choke questions

[killer blues]

I am starting a JTM45 build. What would be the differences between a 7H and 10H choke? Thanks!!

[Old Tele man]

...uh, let me guess: about 3H!

...actually, choke 'size' (L value in Henries) affects:

A) ripple, ie: ripple factor = 0.83/L*C

B) critical (minimum) inductance: L => RL/1130

...so, "how much" ripple can you stand and "how much" current (whence: RL = Vo/Io) you gonna need?

[killer blues]

thanks for the reply OTM. Chokes are inductance devices that affect bass response if I am correct. I have both, and the norm is to use a 7H in a JTM45. They are bass heavy, and when pushed, they can get very unfocused in the low frequencies. If the 10H choke allows for this, I don't want to use it. Of course, I could be way off "bass" here

[Old Tele man]

...if you notice, nowhere in my posting did I mention anything about TONE, only power supply ripple and voltages.

...a choke affects playing "sag" and "browness" far, far more than amp TONE.

...I'd measure both and use the one with the lowest DC-resistance, as "more" voltage tends to brighten (and tighten) an amp.

...since 7H is standard, go with that...however, I would lean towared the larger 10H as it would provide better filtering (and should have lower DC-resistance).

[killer blues]

thanks OTM I was leaning in that direction

[donnyjaguar]

At the risk of sounding like a pedant, would the 7H not have lower DC resistance by virtue of the fact there is less wire in it?

[Old Tele man]

...not necessarily so, especially if the 10H was wound with bigger gauge (and thus lower resistance) wire...of course, it'd co$t much more for that added copper!

[killer blues]

I pm'd George Metropoulis and he said the 10H would be stiffer, and better suited to a heavy-handed guitarist. Consequently, it also has the lower DC resistance of the two. Thanks again OTM