Search found 17 matches
- Sun Mar 20, 2011 5:31 pm
- Forum: Trainwreck Discussion
- Topic: DIY Airbrake...
- Replies: 448
- Views: 208200
Re: DIY Airbrake...
I don’t think you have done anything wrong as maximum attenuation is about -20db with a 16 ohm speaker load. That would equal about 1W with an input of 100W. Speaker sensitivity is usually around 100db which means that 1W will be pretty loud. This statement is from DR Z homepage. (The Air Brake has ...
- Mon Nov 01, 2010 1:12 am
- Forum: Trainwreck Discussion
- Topic: Airbrake schematic or layout
- Replies: 121
- Views: 102946
Re: Airbrake schematic or layout
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
Mike
- Tue Oct 05, 2010 9:48 pm
- Forum: Trainwreck Discussion
- Topic: Hook Up Wire for Airbrake
- Replies: 6
- Views: 2194
Re: Hook Up Wire for Airbrake
I have set up an Excel calculator so feel free to use.
Mike Lind
Mike Lind
- Thu May 06, 2010 10:19 pm
- Forum: Technical Discussion
- Topic: Headphones from speaker jack?
- Replies: 3
- Views: 1069
Re: Headphones from speaker jack?
Some numbers and links to get you started. IEC standard might be a good starting point and it stipulates 5V, 120R. A voltage divider circuit should be sufficient for this purpose so you first need to calculate the output power of your amp and to what load you are connecting it to. 100W into a 4R loa...
- Sun Apr 18, 2010 6:12 pm
- Forum: Trainwreck Discussion
- Topic: DIY Airbrake...
- Replies: 448
- Views: 208200
Re: DIY Airbrake...
By switching your amp to 8 Ohm you are actually decreasing the mismatch as the Airbrake will start at around 10 Ohm with a 16 Ohm load. The load will then increase with attenuation to about 22 Ohm with a 150R Rheostat. Ken Fischer quote: "On these high powered British amps, due to their unique trans...
- Thu Apr 15, 2010 10:47 pm
- Forum: Trainwreck Files
- Topic: Attenuators
- Replies: 3
- Views: 8348
Re: Attenuators
I have added a Minimum Attenuation Calculator so it automatically gives you "Min Att" for different input and output loads.
Mike
Mike
- Fri Mar 26, 2010 4:02 pm
- Forum: Technical Discussion
- Topic: Attenuators
- Replies: 0
- Views: 7117
Attenuators
I have added a spreadsheet document in the files section containing calculators for L, T and Pi attenuators. This will make comparison easier as you only have to fill in values once for all calculators.
Power Dissipation is included and also Impedance Matching for T and Pi.
Mike
Power Dissipation is included and also Impedance Matching for T and Pi.
Mike
- Fri Mar 26, 2010 3:51 pm
- Forum: Trainwreck Files
- Topic: Attenuators
- Replies: 3
- Views: 8348
Attenuators
*Updated 16-Apr-2010 rev1 with "Min Att" Calculator.
This spreadsheet contains L, T and Pi attenuators with Power Dissipation.
T and Pi also has Impedance Matching.
This arrangement should make it easier to compare resistor values etc.
Mike
This spreadsheet contains L, T and Pi attenuators with Power Dissipation.
T and Pi also has Impedance Matching.
This arrangement should make it easier to compare resistor values etc.
Mike
- Sat Mar 20, 2010 5:40 pm
- Forum: Trainwreck Discussion
- Topic: DIY Airbrake...
- Replies: 448
- Views: 208200
Re: DIY Airbrake...
Pi updated with Impedance Matching.
I have added a Pi Attenuator and a L-PAD calculator in the files section so check them out.
Mike
I have added a Pi Attenuator and a L-PAD calculator in the files section so check them out.
Mike
- Sat Mar 20, 2010 5:34 pm
- Forum: Trainwreck Discussion
- Topic: Pi Attenuator Ver2 (obsolete)
- Replies: 0
- Views: 7738
Pi Attenuator Ver2 (obsolete)
Replaced by Attenuator spreadsheet. Updated with Impedance Matching. This is a Pi Attenuator calculator with power dissipation. The main purpose is to give correct impedance at both the input and output and give you the minimal power rating for the resistors. I have not included impedance matching a...
- Thu Mar 18, 2010 9:47 pm
- Forum: Trainwreck Discussion
- Topic: L-PAD Attenuator (obsolete)
- Replies: 0
- Views: 7593
L-PAD Attenuator (obsolete)
Replaced by Attenuator spreadsheet.
I have included power dissipation in this L-PAD calculator which may be useful if you decide to build one.
Mike
I have included power dissipation in this L-PAD calculator which may be useful if you decide to build one.
Mike
- Tue Mar 16, 2010 1:48 am
- Forum: Technical Discussion
- Topic: Line out vs pwr scaling
- Replies: 5
- Views: 1675
Re: Line out vs pwr scaling
I have not tried the VVR3 but maybe Dana can fill in. Power Scaling have a dynamic range of about 40db which should be enough for home use. I feel that this have less effect on tone that any attenuator I've tried but someone might disagree. It works great on Marshall style amps but might not work as...
- Tue Mar 16, 2010 1:14 am
- Forum: Trainwreck Discussion
- Topic: Redesigning the Airbrake
- Replies: 5
- Views: 2175
Re: Redesigning the Airbrake
R1=pararell resistor or shunt R2=series resistor R3=rheostat Zo=speaker load Zi=input impedance The Airbrake attenuator is basically a Pi Attenuator with the speaker replacing the last shunt. R1 sets the maximum impedance of the circuit and R2-R3 sets the maximum attenuation. With a 25R R1 the sprea...
- Sun Mar 07, 2010 10:26 pm
- Forum: Trainwreck Discussion
- Topic: Airbrake: More Attenuation on Bedroom Setting/Attaching Base
- Replies: 1
- Views: 898
Re: Airbrake: More Attenuation on Bedroom Setting/Attaching Base
You need to increase series resistance. With a 25R shunt and 25R series resistor the maximum attenuation with a 8 ohm load is about -10db. With an added 150R rheostat you will get down to about -23db. Probably to loud for home use as you might want to reach at least -40db. The version with the adjus...
- Fri Feb 26, 2010 8:33 pm
- Forum: Trainwreck Discussion
- Topic: DIY Airbrake...
- Replies: 448
- Views: 208200
Re: DIY Airbrake...
The switch in this layout is of the "shorting" or (Make-Before-Break) type. If you use the "non shorting" (Break-Before-Make) type you might experience a pop when you switch attenuation levels. From a technical standpoint a BBM switch would be more suitable for higher currents, but the jury might st...