Ramsey Electronics Stereo Amplifier SHA1 User Guide

STEREO  
HEADPHONE  
AMPLIFIER  
Ramsey Electronics Model No.  
SHA1  
Need a way to listen to line level audio from a tape deck or CD  
player? Need a way of boosting up any low level signal to  
earphone level for top quality stereo listening? This kit has CD  
quality audio capabilities with super low distortion, a wide  
frequency spectrum, and a superior signal to noise ratio!  
Uses the LM386 audio amplifier ICs.  
Better than 100dB Signal to noise ratio.  
10Hz to 100kHz power spectrum (+-3dB)  
Almost 1W output per channel when run on 9V battery  
Accepts mike or line level  
Handy phono type input, and 1/4” stereo headphone output  
Operates on 9 to 15 volts DC  
Independent left and right volume controls  
Super easy hook-up with push-button sibilance filter.  
Informative manual answers questions on theory, hookups and  
uses - enhances resale value, too!  
Add our custom case and Knob set for a finished “Pro” look.  
Download from Www.Somanuals.com. All Manuals Search And Download.  
Ramsey Publication No. MSHA1  
Price $5.00  
KIT ASSEMBLY  
AND INSTRUCTION MANUAL FOR  
STEREO HEADPHONE  
AMPLIFIER KIT  
How does it work.................... 4  
Assembly Strategy ................. 6  
Parts List ................................ 7  
Parts Layout Diagram ............ 8  
Part Values Diagram.............. 9  
Schematic .............................. 10  
Assembly Steps ..................... 12  
Testing the SHA1................... 16  
Troubleshooting ..................... 17  
RAMSEY ELECTRONICS, INC.  
590 Fishers Station Drive  
Victor, New York 14564  
Phone (585) 924-4560  
Fax (585) 924-4555  
SHA13  
Download from Www.Somanuals.com. All Manuals Search And Download.  
What is it and how does it work?  
Let’s take a look at the schematic diagram, and we will follow  
through from input to output to get a general idea how this kit  
works, and why. We will look only at the left channel circuitry  
starting at J1 since the right channel is identical to the left.  
A line level audio signal is placed in J1. Line level means an audio  
signal of around 1V peak to peak, and will give a reading of 0dB  
on a VU meter. The audio passes through C1, a coupling  
capacitor. This capacitor prevents DC from entering the circuit  
from external components and interfering with audio quality. The  
capacitor lets the audio pass through to R3, the left channel  
volume control.  
The volume control simply varies the incoming signals level that  
goes into U1, the LM386. U1 is a fully integrated audio amplifier,  
capable of driving low impedance loads. It requires very few  
external components, runs very efficiently, and has great fidelity.  
With the sibilance switch open, the audio passes directly into U1,  
and the signal is amplified to drive a low impedance speaker like  
those in your earphones.  
With the sibilance switch closed, the capacitor C12 is switched  
into circuit. This capacitor shunts some of the higher frequencies  
to ground, but leaves the lower frequencies alone. C12 creates a  
low pass filter when combined with R2, thereby reducing the level  
of high frequencies that are amplified in U1. This is really handy if  
you have a noisy weak station coming in, or the signal source is  
really tinny sounding like from a poorly recorded CD.  
R4 and C5 on the output side of the LM386 is for preventing  
oscillations due to the inductive nature of a speaker coil being  
driven by the LM386. This makes the load of the speaker look  
more like a resistive one than inductive, which prevents  
“motorboating” of the audio signal.  
SHA1 4  
Download from Www.Somanuals.com. All Manuals Search And Download.  
C3 is another coupling capacitor, and it serves the same  
purpose as C1 at the start of the circuit. This prevents the DC  
portion of the signal on the output of U1 from being sent to the  
earphones.  
VR1, C15 and C16 supply the regulated DC voltage for the  
circuit.  
SHA15  
Download from Www.Somanuals.com. All Manuals Search And Download.  
