Dynaco PAS 2 value and difference to PAS 3?

You shouldn't pay more than $200 for a Pas 2 or Pas 3 preamp in excellent condition. The Pas 3x is a little different. When the tone controls are in the center position the tone control circuit is defeated. These are entry level tube preamps at their best and sound their best with the Dynaco tubes which were actually relabeled Telefunkens. The sound is soft and lacking in dynamics compared to modern tube preamps. Many people have modified these preamps in the past usually by beefing up the power supply to improve dynamics and bass. The Dynaco was a very cheaply built product designed for a price point. For a little more money you can get a real preamp like Cary, CJ, Audible Illusions, VTL, Counterpoint or Music Reference. Stay away from the early Audio Research preamps. They usually have problems and it costs a fortune to have them repaired. I speak from experience. Good luck and happy listening.

Thanks guys!

You have been very helpful.

I run a Dynaco PAS-3X in my 'second' system (McIntosh 250 / Dynaco PAS / Dynaco AF-6 tuner / KEF Q60 speakers / Panasonic linear turntable and Pioneer CD player). The PAS is a very pleasant preamplifier and with a SDS Power Supply board, new coupling capacitors and tone control bypass it does a competent job. As mentioned above, it isn't exactly the most detailed or revealing preamplifer, but it is very musical. Perfect for less-than-stellar recordings and less than perfect audio systems.

They do have a high output impedance and work better with an amplifier of higher input impedance.

Again, there is no need to bypass the tone controls on the Pas 3x because the tone controls are bypassed when set to the neutral position. The Pas2 and Pas 3 do not have this tone defeat circuit, so you may want to bypass tone controls on those units.