Fox Vintage Amp reverb units project

[Ken Fox]

Work in progress for 12 more units. First built these in 2010. Work in progress. Weeks one was cabinet building. Week two was Tolex Week three was making the circuit boards. Workin now to complete in about two more weeks

Reverb unit

These are based on the reverb circuit of the old Premier 90. I have made many improvements to the original circuit. This is just the best sounding reverb units I have ever heard. Much more like hall reverb, as it used a re-circulating reverb signal. Unlike the Fender 6G15 reverb circuit it feeds part of the reverb output back to the tank input for very natural decay.

Our circuit boards and cabinets are all hand made here in the shop! I also use original style cloth covered, push back wire.

Tubes are 12AY7 and a 12AT7 (ECC81) to drive the reverb transformer and tank input.

Power supplies are both full wave bridge rectified and filtered. Unlike the original Premier I use a choke on the power supply and more plate voltage to get cleaner headroom thru the unit.
The Premier was prone to distort when driven hard. We solved that by using a larger power transformer.


The reverb tank is an Accutronics, 3 spring, long decay.

I use an 18" IEC male pigtail, allowing disconnection of the the supplied IEC power cord.
That way you only have about 12" of power cord to stuff back in to the cabinet for travel.

This also acts as a tube buffer for your instrument, no need to run a buffer other than the reverb unit if desired. You can sit is beside you and have full reverb control at your fingertips as well as not needing a Matchbox or other buffer. Also features a variable input impedance control for 27K to just above 1 meg input impedance.

[Ken Fox]

Pictures

[Ken Fox]

Please excuse pix orientation. Hard to get them right from an iPhone

[Ken Fox]

This is a video with audio I made many years ago with one of my reverb units


https://youtu.be/DS25fMFgDeA?si=R1iiXnjlDMrwawfR

[Ken Fox]

https://youtu.be/4AKP_-7fhzY?si=O43--YDOFXc8ifZq

With a 1970 ES335. Lots of cool vintage amps I repaired and/or restored