RAMSEY “LEARN-AS-YOU-BUILD” ASSEMBLY STRATEGY  
Be sure to read through all of the steps, and check the boxes as  
you go to be sure you didn't miss any important steps. 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 good soldering technique - let your soldering iron tip gently  
heat the traces to which you are soldering, heating both wires and  
pads simultaneously. Apply the solder on the iron and the pad  
when the pad is hot enough to melt the solder. The finished joint  
should look like a drop of water on paper, somewhat soaked in.  
Mount all electrical parts on the top side of the board provided.  
This is the side that has little or no traces on it. When parts are  
installed, the part is placed flat to the board, and the leads are  
bent on the backside of the board to prevent the part from falling  
out before soldering (1). The part is then soldered securely to the  
board (2-4), and the remaining lead length is then clipped off (5).  
Notice how the solder joint looks on close up, clean and smooth  
with no holes or sharp points (6).  
SHA1 6  
Download from Www.Somanuals.com. All Manuals Search And Download.  
SHA1 PARTS LIST  
Semiconductors  
2 LM386 Audio Amplifier ICs (U1,2)  
1 1N4002 rectifier diode (Black body with white stripe on  
one end) (D1)  
1 7808 Voltage Regulator (U3)  
Resistors  
2 4.7K ohm resistors (yellow-violet-red) (R2,7)  
2 2 ohm resistors (red-black-gold) (R4,8)  
2 10K ohm potentiometers (R3,6)  
Capacitors  
5 .01uF ceramic capacitors (Marked .01, 10n, or 103)  
(C4,8,10,12,14)  
4 10uF electrolytic capacitors (C1,6,15,16)  
1 470uF to 1000uF capacitor (C2)  
2 220uF capacitors (C3,7)  
2 .1uF ceramic capacitors (Marked .1 or 104) (C5,9)  
2 100pF ceramic capacitors (Marked 101) (C11,13)  
Miscellaneous  
2 DPDT switches (S1,2)  
1 9V Metal Battery Holder  
1 9V Battery Connector  
1 1/4” Stereo earphone jack (J3)  
2 RCA Jacks (J1,2)  
1 Power Jack (J4)  
SHA17  
Download from Www.Somanuals.com. All Manuals Search And Download.  
PARTS LAYOUT DIAGRAM  
SHA1 8  
Download from Www.Somanuals.com. All Manuals Search And Download.  
PARTS VALUE DIAGRAM  
SHA19  
Download from Www.Somanuals.com. All Manuals Search And Download.  
SHA1 10  
Download from Www.Somanuals.com. All Manuals Search And Download.  
SHA111  
Download from Www.Somanuals.com. All Manuals Search And Download.  
ASSEMBLING THE SHA1 HEADPHONE AMPLIFIERS:  
Sort out all of your parts to begin with, making sure you have all  
of the parts required. You can use old egg cartons to hold  
various parts to make them easier to find. Make sure to mount  
parts on the correct side! You will want to use the parts layout  
diagram to assist you in finding where the parts go.  
ˆ 1. Orient the board in the same direction as the parts layout  
diagram.  
ˆ 2. Install C12, a .01uF ceramic capacitor (Marked .01, 10n,  
or 103)  
ˆ 3. Install C14, another .01uF ceramic capacitor (Marked .01,  
10n, or 103).  
ˆ 4. Install R2, a 4.7K ohm resistor (yellow-violet-red).  
ˆ 5. Install R7, another 4.7K ohm resistor (yellow-violet-red).  
ˆ 6. Using a scrap piece of component lead, install JMP2.  
These jumpers act as “bridges” over other connections,  
allowing us to create a well routed PC board.  
ˆ 7. Using another scrap component lead, install JMP1.  
ˆ 8. Install C10, a .01uF ceramic capacitor (Marked .01, 10n,  
or 103).  
ˆ 9. Install C8, another .01uF ceramic capacitor (Marked  
10n, .01, or 103).  
ˆ 10. Install D1, the 1N4002 rectifier diode. Make sure and  
install the lined end (cathode) of the diode in the same  
direction as shown in the diagram. This diode prevents us  
from accidentally charging an installed battery while external  
power is applied.  
