This file is broken into parts. Each major division marks where the parts list for one piece of the circuit and a parts list for another piece begins. For each of the parts list, the table contains the number of parts that the circuit actually requires, along with the part numbers of both Digi-Key and JameCo parts. The total at the bottom of each list reflects the total price of all the parts if purchased through that particular distributor.
Also listed are the prices per each set of components if more than one set of parts is purchased (up to 10). For the most part, quantity discounts usually start at quantities of 10 or more. Thus if you can get 9 of your closest friends to purchase parts at the same time you do, you will save some money.
Keep in mind that Digi-Key doesn't charge for shipping UPS ground, so the total price listed will be pretty close to what you'll actually pay for the parts. JameCo, on the other hand, charges $7.25 for shipping UPS ground. I didn't add JameCo's shipping charge to the JameCo totals, because you'll need to know the total cost of the parts to determine if you'll meet their $30 minimum order. If you add up the JameCo price column, remember to add $7.25 to determine what you'll have to pay.
At the end of all the individual parts lists, I have included a particular list that may be of interest. The parts list contains listings for all the parts that you will need to build the entire circuit. The parts list is optimized for both JameCo and Digi-Key ordering. There may be a problem with ordering parts for just one board because JameCo has a minimum order of $30. Digi-Key charges a $5 service fee for orders under $25. If your order comes up short for Digi-Key, I highly recommend that you find some filler items to get the total up to $25 so that you're only paying for the parts. If you come up with less than $30 for an order to JameCo, you are going to have to add some filler items, so that they will process the order.
The catalogs that I am referencing are: Digi-Key #931 (January-February 1993) and JameCo Winter Catalog.
V1.00 Stereo Sound Board:
| My | JameCo | Digi-Key
Quantity | Part # | Part # | Total Cost | Part # | Total Cost
Statistically, using the best prices, 1 board could cost you as little as $13.96. However, this statistical value, is a bit impossible because in order to arrive at this price you would be ordering less than $30 from JameCo which won't process orders that small. You would also be ordering less than $25 from Digi-Key which would access you a $5 service charge.
The next question is what to build this circuit on. I didn't specify any such board in the parts list above because JameCo and Digi-Key both overprice such boards. This is going to sound strange, but I actually recommend that you purchase the boards at Radio Shack for the best price. (Yeah, I know, I should be shot for even suggesting Radio Shack, but their pricing is actually about four to seven times cheaper than either Digi-Key or JameCo when it comes to circuit boards.) The circuit should fit on two 276-170 for $5.58 total. The circuit might actually fit on one 276-154 for $3.49. If it does, the fit might be a little tight. The boards listed above are for solder assembly. You can find even cheaper boards if you want to do wire wrap assembly. If you do wire wrap you will need to specify wire wrap I.C. sockets in place of the I.C. sockets already specified in the parts list.
Note <A> - KS555 substitution
The KS555 was a low power 555 timer that Digi-Key used to sell. I have specified a CMOS 555 timer in its place for the Digi-Key order and just a low power 555 for the JameCo order. Although it should make absolutely no difference, if you have any problems with either, you may want to try an LM555. I wouldn't recommend starting out with the LM555, it has some major disadvantages.
Note <B> - Green LED
Both the green LED and the red LED are point source LEDs. The advantage of point source LEDs is that they are significantly brighter, the disadvantage is that they don't have as wide of viewing angle. In the JameCo order, the green LED is actually a yellow LED. (I kind of suspicious of it because of its low price. It may not be very bright.) For some reason, JameCo doesn't sell point source green LEDs. If you actually want a green LED, you'll have to specify a diffused LED such as part # 34761 for $0.16 each or you could order a super bright (point source) green LED, part # 11359, for $0.79 each.
In the Digi-Key order, both LEDs are specified in a quantity of 10. As it happens, this is the smallest quantity that you can purchase from Digi-Key. A few other parts from Digi-Key are also subject to the same minimum quantity rule. Besides the minimum quantity being 10, the increment size is also 10. (ie. if you need 21, you would have to order 30)
Note <C> - 0.1 uF capacitor
If you've looked at the schematic and can't figure out where I got 16 capacitors from, then you've forgotten about the decoupling capacitors.
Note <D> - Quantity discounts
Remember that when ordering several parts, it is sometimes cheaper to order more parts than you actually need. Case in point, when ordering 1000 uF capacitors through Digi-Key, eight capacitors will cost you $2.40 and ten capacitors will $2.40. Similarly, eight 2N3906s will cost you $1.84, where as ten will only cost you $1.79.
