[1755] Calculate Slew Rate

Date: February 20th, 2015 | Comments : none | Categories: DIY.

How Fast Does your Opamp Need to Be?

slew rate of lm308


This calculator is used to find the slew rate needed to reproduce a signal at a specific frequency.

For example, the 0VU level of the -10dBV signal used in most semi-pro equipment is 0.894v p-p. We use this value with the maximum frequency that will be passed through the circuit. Try 20,000 Hz as an example.

The +4dBu signal is 3.47v p-p and you can use the calculator to find out how much faster the amplifier needs to be to push this higher signal level.

The Rat pedal opamp would need to slew about 8.0v at 10kHz. Find the slew rate needed for the opamp.

In the Lab Notebook at http://www.muzique.com/lab/slew.php.

 

[1744] PAM8403 Class D Audio Amplifier

Date: January 24th, 2015 | Comments : [1] | Categories: DIY.

PAM8403 Class D Audio Amplifier

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[1730] AC125 Germanium Transistors

Date: January 22nd, 2015 | Comments : [2] | Categories: DIY.

ac125 transistors

I have a limited number of AC125 PNP germanium transistors available.

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[1727] Delay Time Calculator

Date: January 20th, 2015 | Comments : none | Categories: DIY.

delay pedal

Calculate the number of milliseconds delay to enter into your echo pedal.

 

[1721] Notch Tone Control

Date: January 12th, 2015 | Comments : none | Categories: DIY.

bridged-tee tone control

A bridged-t notch tone control in the Lab Notebook. Enjoy!

 

[1665] Good Band Names

Date: January 11th, 2015 | Comments : [3] | Categories: DIY.

I’ve updated the page of FREE Band Names… check it out if you need a name for your rock-n-roll ensemble!

Good Free Band Names

 

[1740] AC176 Germanium Transistors

Date: January 5th, 2015 | Comments : none | Categories: DIY.

ac125 transistors

I sorted through a bag of AC176 NPN germanium transistors. There were 100 transistors in the sealed bag, and above are the cups with the results of the sorting.

The one on the right is very low gain transistors that are only suitable for use as diodes. The cup in the middle holds transistors with good gain but excessive leakage. On the far left is the cup with the good transistors… there are 2 of them out of the bag of 100. Not good.

 

[1714] Small Signal Transistor Packages

Date: December 29th, 2014 | Comments : none | Categories: DIY.

TO-18 transistor package

I posted photos of several types of small signal transistor packages in the Lab Notebook.

 

[1696] 1P6T Rotary Switch

Date: December 29th, 2014 | Comments : none | Categories: DIY.

1P6T rotary switch

This is the 6-position rotary switch as sold by Small Bear and other online stompbox parts vendors.
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[1691] Stompbox Patents

Date: December 11th, 2014 | Comments : none | Categories: DIY.

I have added the Maestro Fuzztone patent to my page of effects related US patents.

I often see users comment in online fx forums that you cannot patent effects pedal circuits, which is not true, as evidenced by the many patents I have listed on the US patents page.