SHA1 12  
Download from Www.Somanuals.com. All Manuals Search And Download.  
ˆ 11. Install U2, one of the LM386 audio power amplifier ICs.  
Check the orientation of this chip to make sure the dot or  
notch representing pin one is in the same direction as shown  
in the parts diagram. Make sure all eight pins are through  
the board before soldering. Note that it is very easy to have  
a pin folded under the IC instead of being though the holes.  
This problem is easy to remedy before you solder the IC.  
ˆ 12. Install R8, a 2 ohm resistor (red-black-gold).  
ˆ 13. Install C9, one of the .1uF ceramic capacitors (Marked  
104, or .1).  
ˆ 14. Install C13, a 100pF ceramic capacitor (Marked 101).  
ˆ 15 Using a scrap piece of component lead, install JMP5.  
Note that this part does not need to be bent as shown in the  
diagram, just make sure that it is installed in the correct  
holes.  
ˆ 16. Install C4, a .01uF ceramic capacitor (Marked .01, 10n,  
or 103).  
ˆ 17. Install R4, a 2 ohm resistor (red-black-gold).  
ˆ 18. Install U1, the remaining LM386 audio amplifier IC.  
Again make sure that all eight pins are through the board  
before soldering and that the part is installed in the correct  
direction.  
ˆ 19. Install C11, a 100pF ceramic capacitor (Marked 101).  
ˆ 20. Install C5, a .1uF ceramic capacitor (Marked 104 or .1).  
ˆ 21. Install JMP4 using a scrap piece of component lead.  
ˆ 22. Install C2, a 470uF to 1000F electrolytic capacitor. Make  
sure and mount this part in the correct direction! If you look  
at the component you will see a stripe down one side,  
SHA113  
Download from Www.Somanuals.com. All Manuals Search And Download.  
usually indicating the negative (-) terminal of the component.  
You will notice on the parts layout diagram that the hole for the  
positive terminal is denoted, not the negative one. You will  
want to install this component with the positive (+) lead in the  
same orientation as shown in the parts layout diagram. If you  
do not install it correctly, you will end up with all sorts of  
problems in the circuit.  
ˆ 23. Install C3, a 220uF electrolytic capacitor. Again pay close  
attention to the orientation of this component!  
ˆ 24. Install C7, another 220uF electrolytic capacitor. Again note  
the orientation.  
ˆ 25. Install C6, a 10uF electrolytic capacitor. Orientation!  
ˆ 26. Install C1, the remaining 10uF electrolytic capacitor.  
ˆ 27. Install J3, the 1/4” earphone jack. Make sure all the pins  
are soldered for good mechanical stability.  
ˆ 28. Install J1, one of the RCA type jacks.  
ˆ 29. Install J2, the other RCA type jack.  
ˆ 30. Install S1, a DPDT switch. Make sure the part is mounted  
flush to the board before soldering all six pins.  
ˆ 31. Install S2, the other DPDT switch.  
ˆ 32. Install R3, one of the 10K ohm potentiometers.  
ˆ 33. Install R6, the other 10K ohm potentiometer.  
ˆ 34. Using a scrap piece of component lead, make a jumper  
that mounts through the holes where the battery is to be  
mounted. Thread the jumper through the metal 9V battery  
holder and then solder the jumper to mount the clip to the PC  
board.  
SHA1 14  
Download from Www.Somanuals.com. All Manuals Search And Download.  
ˆ 35. Install C16, 10uF electrolytic capacitor. Watch polarity!  
ˆ 36. Install U3, the 7808 voltage regulator. You will want to  
bend the center lead out and orient the part so that the  
writing on the front of the part faces the outside of the board.  
Solder all three leads.  
ˆ 37. Install C15, the last 10uF electrolytic capacitor. Again, be  
sure to orient the cap as the silkscreen shows.  
ˆ 38. Install the battery connector by soldering the black wire  
into the hole marked (-), and the red wire into the hole  
marked (+).  
