While looking for pots I found a couple of suppliers in Hong Kong. I bought 4 of them for one man, waiting on their delivery, but was contacted by another man who said he could supply me with pots for a better price. Here are the pots: ALPS 100K AUDIO AMPLIFIER POTENTIOMETERS Made in Japan...

I would like build a preamp and a portable speaker for an acoustic bass guitar. I've been looking around the internet and have not found any pages explaining what needs to be done. Impedance is my first problem and I have not yet come to really understand it. Is it possible to use a headphone...

Possum used a link, in a reply, to a Stereophile review. I found it fascinating reading. http://www.stereophile.com/showarchives.cgi?54:1 I need to build a few buffering circuits and was wondering if the BUF-03, mentioned in the article, is still a great buffer? I see the article was...

I bought a Noble stereo 50k pot but don't know if it is an audio or linear taper. How can I test it to find out? What does the different ohm ratings of pots do to audio. I see them from 10k to 500k. Is one better than another? Why does the Noble pot have 4 pins for each pot? Are all Noble pots...

I'm having a tough time with volume potentiometers. I understand carbon pots are cheap and add noise. Mouser and Digi-Key have a bunch of precision wirewound pots but they are all linear tapers. Is conductive plastic better than all other materials I've read that we need a log or audio taper. Is...

I am trying to add an LED as an ON indicator to a toggle switch. Mouser offers a plug for an LED with a built-in resistor. My problem is I don't know how to figure out the resistor size I need. I will be switching 15volts on and off and the LED only needs 2.2 volts at 20mA. Can someone help me...

I have a small portable mixer (4 channel) that is power by a 9volt battery. It is a Boss Micro Mixer Km-04. I run out of headroom real quick with this thing and a battery only last a couple of days. I use it right beside my Szekeres headphone amp and it's oversize regulated 15 volt power supply...

I have a pair of Bach-Simpson larger VU meters that I want to use with a stereo mic preamp that I am building. I bought these meters from a guy in Canada who parts out large mixing boards as sells the parts. I was thinking of using the VU And PPM Audio Metering drive that is on Elliott Sound...

I built a Szekeres headphone amp (with the gain stage) and would like to send 2 inputs into it. I have a portable CD player and a midi drum pad that I would like to be amplified by my headphone amp. Both devices have their own volume control. Can I take both Left channels and both right...

In my search for a power supply I ran across this guy. rockyroad93@home.com His name is Rocky and he is selling + - 15volt 3 amp power supplies for $10 each. (Plus $10.75 shipping) I bought one to power my Szekeres headphone amp and the PS is silent. They were originally purchased for use in...

I've finished building my first Szekeres MOSFET headphone driver and now need to finish the power supply. It has a low hum. I've decided to build Elliott's "Simple Capacitance Multiplier Power Supply For Class-A Amplifiers" I'm trying to find all the parts and I have no clue what a BD139 Driver...

I am ready to solder my Szekeres amp together and when I looked for a board to put it on I was somewhat surprise by my choices. Vector Prototyping Boards seem to be what I need but they are expensive. In fact it is the most expensive part of this project. I'm looking at the Circbord (Mouser...

I’ve bread boarded my Szekeres headphone amp and it sounds good except for a slight hum. My power supply concise of a car battery eliminator (12volt at 3 amp) with 8000mf caps across the output. The power supply says it is filtered. I did some test on the power supply to find out how a load...