chokes in tube amps

[rabies]

apparently the JVM amps don't have chokes. there are mods for adding this component. I'm assuming most other current models/makes (e.g. Mesa) have chokes. Is Marshall simply cutting corners to decrease cost here? JCM 800 and other older Marshalls had chokes, right?

 

[O'Rourke]

The 2203/2204 Marshalls and the NMV ones had chokes, not sure on the other 800 models. Basically a resistor is cheaper, although not having a choke doesn't mean the amp sucks. Lots of amps don't use a choke and sound fine including many relatively high dollar amps.

 

[OBGYNkanobi]

It shouldn't be too dificult to install one. I put one on my Voodoo modded 6505+ a few years ago, and it sounded great. The one that Voodoo/Merc recommended wa a 10H choke, and it sounded super tight and nasaly, but a 100ma, 3H Marstran C1999 choke was money. I didn't have to make any adjustments to the screen filtering; it sounded tighter (in a good way) and more musical. The 3H 250ma choke from Mercury magnetics is also a good option; it's a little more efficient and will maintain a more consistent H rating under load. The Marstran is my favorite though.

 

[JMP2203]

im curious abouth this,

some people say a choke make the amp tighter but my JVM210h its really tight man

ENGL amps also do not use choke and are the tightest amps arround, i had and SE time ago

 

[CECamps]

It's a cost thing. For a big manufacturer, a 5 watt resistor might cost around 20 cents or so versus $10-$30 for a choke (depending on manufacturer/construction/design). A choke takes up way more real estate in the amp chassis too.

Chokes are a much better filtering component in an amp's power supply though buy & large. The degree of advantage is based on the choke's specs and the power supply design though. In some cases an arbitrary swap of choke-for-resistor may not result in any noticeable benefit. But a well-incorporated filter choke will turn a good power supply into a great one.