
 is closed enough?

Kevin, thanks for the phone help and quick delivery of the parts. I swapped the D150 in bad channel and voltage ratings are holding spot on. The new MP rating is 0.638 while the old were 0.623 (I still had the package). That's less than 2.5% variance by my math. Is that close enough in your opinion given the variances possible in all other matched parts and the difficulty in swapping the left D150? I have not listened yet.

Thanks again
"Anyone who understands jazz knows that you can't understand it. It's too complicated. That's what's so simple about it." - Yogi Berra.

Cpwill

 

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RE: D150 How closely matched, posted on October 18, 2014 at 15:53:06
KevinC
Manufacturer

Posts: 2984
Location: NC
Joined: April 19, 2001
 The absolute value of the number on the bag is not relevant for your purposes. That fact that you have a matched pair is relevant...

Kevin Carter
K&K Audio
www.kandkaudio.com

 

RE: D150 How closely matched, posted on October 19, 2014 at 07:09:24
Cpwill
Audiophile

Posts: 1096
Location: DC
Joined: December 22, 2003
Contributor
  Since: October 24, 2008
 Thanks, but not sure my question was clear enough. Currently, I have the new D150 only in the right channel, the channel that was previously dead. The right channel now measures correctly and plays music. The left channel still has the D150 from the original upgrade kit. It also measures correctly and plays music. The MP numbers on the respective bags - new replacement pair v. original upgrade kit pair - are within 2.5% of each other. Is that close enough, or should I change out the left D150 for an exact match, even though changing the D150 is a pain in the ass?

Thanks again.
"Anyone who understands jazz knows that you can't understand it. It's too complicated. That's what's so simple about it." - Yogi Berra.

Cpwill

 

RE: D150 How closely matched, posted on October 19, 2014 at 07:22:02
KevinC
Manufacturer

Posts: 2984
Location: NC
Joined: April 19, 2001
 Yes, I didn't understand the intent of your question. I sent you a pair with the intention that you replace both as I talked about on the 'phone.

I don't really know if the small difference between the bias voltage as tested is enough to cause an audible problem. If I were worried, I'd settle that by listening to a mono record and deciding whether the image is centered. If it isn't then I'd swap the interconnects from the turntable and going to the preamp R for L and L for R, to see if the off-center image moves to the other side of center or not, if it does, then perhaps you need to change the other original MOSFET out.


Kevin Carter
K&K Audio
www.kandkaudio.com

 

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