Sequential Prophet 5 Synthesizer Replacement Power Supply

Description: Item Description: This auction is for one replacement power supply for the Sequential Circuits Prophet 5 Analog Synthesizer. This power supply is assembled and tested. Pictures show the new supply board and the the older version of the supply board installed in a Prophet 5 (not included). This is a new version of the supply that does not have a linear post regulator for the +5V. The +5V output has a comparator/MOSFET based over voltage cutoff. Only the +15V and -15V regulators are mounted on the back wall/heatsink. This supply is a new replacement that was designed to address the over heating issues that can occur with the original power supply when options are added to the synthesizer. It will also run cooler in a stock synthesizer. The rectifier diodes, filter capacitors, and the +5V regulator have higher ratings than the original parts. The silkscreen on the board shows the -5V and +12V for the REV 3.0 supply. For the Rev 3.1, those pads are not connected on the board. For the Rev 3.2 and later, the -5V becomes -22V and the +12V becomes +22V. Both have 5 ohm (nominal) resistors in line on the board. There are three pictures showing the Mini Fit pinout for all three versions. 1. Four 1/8" (0.125") mounting holes will be needed in the bottom of the chassis as this supply is not attached by clamping the filter capacitors. The mounting hardware is included. The standoffs are swaged/soldered to the board. The board can be used as a template for marking the hole positions by using a nail that fits through the standoff to mark the centers of the holes. Dimensions for the hole locations are also in the silkscreen on the back side of the board. The 5th standoff in the middle of the board is optional. 2. The two TO-220 packaged regulators for the +15V and -15V are mounted using the same holes as the originals. New sil pads are included. The new regulators do not need the plastic shoulder washer, the tabs are not electrically conductive but are thermally conductive. Re-use the original screws. 3. The +5V supply now uses a switching regulator that can be adjusted using a on board pot to provide up to +6V to the main board. It should be adjusted to match the voltage output (typically 5.8V) from the original power supply, assuming it still functions. There is no noticeable noise in the audio output due to the switching supply, the processor bus running around the main board is far noisier. The new +5V supply also has over-voltage protection unlike the original. The increase in voltage to about 5.8V for the original 5V supply was implemented by inserting a 1N4002 diode in the ground lead of the LM340T5 regulator. The original LM340T5 regulator had to dissipate over 13W. 4. All rectifier diodes are now 100V 3A rated. 5. The main filter capacitors are now rated at 35V or 50V depending on part availability. This provides an additional 10V or greater margin vs the original 25V parts. 6. The board can be configured with the -5V and +12V regulators for Rev 3.0 or for any of the later revisions. Let me know which revision you need prior to shipment. 7. The DC power connection pads are located in about the same locations as on the original board. The wires will need to be un-soldered from the original board and soldered to this board or crimped to pins inserted in a MOLEX Mini-Fit Jr Connector Housing (not included) if you want to make use of the on board connector. The eight pin MOLEX Mini-Fit Jr connector on the board has all of the required voltages. This can be used if you have the ability to crimp the output wires to the mating pins/housing (not included). If using the Mini Fit Jr connector you will need one MOLEX 39-01-2080 housing and eight female pins 39-00-0039 for each board. Pictures of the pinout (top view) showing the voltages for each revision are in the listing. 8. The three AC leads from the transformer are now connected to a screw terminal block. 9. Adjustments for the -15V and +15V are similar in range to the original power supply. Installation instructions will be provided, but the user must be capable of un-soldering and soldering wires, optionally crimping wires, drilling holes, and basic mechanical assembly. Be sure to measure the original voltages and label the original wires for voltage so there is no confusion when connecting them to the new power supply. Feel free to contact me through EBAY for additional information or questions. It may take 24 hours or so for a response, I usually do not get online until evening. PayPal Confirmed Address: PayPal address must be confirmed and must be the same as the shipping address. Returns: Returns are accepted for this item. Please notify me of any issue within 30 days of receipt of the item. Feedback: Feedback is important to me, please email or contact me with any concerns, issues or problems before leaving feedback and give me the opportunity to work things out if needed. I always leave positive feedback after receiving feedback from the buyer, that way I know the buyer is happy and the transaction is complete. Shipping : Shipping is direct to USA or international via the EBAY global shipping program.

Price: 150 USD

Location: New Hartford, Connecticut

End Time: 2023-09-26T19:48:56.000Z

Shipping Cost: N/A USD