AC-300C Sound System
The AC-300C was manufactured between July 1991 and May 1996. The following repair sheets are designed to help repair technicians and qualified owners repair and maintaining the AC-300C.
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INSTRUCTIONS FOR REMOVING AMPLIFIER FROM CASE
AC-300, AC-300A, AC-300B, & AC-300C
Slide a screwdriver under the chrome handle cover and snap it off, exposing the two screws which hold the handle in place. Remove these screws. On the opposite side of the unit, locate the two rubber feet. Remove the screws that hold these two feet in place.
Before removing the amplifier from the case take off the platter and set it off to the side. Also, make sure the tone arm is locked in it's clip. The entire unit will now slide out of the carrying case. Be careful that the circuit breaker does not hang up on the case when removing the amplifier.
INSTRUCTIONS FOR CHANGING MOTOR IN AC-300A, AC-300B, OR AC-300C
Slide a screwdriver under the chrome handle cover and snap it off, exposing the two screws which hold the handle in place. Remove these screws. On the opposite side of the unit, locate the two rubber feet. Remove the screws that hold these two feet in place.
Before removing the amplifier from the case take off the platter and set it off to the side. Also, make sure the tone arm is locked in it's clip. The entire unit will now slide out of the carrying case. Be careful that the circuit breaker does not hang up on the case when removing the amplifier.
Locate the tension spring which provides the spring tension to hold the motor assembly up so that the drive wheel contacts the underside of the platter. Remove the nuts and washer from this bolt, remove the spring and the motor assembly will swing out so that you can get at it.
Unsolder the three leads, the two going to the motor and the one ground lead. Remove one of the hex bolts holding the motor mount to the bracket, slide the grommet off the other bolt and the motor will come out. Remove the two bolts holding the bracket to the motor.
Install the replacement motor by following above instructions in reverse order.
Please return the old motor to us for inspection.
TO RECALIBRATE AC-300C FROM 50 TO 60 HZ
Lift off the turntable platter and set it off to the side.
To remove the chassis from the case: stick a screwdriver under the chrome handle cover and snap it off. Remove the 2 screws holding the handle, and the 2 rubber feet on the opposite side. Tilt the unit on its side and slide the AC-300C out of the case.
Turn the AC-300C chassis up side down, control panel away from you, on a pillow or soft foam to protect the tone arm. Locate the speed control transport, the throwout (which disengages the motor in the off position), and the microswitch that turns off the motor when the speed control is in the off position (see drawing below).
Before actually adjusting the speed do the following two procedures. First, loosen the screw on the fiberglass plate holding the microswitch (see drawing) and pivot it to the rear of the amplifier so that it is out of the way. Second, loosen the two 1/4 inch hex nuts holding the throwout and slide it all the way toward you, out of the way.
Set the unit on its side, so you can see and reach both the top and underside of the system. Move the speed control so that the knob is pointing at 38 R.P.M. (This should be the speed at which you currently have to set the system in order to play 45 R.P.M. records). Note the position of the motor and speed control transport; this is the position you want the motor and speed control transport to be in when the knob is pointing at 45 R.P.M.
Holding the motor in place, loosen the 2 screws on the speed control transport and move the knob to 45 R.P.M. and then lightly retighten the 2 screws.
Now you can plug in the power cord, put on the platter, and check if the speed is set correctly. If more adjusting is necessary be sure to unplug the power cord before readjusting the 2 screws on the speed control transport. Do this as many times as necessary to get the speed set correctly. Only when the speed is correct should you firmly tighten these 2 screws.
BE SURE THE SPEED IS ADJUSTED CORRECTLY BEFORE PROCEEDING!
Now that the speed is set correctly unplug the unit, move the knob to the off position, and turn it over again on the pillow or foam. Loosen the screw on the fiberglass plate (see drawing) and rotate the brown microswitch until there is about 1/16 inch of clearance between the leaf and the body of the switch. Retighten the screw.
Loosen the two 1/4 inch hex nuts holding the throwout (see drawing) so that it can be repositioned. Keep the speed control in the off position, and lift the motor slightly so that you can slide the throwout back under the motor mount (metal piece) so it rests on the ledge shown in the drawing. This holds the drive wheel away from the platter in the off position. Retighten the nuts so that they are firm but not extremely tight. If you over tighten them the speed control can bind and not move freely.
Turn the unit right side up, plug in the power cord, and turn it on. Check to be sure that the turntable strobes correctly; that the motor turns off when the speed control knob is in the off position, that the speed control moves freely, and that the drive wheel disengages from the platter when the speed control knob is in the off position.
Reinstall the chassis in the case and the job is finished.
TO RECALIBRATE AC-300C FROM 60 TO 50 HZ
Lift off the turntable platter and set it off to the side.
