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Ramsey Electronics Model No. R2XL1
Have you ever found yourself with two RCA outputs on your
audio equipment and you somehow have to connect them to
XLR inputs. While wiring RCA levels directly to XLR can work,
the levels will be way too low! So what do you do?
Here is the answer to your conversion dilemma. The R2XL1 not
only converts your connection types from RCA to XLR, it also
gives you the added advantage of independent channel gain
control for the proper levels!
• Pow
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RAMSEY TRANSMITTER KITS • FM100B Professional FM Stereo Transmitter • FM25B Synthesized Stereo FM Transmitter • MR6 Model Rocket Tracking Transmitter • TV6 Television Transmitter RAMSEY RECEIVER KITS • FR1 FM Broadcast Receiver • AR1 Aircraft Band Receiver • SR2 Shortwave Receiver • SC1 Shortwave Converter RAMSEY HOBBY KITS • SG7 Personal Speed Radar • SS70A Speech Scrambler • BS1 “Bullshooter
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Ramsey Publication No. MR2XL1 Price $5.00 KIT ASSEMBLY AND INSTRUCTION MANUAL FOR R2XL1 RCA TO XLR LEVEL CONVERTER KIT TABLE OF CONTENTS Introduction .......................................... 4 Circuit Description ................................. 4 Parts List ............................................... 7 Schematic Diagram .............................. 8 Parts Layout Diagram ........................... 9 Learn as You Build ............................. 10 Assembly ........
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INTRODUCTION Welcome to another quality kit brought to you by Ramsey Electronics, Inc. This kit was designed to allow you to connect consumer audio devices to pro- fessional equipment with as little hassle as possible. You would think that a product like this was readily available, but it isn’t. Now you can easily go be- tween a standard CD player and a studio style mixer, or even run a profes- sional stereo transmitter directly from your computer! It’s true that with the correct wiring that
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The next component in line is R4. This 1K resistor in combination with R3 and R5 sets the gain of the first inverting opamp stage (U1:C). An inverting opamp will take the signal presented on its input and flip the polarity of the sig- nal on its output giving you the inverse value of the original. In our case, the resulting output signal from the opamp (pin 8) will be opposite in polarity to that of the original input signal on the left hand side of R4. The amplitude of the signal will als
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determine that the total gain of the circuit is 20.2 by multiplying the series gain values together (10.1 x 2). This gives us plenty of control to get our low level RCA signals up to the higher XLR requirements. This may be more than you ever wanted to know about a preamplifier de- sign, but we aren’t done yet! The output of the two opamps in the last stage are sent through another set of coupling capacitors that removes any DC com- ponent we may have accidentally added when we amplified the
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RAMSEY R2XL1 PARTS LIST Semiconductors 6 1N4002 Rectifier Diodes (D1, 2, 3, 4, 5, 6) 1 78L12 +12V Voltage Regulator (VR1) 1 79L12 –12V Voltage Regulator (VR2) 2 LF347N Quad FET opamps (U1, 2) Resistors 2 10K ohm potentiometers (R5, 11) 6 1K ohm resistors (brown-black-red) (R1, 2, 4, 7, 8, 10) 2 10K ohm resistors (brown-black-orange) (R13, 14) 2 100 ohm resistors (brown-black-brown) (R3, 9) 2 560 ohm resistors (green-blue-brown) (R6, 12) Capacitors
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R2XL1 • 8
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R2XL1 PARTS LAYOUT DIAGRAM R2XL1 • 9
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RAMSEY “LEARN-AS-YOU-BUILD” ASSEMBLY STRATEGY Be sure to read through all of the steps and check the boxes as you go along to be sure you don't miss any. Although you may be in a hurry to see results, before you switch on the power check all wiring and capacitors for proper orientation. Also check the board for any possible solder shorts and/or cold solder joints. All of these mistakes could have detrimental effects on your kit, not to mention your ego! Kit building tips: Use a g
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We sincerely hope you put this kit together by carefully following the direc- tions. This project will not work as well as you wished if you just slap it together without following good assembly techniques and all of the instructions. No matter how clear we may think our manual is, if you have any questions give us a call at the factory instead of jumping to conclusions. We will be happy to help you with any problems. Keep in mind that we want to mount all the parts AS LOW AS POSSIBLE to t
