Marchand Electronics manufactures and sells hand built and custom designed audio equipment. Phil Marchand produces active, passive, solid state and tube crossovers, power amps for audio or laboratory usage, tube and solid state pre-amps, bass eq, discrete op amps, and many more items.
It’s worth noting he has three free
software tools for the audio enthusiast. The coolest is simple component calculator for capacitor and resistor values for a variety of crossover models with crossover frequency and slope variables. I know this can probably be accomplished easily in excel these days but I’m personally a fan of dedicated tools that do one thing well.
Andrea Ciuffoli over at audiodesignguide has a great DIY post on a tube driven phono-preamp with a near perfect RIAA curve. What makes this design especially nice is its simplicity (only 13 components per channel).
An great looking DIY pre-amp for sale via DIY Audio in this post.
Pass B1 Buffer Preamp sale. – diyAudio.
I love the simplicity and classic styling of this DIY vacuum-tube, RIAA EQ curve, phono pre-amp. Bruce Heran via the DIY Audio Projects forums offers up exceptional build notes, pictures, and schematics of the build here. Admittedly I don’t know a thing about valve pre-amps and amps so I can only really comment on how much I like how it looks.
DIY Audio Projects – Hi-Fi Blog for DIY Audiophiles: Groovewatt Tube RIAA Phono Preamp.