Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => AmpTools/Tech Tips => Topic started by: PRR on December 22, 2017, 07:13:42 pm
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https://www.mouser.com/productdetail/epcos-tdk/b32778p6506k000
B32778P6506K000
Mfr.: EPCOS / TDK
Film Capacitors 50uF 10% 630Vdc AEC-Q200 LS 52.5MM
B32778P6506K000 Datasheet (http://www.mouser.com/ds/2/400/MKP_B32774P_778P-1220067.pdf)
Length: 57.5 mm Width: 35 mm Height: 50 mm
$10.94
(https://www.mouser.com/images/tdk/images/B32778P_DSL.jpg)
You can get 50uFd 450V e-cap for less. It may be a little smaller. It may last decades or just a few years.
The film-cap is likely to last a lifetime, especially in 500V 300mA filter duty.
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Why are there 4 leads? Nevermind. I just read the data sheet. Parallel leads
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I had assumed, being tall and heavy, if you solder it 2-leg to a PCB it would fail a shake-test (rip off the PCB).
For our purposes, I'd glue a few in a corner and solder to the legs. They should out-live us all, so glue is not a major sin.
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I've toyed with using motor run caps: https://www.ebay.com/itm/50uF-MFD-370V-440V-VAC-Oil-Filled-Motor-Run-Capacitor-CBB65-50x100mm/272877458990?hash=item3f88c3962e:g:fgMAAOSwEIFZ2FPt
They can be anywhere form about $8 to $35. But they're huge: 100mm or more tall; 50mm or more wide. Also the can is live if stacked, say for voltage doubling. The TDK plastic caps do seem appealing.
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JJ I have loads of those start/Run caps, some as big as car batteries. I never thought about using them, I figured the electric would be dirty coming out. I can atest that i have caps in HVAC units from the 80’s still going.
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My research - on hi-i forums, tells me motor run caps are desirable. Supposedly caps in oil, even as filter caps, are good for bass response.
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Another link, more choices: Mouser big film caps, 20uFd (https://www.mouser.com/Passive-Components/Capacitors/Film-Capacitors/_/N-9x371?P=1z0wqrd&Rl=9x371ZergjZ1yo19lmZ1ykkhe8SGT&Ns=Pricing%7c0)
You can try to modify the search for 40uFd etc.
FFLI6B3007KJE 800v 3,000uF will keep your VT-40 from sagging ($485.68).
FE52N6J0506KB 550V 50uF $7.29 will serve a lot of amps and may never die.
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I got a triplet of 10,000uF 450VDC if you're interested, they're about a foot tall n 4" dia. so you might need a spare cap, cab :icon_biggrin:
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FWIW I've also been thinking about ceiling fan motor caps, 'cause I like l low value K bypass caps: https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2053587.m570.l1313.TR10.TRC1.A0.H0.Xceiling+fan+capacitor.TRS0&_nkw=ceiling+fan+capacitor&_sacat=0
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We all use box capacitors in pedal builds these days and there is lots of options especially in choice of manufacturers. Why dont we use them more in amp builds? I think red Wima’s, Blue Epco’s, etc....would look great on these boards from Doug. Ok, they have short leads but you can work around that one
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box capacitors in pedal builds
Voltage probably limits some :dontknow:
and black n gold FT caps look real pretty and they have an analog shape :icon_biggrin:
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I've just seen this, the price is really cheap
https://www.banggood.com/it/12uF-AC-350V-Generator-Capacitor-55x33x20mm-Capacitor-p-1098043.html?rmmds=search&cur_warehouse=CN (https://www.banggood.com/it/12uF-AC-350V-Generator-Capacitor-55x33x20mm-Capacitor-p-1098043.html?rmmds=search&cur_warehouse=CN)
https://www.banggood.com/it/24uF-Generator-Capacitor-350AC-Capacitor-p-1093659.html?rmmds=search&cur_warehouse=CN (https://www.banggood.com/it/24uF-Generator-Capacitor-350AC-Capacitor-p-1093659.html?rmmds=search&cur_warehouse=CN)
(https://i.imgur.com/KsavTWy.jpg)
Franco