Neither of my Sorado transformers says "Dynaco," although the ones in the Sonic that I had in the late 60's did. When did the Schumacher trannies come in? What do you mean by "tighter" - does that mean less low bass? I picked up a couple of .25uF 6PS caps on ebay and may try them. My filter cap job brought me to 110/50/22/22 if I remember right, thanks to your recommendations. Inrush voltage with a Weber Copper Cap was tested at: 601V; A: 545V; B: 469V; C: 354Volts. With the 5ARU tube, it was 576, 545, 463, 353. Thanks so much for your help. I've learned so much from this forum.
By the way, will I need to re-bias after changing coupling caps?
There should be an EIA code stamped into the transformer end bells.
http://www.triodeel.com/eiacode.htmhttp://users.eastlink.ca/~mitchlane/EIA_Codes.htmlI forget right now what the code is for Dynaco but Schumacher is 606.
Tighter would mean that the bass note will hold together a bit better than with the larger cap and be less mushy sounding. It is a subtle thing, and really just try it and see. Change both caps at the same time, then go back to the 0.1uF ones. Your ears will lose the memory of the sound during the time it takes you to switch between each, but if you play around a bit then you should be able to hear the differences.
The changeover likely happened by 1969 but some late 1968 models could have the Schumacher transformers also. No need to rebias when changing coupling caps...just make sure your work is good and the soldering is done well. All the usual safety rules apply for working with high voltage devices so if you don't know what you are doing fully, then please have others more qualified to do the work. The 6PS Orange Drops are radial caps so they will mount differently than the axial caps that were in there. Be careful about bending the leads and use needle nose pliers to bend the leads after the bend that they already have in them...do not bend right at the body of the cap, or you risk damaging the cap.
With the other changes you made to the amp, you have a stronger and tighter bass than it had stock, so the cap change will be slightly more of the same. Also, I will reiterate what I stated in those posts that you worked from for the cap job.....do not use the 5AR4 anymore in that amp unless you change the first cap to a size smaller than 60uF. The Weber Copper Cap or some other solid state rectifier must be used with the large first cap value or damage will occur to the rectifier tube, and possibly other things in the circuit. If you stick with the solid state rectifier/Weber Copper Cap then it will function fine.
Happy to help...keep learning and pass on what you have learned. Thats all I'm doing.
Greg