ˆ 39. Install J4, the power jack.  
Well, it looks as if we finished our new headphone amplifier!  
Now would be a good time to check out your assembly for any  
mistakes. Check all of your solder joints for cold solder  
connections, and then check all of your traces and pads for any  
solder bridges. Last of all check the orientation of all your parts  
against the parts layout diagram.  
SHA115  
Download from Www.Somanuals.com. All Manuals Search And Download.  
TESTING THE SHA1  
You will need the following equipment for this test.  
 Audio source such as signal generator, CD player, or  
tape deck.  
 RCA jacks to feed audio to the SHA1  
 Good quality headphones.  
 A 9 volt battery or DC power supply  
Simply connect your SHA1 up as if you were going to use it.  
ˆ 1. Connect your signal source to the two RCA jacks on the  
SHA1.  
ˆ 2. Hook up the 9V battery or power supply.  
ˆ 3. Turn the volume controls all the way counter clockwise.  
ˆ 4. Plug in your earphones.  
ˆ 5. Slowly turn up the volume slowly on each channel.  
ˆ 6. Use your ears and the troubleshooting guide to determine  
if the unit works  
SHA1 16  
Download from Www.Somanuals.com. All Manuals Search And Download.  
TROUBLESHOOTING TIPS  
PROBLEM: No sound out of any channel.  
SOLUTION: Use a DMM to check the power supply voltage, do  
you have a fresh battery? If everything is OK, check your  
assembly, especially your parts orientation (D1?). Also check  
your earphones for proper operation as well as your sound  
source.  
PROBLEM: One channel is out, the other works OK.  
SOLUTION: You may have a short or open somewhere  
through the circuit. This is where an oscilloscope would come in  
handy. Insert an audio signal into both of the inputs, then trace  
through the circuit with the probe. When you have gazinda  
(input) with no gazada (output), you will then know where the  
problem lies.  
PROBLEM: Sound is terrible or “motorboating”  
SOLUTION: Check your power supply voltage or your battery.  
PROBLEM: I just can’t get the #@%*$#&! thing to work! It’s  
Ramsey’s fault!  
SOLUTION: Read the warranty information towards the back of  
this manual.  
SHA117  
Download from Www.Somanuals.com. All Manuals Search And Download.  
SHA1 18  
Download from Www.Somanuals.com. All Manuals Search And Download.  
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 you need help, please read through your manual carefully, all  
information required to properly build and test your kit is contained within the pages!  
1. DEFECTIVE PARTS: It's always easy to blame a part for a problem in your kit, Before you conclude  
that a part may be bad, thoroughly check your work. Today's semiconductors and passive components  
have reached incredibly high reliability levels, and it’s sad to say that our human construction skills  
have not! But on rare occasions a sour component can slip through. All our kit parts carry the Ramsey  
Electronics Warranty that they are free from defects for a full ninety (90) days from the date of  
purchase. Defective parts will be replaced promptly at our expense. If you suspect any part to be  
defective, please mail it to our factory for testing and replacement. Please send only the defective part  
(s), not the entire kit. The part(s) MUST be returned to us in suitable condition for testing. Please be  
aware that testing can usually determine if the part was truly defective or damaged by assembly or  
usage. Don't be afraid of telling us that you 'blew-it', we're all human and in most cases, replacement  
parts are very reasonably priced.  
2. MISSING PARTS: Before assuming a part value is incorrect, check the parts listing carefully to see  
if it is a critical value such as a specific coil or IC, or whether a RANGE of values is suitable (such as  
"100 to 500 uF"). Often times, common sense will solve a mysterious missing part problem. If you're  
missing five 10K ohm resistors and received five extra 1K resistors, you can pretty much be assured  
that the '1K ohm' resistors are actually the 'missing' 10 K parts ("Hum-m-m, I guess the 'red' band  
really does look orange!") Ramsey Electronics project kits are packed with pride in the USA. If you  
believe we packed an incorrect part or omitted a part clearly indicated in your assembly manual as  
supplied with the basic kit by Ramsey, please write or call us with information on the part you need  
and proof of kit purchase  
3. FACTORY REPAIR OF ASSEMBLED KITS:  
To qualify for Ramsey Electronics factory repair, kits MUST:  
