Capturing Audio without Injury

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  • JLM World Power transformer kit, AC/DC (Ver. 2) 3 rail kit & Power Station (Ver. 2) 5 rail kit & 24v Simple Zener Reg Power Supply kit building info below     Kit Reviews here

  • JLM World Power kit is a fully fused & 120v/240VAC switchable 30VA PCB power transformer to dual low voltage AC out.
  • Kit can be ordered with 3 different transformers with either 2 x 9vac or 2 x 12vac or 2 x 15vac outputs.
  • This kit with either a AC/DC or Powerstation kit will give you a full power supply solution that will work anyway in the world.
  • The World Power PCB is 3.6" (91.5mm) wide x 2.5" (63.5mm) deep x 1.575" (40mm) high with 30VA transformer fitted.

  • JLM AC/DC Ver. 2 kit is a Linear based universal power supply with can generate 3 voltage rails from a single or dual 24 to 30vac.
  • It has one pump charge rail for 48vdc, 1 +/- Rails that can be set from +/-2v to 37v by a 25turn trim pot.
  • All regulators are on one edge for easy heatsink or case mounting.
  • Can supply 1amp per +/-V rail and 300mA +48vdc. 1amp for +/'-V rails can be boosted to 1.5amp with 4 extra 1N4007 diodes.
  • The AC/DC Ver. 1 & 2 PCB is 3.3"wide (83mm) x 1.7"deep (43mm) x 1.1" (28mm) high from top of tallest cap to lowest solder joint under the PCB.
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  • JLM Power Station Ver. 2 kit is a Linear based universal power supply with can generate 5 voltage rails from a single or dual 24 to 30vac. It has one pump charge rail for 48vdc, 2 +/- Rails that can be set from +/-2v to 37v by a 25turn trim pot.
  • All regulators are on one edge for easy heatsink or case mounting. 
  • Can supply 1amp total shared between  both +/-V rail and 300mA +48vdc. 1amp total for +/-V rails can be boosted to 2amp with 4 extra 1N4007 diodes.
  • The Power Station Ver. 1 & 2 PCB is 4.06" wide (103mm) x 1.7" deep (43mm) x 1.1" (28mm) high from top of tallest cap to lowest solder joint under the PCB.

  • JLM Simple 24v zener kit is a very simple Linear based universal power supply with can generate 24v from a single 30v to 48vdc rail.
  • It can do other output voltages by changing to different voltage zeners or if running from a regulated higher rail a resistor can be used in place of the zener.
  • Using on of the 48v 380mA SMPS prebuilt supplies and a simple zener kit is the easiest and cheapest way to power 2 x 1073 , 1290, 1272 neve modules.
  • Or 2 x V672 modules etc that need 24v to run and 48v rail for phantom power. Because there is no power transformer involved there is no hum problems due to coupling to the audio transformers.
  • Regulator is on one edge for easy heatsink or case mounting. 
  • Can supply 1amp
  • The simple zener PCB is 1.2" wide (103mm) x 1" deep (43mm) x 1.1" (28mm) high from top of tallest cap to lowest solder joint under the PCB.

 

  • ALL 120/240v mains wiring MUST be done by a Qualified Technician.
  • What Power Transformer secondary volts do I need?
  • The transformer secondary AC volts needed depends on the +/- dc regulated voltage rails wanted. If you want +/-34vdc regulated for 99v you will need 37v to 40v unregulated which would need one or two 26vac to 28vac transformer secondary windings. This might sound like a odd voltage value but in reality when you take the fully loaded voltage and add the regulation percentage specified by the transformer manufacture to get the no load voltage it all works out. So if the voltage output of a transformer is stated as 25vac at full load by adding the 10 to 20% regulation amount you will end up with 27.5vac to 30vac unloaded with is perfect. Also if you use one 25vac winding then the refresh rate to the large storage capacitors will be 50 or 60Hz depending on the country you are in. If you use two 25vac windings or a 50vac centre tapped winding the refresh rate will be 100Hz or 120Hz which will almost half the amount of ripple on the large storage caps. Also the dual 25vac has symmetrical ripple.
  • Step by step build for PowerStation Ver. 2 and AC/DC Ver. 2 kits
  • PowerStation PCB and kit of parts
  • All PowerStation Ver 2 & AC/DC Ver 2 PCB's have been bare board tested for shorts and breaks in tracks but it is always worth having a good look over the PCB for any damage before starting to assemble.

 
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  • 1.Install all resistors in there correct locations using chart to the left or better still by using a multimeter with no leads fitted and bending the legs of the resistor and putting them in the meter sockets to double check you have the right value before putting it into the PCB. Fit all resistors before soldering them as this can also help check that you haven't put a resistor in the wrong place.
  • 2.Install all diodes which all face in one direction. (Grey band lines up white white band on PCB)
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  • 3.Install 0.1uF bead cap which can go in either way around.
  • 4. Install the 5 x 5k trims pots with adjust screws closest to the large caps as shown.

