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Tube Preamp Paired with Tube Phono Stage?

Hello everyone. I wanted to know if you paired a tube preamp with a tube phono stage, would that be overkill with respect to the warm sound qualities produced by the equipment? I have a PrimaLuna Prologue Three with all NOS tubes, Clearaudio Smartphono, and CODA Technologies 10.5r SS amplifier. My turntable is the Pro-Ject Debut III with Ortofon OM40. I was considering upgrading to the Clearaudio Basic+ with battery pack OR checking out the new Manley Chinook. But, with two tube units combined, would that be problematic? Thanks for your input.
wescoman
jtwrace's avatar
jtwrace
443 posts
 
Glad to hear that. I"m looking pretty hard at the Chinook. A friend of mine just got a Zesto Andros....now I'm wondering if I should really stretch. Yikes!
actusreus
733 posts
 
I'm also looking at the Chinook as a potential upgrade to my current phono stage. It's got everything I'm looking for, except one thing: a relatively low gain of 60 dB for MC. This would suggest that it's not adequate for MC cartridges with an output below 0.5 mV, which eliminates a lot of great cartridges. This is almost as frustrating as John Curl's JC-3 phono preamp offering only one impedance setting of 100 Ohms for MC. That one I'll never understand.
lewm
13,173 posts
 
Dear Actusreus, If what you say is true about the JC3 load resistor for MC, I share your chagrin, but one might always open the chassis, find said 100R load resistor, remove it, and replace it with a resistor of the desired value. I do agree that the task is tedious, if one wants to play with a variety of cartridges and/or experiment with different load values.
atmasphere's avatar
atmasphere
11,861 posts
 
This is almost as frustrating as John Curl's JC-3 phono preamp offering only one impedance setting of 100 Ohms for MC. That one I'll never understand.

The reason is if the preamp is resistant to RF at its input, the load on the LOMC is not critical. Its only there to reduce RF caused by the inductance of the cartridge interacting with the capacitance of the interconnect cable, which can form a tuned RF circuit. The resistor destroys the 'Q' of the circuit. IOW if the preamp works right, the value of the resistor is not important since it only works at RF frequencies.

This says to me that Mr. Curl's preamp must be pretty resistant to RF issues.
jmcgrogan2's avatar
jmcgrogan2
6,346 posts
 
Actusreus, I would think that 60 db of gain from a phono stage would be enough for any cartridge, unless possibly if you are considering running through a passive controller instead of an active preamp. Most will run the Chinook through an active line stage preamp (as the OP is here) which will add more than enough gain for any cartridge.
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