Update – extra schematics and timing diagrams added (see below). Also TLP222G optofets are available in the shop here.
Here are a couple of options for generating proper 48V phantom power from a 9V supply. Before we get stuck into the details I should point out that the quiescent current for the first option is about 27mA and for the second about 52mA, so don’t be thinking you can run this from a PP3/1604/6LR61 […]
Update: reStomp re-ampers now available for sale in the shop.
I had an enquiry about re-amping and decided to look into the idea more closely. Traditionally, when recording a guitar (particularly an electric guitar), it is usual to experiment with the combination of guitar, pickups, effects and amplifier to get the required sound […]
Update: Remote controlling the True Bypass here.
Update: SMD version here.
Update: True Bypass Relay with muting here.
Update: True Bypass kits are available to buy in the shop here.
Update: True Bypass bare PCB’s now available for […]
I wanted an analogue chorus-pedal for my modular stomp-box and after acquiring a few MN3007’s from Hong Kong, I decided to build the Hollis Zombie Chorus as a starter-for-ten – which I did – and I was a bit disappointed with the result. It may be that the PCB design was sub-optimal […]
Update: Fully built and tested Altoids Piezo Preamps are available for sale in the shop here.
I’ve been taking my Altoids piezo DI box to open mic nights and have had some interest and feedback. People seem to like the concept but are less impressed with the […]
There is an update to this article here.
As I mentioned in my post on the vagaries of phantom power, I have been looking at designs for a compact self-contained box to connect an upright bass to the PA. The bass pick-up […]
One of the first stomp boxes I made (and arguably my favourite so far) is the Hollis Flatline Opto Compressor.
Here is John’s original schematic amended to show the topology a little more clearly:
The first stage of the TL072 dual op-amp is configured as a non-inverting amplifier.
Now, excluding […]