Marsh P2000T hybrid preamp....Should I modify??

Dimitry,

Can you give me some input on the inverted polarity of the P2000T output. The manual says this:

"The output signal is inverted polarity to the source signal, you may need to change the polarity of both left and right speakers cables to get correct program polarity"

Do I really need to hook my speakers up + to - and - to +??

Yes,

If nothing else in your system inverts polarity. In my system, my cd player and amp both invert polarity, so they cancel each other out and I hook my speakers up normally (+ to +, etc.)

Regards,

Well, polarity is a complex issue. Some people are sensitive to it, some are not. In a well recorded material, where relative polarity of all tracks is maintained, inverted polarity at playback is heard as lack of ambiance and pace in the mid-bass.

However, most material is not recorded in such a fashion. Often different tracks have different polarity and final polarity of the master is either "in-phase" or "out-of-phase" with the original event.

Therefore, since polarity is essentially random on most recorded material, it is not really necessary to maintain it on playback.

However, for those rare records and CDs that are recorded in constant and correct polarity it is nice to have it right on playback.

So, I do hook my speakers backwards, as per Marsh's manual. Since their manual is the first manual for a tube product that never mentions the word "tube" it is remarkable that they decided to include the relatively exotic topic of polarity into it.

I wrote to Marsh, that since their manual excludes instructions on how to change the tubes entirely, they should expect customers to start returning them in about a year, complaining of lack of air and drive.

I can report good results from bypassing the main coupling caps with REL TFT 0.1uf 400v units. The sound has gain more air and presence and improved in the areas of pace and drive.

However, the soldering required is a bit tricky, as the leads from the bypass cap can't touch the ground plane of the PWB and the main caps leads are only about 1/8" above it. Can be done - just need to be careful.

That, my friend, is why I am paying a pro to do this!! I am not a DIY type of guy when it comes to electronics.

My preamp will be delivered today...I can't wait to hear it. BTW, I also bought an Onyx XCD-88 HDCD player from Underwood HiFi with a level 1+ modification. It is the same machine as a Music Hall CD-25 which I have read many good reviews on!! Both ar made by Shanling.