Airbrake schematic or layout

[Structo]

Did you look on page 6?

[terryrocks]

yes, the pdf is of the layout.

[istikis]

I have the schematic and parts list to order a "mouser Spain" but I have a question and would like to help me resolve. This attenuator is used for my amp? (Peavey VK 100watts). and if you can add a "LINEOUT" for direct recording interface sound?. and how to do the LINE OUT?. thank you and please forgive my English so basic and bad.

Greetings from Spain!!!!!!

[MasterDisaster]

Download this Line Out schematic/calculator and it will give you the resistor values. Default values assumes a 50W amp at 8 ohm but it will work for just about anything if you use a pot for R2.

Mike

[vibratoking]

I would like a copy of the schematic if anyone would be so kind to oblige.

lbieber@q.com

Thanks

[Roadstarrodgers]

Me too...can someone please send me the schematic for the Airbrake?

[jaysg]

Please look in "Trainwreck Files". That's where definitive schematics and layouts reside.

[Lowlife]

Hi all
I know many of you have been asked the same questions over and over again about this Attenuator, but i have one additional question, having browsed through pretty much all the threads in here.

My amp is a marshall 100W, 16 ohm, and it seems to me that the Air Brake is optimised for for 8 ohm, so I'm considering whether i could mod the original design with some different higher resistance values to make it optimised for 16 ohm.

Anyone tried that?

[vibratoking]

You can modify it to be closer to 16 Ohms, 8 Ohms, 4 Ohms, or almost anything else. Any modification will always have some error in load matching that is dependent on how much attenuation is used. This error is unavoidable without excessive switching and power resistors.

In my experience, the problem with the Airbrake is not the impedance matching. It is with the sound degradation that occurs when using the amount of attenuation that I find necessary to bring the volume to an acceptable level. This is a personal thing and YMMV.

[klg335]

I'm a newbie, so forgive me for adding to this thread that appears to have annoyed everyone
I would like to build this attenuator and I believe I have found most of the information I need and parts lists.
Can anybody tell me the difference between the II and III version? Is there any layout/schematic for the III version?
I found the spreadsheet for the parts for all 3 versions. Is that the one I should reference?
I found a layout for the II version (w/out bedroom,added resistor), is that the correct one?
If anybody could help me on this, I would be truly grateful.
Thanks

Kirk

[Bruciep07]

I'm a newbie, so forgive me for adding to this thread that appears to have annoyed everyone
I would like to build this attenuator and I believe I have found most of the information I need and parts lists.
Can anybody tell me the difference between the II and III version? Is there any layout/schematic for the III version?
I found the spreadsheet for the parts for all 3 versions. Is that the one I should reference?
I found a layout for the II version (w/out bedroom,added resistor), is that the correct one?
If anybody could help me on this, I would be truly grateful.
Thanks

Kirk

Just look in...

https://tubeamparchive.com/viewtopic.php?t=8733

Third file listed on the page (attenuator_layout_final_195.pdf)

It's the airbrake layout with all (well almost all) part numbers listed from Mouser, makes it really easy to see how it works, how it goes together, and what you need to buy...

[klg335]

Thanks for the reply.
I have that information, but I just noticed that the Airbrake III calls for two adjustable resistors and mentions a footswitch.
How is the footswitch wired in? (That would be cool, if it works)
On the one adjustable resistor that has only one clamp - where is that one suppose to be set?(8 ohms?)
Thanks for any help.

Kirk

P.S. Of the different versions of the Airbrake builds, which is everyone most happy with? I don't need the "bedroom" I'm leaning towards the II or III version, any advice to which one to build?

[Bruciep07]

Thanks for the reply.
I have that information, but I just noticed that the Airbrake III calls for two adjustable resistors and mentions a footswitch.
How is the footswitch wired in? (That would be cool, if it works)
On the one adjustable resistor that has only one clamp - where is that one suppose to be set?(8 ohms?)
Thanks for any help.

Kirk

P.S. Of the different versions of the Airbrake builds, which is everyone most happy with? I don't need the "bedroom" I'm leaning towards the II or III version, any advice to which one to build?

I didn't notice a footswitch on the schematic, must have missed it. The adjustable resistor (R1) gets just one clamp directly in the center, so from the center lug to each end lug, you shoul get near identical readings(12.5 ohms +/- 20% for a 25ohm resistor). Look back at the link I posted above, the airbrake III schematic shows the math for Rt in every position that the switch is in, as well as attenuation in dB. I have only built one airbrake (copied a real one) so I can't attest for other versions, but mine doesn't seem to color the sound too much in the first 2 positions, after that, it starts to get a little "buzzy" sounding... It's cool to be able to crank your amp and turn all the way to "bedroom" but it doesn't sound anywhere near the same... Very "solid state" soinding if that makes any sense... I don't know if that's a good description or not but fully attenuated, my express sounds a lot like a $50 fender practice amp...

[M Fowler]

A guy posted this one with foot switch.

[klg335]

Thanks!

It's hard to see how the footswitch is wired. I checked his post and he had a hand drawn diagram, but still unclear. The inputs are labeled - "in", "out" and "spkrs"???
Does the footswitch wiring switch between full volume and attenuation?
Any input on how it's suppose to be wired?

Thanks and Merry Christmas!

Kirk