We stress out about every part of our product so you don't have to. Take the cables: The wire insulation is irradiated PVC, which is more...

A few users have mentioned that the connection markings on the new boards look like there are two "+" connections. If you look close...

At the heart of the new preamps is a new filter circuit with ultra stable performance, higher resonant boost, and reduced noise. They are...

I've been head down for three months working furiously to redesign the Underhill Preamp line. The website will be updated shortly. Key...

This is the PD preamp with dual FV Variable Q filters. Turner multicoil pickups. https://www.facebook.com/mark.manley.188/videos/15493268...

I am working on re-packaging the modules into an architecture similar to a pedal board. Some possible benefits are: Swappable buffers,...

These can be used for setting the bass and treble frequencies internally with an ET5 Equalizer. Boost/cut is then handled with single...

The miniature cables used on Underhill preamps and filters are quite robust, and can carry a lot of current (Apple uses them for the...

These have new tunings and use less power... Check them out.

I'm thinking about making a little trimmer board that can be plugged into the bass and treble frequency connectors on the ET5 3 Band EQ....

We are moving this weekend, back to Mount Vernon, WA. With all of the mess I have run out of some modules, and won't be fully...

A tasty preamp demo from Manley is up on YouTube. It's the PD Preamp with FV Variable Q filters and an FT treble boost plugged in. It...

I've been working furiously to re-design the prototype Grinder bridge for manufacturing. The design is ready, and new tools and materials...

This should make it easier for new customers to figure out what they need to order...

The new Preamp Guide is the place to start when deciding how to put together your preamp. When you find a configuration that looks right...

They have arrived, and are getting into the test queue. If they meet my requirements, expect to see them around mid-April. Once they are...

Here's a cool trick I thought of in the middle of the night. You can use an S3 Switch with an FS5 filter to set up a Bypass/Q1/Q2 toggle....

Manuals for the FS5, FV4, and FT4 are complete. PS4, PD4, and FE4 manuals are coming soon... See them on the support page.

With many onboard preamps, the pots are soldered onto the preamp circuit boards. If you break a pot or wear it out, you have to return...

They are fully tested and tuned, and up for sale on the web site. I am frantically working on user manuals that should be in the support...