1966 Harmony H415 Amplifier – Vintage 2x12 Tube Workhorse

This 1966 Harmony H415 amplifier is exceptionally clean. We shot this beauty in natural sunlight to show off details (pardon green reflections). It has developed cult status for good reason. A formidable recording/session amp for sure. It excels at ripping mids, not too bright, zero mud and can get damn edgy when pushed. The tremolo provides adequate results. 

Manufactured by Sound Projects Company – Lectrolab, this amp features true point-to-point soldering and uses all high end components. When we got this amp, it had never been opened. Not a single solder point ever touched. We installed a 3-prong grounded cable and fresh power resistors. These upgrades greatly improve the noise floor. All the tubes are factory stock with “Harmony’ screenprint still visible on a few. Tube layout is 2x 6BQ5 power tubes, 5YGT rectifier, 2x 12AX7 preamp tubes and a 6AU6 driving the tremolo. Stand-by switch is a bonus here. It sports two instrument inputs on channel 1 with volume and tone controls and two inputs on channel 2 with volume and tone. One of which is instrument input and one a microphone input. Unlike the instrument inputs which use resisters to pad voltage, the “MIC” input is wide-open, making full use of the 12AX7’s. Pro Tip on this in a bit. You also get two pristine Jenson C12R 12” speakers and a pine wood cabinet. The removable back panel still has the glued-on schematic and tube layout diagram. The baffle board is particleboard and if looking at the back, the bottom right corner exhibits some wear. We installed a screw with a washer to make sure it holds tight. Front chromed plate with Harmony screenprint exhibits two minor blemishes. Speaker cloth has one tiny hole and minor blemish right below it. Overall, if one wants to make this look nearly brand new, it is achievable.

This amplifier is a beast, guaranteed. The hype is on point. Using a 1960 Harmony Meteor for reference, plugged into channel one provides clean bell-like behavior. At full whack it exhibits serious overdriven grunt. Plug into the “MIC” channel on full whack… a gorgeous wash of brown overdrive.

Pro Tip Note: This amplifier, unlike a lot of big hitter brand amplifiers, allows jumping. Not only that, phase stays intact when doing so. Plug your guitar into Channel 1 first input. Use a patch cable and jump from Channel 1 second input to Channel 2 ‘MIC” input. This gives you full control of both volume and tone controls on Channel 1 and Channel 2. The result of doing this allows for fine tuning the mix of your tone. Another result... it causes this amp to explode into perfect overdriven mayhem with zero breakup!

SPL at 6’ is 112 dB, more than needed for a typical session. This is simply one of those amps that can handle everything it is built to do. We consider this model to be the perfect specimen of form + function. You will not be disappointed!

As a special bonus, it comes with a custom cover. Tremolo footswitch is not included but a standard on/off switch will do.

As with any 60-year-old Vintage Tube amplifier, if you truly want this Harmony H415 to knock the shit out of any small 2x12" combo on the block, a capacitor refresh is key.

Middle back panel will be removed for shipping. All tubes will be removed for shipping. Please follow EXACT tube placement as indicated on panel diagram. Not following these exact instructions can cause serious damage to this amplifier. We are not responsible for post-sale accidents of any kind. 

Beautifying not implemented except dusting for photos using a microfiber cloth.

2026 SLT Vintage