FYI: Analog Devices SSM2142 as balanced driver

K&K Audio / Lundahl Transformers

Welcome! Need support, you got it. Or share youe ideas and experiences.

I posted this over at Tube DIY and figured that folks here might be
interested as well ; given that it applies to people using the Lundahl
input transformers.
One of the "issues" with driving an input transformer is the net capacitance of the cable, the transformer and the input tube. Some girlie man preamps arent up to the task of driving this combination very well. The solution is a line-out transformer on the other end. :) However, for some of us, thats pretty expensive to do all at once.
A nice solution I'm getting awesome results with is a chip from Analog Devices specifically for driving balanced lines... It's a little $4 bugger you can order from Digikey. The AD SSM2142. You can make it work with a +/- 9VDC supply (batteries), or, a +/- 15V supply if you need high line levels. The chip is a monolithic - and the resistors in it are laser trimmers at production time... If you drive a Lundahl (or Sowter in my case) with it, you get all the CMRR benefits of a balanced line. You can build a balanced buffer box for about $25. The connectors will be the dominant cost... It's a nice holdover if you've stretched your budget.
Sound wise, these chips are transparent.. i.e. cant hear them. For others, it might appear as a "big change" - especially if you have noisy single ended interconnections, the chip driving a Lundahl (in balanced mode) be 80dB quieter. Further, you can order 2 free samples from the ADI web site....
I'd like to hear Kevin's analysis on this... :) Let's put that PhD EE to use for the public good! :)
-- Jim

http://www.analog.com/en/prod/0,,765_1075_SSM2142,00.html (Open in New Window)

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Parts Connexion

Topic - FYI: Analog Devices SSM2142 as balanced driver - Jim Doyle 07:09:40 04/6/06 (5)

Re: FYI: Analog Devices SSM2142 as balanced driver - Jim Doyle 16:03:07 04/7/06 (1)

Re: FYI: Analog Devices SSM2142 as balanced driver - Dave Davenport 21:38:19 04/7/06 (0)

Re: FYI: Analog Devices SSM2142 as balanced driver - Dave Davenport 15:35:57 04/6/06 (0)

Re: FYI: Analog Devices SSM2142 as balanced driver - KevinC 15:17:14 04/6/06 (1)

Re: FYI: Analog Devices SSM2142 as balanced driver - David Vair 17:34:39 04/6/06 (0)

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