Note <E> - 5.00 K resistor quantity and minimum quantity
4.7 K ohm resistors are specified as substitutions for the 5.00 K resistor specified in the circuit. The 5.00 K value isn't critical.
The minimum quantity of resistors that you can order from JameCo is 100. (You'll have a lot of spares leftover.) The minimum and incremental quantity that you can order from Digi-Key is 5.
Note <F> - 500 ohm resistor substitution
470 ohm resistors have been substituted for the 500 ohm resistors.
Note <G> - DB-25 connector
You can either plug the DB-25 connector into the parallel port making sure to run the wires long enough. The other (and much preferred) alternative is to mount the DB-25 connector as close to the sound board as possible and use a shielded DB-25 extension cord to bridge the gap.
Note <H> - Heat sink
The heat sink is for the 7805 voltage regulator. It is highly recommended that use one.
Note <I> - I.C. sockets
The I.C. sockets are not required. However, they are highly recommended. If you've ever had to desolder a 14 pin chip, you'll understand why. Most of the chips used in this circuit are CMOS, in other words, they can be easily damaged if not properly handled. Almost all chips will be damaged if you connect them incorrectly.
Note <J> - Total price computations and general notes
The 1 of 1 board price for JameCo is unrealistic since they won't process that small an order. The 1 of 1 board price for Digi-Key reflects the $5 service charge because the total was less than $25. If you were to order something else to push the total order over $25, then the components for the board would only cost you $22.70.
It is important to note that Digi-Key gives a 10% discount on orders greater than $100. The single board prices from 7 to 10 total boards reflects this discount.
V1.50 Adapter Module:
| My | JameCo | Digi-Key
Quantity | Part # | Part # | Total Cost | Part # | Total Cost
Statistically, using the best prices, 1 board could cost you as little as $3.18. However, this statistical value, is a bit impossible because in order to arrive at this price you would be ordering less than $30 from JameCo which won't process orders that small. You would also be ordering less than $25 from Digi-Key which would access you a $5 service charge.
The next question is what to build this circuit on. The circuit should fit on one (Radio Shack) 276-159 for $1.49. The boards listed above are for solder assembly. You can find even cheaper boards if you want to do wire wrap assembly. If you do wire wrap you will need to specify wire wrap I.C. sockets in place of the I.C. sockets already specified in the parts list.
V1.50 Power Supply Board:
| My | JameCo | Digi-Key
Quantity | Part # | Part # | Total Cost | Part # | Total Cost
Statistically, using the best prices, 1 board could cost you as little as $20.96. However, this statistical value, is a bit impossible because in order to arrive at this price you would be ordering less than $30 from JameCo which won't process orders that small. You would also be ordering less than $25 from Digi-Key which would access you a $5 service charge.
The next question is what to build this circuit on. If it's possible, it is a good idea to put the voltage regulators and associated circuitry on the same board you're putting the sound circuitry on. (If you don't, it will be necessary to add another 100 uF capacitor across the power supply lines.) That just leaves the transformer and high voltage circuitry. In any case, you should try and find a box for the high voltage circuitry (preferably one that isn't flammable). It is not a good idea to leave high voltage circuitry out in the open where someone or your favorite house pet can touch the circuitry and accidentally kill themselves. (Remember: You don't have to be grounded to get a really nasty shock from touching high voltage. Also, if you are grounded, the shock is likely to be fatal.)
When routing wires in and out of an enclosure, always use a grommet and strain relief. The grommet keeps the enclosure from stripping the insulation off the wires and the strain relief prevents the wire from being pulled out.
This is probably a good time to point out that JameCo currently sells a power supply that is adequate for this purpose for less money than it costs to build one. So why do I suggest building a power supply when it would be easier just to specify the one that JameCo has? Well, the power supply that JameCo sells, lists the quantity that they have in stock leading me to believe that what they have is surplus. In other words, once they run out, that will be the end of them. Actually, they have two power supplies that would be adequate.
The first one is part # 76611, a 23 watt power supply of which they had about 1,650 of when they went to print the catalog that costs $12.95. It has +5, +15, and -15 volt outputs. If you use this one, make sure you leave out the 14 volt zener diodes. To make this power supply operationable, you will have to purchase a power cord for it. It is an open frame power supply, so you should put it in an enclosure of some sort. If you use this power supply, don't use the 7805 voltage regulator (if it's already a part of the sound board, you will have to remove it). Connect the five volt line of this power supply directly to the five volt line on the sound board.
