choke for plexi suggestion needed

rockstah · Post by **rockstah** » Tue Aug 15, 2006 2:07 pm

hey guys, there has been some talk in the past about chokes and there values.

as i dont know much about chokes so what would you guys suggest for my new plexi build?

100 ohm? 200 ohm?

please add your two cents here.

Mark

Flames1950 · Post by **Flames1950** » Tue Aug 15, 2006 5:46 pm

What plexi were you going for this time? I know you've told us but I forgot........

If it is a '65 or early '66 era 100 I'd get a hold of Brian Wallace and try the RS 20H 690 ohm repro he did. (Hey, someday I'D like to try it too......

) For later '66 George's 384-114 (that's what the store says, I thought it was a 352-114??) repro would be nice and authentic; maybe it would even be appropriate for a slightly later amp too, I don't know........those are for something sticking close to the original stuff of course, but what you're building may dictate something different.

rockstah · Post by **rockstah** » Tue Aug 15, 2006 5:52 pm

Andy, thanks for the reply.

this amp is a going to have four preamp tube, post phase inverter master volume. a hot rod. it of course may just end up being another 12 series build but its what it will start as anyway.

Mark

Flames1950 · Post by **Flames1950** » Tue Aug 15, 2006 6:17 pm

Ah, that's right.........personally I'd go with something in the 10H range and a good solid current rating to keep the ripples away, it always sounds to my ears like added gain stages or overdrive pedals make any slight ghosting stand out that much worse........

rockstah · Post by **rockstah** » Tue Aug 15, 2006 6:23 pm

indeed i am concerned with the ripple as well as the choke doing its job. there was a topic, which i cant find yet( searching), Larry was talking about some testing he did on a choke, i think it was rated at 100 ohm and it basically failed..said something liek getting one thats at least rated at 200 Ohm or something like that.

my first build has the 5Hy HTS - 7262 which i think is rated at 100 ohm. i think this is the same one in Georges 12 series. figured while i was looking for another and i would research it further this time around.

at this point lets just say im looking for a good choke for a 12 series plexi. make it easy.

Flames1950 · Post by **Flames1950** » Tue Aug 15, 2006 6:36 pm

I think the thread you're thinking of was referring to the mA rating that the inductance was rated at, and how fast the inductance dropped when the choke was pushed past that mA rating. They thought that a choke of at least 200mA would be sufficient to keep the smoothing circuit working properly in a 100-watter. MM only had one or two up to the task using that mA rating as a criteria IIRC.

novosibir · Post by **novosibir** » Tue Aug 15, 2006 7:11 pm

To correct some possible opinions, here a part out of an email from Paul Patronete @ Mercury Magnetics to my request due to the from Flames above mentioned thread a while back:

Sergio also said that the 100mA on the MC10H choke is an arbitrary number. He said the MC10H choke can easily handle 300mA! If you go with a higher Henry choke (MMC20H), Sergio said you will get more tonal filtering. On your next order I suggest you try the R115C (15 Henry), MMC20H (20 Henry) and the MMC-3H (3 Henry) chokes. These three pieces are vastly different and will give you a testing ground for different inductance in different circuits.

Larry

rgalpin · Post by **rgalpin** » Thu Dec 07, 2006 8:17 am

trying to understand how the choke affects the circuit...

Sergio said you will get more tonal filtering.

sounds like this says that the higher the value in Henries, the more filtering you get.

my experience is that things sound best when you use the least amount of filtering possible - so, i'm thinking it's a game of "how low can you go?" same as the filter caps IMO.

go with something in the 10H range and a good solid current rating to keep the ripples away

ripples... hmmm... i hear ripples in real fat EVH stuff - like the beginning of Unchained. i think it's a major part of the sound. i'm thinking, "ripple = good."

time to start lowering mr. henry i think. if this is wack thinking, someone please guide me back to the path of tone righteousness.

mightymike · Post by **mightymike** » Thu Dec 07, 2006 8:54 am

The higher you go the more clean and vintage it is.

The 7262 is in my signature clips, but I also have another one like the Metro Choke George is selling in the store, and it's almost identical

The 7262 is a 5h, and I believe the one in George's store is no more than 2H in difference, and the same 105? Ohms, and the same ratings for current and voltage.
I have it written down somewhere, but you could always call Alden at Heyboer and ask about the specs for the different part #s. I bet it would be hard to hear the difference, but the one George is selling might look more accurate. I haven't really sat down and compared.

Both of these chokes are rated high enough, and have work well so far for me.

If you're looking for something different get a 15 or 20 Henry, because I think the one you were talking about is going to be almost identical sounding to the 7262.

Both fit George chassis. The 10H MM Choke is too wide, there 3.3 Henry has 4 bolts, but you could mount it diagonal like Ralle. They do have one that fits the 2 7/8 mount, but I forget the name (Mar something), and didn't like the rating for some reason I can't remember, because it's been a while.

I have a brand new 10h MM Choke for sale....$20 plus $8 for shipping

rgalpin · Post by **rgalpin** » Thu Dec 07, 2006 9:33 am

good info.

mike, by "cleaner" do you mean less gain? because i think a lot of the more vintage sounding amps are looser in the filtering - which produces, IMO, a more organic, complex sound which you could almost call "dirtier." not to be confused with "gainier."

and that is what i am looking for - "richness" but not at the expense of headroom. so i am looking for every little possible detail that might add richness, complexity, chewiness to the tone with out adding any gain.

when someone says "ripple" i'm thinking - yeah let's have some ripple. when someone says tonal filtering - i'm think - ew no, not that! this is where i'm getting the "how low can you go?" philosophy - which seems to work well for the filter caps - now that there is some consesus that lowering the filter caps values through out the amp produces goodness.

it would be cool to get some opinions on what someone might expect to hear - albeit subtle - in the difference between a 2H choke and a 20H. just to illustrate what the value change would do.

awangotango · Post by **awangotango** » Thu Dec 07, 2006 8:28 pm

does anyone know how many henry's a choke from a '71 superlead is ?

mightymike · Post by **mightymike** » Thu Dec 07, 2006 8:34 pm

Get 2 of them, they're like $20 each at Heyboer

Get a 3 or 5h and a 20h, and a/b it on a swtich.

There is no right answer, just what you like more.

rockstah · Post by **rockstah** » Thu Dec 07, 2006 8:39 pm

how would one measure henries?

awangotango · Post by **awangotango** » Thu Dec 07, 2006 8:47 pm

seems like the choke is uncharted territory and a good place for some solid a/b'ing. I'm like rgalpin in that i'm looking for dirty but controlled raunch and choosing the correct choke seems like it would be a subtle but important decision.

Post by **Brian Wallace** » Thu Dec 07, 2006 10:16 pm

awangotango,

That choke would be a 3H one. Also, if you raise the Henry value, you will not only "clean" the amp up, you will also make it stiffer on the feel and note attack. This is really not a vintage feel as most chokes used by Marshall are the 3H rated ones.