A comparable phono preamp

I would need to spend 10 to 12000 and would rather spend that on better interconnects and speakers.

Hmm, better cabling obviously makes a difference BUT strongly feel that a primary upgrade ( table /arm /cart / phono ) will be a better investment in this case, as described...

As avanti mentioned is appears that you may need lower gain capability with the HIGH OUPUT Linn cartridge.

If you are interested in an inexpensive stop gap (while maintaining use of the Linn cartridge) you might look @ the Schiit Mani-2 phono preamp (make certain it's the updated "2" version).

It's well reviewed, gain can be set as low as the mid 30's (to see if this is the problem) and it's $150.

You could also compare it to your current phono pre in regard to analog/digital transfer.

The last tube phono preamps I tried in my meager setup were an Audion Sterling and an EAR 834P (MM only), so I'm not up to date on what's good now and/or what models have user adjustable gain.

DeKay

I highly recommend the Sutherland offerings. They have models to meet a variety of budgets and provide tremendous value with wide range of impedence and gain adjustments. 

Take a look at what Darlington Labs has to offer. MP7/SU7 combo starting at $1000. Read what people are saying. I've been very pleased with my MP7 and Keith is great to work with!! Not upgrading any time soon...

@avanti1960 1++  You are probably overloading the NAD which would result in the sound you describe. You really do not want a MM cartridge output higher than 5 mv. Avanti's suggestions are fine but probably more expensive than you would like. It would be less expensive to go for something like a Parasound JC3+ and a lower output cartridge like one of the high output Soundsmiths which put out about 3 mv.