Don Sachs Owners Thread

@bugredmachine thanks for the capacitor and circuit board images. Amazed at how much smaller the new caps are. For this hobby, it is great to have soldering skills.

@lous  the previous owner sent the model 2 to Don for updates. It has the 6BY5 rectifier, not sure about the caps. I'll have to pop the bottom and take a look.

Yesterday I removed the Pioneer M22 (30 watts x2 class A) and tried the similar speced Pass A3 volksamp. The Pass is MOSFET and the Pioneer is bipolar. There are differences, but both sound fine. I was worried about their lower 47K input impedance vs the VTL ST150's 130K. There was a little less bass but that could be transistors vs tubes and the VTL having twice the power in triode mode. Still fun to hear the D Sachs linestage with all these amps.

Thanks,

aldnorab

@aldnorab

Yes, if you have 2 outputs, you should probably put .5uf on one output for the 47K amp, and 1.33uf for the 130K amp, and mark them. You may wantto check with Don, but I believe that those values will give you better impedance matching, and minimize frequency roll off.

BTW, the old tubes you were using are okay for an older Freya preamp, due to its issues that need compensation. The tubes on the right are buffers and are less critical, the ones on the left should ideally be E-6SN7s and second to them, in current production tubes would, would be one of the various Treasure tubes. The E-6SN7s are going to just barely fit. The latest preamp addresses that.

Best Regards,

Lou

I threw out this question on the Linlai thread. Has anyone tried the non-Elite versions? I ordered set anyways to "have". 😎

@lous thanks. Wouldn't the cap values be reversed? Lower input impedance needs higher cap value?

Thanks,

aldnorab

@aldnorab I really have forgotten my formulas, but no, Don installed .47uf caps for a 50ohm load, and 1uf for a 100k ohm input amp. Then there's this;

The chart they show shows increased impedance with increased capacitance.