bwahhhhaaaahehhehhehhhehheh hah..

oh man... so are you hearing a difference in the topology or are you saying the actuall tubes used??? and are you sure it's not the difference in say rail voltages... coupling caps... trannies....

no its cool nevermind, im aware that they both share the same preamp section i believe but that the summit is solid state power section. the pendulum has two power tubes which should be interesting, maybe an almost relative sound to the 610 but i don't know i'd have to hear it.

The MDP-1 has (2)12AX7's and (2) 6922's, according to their spec sheet. There are no "power tubes" in the unit. The 6922's are more than likely used in the gain cell design. There are several manufacturers using them that way, handed down from the RADAR industry...

you got me, the 6922 is a preamp tube. is the 6072a also a preamp tube?

Yes

aqualand666 wrote: i notice the difference in the tube complement, anyone experience this difference audibly?

The Pendulum Audio MDP-1a is one of the finest sounding preamps on the planet. Euphonic, sensual, yet detailed and accurate. Plus, it has a robust feature set. I've used one for almost 6 years.

The Summit Audio TPA-200B is a very nice pre, capable of clean to dirty, with a pleasing sound overall.