50mfd electrolytic caps on my Eico MX99

[CJVx]

This multiplex adapter is working very well, I replaced all of the electrolytic capacitors etc. there was a pair of 50mfd/350v dry electrolytic caps in series with the stereo outputs. I replaced these with modern electrolytics (47mfd/350v). I feel like it could sound better, and I'd like to start here by upgrading these capacitors. Problem is there isn't enough room for a film type capacitor at these ratings, however, I have some nice 10mfd/500v film caps that will fit.

Do you think I will lose any low frequency response by going down to 10mfd when using with my tuner input on a Scott 222c?

 

[gadget73]

personally I doubt the caps have much to do with the sound quality. Align it if it hasn't been done and go from there.

 

[drew_t]

http://akdatabase.com/AKview/displayimage.php?album=42&pos=31

Are we talking about C23, 24? The voltage rating in the schematic/parts list is only 150 volts.

 

[Steve O]

http://akdatabase.com/AKview/displayimage.php?album=42&pos=31

Are we talking about C23, 24? The voltage rating in the schematic/parts list is only 150 volts.

Even a 150V / 50uF film cap will be quite large. If a cap this large must be maintained, I’d be inclined to use a quality electrolytic and bypsss it with an “audio grade” 0.47-1.0uF film cap.

Looking at the circuit, 50uF is way overkill IMO. If this were mine, I’d go for a 4.7-10uF film cap and not worry any further.

 

[gadget73]

Its working into an 18K load (R47, R48). In reality it'll be slightly less than that since the input impedance of the amp will be in parallel with that but most tube gear is high enough that it won't matter enough to worry over.

-3db point with a 50uf cap is 0.18 hz. -3db with a 10uf cap is 0.88 hz. -3db with 1uf is 8.84 Just keep in mind that there is phase shift as you approach the -3db point so you don't want to skirt that too close.