As previewed in an earlier post, this is a preamplifier designed by Shaan and offered for sale in a group buy at DIY Audio. It is fully discrete, Class A with an integrated power supply. The twist is that it offers adjustable (from less than 0.001% to over 1%) single-ended, predominantly second harmonic distortion. In…
Category: DIY Audio
Let’s have some (en)closure on this.
I don’t get too many comments or questions on this blog, but what I do get are usually positive and encouraging. Occasionally there are technical questions, many of which are beyond my knowledge, I’m just a builder of other peoples designs, so I’ll usually direct those to the relevant places for more help. I have…
Custom labelling for enclosures on the cheap
Many of the enclosures I’ve used for my builds have plain brushed or anodized aluminium fronts. With these, all customization, drilling, labelling etc. is left to the builder. I’m actually quite fond of this plain, minimal look but occasionally some lettering would be helpful. This applies to the rear as well, I’m thinking RCA jacks…
Elliott Sound Projects P113 Headphone Amplifier
I’m a fan of the projects on Rod Elliott’s ESP site as they come with lots of information to help you understand the circuit, and most are simple and robust enough for entry-level DIY hobbyists. Yet this does not mean these are low audio quality circuits, Rod specifies this P113 headphone amplifier as a very…
PeeCeeBee Preamplifier Preview
An envelope dropped through the letterbox yesterday morning containing a PCB I’m quite excited about, a preamplifier with a twist. In a similar vein to the Pass H2 harmonic generator, this preamplifier has a real-time, adjustable harmonic distortion level. The circuit was designed by Shaan and is offered for sale in a group buy on…
Amplifier soft-start and low voltage illuminated on/off switch – H9KPXG
Regular DIYAudio contributor Mark Johnson has kindly released this project into the public domain. The impetus behind the project was the desire for the designer to safely use a low current, front panel switch of the anti-vandal type in power amplifiers. The board incorporates inrush current limiting, wiring for the on/of switch and an auxiliary…
DC Splitter for Bench PSU
There is often a need for a dual voltage supply when dealing with audio (op amps often require dual supplies for example) but there may not be a suitable one at hand. There is, however, usually a single supply, a wall adaptor, bench supply etc. and, at its most basic, all that is required to…
Another buffered opamp headphone amplifier
For no particular reason I built another headphone amp. This one is similar to the Emmeline XP-7 clone I built, in that it utilises op-amps with buffers. The complete setup comprises three components; the amplifier itself, a dual power supply, and a delay circuit, all of which are slowdiyer designs. The amplifier is relatively straightforward…
A simple opamp tester
I’ve been having some problems with what should have been a straightforward build of a headphone amplifier and wasn’t sure if I’d damaged the op amps or if they were still useful. I came across this tester circuit at Tangentsoft and decided to build it. It requires a TLE2426 rail splitter virtual ground, a few…
Headphone amplifier power outputs
Following on from my last post where I showed the headphones dummy load, I thought I would post the measurements I obtained from the other headphone amplifiers I have built. It’s also an excuse to play around with my new toys. I knew that eventually I would end up with an oscilloscope, I spent a…