UralTone Bias Tool Deluxe DIY build guide

UralTone Bias Tool Deluxe DIY build guide

UralTone Bias Tool Deluxe is easy to operate meter made for setting output tube bias correctly. It guides the setting the bias right by selecting the output tube type and style of the amplifier. On this article is shown the assembly of the diy version of the Bias Tool Deluxe.

UralTone BiasTool Deluxe - BOM

UralTone BiasTool Deluxe user manual

Check all the parts

Always check first that all parts are included in the delivery. If you find any problems please contact us by email or through the "contact us" form on the pages. Note that the components may look slightly different than in the photos. Also, note that the voltage specs of the parts may be higher than what is listed. Read all the notes at BOM (bill of material) carefully.

Building the Bias Tool Deluxe kit

Follow the order in which the images below are assembled. We try to keep component manufacturers and types the same, but sometimes we have to change the manufacturer or model of a part due to poor availability. So if a part is a slightly different color or higher voltage rating, all is good, each component has the required values marked on the side of the part.

Bias Tool Deluxe uses pre populated and pre programmed PCB and most of the components are already soldered to board. On kit version, display, switches and connectors are soldered by user as well of fitting the board to enclosure.

Bias Tool Deluxe prepopulated PCB. Note: the pictures are taken from the prototype series of the boards (Rev G). The build procedure is however same with later versions of the PCB.

Start by cutting 15 pins long pinheader with 1.27" pitch.

Solder the pinstripe to LCD by the shorter side of the pins.

Note: Do not mind if there's solder bridges between the pads. These are easy to remove with solder wick.

Set the display on its pads.

Solder first one pin on other end of the strip and check the LCD is aligned straight. When position is ok solder the opposite end and double check the orientation. It's still possible to realign the LCD by heating the solder on other end while turning the LCD.

When the LCD position is ok, solder rest of the pads. Same rule applies as on LCD pads, if there's shorts between pads, use solder wick to remove the excess solder.

Modify the stereojacks as in picture. This turn these as PCB versions.
Note: make sure not cutting the contact too short. Make also sure, the solder pin is not too wide and won't fit through the pad. If the connector is pressed in by force the contacts will move inwards and short circuit to ground. Check the connector with multi meter measuring resistance between ground and tip / ring.

Solder the connectors on PCB. For ground connection, solder short wires form solder lugs on the sides to board. Check both of the connectors ring / tip - ground resistance. If any of contacts gives zero ohms / short, check the pins aren't pushed in.

Continue by soldering the switches with led on the PCB. Red led button has red paint on anode terminal of the led pins. (Top / middle pin). You may test the leds with multimeter continuity / diode forward voltage setting. Usually this gives some voltage to power the leds with lim light.

Buttons needs to be aligned straight. Solder first one corner and adjust the position by heating the solder if needed.

Make sure the buttons are on straight angle both horizontally and vertically (picture above).

When all buttons are straight, solder all six pins od each button.

Solder the power switch. It's soldered to bottom side of the PCB.

Switch soldered to bottom side.

Guide the battery clip wires through the holes of the PCB and set the wire ends to pads.

Solder the battery clip wires and pull the excess loops of wire off. The electronics are done. Test the meter briefly, set on power and test all buttons. Leds are on during the power on. Remove the jack nuts if they're fitted to jacks.

Prepare the plastic enclosure. Depending the selected level of finish you may need to drill the holes for jacks and buttons. The kit is supplied with drilling template. Cut the template on vertical edges and shorten it on top and bottom.

Align the drilling template on top of the enclosure as on picture above.

Use sharp object to mark starts for drilling

The enclosure is soft ABS so it's really easy to mark it.

Drill first small guidance holes with 3mm drill. If the alignment goes off, you still can save the situation by filing the misaligned hole towards right position with round small file. Note: Panel will cover the button holes, so these doesn't need to be tip top.

Do the final holes, 9.5mm for buttons and 6mm for jacks. The enclosure is soft plastic so the drill bit may bite really quickly. Proceed with care.

Drill the button and jack holes by using the template. Cut the rear of the jack holes as in picture.

Set the PCB on tip half of the elcosure and mark the place for the hole of power switch.

Drill a 6mm hole. It' located on bottom half of the elcosure. Make sure the pcb sits properly on top half of the enclosure and confirm the buttons have enough of clearance to move freely. If needed, file, cut, drill or what best works to enlarge the hole.

Press in four self adhesive PCB mounts.

Press the PCB on top part of the enclosure and remove the protection sheets of the adhesives. Remove the battery cover from bottom half and pull the battery clip wire out. Make sure it's not kinked on outer seams of the case halves. Press the sides together. The adhesive on the PCB mounts are strong so aim carefully and success at once.

Press firmly so the PCB adhesives sticks to bottom half

The meter top is possible to lift up. If all is ok, remove the protective film on LCD, set the top part back and screw four screws on bottom side.

Fasten the front panel by dual sided tape, super glue or use two small screws. Clip on the battery. Meter is ready for action!