If using motor capacitors, try to use running types instead of starting capacitors. The starting capacitors maybe cheaper but are not usually designed for continuous operation. Also, try to use a self-healing type of capacitor usually marked with an "-SH", e.g. 400V MPP-SH.
Be aware of the substantial AC currents that flow through a supply decoupling cap.
Those caps are only charged during a very small time when the rectifier diodes conduct, often just 10% of the time, and in that time they have to fully (re)charge the caps.
So these caps often see several amps of charge pulses and you must select caps that can handle that.
If the cap is underrated in AC current, lifetime is seriously shortened.
Most elecs will have the AC current limit specified. You all DO read the spec sheet, right?
Jan
Those caps are only charged during a very small time when the rectifier diodes conduct, often just 10% of the time, and in that time they have to fully (re)charge the caps.
So these caps often see several amps of charge pulses and you must select caps that can handle that.
If the cap is underrated in AC current, lifetime is seriously shortened.
Most elecs will have the AC current limit specified. You all DO read the spec sheet, right?
Jan
Thanks!
User 'dimkasta' set me up nicely in Post 8 with this link to Mouser: https://www.mouser.com/c/passive-co...rt-capacitors-motor-run-capacitors/?instock=y
Based on all the info I've made a preselection for these motor run caps from Kemet:
https://nl.mouser.com/datasheet/2/212/KEM_F3115_C28-1775005.pdf
I've read the specsheet and relating to your remark about the current spec. the only reference to it in this specsheet under the heading ´Performance Characteristics´ is:
Maximum Permissible Current: 1.30 x rated current. Could not find the rated current though...
I'm routinely using (semi)easily available in my neck of wood - Icar or Ducati caps
I like them 'Talian, currents I'm putting them on are much smaller than currents they're designed to conduct in few KW motors, so no brainer
just a remark - when anyone sez "motor-run cap", that firmly and logically excludes "motor-start cap"
later ones are made for much greater currents, but for intermittent work ( they're outa circ when motor got to speed)
I like them 'Talian, currents I'm putting them on are much smaller than currents they're designed to conduct in few KW motors, so no brainer
just a remark - when anyone sez "motor-run cap", that firmly and logically excludes "motor-start cap"
later ones are made for much greater currents, but for intermittent work ( they're outa circ when motor got to speed)
It will also be audible to replace the fat ground plate with wire. And I would also remove the eyelets. They are also audible. Use plastic screws to connect. Then remove the small bridging capacitors. Without replacement. Then put the 2 x 2 remaining fat caps at ONE circuit each!
I did always found that number of audiomyths is significantly smaller than my need for overindulgence
came to Gordian solution - I'm perfectly capable to invent my own audiomyths and to cover them
imagine my green, while sleeping ..........
came to Gordian solution - I'm perfectly capable to invent my own audiomyths and to cover them
imagine my green, while sleeping ..........
;-)
I prefer, and suggest: NO bridging caps. It sounds like distorting mirrors at the carnival.
Better: better amp, better speakers, better sources.
I prefer, and suggest: NO bridging caps. It sounds like distorting mirrors at the carnival.
Better: better amp, better speakers, better sources.
The picture I supplied is not of the SA/1 amps I posses.
I only replaced the four 29000uF 35 year old Mallory's with fresh CDE 100.000uF and then wondered if I would do some further enhancement with these old Thresholds, hence my question on this forum.
Attachments
just try it and make your own conclusions
that's the main teaching purpose of this forum
that's the main teaching purpose of this forum
No large metal plates in audio electronics. We do not want to ground bridge piers, but "define current" feasible ;-)
One example only;-)
One example only;-)
generally ....... too much generalizations are not overly of benefit 
if metal plate is big enough, you'll not hear difference
or you can go total fancy - use that water-jet cutter you have in backyard, and make slits in metal plate, defining current paths
if metal plate is big enough, you'll not hear difference
or you can go total fancy - use that water-jet cutter you have in backyard, and make slits in metal plate, defining current paths
Colorless green ideas sleep furiously... Noam ChomskyI did always found that number of audiomyths is significantly smaller than my need for overindulgence
came to Gordian solution - I'm perfectly capable to invent my own audiomyths and to cover them
imagine my green, while sleeping ..........
generally ....... too much generalizations are not overly of benefit
if metal plate is big enough, you'll not hear difference
or you can go total fancy - use that water-jet cutter you have in backyard, and make slits in metal plate, defining current paths
instead of editing upper one
I will make that metal plate (post #1) differently, yes, just for heck of it
feeding GND wire staying in same place ......... or moved right in between final caps
metal plate 20-40mm longer on side of final caps, forming free area ....... then outgoing GND wire ditto on mid of edge
sound difference - probably yes
how much - depends and who knows
Or take them out of my X600.5's.generally ....... too much generalizations are not overly of benefit
if metal plate is big enough, you'll not hear difference
or you can go total fancy - use that water-jet cutter you have in backyard, and make slits in metal plate, defining current paths
Brass looks great also ;-)
I once had a pair of Threshold S/1000's (SA/1 hardware but then in bridged mode to get 500 Watts at 8 Ohms) that had a hum over the speakers.
I cleaned all GND connectors and surfaces with a contactcleaner going to this metalplate and the hum went away. Just simple as that.
I cleaned all GND connectors and surfaces with a contactcleaner going to this metalplate and the hum went away. Just simple as that.
Pray tell us why this procedure could be audible? Also, with plastics screws you can never have enough torque for a tight connection. So, in brief, I wonder what's wrong with the iron?
https://www.bossard.com/global-en/a...ing-torques-for-plastic-screws--polyamide-66/
Same here, what about the metal case, serving as ground? What about copper plates?