Category: WIP

Retro Sonic Vintage Vibes

The MN3002 BBD in a Retro Sonic Vintage Vibes started making noise. All working conditions are in order so the guess is the BBD chip is not as it should.

The BBD is a MN3002.

Since the MN3002 BBD is hard to find, an extra adjustable low pass filter stage is installed. Allowing the user to set the cutoff frequency. Accessible with the bottom lid of next to the input jack.

A Boss DS-1 in need of service.

It got fed 18V instead of the usual 9V, bypass is working fine but quiet when effect is engaged.

A voltage reading of the op-amp indicated it was fried, +9V on all the pins but the GND connection. Here replaced with a JRC4558, also take a look at the bigger 100uF capacitor to the left.

Here it is desoldered. It did not survive the 18V it was feed. Replaced with a new one and the circuit is working again.

A Supa Tonebender in near mint condition, giving a very weak output signal.

Guts reveals what appears as all original.

Signal generator and a scopemeter isolated the problem to the bypass switch.

Not the typicall bypass switch construction. Note the date stamp 10 MAY 1976.

However a construction that is easy to service.

After a cleanupof the switch and the Radiohm potentiometers, the pedal is back in working condition.

My favorite chorus pedal the Boss CE-2 on the workbench for an ACA to PSA mod and a recap.

Solder side of the circuit board.

Component side.

For the ACA to PSA mod we want to remove D5 and R53 and jumper them.

Component side after the recap and ACA to PSA mod.

Trying a new circuit, a low gain overdrive with an interesting tone control.

Circuit board for the Lady Luck tube vibrato pedal.

A customer sent a mail with a picture of his pedal board.

There’s four zeta sound pedals on the board. At the top left Eko, a custom orderd analog delay pedal, bottom left Magic Drive another custom order, bottom middle the Turtle Clipper and on the bottom right a zeta sound clone if the R.M Octavia.