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R2XL1 ASSEMBLY We will start with the lowest profile components first and then work our way up to the largest. We do this to make assembly much easier since fitting a short component between two big ones can be a real pain. 1. Install D1, one of the 1N4002 diodes (black body with white stripe marked 1N4002). Note that diodes can only conduct in one direction so part orientation is critical! The diode will have a white stripe indicating the cathode end while the parts layout diagram shows
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14. Install R1, a 1K ohm resistor (brown-black-red). 15. Install R2, a 1K ohm resistor (brown-black-red). 16. Install R3, a 100 ohm resistor (brown-black-brown). 17. Install R4, a 1K ohm resistor (brown-black-red). 18. Install U1, the other LF347 quad opamp. Again make sure you orient it correctly! It is in the same orientation as the last part. Dimple indicates the pin 1 end. Check to make sure all pins are through, then solder all 14 pins! 19. Install C7, a 10 uF electrolytic capa
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30. Install VR2, the 79L12 negative –12V regulator. Again make sure and install it with the orientation shown on the diagram. 31. Now it is time to install the larger components. We will begin with the jacks. Install J2, one of the PC mounted XLR connectors. You must be careful when installing these parts that all the leads go in the respective holes. For example there is a little pin in the middle of the bottom which is used to ground the cable case. This can easily get bent over. Make
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At this point it is time to go back through and check your assembly methods for: • Diode orientation. Make sure the cathode and (the line) is in the same ori- entation as shown on the assembly diagram. • Electrolytic capacitor orientation. Make sure the negative side of the ca- pacitors are not in the positively marked holes! • IC orientation. Let’s hope you did this right, they are hard to move once soldered! • Check for cold solder joints. Make sure all connections look nice and c
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PROFESSIONAL AUDIO WIRING You would think it would be easy to connect professional audio equipment together, but unfortunately it’s not. There can be all sorts of issues that come up; usually it is AC line hum in your equipment you have to deal with. This is normally caused by ground loops in the equipment. This effect can be caused by only a very little current and can wind up having a tremendous impact on your sound and sanity. We will try to clear some issues up for you by showing you
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If neither of these methods works and you have a source of RF nearby like a transmitter, it may be RF causing interference. This is a more difficult problem to fix, but not impossible. The first thing to do is move equipment away from the RF source. The next is to put the R2XL1 inside of a metal case. The last method is to use RF chokes on your audio cables (usually snap-on ferrite beads of various sizes). You should be able to find these at most electronic supply stores. ASSEMBLY INSTR
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TROUBLESHOOTING PROBLEM: I have no audio gain, in fact it only attenuates! SOLUTION: You will need a voltmeter to check your power. Look at pin 4 of U1 for +12 volts, and pin 11 for –12 volts. It may not be exactly that voltage, but +- 0.5 volts if fine. Without power applied the R2XL1 will pass through au- dio, but not much. PROBLEM: Sound is very badly distorted. SOLUTION: You may be using a high level source into the R2XL1 causing it to overload. Using this to convert from speaker
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The Ramsey Kit Warranty Please read carefully BEFORE calling or writing in about your kit. Most problems can be solved without contacting the factory. Notice that this is not a "fine print" warranty. We want you to understand your rights and ours too! All Ramsey kits will work if assembled properly. The very fact that your kit includes this new manual is your assurance that a team of knowledgeable people have field-tested several "copies" of this kit straight from the Ramsey Inventory. If
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R2XL1 RCA TO XLR LEVEL CONVERTER KIT Quick Reference Page Guide Introduction ..........................................4 Circuit Description .................................4 Parts List ...............................................7 Schematic Diagram ..............................8 Parts Layout Diagram ...........................9 Assembly ............................................ 12 Using the R2XL1 .................................15 Professional Audio Wiring ...................
