Yes! That looks like a very good match. Thank you!How about KSA940 / KSC2073?
Ok, so: why replacing Hitachi C1344 transistors with BC546B? Also, why add an 1uf MKT to 3.3k resistors to main caps? Last one: why doubled main capacitors from 6800 to 12000 etc? Is it significant improvement? I am asking because those caps are 1/2 price od restoration parts costs
I am aware that those questions are mainly aimed to the author od this thread however i sent private message (no answers yet) but the author was last seen here in 2019 so I am asking everyone of you dear users
Od course i will start new thread with my own restoration. Now i put questions here because they are connected with authors posts.
Thank you all in advance.
Hey ... Where ya been?? Nice to see you posting again!I use "BC" transitors because thats what we use in Europe
the 1uf MKT on the maincaps is called bypass caps. i just put them there for good meashures its not gonna improve anything...Really.
main cap size is determined by physical size. so they fit the clamps. its been 40 years gone by and caps today pack more uf per size than in 1980.
The amp is still in its new home and working perfectly.
I do question increasing the capacitance on the filters that significantly. I was of the opinion it is OK to incease a bit, maybe 10-20% depending on parts availability, but to target the factory spec on capacitance. However, it is my understanding that it is OK to increase on the voltage side. I went with 2x 6800uF/100V/20%/105C (DigiKey, 338-381LL682M100N062-ND; Cornell-Dubilier) from the factory 6800uF/80V spec. For the other filter I kept to the 5600uF/40V/20%/105C factory spec (Digi-Key,399-19618-ND, Kemet).I own two SR-903's and bought for each the LED lighting kits (7x indicator lights + 6x panel lights) on eBay; for about $90 in total, incl. international delivery charges. Did the install this afternoon on the first unit...piece of cake. Checked polarity for the indicator lights with the multi-meter. Fantastic results. Very happy with this necessary "upgrade".