The second power supply is part # 77972, a 40 watt power supply of which they had about 2,150 of when they went to print the catalog that costs $14.95. It outputs six different voltages; the ones that we are interested in are: +5, +12, and -12. To make this power supply operationable, you will have to purchase a power cord for it. It is an open frame power supply, so you should put it in an enclosure of some sort. If you use this power supply, don't use the 7805 voltage regulator (if it's already a part of the sound board, you will have to remove it). Connect the five volt line of this power supply directly to the five volt line on the sound board.
Note <A> - Choice of fuse
In most instances when something in the circuit shorts, almost any size fuse will blow because the circuit will try to pull at least double digit current. When I was drawing up the schematic, I specified a 1 amp fuse based on this particular idea. Above I have substituted a 0.25 A fuse for the original specified value. This value corresponds better to what the rest of the components on the secondary side of the transformer are actually capable of. Since fuses protect mostly against short circuits, the major factors in determining the size of the fuse is: will it support the current that the circuit needs without blowing and will it blow when there is a short circuit.
Note <B> - Transformer
The Digi-Key transformer has a dual secondary. Remember that windings on a transformer are polarized. Connecting them incorrectly will produce no voltage. Connect a "+" side of one of the secondary windings to the "-" side of the other secondary winding. Now you can treat the transformer as if it were centertapped. (Connect a DMM set to AC volts across the two open sides of the windings to verify that there is roughly 24 volts. If the reading is close to zero, then your centertap has 2 "+" or "-" winding terminals incorrectly tied together.)
Note <C> - 22 V ZNR
JameCo doesn't sell anything that is equivalent to the 22 V ZNR. If you want them, you will have to order them through Digi-Key.
Note <D> - Bridge Rectifier substitution
You can save yourself some money by constructing your own bridge rectifier out of four 1N4001s, if you know how. When I do a major overhaul of my schematics, I'll draw the bridge rectifier out of diodes instead of just using the bridge rectifier symbol. (Currently, my own sound board uses a bridge rectifier that I purchased at Radio Shack.)
Note <E> - Transient Voltage Suppressors
The JameCo part number specifies regular zener diodes, where as the Digi-Key part number specifies transient voltage suppressors. In essence, both work roughly equivalent for this purpose. The advantage of the transient voltage suppressors is that they have a very fast reacting time, where the zener diodes are pretty slow by comparison.
V1.00 Stereo Sound Board with V1.50 Adapter and Power Supply:
| My |
Quantity | Part # | Part # | Total Cost | Company |
Refer to the V1.00 notes above for information also pertaining to this parts list.
Note <L> - DB-25 connector
The reason that there is only one DB-25 connector specified in this parts list is because it is inferred that you should build the V1.50 adapter circuit on the same circuit board as the V1.00 sound board. Therefore, no connector is needed to interface between the two circuits.
Note <M> - Power supply
The power supply that is specified in this parts list is one of the recommended preassembled JameCo ones. If they don't have that one in stock, try to get the other one I have mentioned above. If that one is also unavailable, then you have the choice of building the one in the power supply schematic or trying to find a different preassembled one.
DISCLAIMER:
Any damage you do to yourself, your computer, your stereo, or anything or anyone else is your own fault, not mine.
To the best of my knowledge there are no errors in the circuit schematic or the parts lists. However, the parts lists don't reflect all of the same components used in my own sound board. As my own sound board was built out of what I had laying around at the time. It would be a good idea to obtain the referenced catalogs and compare the specified part numbers to make sure that I didn't make any typographical errors. (The values of the parts in the V1.00 and V1.50 sound circuitry have been confirmed to work, however different part numbered parts were used in my circuit as compared with this parts list.)
This circuit schematic and associated documentation files have been given to you in hopes that you will copy it, distribute it, and use it to build this circuit.
Altering this file (like removing my name) or any of the other files in this ZIP file is strictly prohibited and illegal. Selling this file for a profit is strictly prohibited and illegal.
I don't expect any fee for using this file. However, if you find this schematic to be of great use, a donation of $5 would be greatly appreciated. This schematic took me more time to draw up and document than the circuit took to construct and debug.
Send any questions, comments, and donations to:
Dave Boyd
W2740 Rock River Paradise
Watertown, WI 53094
You can also Email me via EXEC-PC BBS at (414) 789-4210.
 (1993).iso/music2/pcstgif4.arj/PCSTAD1B.GIF){kind=link}