EZ190 Assembly Guide
Capacitors This picture shows the different types of capacitors used and how they are symbolized and mounted on the PCB. Don t mess this up or bad things will happen!!! Electrolytic Tantalum Ceramic Axial 681 16 681 or Radial 470uF 6.V 470uF 6.V Polystyrene 681 orientation doesnt matter negative symbol on this side positive symbol on this side positive symbol on this side (values are read as following: 68pF=680 680pF=681 6800pF=68, etc.) Be careful with applying too much heat to polystyrene caps! Use a Soldering Heat Sink Clip Tool (Radioshack part #76-1567) on the wire lead between the solder joint and capacitor body when soldering to prevent damage. 470u/6.v u/16v 680p Electrolytic Tantalum Ceramic or Polystyrene
Transistors These are the different types of transistors used and how they are symbolized and mounted on the PCB. BC184C line up the D shaped body of the BC184C with the D on the PCB You may also want to use a Heat Sink Clip Tool while soldering these. N055 6- Screw N055 Heatsink Spacer PCB 6- Nut Screw N055 to the PCB before soldering to avoid putting strain on the solder pads. The Spacer can be made by cutting a /8 6- aluminum standoff in half. Digikey Part # 09K-ND. Standoff must be metal (conductive). The N055 can only be mounted one way. If the holes don't line up, flip 180 degrees.
Transformers There are two (mic input, line output) transformers; here s how to wire them to the EZ190 PCB. 10468 (mic input - Carnhill VTB9045) 7 XLR PIN1 XLR PIN XLR PIN 6 5 4 7 8 9 10 11 cable shield (10468) SHLD/10 You ll want to use shielded wire from the PCB to the transformer, and the transformer to the XLR connector. I use shielded mic cable for this (Canare L-BAT) and run the PCB-->Pin 10 and Pin 6-->XLR Pin 1 through the drain wire (shield). Also, note that drawing EH100 calls for a 180pF capacitor between pin 7 and 10 on the transformer; this capacitor is on the EZ190 PCB. :-) LO1166 (line output - Carnhill VTB9049) XLR PIN 6 8 10 4 (LO1166) 1 XLR PIN 5 7 1 cable shield SHLD XLR PIN1 use for cable shield only; leave disconnected otherwise Please note the.01uf cap and 1K5 resistor connected between Pin 8 and 5
Rotary Switch The rotary switch is a Grayhill 71BDF0-0-1-AJN Here are some hints: insert stop pin here (1 o clock) On the EZ190 V.0 boards the 71BDF0-0-1-AJN should drop right in, but you may have to push a few of the pins around with a small screwdriver in order for them to line up with the holes. I ve had to do this with nearly all the switches. Not to worry; they ve all gone in every time. :-) Use some fine.015 solder with a fresh (sharp) soldering tip. These pins are only.075 apart and it s easy to get a solder bridge between pins. Now s not the time to have shaky hands. Also, some of the pins on the middle row don t have solder pads; they are unused switch positions. Don t worry about adding solder to these pins. I recommend inserting one stop pin at the 1o clock position. This will give you a stop between 75dB gain and 0dB gain. You can use the little sticker to cover the stop pin to prevent it from falling out.
Resistors There s not much to know about the resistors used for this project other than perhaps their notation. A 51000 Ohm resistor will be symbolized as 51K, a 5100 Ohm will read 5K1 and a 510 Ohm resistor will read as 510R. This to avoid confusion or perhaps add more confusion; whichever you prefer. :-) 51000 Ohm Resistor 5100 Ohm Resistor 510 Ohm Resistor 51K 5K1 510R BIAS After you ve hooked everything up you ll need to set the bias of the driver stage. Do this by setting the gain switch to full gain (75dB) and then running a 1K sine wave into the mic input until clipping. (It s ok if you actually hear the mic pre at this point) Look at the signal with an oscilloscope. More than likely the waveform is only clipping on one side. Adjust the trimpot until clipping is equal on both sides of the waveform. trimpot 5K LOG unequal clipping equal clipping
QUALTEK 761-18/00.6 X 1.06 Panel Cutout AMVECO TE6085-ND Shown wired for use in countries with 10V AC utility power. JLM ACDC Power Supply Be sure to properly heatsink the two LM17 s. Use either the PSU case or a dedicated heatsink such as Digikey part# HS76-ND PSU Case 4-pin power cable shield and EZ190 rack case 48 4 4V 48V 0V JLM ACDC T D connect right pad to center All audio 0V should star from this 0V point. Do not connect 0V to case. If your grounding is correct you should measure 10ohm between rack case and 0V.
