Power brake attenuator question

[jackplug1]

Has anybody built this:

https://blueguitar.net/new/schem/misc_mod/volreduc.gif

If so is any good or are there better designs out there now?
What sort of choke/inductor is that, is it and air core type or does it have an iron core,
the wattage rating seems excessive at 150watt

[CO_Hoya]

I built a version of the Hewitt (JohnH) attenuator recently, kind of a fun project.

Simple Attenuators - Design And Testing (Marshall Forum)

The thread linked above is a long one and it can be hard to glean info, but the circuit designer and a couple of others there have been good about answering questions, etc.

[PRR]

...What sort of choke/inductor is that, is it and air core type or does it have an iron core, the wattage rating seems excessive at 150watt...

Get it from a Loudspeaker Crossover Parts catalog. PartsExpress is suitable in North America.

[acheld]

Try this:

https://www.marshallforum.com/threads/simple-attenuators-design-and-testing.98285/

Well tested, works nicely.

[Joel]

I built two of JohnH's M2's last year.  I'm still very happy with them.

[jackplug1]

The simple attenuator article is quiet interesting.
Would the line out on the schematic in the original post (mission amps) benefit from an isolation transformer?

[Blueboozer]

I built one of these a while back and it works pretty well.

[jordan86]

I built one of these a while back and it works pretty well.

Is this a clone of a Trainwreck/ Dr Z Airbrake?

[Blueboozer]

I believe so. 

[jackplug1]

I built one of these a while back and it works pretty well.

The resistors a very expensive at £25, maybe you could make them from a ceramic electic fire element