To remove the chassis from the case: stick a screwdriver under the chrome handle cover and snap it off. Remove the 2 screws holding the handle, and the 2 rubber feet on the opposite side. Tilt the unit on its side and slide the AC-300C out of the case.
Turn the AC-300C chassis up side down, control panel away from you, on a pillow or soft foam to protect the tone arm. Locate the speed control transport, the throwout (which disengages the motor in the off position), and the microswitch that turns off the motor when the speed control is in the off position (see drawing below). Loosen the 2 nuts holding the throwout and slide it all the way toward you, out of the way.
Set the unit on its side, so you can see and reach both the top and underside of the system. Move the speed control so that the knob is pointing at 52 R.P.M. (This should be the speed at which you currently have to set the system in order to play 45 R.P.M. records). Note the position of the motor and speed control transport; this is the position you want the motor and speed control transport to be in when the knob is pointing at 45 R.P.M.
Holding the motor in place, loosen the 2 screws on the sped control transport and move the knob to 45 R.P.M. and then lightly retighten the 2 screws.
Now you can plug in the power cord, put on the platter, and check if the speed is set correctly. If more adjusting is necessary be sure to unplug the power cord before readjusting the 2 screws on the speed control transport. Do this as many times as necessary to get the speed set correctly. Only when the speed is correct should you firmly tighten these 2 screws.
BE SURE THE SPEED IS ADJUSTED CORRECTLY BEFORE PROCEEDING!
Note: When properly recalibrated a 45 R.P.M. record will play correctly at "39" on the speed control when using 60 Hz AC power.
Now that the speed is set correctly unplug the unit, move the knob to the off position, and turn it over again on the pillow or foam. Loosen the screw on the fiberglass plate (see drawing) and rotate the brown microswitch until there is about 1/16 inch of clearance between the leaf and the body of the switch. Retighten the screw.
Keep the speed control in the off position, and lift the motor so that you can slide the throwout back under the motor mount (metal piece) so it rests on the ledge shown in the drawing. This holds the drive wheel away from the platter in the off position. Retighten the nuts so that they are firm but not extremely tight. If you overtighten them the speed control will bind and not move freely.
Turn the unit right side up, plug in the power cord, and turn it on. Check to be sure that the turntable strobes correctly; that the motor turns off when the speed control knob is in the off position, that the speed control moves freely, and that the drive wheel disengages from the platter when the speed control knob is in the off position.
Reinstall the chassis in the case and the job is finished.
INSTRUCTIONS FOR REMOVING AMPLIFIER FROM CASE and REPLACE THE DIODE PACK. AC-300, AC-300A, AC-300B, & AC-300C
Slide a screwdriver under the chrome handle cover and snap it off, exposing the two screws which hold the handle in place. Remove these screws. On the opposite side of the unit, locate the two rubber feet. Remove the screws that hold these two feet in place.
Before removing the amplifier from the case take off the platter and set it off to the side. Also, make sure the tone arm is locked in it's clip. The entire unit will now slide out of the carrying case. Be careful that the circuit breaker does not hang up on the case when removing the amplifier.
The diode pack is located near the heavy black power transformer near the rear of the amplifier. Make note of how the diode pack is oriented in the machine and then unplug it. Plug in the one sent to you.
You are now ready to put the amplifier back in its case and check it out.
Please contact us immediately if this did not fix the problem with your system. If your system is now back in working order please return the defective diode pack to us.
VOICE & MUSIC
How to record your voice on one track and the music on the other track using an older Hilton AC-300 or AC-200. The instructions also work for the AC-300A, AC-300B, and AC-300C.
These instructions will work with any MiniDisc recorder. They will also work most Computers and CD recorders as long as they have a “Line” level input.
You will need Hilton “Stereo Recording Isolation” cord. These sell for $28.50. You will need to tell us if you are using a “Walkman” or a larger “Shelf” type MiniDisc Player/Recorder. The small Walkman type systems use a Stereo 3.5mm connection while the Shelf type units have Dual RCA input connections. The Hilton “Stereo Recording Isolation” cord allows you to safely connect your MiniDisc to the ¼” speaker jacks on the back of your Hilton sound system.
You will want to decide right at the start if you want the Music on the Left or the Right channel of your recordings. Whichever way you decide *** Be Consistent *** so your recordings are always the same.
