This is a blank (unassembled) PC board to build a high voltage linear voltage regulator.  It is a floating "Maida" type regulator, using an LM317 and a high voltage N-channel power MOSFET.  This is typically used for tube audio circuits, to create a regulated B+ or screen voltage supply from a higher B+ supply voltage.
For full details on the design, including  the schematic and other information refer to my web site.  eBay will not allow me to post the link here any longer, so you will need to do a web search.
This auction is for is a single PCB only, no parts or anything else is included.   The heatsink shown is also not included - it is available separately
from my eBay store, or from Landfall Systems.   Photo of completed unit is for reference only!  
Will ship anywhere.  Flat rate shipping is shown.  Payment by PayPal only.
LIABILITY DISCLAIMER
A person who constructs or works on electronic equipment may be exposed to hazards, including physical injury, the risk of electric shock or electrocution, and exposure to hazardous substances such as lead, mercury, and other inorganic or organic compounds.  These hazards can result in health problems, injury, or death.  Only qualified persons who understand and are willing to bear these risks themselves should attempt the construction of electronic equipment.  By purchasing this item, the buyer acknowledges these risks.
Vacuum tubes operate at high temperatures, may contain toxic substances, and may have exposed parts that carry hazardous voltages.  There is a risk of electric shock, electrocution, burns, or fires that is inherent in the construction and use of vacuum tube equipment.  By purchasing this item, the buyer acknowledges these risks.
IN NO EVENT SHALL THE SELLER BE LIABLE FOR ANY SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES OF ANY NATURE including, but not limited to, property damage, personal injury, death or legal expenses. Buyer's recovery from Seller for any claim shall not exceed the purchase price paid by Buyer for the goods, irrespective of the nature of the claim, whether in warrant, contract or otherwise. By purchasing this item, BUYER AGREES TO INDEMNIFY, DEFEND AND HOLD SELLER HARMLESS FROM ANY CLAIMS BROUGHT BY ANY PARTY REGARDING ITEMS SUPPLIED BY SELLER AND INCORPORATED INTO THE BUYER'S PRODUCT.
If you do not agree to this disclaimer, DO NOT BUY THIS ITEM.