1. NOT be assembled with acid core solder or flux.  
2. NOT be modified in any manner.  
3. BE returned in fully-assembled form, not partially assembled.  
4. BE accompanied by the proper repair fee. No repair will be undertaken until we have received the  
MINIMUM repair fee (1/2 hour labor) of $25.00, or authorization to charge it to your credit card  
account.  
5. INCLUDE a description of the problem and legible return address. DO NOT send a separate letter;  
include all correspondence with the unit. Please do not include your own hardware such as  
non-Ramsey cabinets, knobs, cables, external battery packs and the like. Ramsey  
Electronics, Inc., reserves the right to refuse repair on ANY item in which we find excessive  
problems or damage due to construction methods. To assist customers in such situations,  
Ramsey Electronics, Inc., reserves the right to solve their needs on a case-by-case basis.  
The repair is $50.00 per hour, regardless of the cost of the kit. Please understand that our technicians  
are not volunteers and that set-up, testing, diagnosis, repair and repacking and paperwork can take  
nearly an hour of paid employee time on even a simple kit. Of course, if we find that a part was  
defective in manufacture, there will be no charge to repair your kit (But please realize that our  
technicians know the difference between a defective part and parts burned out or damaged through  
improper use or assembly).  
4. REFUNDS: You are given ten (10) days to examine our products. If you are not satisfied, you may  
return your unassembled kit with all the parts and instructions and proof of purchase to the factory for  
a full refund. The return package should be packed securely. Insurance is recommended. Please do  
not cause needless delays, read all information carefully.  
SHA119  
Download from Www.Somanuals.com. All Manuals Search And Download.  
SHA1 STEREO HEADPHONE AMPLIFIER KIT  
Quick Reference Page Guide  
How does it work .............................. 4  
Assembly Strategy............................ 6  
Parts List........................................... 7  
Parts Layout Diagram....................... 8  
Part Values Diagram ........................ 9  
Schematic......................................... 10  
Assembly Steps................................ 12  
Testing the SHA1 ............................. 16  
Troubleshooting................................ 17  
REQUIRED TOOLS  
Soldering Iron Ramsey WLC100  
Thin Rosin Core Solder Ramsey RTS12  
Needle Nose Pliers Ramsey MPP4 or RTS05  
Small Diagonal Cutters Ramsey RTS04  
<OR> Technician’s Tool Kit TK405  
ADDITIONAL SUGGESTED ITEMS  
Holder for PC Board/Parts Ramsey HH3  
Desoldering Braid Ramsey RTS08  
Digital Multimeter Ramsey M133  
Price: $5.00  
Ramsey Publication No. MSHA1  
Assembly and Instruction manual for:  
RAMSEY MODEL NO. SHA1  
TOTAL SOLDER POINTS  
about 100  
ESTIMATED ASSEMBLY  
TIME  
Beginner...............2.0 hrs  
Intermediate .........1.0 hrs  
Advanced ..............75 hrs  
RAMSEY ELECTRONICS, INC.  
590 Fishers Station Drive  
Victor, New York 14564  
Phone (585) 924-4560  
Fax (585) 924-4555  
Download from Www.Somanuals.com. All Manuals Search And Download.  

Q See Home Security System QSPDC User Guide
Radica Games Games i7003 User Guide
Radio Shack Cordless Telephone TAD 727 User Guide
Renesas Switch 2SK3069 User Guide
Ricoh All in One Printer SP 3400SF User Guide
Roksan Audio CD Player Kandy MkIII User Guide
Samsung Cell Phone T939 User Guide
Samsung DVD Player AK68 01765B User Guide
Samsung Telephone SPH A540 User Guide
Sanus Systems TV Video Accessories WFV66 User Guide