Hi, this is Wayne again with a topic “Weekend Projects – Vinyl Digitizer Phono Preamp”.
Hi i’m eric weinhofer with make in the past. You probably stumbled across an amazing old vinyl lp like this one at a record, store friend’s house or a yard sale, but reluctantly passed it by because in our digital world, vinyl records like this are about as convenient as a telephone hanging on a wall. Next time don’t pass them up snap them up and digitize them with the vinyl digitizer phono preamp, designed by ross hershberger, you can swing by your local radio. Shack to pick up most of the parts needed for this build you’ll also need the following basic tools: the vinyl digitizer phono preamp is a moderately difficult build.
We recommend you start with something a bit easier if you haven’t worked with electronics. Previously, our project page has a lot more details about the digitizer, including schematics, troubleshooting tips and more you’ll start by building the preamp circuit. It’S based around an operational amplifier or op amp chip with circuitry that filters and equalizes the sound frequencies, specifically for playing back vinyl records in order to cut an effective groove, an equalization curve is applied to the program material.
As the record is cut, this filter is called the riaa equalization curve and allows for longer plane records, reduces noise and minimizes wear and damage to the record. It also means that the signal coming directly off the turntable will need the inverse filter curve applied to it. In order to sound right, which is where our preamp circuit comes in first take a minute to get oriented with the circuit board and labeling convention, as shown on the project page, be sure to check it out before you begin the build it gets complicated.
So little time now will save you lots of time later. Okay, let’s get started start by adding the eight pin dip socket and then two 0.1 microfarad film, capacitors next we’ll add three resistors and then two pairs of resistors and capacitors wired together in parallel, followed by a large 0.47 microfarad capacitor, then install three more resistors and Two more capacitor resistor pairs in parallel, install two .033 microfarad capacitors and then install the final .47 capacitor in place, making sure to leave room for wire connections and the mounting screw now. It’S time to add all the wiring to the circuit board.
There are eight wires and two battery connectors that need to be soldered in place, refer to the schematic and the photos on the project page to locate all the connection. Points you’ll also need to solder an insulated jumper wire on the front and the back of the pcb now that you’ve added all the components needed for the circuit go back and carefully inspect the solder side of the pcb look for cold solder joints wires, not fully Soldered, and especially for solder bridges between traces next you’ll solder, the output plug to the appropriate wires before soldering. You might want to use a multimeter to determine which solder tabs on the plug connect to the tip of the plug.
Our left signal the ring of the plug our right signal and the body of the plug, which is ground now add the input jacks by soldering on their corresponding wires. The last component is the power switch, simply solder, the last two wires to the center pair of terminals and you’re done with the electronics. Now that the guts of the project are ready to use, you’ll put them in an enclosure for protection, you only need to drill a few holes in the project, enclosure for the switch plugs and optional power, led following the templates provided on the project page.
Speaking of the optional led check out the project page to learn more about how to add a simple power indicator to your project. Once your enclosure has been prepped, you can add the op amp chip to the socket on the pcb all the input and output jacks and two nine volt batteries close up the enclosure and you’re ready to hook everything up and start digitizing to do this set the Diamond audio usb external sound card on top of your vinyl digitizer phono preamp, and plug the pre-amp’s output plug into the sound card’s line-in jack, using the supplied usb cable connect, the diamond sound card to your computer, plug the turntable’s left and right output plugs into the Input jacks of the vinyl digitizer phono preamp start the audacity software and select the external usb audio device as the input turn the vinyl digitizer phono preamp on and start a record playing press. The r key on your computer keyboard to begin recording press the space bar to stop recording it’s that easy you’ll have to adjust the recording level of the software to get adequate volume while avoiding signal clipping. It usually falls between 0.2 and 0.3, depending on the record. If the continuous display of the recorded wave shows a lot of vertical red lines, the signal is clipping simply turn down the input level until most of the clipping disappears and you should get a clean recording the preamp amplifies. The tiny signal from the turntable’s phono cartridge applies the riaa playback curve and optimizes the gain to be compatible with the diamond usb sound card from there.
The sound card converts the input signal to a digital data stream and the audacity software nimbly turns those old 45’s. 78S and lps into new mp3s or the digital audio format of your choice now get out your record collection and move it on over to the digital world. There’S an amazing amount of musical content stuck in the analog world waiting to make the jump. If you decide to make your own vinyl digitizer, phono preamp, let us know in the comments on the project – page children, you .