Hagerman Technology

10/30/2026

Well this is embarrassing. Turns out many of the power inductors used in recently built CORNET MM are overheating. Odd, since I've been using this exact part since the CORNET3 launch in 2014. My best forensic analysis indicates the manufacturer changed their core formula (powdered ferrite), or perhaps I just bought a bad batch? The current rating is more than enough, but it seems the Volt-second rating of the core is now lacking. Hence, core gets too hot over time.

If you have a CORNET MM built in 2025 or 2026 you could have this issue! The inductor sits on PCB near on/off switch. If it has this brown color, then it will likely fail soon. Best to send in your unit for warranty repair before it goes catastrophic. See my website for return address.

I've located a new inductor with a very low loss core that does the job with a much lower temperature rise. It's not a simple swap, as a few of the resistors in the oscillator circuit need to change as well.

All new CORNET MM starting this week (order 6384 and up) have the upgrade.

10/29/2026

https://www.youtube.com/watch?v=zNE2GMuAxB4

10/29/2026

https://www.youtube.com/watch?v=tepVPqXyyCM

Want to enhance the tone and feel of your amp modeler? Try throwing...

10/28/2026

Coming November 1st...

10/25/2026

https://joshuaheathscott.substack.com/p/the-art-of-making-a-guitar-pedal

FOUR CREATIVE STEPS I GAVE A ROOM OF PAINTERS, WRITERS AND POETS

10/14/2026

Got em! A lifetime supply of NOS TUBIFIER tubes and NOS pentodes for POWER BABY.

10/13/2026

https://www.youtube.com/watch?v=CtTuwJBRiD0

In September 1947, RCA registered a small glass tube with two ampli...

10/13/2026

Ok hive, I need help here. Made me a simplified tube line art drawing, a PNG file. I then converted its palette down to 2 colors and placed it into my TUBIFIER pedal artwork in Adobe AI, re-sized, etc. Looks fine. But I need to get it to fill as RDG_WHITE. I have the swatch already installed and all lettering prints white. But if I change tube to RDG_WHITE and save file, it does not stick. When I re-open file, color swatch is undefined. How do I get RDG_WHITE to stick?

10/11/2026

Two new projects in the works...

First up is BUGLE ZERO, an opamp-based transimpedance input phonostage. Basically, I replaced the first stage of a BUGLE with the PICCOLO ZERO stage, then inverted output stage, simplifying things as I went.

Got initial prototype dialed in already. I can't believe how good and quiet this thing sounds! And the bass, oh my goodness, most solid and defined I've created yet.

Second is the TUBIFIER PRO, a tube buffer designed to give you the same second harmonic distortion characteristic of a single-ended tube output stage. You know, those mega-buck 300B or similar amplifiers? Yeah, that sound. Place the TUBIFIER PRO ahead of your solid-state power amplifier to get the same tones at a fraction of the cost. Similar to the BARITONE, but with 10x the warmth. It is preset internally for unity gain and has a switch to select output as either direct (bypass) or tube, so you can switch on the fly. Probably best used for jazz or simple vocals.

Also perfect for studio use, where you can warm up each track separately!

10/08/2026

https://www.hagamps.com/products/tubifier-tube-buffer

TUBIFIER STEREO is an always-on vacuum tube buffer providing warmth and tonal enhancement. This pedal will give your solid-state or digital rig that vacuum tube feel, with compression and a fuller, thicker tone. Gain is preset at factory to unity. For more flexibility and a footswitch, check out my....