freestompboxes.org

HNY wrote:problems with your eyes?

um... im at work and there are guys here who are way better at than I am... so...yeah....just throwing it out there bud


Here is some more information


SP-1 Spectrum
the SP-1 is a parametric equalizer with one frequency band only. The spectrum knob sets the frequency range in the interval 500Hz to 5kHz. The balance knob sets the peak within the range. The SP-1 was more popular with keyboard players than with guitar players. Today it is one of the most sought after collectors items and a mint condition SP-1 doesn't come cheap.

Version Differences
The first models featured the clear plastic switch and immediate LED as well as the silver thumb screw. The switch was later changed to black, the LED was made permanent and the black thumb screw was the last change made before it was discontinued 1981.

Specifications

Controls: Balance, Spectrum
Connectors: Input, Output, AC Adaptor
Current Draw: 23mA
Weight: 410g (15 oz.)
Input Impedance: 1 Mohm
Output Impedance: 1 kohm
Residual Noise Level: less than -98dBm (IHF-A)
Recommended Load Impedance: More than 10kOhm
Recommended AC Adaptor: ACA Series
Labels

Black - Made In Japan
The SP-1 was sold from November 1977 to November 1981.

Thanks! You can get the first page of your manual here http://www.godiksennet.com/images/sch/SP1.JPG...

I recently acquired a SP-1 myself and its guts looks slightly different, so here are some pics I took. Weird switch in there too by the way.

Here's a PCB and a DIY schematic (true bypass w/ FET switching removed):
https://aionelectronics.com/project/chr ... equalizer/

The dual 10kA/10kC pot requires a little effort to put together, but there are instructions in the documentation for how to make one out of a dual 10kA pot and a "donor" single pot.

Not necessarily trying to hawk my stuff here, it's just bound to be useful info for someone making their own.

Two page services notes

I made for myself an approximate PCB-layout in order to retracing the schematic and to get a better overview of the componet values.

I forgot a conductor track, here the corrected layout: SprintLayout6 file: