Chokes/Inductors?

Psychobiker

Hi,

Based in Galway, and I'm just wondering where I can lay hands on a 10-20H (yes, henry ) choke for my valve amp. + - 200mA capacity.
Maplin, no. Galway rewinds didn't know what I was talking about

L

mawk

are you missing a Mu in there by any chance? 20 henry(ies) is pretty big.

a quick googling seems to show good amps peaking about 1H. but ive never had a peek inside a valve amp, so i could be wrong

anyways:
http://radionics.rs-online.com/web/search/searchBrowseAction.html?method=retrieveTfg&Ntt=Inductors&Nr=AND%28avl%3aie%2csearchDiscon_ie%3aN%29&Ntk=I18NAll&Ntx=mode%2bmatchallpartial&N=4294956851&Nty=1&binCount=71&No=25

radionics have lots of chokes, probably one to suit you

Psychobiker

Oh boy have I ever scoured Radionics!! Nope, neither them, farnell, peats...nobody.

I didn't miss a µ, 'tis over 5H I need to pull the ripple down to something tiny (<50mV).
It's a single-ended amp, most of the more commercial ones (and solid state now) are pushpull class AB or B, which can happily tolerate 20V ripple as it gets eaten out down the line of phase inversion etc.

Thanks again,

L

Psychobiker

Rooted out an old toroid from college...7.2H...nice one!!

brings b+ ripple voltage to ~10mV

Pete67

I'd say you got lucky there! Just make sure it's safe - i.e. rated for use at at least 1.5 times your B+ voltage.........

Just curious, what valve are you using for the output of your SE amp?

Pete.

Psychobiker

Tested it to 410VDC no load, so will see what happens when I put laod across it during the week. Tis an old Radionics one...order code obsolete.

Using NOS 6V6Gs : pics of the build are here

http://www.flickr.com/photos/psychobiker/sets/72157604051618142/

Pete67

Very nice - let us know how it sounds when you get done! Did you do the board layout yourself?

Psychobiker

Did, took the plotting loft (schematic...!!) from Boozhoundlabs.com, made footprints and laid out tracks etc on Protel 99SE, and milled the board at college.

L