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Category: PCB’s Page 1 of 2

The LPRO-101 DIY Rubidium Clock Generator

The DIY LPRO-101 ruibidioum clock generator. This box together with some additional electronics on a separate PCB will transform this LPRO unit into stand alone equipment. I’ve always wanted a good and affordable frequency standard for my home lab. Searching the eBay one might find quite a lot of solutions. The good thing is that nowadays we have plenty of options.

ECC88 Preamplifier / buffer

This is a quick entry to demonstrate a simple topology used in this ECC88 preamplifier. I’m using 7V heater variant – PCC88. It seems like the term “preamp” is not quite suitable here because the stage is actually a buffer and there is no amplification whatsoever. The schematic is shown below:


Thorens Power Supply Upgrade TD-150, TD-160

pcbThis is a very neat and nice PCB upgrade for Thorens turntables. It’s possible to use it with almost every other turntable that includes 16 to 24 pole synchronous motor.

The idea was to have a small PCB which includes both protection and power-off function. The PCB itself is a one-sided board with black solder mask on both top and bottom layers. I’ve decided to include optional drills for other capacitor sizes. This will make it possible to “adjust” the board for other Thorens models of even other turntable makes like Linn or Ariston.

USB PCB Design Considerations And Guidelines

There are many DIY USB audio projects floating around the web. However USB routing is not an easy task. There are some rules that the designer needs to follow in order to create a good PCB layout. The following document from Intel gives som basic and advanced guidelines on how to design a USB device and how to route the PCB. Though was it intended for a 4-layer design, many of the tips apply to 2-layer designs as well.

This document provides guidelines for integrating a discrete high speed USB host controller onto a four-layer desktop motherboard. The material covered can be broken into three main categories: Board design guidelines, EMI/ESD guidelines and front panel USB guidelines. Section 1.1 Background provides an explanation of the routing experiments and testing performed to validate the feasibility of 480 Megabits per second on an actual motherboard. Section 7 contains a design checklist that lists each design recommendation described in this document. High speed USB operation is described in the USB 2.0 Specification (

High Speed USB Platform Design Guidelines – >>>[LINK]<<<

IL715 Digital Isolator PCB Design

This project is based on the IL715 digital isolator chip, manufactured by NVE Corporation. This is a simple isolator schematic and a PCB.
Here is the technical datasheet for this chip:


The IC is pretty easy to use. They made the pinout as suitable as it can be. For this project I decided to make a sort of an adapter PCB which can be mounted on suitable female headers to the main PCB. I also decided to put a local voltage regulation just to be on the safe side. Local voltage regulation is proven to a good practice. I’m not quite sure if it serves a good purpose in this particular project but it does no harm either 😉

Of course from the datasheet you can see that there are several variants to this chip depending on the needs. The PCB itself does not change so it’s suitable for all the types. For example when doing a local reclocking near the DAC ship and driving a master clock directly to the DAC’s form external master clock source, you will need to send this clock back to the digital part of the system. This one will feed the digital filter and the servo processor(and of course all the other IC’s that need a clock supply). In this case you can use IL717 IC.

The schematic itself is pretty straightforward as the application is a no challenge to any designer. This is what it looks like:

IL715 Digital Isolator PCB, Schematic design

And this is the PCB:

IL715 Digital Isolator PCB

The complete manufacturing files are available for download HERE

This project is provided to the DIY community for free. Commercial use is not allowed!


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