 
  • 5. Install 10 x 10uF 63v caps all with there positive long leg to the left as shown.
  • 6. Install the 3 x LM317 positive regulators in the 3 left positions and the 2 x LM337 negative regulators in the 2 right positions. Now is a good time to use the mounted regs to mark up the 5 mounting holes in the heatsink or metal case side panel. You can also put the regulators legs in from under the  PCB if you want to bolt the regulators to the same surface as the PCB mounting holes
  • (AC/DC has 2 x LM317 to the left and 1 x LM337 to the right)
  • 7. Install 10 x 1000uF 50v caps all with there positive long leg to the top as shown.

 
  • 8. Slide terminal blocks that sit beside each other into each others tongue and groove joint and then write with a permanent black pen what each terminal is on the terminal block before installing them to the PCB. (eg 0v  +48  +24  +18v  -24v  -18v)
  • 9. The PowerStation PCB with terminal blocks fitted.

 
  • 10. You now need to jumper either T (Tripler) to the centre pad if you are using a 15vac to 18vac transformer or D (Doubler)  to the centre pad if you are using a 22vac to 28vac transformer to get the pump charge for the 48v rail to work.

 

 
  • 11. Check the underside of the PCB for any shorts between any solder pads. Also recheck all parts are in the right way around. You can now connect the 15vac to 28vac transformer to the left side AC connections.  Sit the power supply on a rubber mat and connect a volt meter to 0v and +48v DC outputs. Stand back and turn on. If there is no smoke and the meter reads about 27vdc to 33volts dc all is looking good. If you get higher than 48v on power up there is a short somewhere on the PCB. Use a small screw driver to adjust the 48v 25 turn trim pot until you have 48v. Turn off and move the volt meter to +V1 and turn on. Adjust for the voltage you need and repeat for all dc outputs.
  • (If any output voltage does not follow the trim pot up or down smoothly or seem stuck on full voltage do not just keep turning the trim pot as there is a fault and if you keep winding the pot down it will burn the 5k trim pot and 120R resistor)
  • (Trim pots come set to half way when new and no not need any adjustment before first power up)

 
  • 12. Once all voltages are set you are ready to bolt the power supply to the metal case or heatsink. Peal the white paper backing of the stick on insulators and stick then on to each regulators metal tab. Make sure there are no sharp edges around the holes drilled into the case or heatsink that will cut the silicon insulators. The grey silicon washers do not require thermal paste at all.
  • (We use the 3 or 5 reg bolts to hold the PCB in place to the back or side panel in our full mic pre kits but add 2 x 10mm hex threaded standoffs to the front edge of the PCB to stop the PCB from tilting. We do not bolt the standoffs to the bottom panel as this allows the top and bottom panel to be removed easily for servicing. A small piece of stick on foam on the top of the 1000uF caps pins the power supply between the top and bottom panel securely)
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  • 13. The 3 x 10mm bolt will go through the metal case or heatsink then through the insulator and regulator tab. Slide the white bush down the bolt so the thin tube part slide inside the regulator mounting hole. Fit lock washer and nut and do up firmly but do not over tighten. Check with a ohmmeter that the regulator metal tabs and heatsink or metal case are not shorted together.
  • 14. Turn on and test that the DC outputs are still adjusted ok before connecting up DC outputs and Case ground to right hand front bolt hole on the PowerStation or the Bolt hole above the smiley face on the AC/DC.
  • (If the 10ohm resistor burns up when power is turned on there is a short on one of the regulator tabs to the heatsink or metal case)

  Below shows correct Mains earthing and 0v connections which applies to AC/DC PCB and PowerStation PCB

 Below shows how to get +24vdc and +48vdc from just a 24vac plug pack to run Neve or old Telefunken gear which requires no negative rail. If using 2 x 22v to 2 x 25vac transformer no mod is needed and negative parts can be left off.

  Below shows shows colour code and wiring for Digikey Amveco Toroid series of transformers.

  Below shows shows colour code and wiring for RS single mains voltage Toroid series of transformers.

 Below shows shows colour code and wiring for RS 120v/240v dual mains voltage Toroid series of transformers.

Old Ver 1 AC/DC and Ver 1 PowerStation PCB's below are Linear based universal power supplies with can generate 3 or 5 voltage rails from a single or dual 24 to 30vac. It has one pump charge rail for 48vdc, 1 or 2 +/- Rails that can be set from 5v to 34v by a resistor or 25turn trim pot. All regulators are on one edge for easy heatsink or case mounting. 

  

Old JLML5RPSPCB below is a Linear based universal power supply with can generate 5 voltage rails from a single or dual 24 to 30vac. It has one pump charge rail for 48vdc, 2 +/- Rails that can be set from 5v to 34v by a resistor or 25turn trim pot. All regulators are on one edge for easy heatsink or case mounting. 

JLML5PSPCB is 4.3" (109mm) x 1.45" (37mm)