Airbrake - Custom

[Littlewyan]

I have finally finished my custom Airbrake Attenuator. Its based off of the original Trainwreck Design but works a bit differently and has a few extra features.

1. It has 2 rotary switches that can be switched between using a footswitch. So you can use one for a solo boost.

2. It has a line out with a level control (untested at this moment in time).

3. It has less of an impedance mismatch than the original design. You set the amp to 4Ohms but still plug any speaker into the speaker socket. At the highest attenuation setting the amp will see 9Ohms. I know some people said the original unit sounded a bit buzzy so I thought I'd still go with Ken's original idea of mismatching the impedance but to a lesser degree.

How does it sound? Well I've only played it a few times and I think it sounds ok. I immediately removed the bright cap from the rheostat as the bedroom level setting just sounded wayyy too buzzy with it. The unit still sounds kinda buzzy and I must admit I am leaning towards my other attenuator, which is just a simple LPad. However I will use this at band practice on Thursday and will see then what it sounds like in a much bigger room.

[dorrisant]

I like the looks... Yes, let us know how it sounds. I have hit a point where I must use an attenuator in the shop...

[Littlewyan]

After testing more in my room, the bedroom control actually sounds pretty bad without the cap. I'm going to solder another 0.1uF Cap onto the rheostat in case the original cap wasn't good. Without the cap it loses a lot of high end and even makes the low end chords sound bad. I shall be testing it at band practice tonight.

I put the capacitor back. It sounds much better with the cap although as others have said it can be very fizzy. Without it I lost a lot of high end.

[Littlewyan]

Ok I tried it at band practice and its ok, it does get a little bit buzzy but I am attenuating 14.5dB. It certainly retains the high end better than my other attenuator, the downfall is it means my guitar feeds back a lot easier.

I plugged the line out into the mixing desk and it sounded awful. Really spatty is the only way I can describe it.However my mate said its because the input we used was pre EQ'd for a certain instrument. We're going to give it another go on Thursday in a different input.

So all in all I'd say it was a success! I need to try it on my Marshall as well as some attenuators suit certain amps better. I will report back once I've tried it.

[Littlewyan]

I forgot to report back, sorry about that! The attenuator is the best I've used so far. Compared it with my old LPad attenuator and its a huge improvement. The LPad attenuator did something weird to the tone. I would say it was like putting a blanket over the amp but it wasn't just loss of high end that I got. Anyway the new attenuator is quite transparent compared to it.

[dkochan]

Very cool! Always good to hear a success story in attenuator land. So many of them end up being a disappointment.

I need to get off my butt and "finish" mine so I can commence tweaking.

[Littlewyan]

Which design are you building?