Dynaco PAS-2 DACT Attenuator

Hello,

I will be installing a DACT style attenuator as a replacement for the stock volume control. Would someone be able to tell me how to wire this up without the loudness control.

I assume I just wire lugs 1 2 3 like the original. Remove wires and caps connected to loudness lug.

Do I still need the 4.7k resistors? If so, how are those wired?

This is the attenuator I will be using:

What is the resistance of the new attenuator? As I recall, it is important to match the original in the PAS or the phono section freq response will be altered.

EDIT: I looked it up and the PAS needs a 250K vol control. You could use 200K as well since the original 250K had a loudness tap at 50K into the 4.7K resistor. For a volume control that does not have a loudness tap (like the one you show in the picture) you would not connect the 4.7K resistor and the 0.1uf capacitor that used to go to the loudness tap (4th terminal) on the original vol control.

You can read all about the effects of output impedance on the PAS phono stage here. The original 750K balance control and 250K vol control as well as the 4.7K and 47K resistors are all part of the design, and if you mess with them you will have a slightly different low frequency response as shown.

http://www.audioregenesis.com/documents/PAS_Phono.pdf

I read the same. It’s 250k, just like the original.

Ah, looks like I you posted while I was updating my previous post. You should be good to go with the new attenuator at 250K. Yes, just omit the 4.7K and 0.1uf cap from the old loudness tap.

Thanks so much! I’ll wire up the 250k and leave out the resistors and caps.

Works beautifully! I tried this DACT style that I posted above, and also a Alps Blue Velvet (most likely a fake). The DACT is so much better in every way.

The Alps was very noisy in various settings, and had staticky sounds when adjusting. Also the volume adjustments from step to step was pretty bad. It had huge jumps in volume. I'm just assuming the one I have is a fake? Im assuming the real ones (if you can find them) are better.

The DACT style one is very smooth and quiet. It seems nicely built. And no noise at all. And the volume adjustments between the steps are perfect. Couldn't be happier! I highly recommend this attenuator!

Thanks again.