Hagerman Technology

Hagerman Technology Hagerman Technology LLC is a small company focused on the design and manufacture of audiophile-grade electronics and guitar amplification.

Make music, not noise!

A friend bought a used Carvin XB100, but thought something was off. So I checked it out. Amp was in great shape, but sur...
07/24/2026

A friend bought a used Carvin XB100, but thought something was off. So I checked it out. Amp was in great shape, but sure enough, bias switch was in wrong position (not set to EL34). That pushed it deep into class B. Easy fix.

Photo shows it running at 8 watts and 1% distortion. Everything seemed fine, but when treble was pushed amp would go unstable. This was into an 8 ohm resistive load. Maybe the speaker jack wasn't very tight? With presence set to zero and brightness off, it played well.

Checking inside I noticed feedback capacitor C55 was not installed. Intentional? So I put one in. Didn't really help much, as amp would still go unstable when pushed at high frequencies. Thinking about it now, I should have tried a capacitor 10x larger, which is exactly how I tamed the POWER BABY feedback loop...

New PCB mechanics to fit into updated 2, 3, and 4-knob enclosures. Of course, all hand-built using through-hole parts......
07/23/2026

New PCB mechanics to fit into updated 2, 3, and 4-knob enclosures. Of course, all hand-built using through-hole parts...

FUZZ
NEOKLON
GAMMA RADIATION

Final design, out for test...
07/14/2026

Final design, out for test...

Always trying to improve things, this time updating mechanics allowing for larger k***s on these two pedals. Everyone co...
07/08/2026

Always trying to improve things, this time updating mechanics allowing for larger k***s on these two pedals. Everyone complained about the tiny k***s! I get it. The designs were originally built as kits (akin to the NOTAKLON) and the knob-less pots came in handy to make things easier to assemble.

Anyhow, making it happen. New mechanics, new circuit boards, one more round of prototypes. With luck I can get these into production by Labor Day...

I am discontinuing my Germanium line pf pedals. Selling out remaining stock at (part) cost. Get yours now before they ru...
07/07/2026

I am discontinuing my Germanium line pf pedals. Selling out remaining stock at (part) cost. Get yours now before they run out!

Got an old VacuTrace in for repair. Something very bad happened here, as ten components fried! This plate output stage i...
06/23/2026

Got an old VacuTrace in for repair. Something very bad happened here, as ten components fried! This plate output stage is supposed to have short circuit protection, not exactly sure what happened. I no longer have my factory test station, so working on this is going to be difficult, as I have to fully button it back up to see if repairs were successul. Presently waiting for new output MOSFETs to come in, but luckily I had everything else in stock.

Working on a project that can work with multiple tubes, but they have different pinouts. So making this crude adapter. N...
06/23/2026

Working on a project that can work with multiple tubes, but they have different pinouts. So making this crude adapter. Not how I would do it in production - it's just prototyping. :)

Here we go! Sometimes you just have to listen to the universe, it tells you exactly where you need to go. Don't fight it...
06/19/2026

Here we go! Sometimes you just have to listen to the universe, it tells you exactly where you need to go. Don't fight it. 😉

The question was, how to make a nice overdrive pedal out of this microphonic tube? Regular footswitch made it sing like crazy. But wait a minute, what if there was no footswitch? I could do either a soft-switching type with relay and control circuits, or hey, why not just get rid of it altogether? Make this an always on pedal. Is that outside the box or what?

So let's jam it into a standard 1590B case, see what happens. Oops, no room for tone control. Gone! Now it is just DRIVE and LEVEL. Set and forget. The idea here is to add tube warmth and feel to your rig, nothing more. Ideally, this would be first in chain, always on, sort of like a tuner. I'm pretty sure I could sell this for $129.

Always try something new! Bought a few of these sub-miniature low power tubes originally made for battery powered hearin...
06/13/2026

Always try something new! Bought a few of these sub-miniature low power tubes originally made for battery powered hearing aids and radios. At 20mA heater current I figured these could be a game changer for pedals. Tube tone at low power?

So I got this prototype up and running, sounding good, but not really enough gain to be an overdrive for anything but humbuckers. Will try a transistor front-end for higher gain, let the tube do all the clipping.

Anyhow, maybe it's all for naught? People warned me about this! Every time I hit the footswitch the tubes would ring like a Banshee for about ten seconds. High pitched whine in the low kilohertz. Silicone glue did not help and possibly made it worse. How could these have possibly worked in hearing aids?

Stay tuned...

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Honolulu, HI
96822

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