Dynaco PAS 2 value and difference to PAS 3?

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.

I've been doing mods on the PAS preamps for 30 years. There is **plenty** of reason to bypass the tone controls! Even if set flat, the stock line stage lacks bandwidth and resolution. However the line stage circuit can be seriously upgraded such that the unit will easily keep up with many modern high end preamps.

The phono section is only good for high output MM cartridges, but it too responds readily to upgrade. If you have no plans of using it for tape, the EQ components can be moved to the PCB and the middle wafer on the input selector swich can be eliminated. There are also improved EQ values, and one of the coupling caps at the output of the phono can be easily eliminated too.

They are, IOW, great preamps if you plan to tinker or update. In stock form they are OK but nothing special. The 3 and 3x look a little nicer and that is the only reason to pay any more for them. The filter caps, both high voltage and filament, should be replaced regardless of your plans. I usually replace the filament rectifiers as well- the old selinium units are nasty.

Have fun!