Phantom Power (48V) Here s how you connect phantom power, the phantom power switch and indicator LED. You ll want to pay close attention to the values of the 6K81 resistors. It is preferable to manually pick two resistors that are closest to each other in resistance; use an Ohm Meter to verify. Input XLR connector as viewed from the inside of the case K9 LED 1 6K81 6K81 Switch use 1/8 Heatshrink around each resistor 1/4 Heatshrink 48V 4V 0V 4 1 to 10468 Power 4 pin XLR connector as viewed from the inside of the case
Miscellaneous Building Notes Input XLR connector (to 10468) as viewed from the inside of the case Output XLR connector (from Lo1166) as viewed from the inside of the case Power 4 pin XLR connector as viewed from the inside of the case 10468 - pin 6/GND 1 10468 - pin 5 10468 - pin Lo1166 - pin 5 Lo1166 - pin 8 1 Leave disconnected 48V 4V 0V 4 1 disconnected Also connect PSU chassis to rack case containing the EZ190s. Preferably, use conductor, shielded 18 gauge and use the shield to connect both metal cases together 19 Rack (U) Case Fabrication Front Panel Back Panel 1.0 /8 x 15/16 Greenlee x5 - predrill with /8.75 1/4 x4 1.75 6.5.5 6 4.5.5 4
PIN MIC INPUT PIN PIN 1 R96 6K8 48V 4 5 T1 10468 6 7 10 R97 6K8 K9 C1 180p R8 15K S BA18 / NV U T V P N BA18 / AV U S T V P N J A K L M B F R10 91 R8 18K R44 1K5 70 60 50 R0 K9 R1 K R K7 R11 K7 R1 18K R9 10 R0 0 R99 5K LOG C4 C5 470 100 5V 5V R51 70 / 1W 40 R14 1K R K R15 K9 0 R4 K R16 1K8 R5 K9 R17 1K 0 R6 4K R18 510 SENSITIVITY SWITCH - GRAYHILL 71BDF0-0-1-AJN EZ190 SCHEMATIC AND WIRING DIAGRAM 5 6 1 7 8 4 T LO1166 R56 1 / 1W C7 C8 470 5V 470 5V R64 1K5 C9.01u PIN BALANCED OUTPUT PIN LEAVE DISCONNECTED PIN 1 B 4V B- 0V R98 10 / 1W Case Metal
BA18AM M B F J A J K L C1 10u/5V TANT R1 K C 4700p TR1 BC 184C C5 0p R5 K TR BC184C C 0p R 68K C4 80u/5 C6 80u/5 C7 80u /5 LO1166 1K5.01u TR N055 R6 18K RV1 4K7 R7 47 R8 K R4 1K R 56K NOTE: BA18 / AV CONSISTS OF BA18AM BA18NV C8 10u/5V TANT N U V R9 10K R10 68K C10 1500p C1 15u/4 TR4 BC184C C11 680p R11 K R1 47K C1 u/5 R1 5K1 TR5 BC184C TANT C14 u/16v R14 470 R17 K R15 1K5 R16 10K R18 90 TR6 BC184C C15 u/16v TANT C16 1000p R0 51K C17 400u/4 R19 1K8 C9 100p N P S T V BA18NV