Connect the Hilton “Stereo Recording Isolation” cord with one of the ¼” plugs into a Main Channel speaker jack and the other ¼” plug into a Monitor Channel speaker jack. Connect the other end to the record input of your MiniDisc system. Connect a speaker into the other Main speaker jack so you can hear the music while making the recording. At this point you are properly connected to make a voice on one track, music on the other track recording. It will take a little experimenting the first time to get the level adjusted using the Main Music volume control and the Monitor Voice volume control. You want MUSIC ONLY turned up on the Main Channel of your Hilton and VOICE ONLY turned up on the Monitor Channel. When making your first recordings remember to use the tone controls for your voice and the music for the best recording – this will take a little practice and experimenting! In most cases you will want to decrease the Bass of the music and increase the Treble. Make sure your voice has enough treble to be clear and crisp when played back.
For the best playback on older Hilton systems you will need 2 items. One, a Stereo Signal Booster – this allows you to increase the level coming out of the MiniDisc to match the input of older Hilton systems “Tape Playback” jack. Second, a “playback attenuator” -- this device allows you to connect the voice side of your recording directly into the ¼” Microphone input on any Hilton system. The last of the Hilton AC-300 systems, the AC-300C, does not need the Stereo Signal Booster for playing back your recordings.
It takes a little work and few gadgets to make and playback your Voice and Music recordings but it can be done and work very successfully with older Hilton sound systems. Once you have the recordings and the Signal Booster and Playback Attenuator” you can also play your recordings into smaller single channel Hiltons like the Micro-75A.
CHANGING OUTPUT BOARD AC-300A, AC300B, and AC300C
Slide a screwdriver under the chrome handle cover and snap it off, exposing the two bolts which hold the handle in place. Remove these bolts. On the opposite side of the unit, locate the two rubber feet. Remove the bolts that hold these feet in place.
Make sure the tone arm is locked in it's clip. Lift out the platter, and set it aside. Slide the chassis out of the case, depressing the reset button to clear the case as the chassis slides out.
Turn the unit bottom side up on a soft pad and orient it so that the front panel is nearest you and the speaker jacks are farthest away from you. The main channel output board will be on your left and the monitor board on your right, nearest the speed control arm.
After determining which channel is malfunctioning, unsolder the two wires which are connected to the little round thermal cut off. Remove the four screws which hold the board to the heat sink and then unplug the edge connector. Re-connect the edge connector to the new board before re-installing it on the heat sink. Put a drop of silicone cement or glue where the edge connector meets the board to keep it from working loose. Use GE clear silicone seal or equivalent; do not use any material which is a conductor. If you have further problems, call us.
TO CHANGE MOTOR START CAPACITOR
Slide a screwdriver under the chrome handle cover and snap it off, exposing the two bolts which hold the handle in place. Remove these two bolts. On the opposite side of the unit, locate the two rubber feet. Remove the screws holding these two feet in place. The unit is now unbolted from the case.
Make sure the tone arm is locked in it's clip. Lift out the platter and set it aside. Slide the chassis out of the case being careful nothing hangs up on the back side of the case (where the speaker connections are).
NOTE: Replacement capacitor must be rated at 400 Volt or higher.
The motor capacitor is soldered onto a terminal block as part of the motor assembly. The terminal block will most likely have to be bent slightly away from the motor to get at the capacitor. Carefully remove the old capacitor and install the new one. See the sketch below to locate the proper solder points.
Reverse the above procedures to reinstall the set into the case.
If you have any questions, please call us immediately.
CHANGING OUTPUT SELECTOR SWITCH AC-300, 300A, AC300B, & AC300C
Slide a screwdriver under the chrome handle cover and snap it off, exposing the two bolts which hold the handle in place. Remove these bolts. On the opposite side of the unit, locate the two rubber feet. Remove the bolts that hold these feet in place. Make sure the tone arm is locked in it's clip. Lift out the platter, and set it aside. Slide the chassis out of the case, some models have a reset button on the rear panel, depress this button to clear the case as the chassis slides out.
On the model AC-300 the pre-amp board has to be removed. Remove all of the knobs from the controls on the front panel. Remove the small grounding springs underneath each knob. Remove the hex nuts from each of the control shafts. Stand the unit up so that you have access to the underneath side. Remove the bottom heat plate. Remove the plug-in connector at the end of the pre-amp board, it will be necessary to loosen the spot of clear plastic that holds the connector in place. The entire pre-amp assembly will come out now.
On models AC-300A, AC-300B, and AC-300C remove only the selector knob and the hex nut from the control shaft. Turn the unit bottom side up on a soft pad and orient it so that the front panel is nearest you and the speaker jacks are farthest away from you.
The new switches are slightly different in appearance and how they are connected. The drawings below will help you identify the wires. Locate the selector switch and mark the wires with tape as shown in the drawing below. Unsolder the wires marked "A", "B", "C", and "D". Install the new switch in the position shown in the drawing. Solder the wires you previously marked with tape, to the switch using the drawing as a guide.
Reassemble the unit by reversing the above procedure. If you have any difficulty please do not hesitate to contact us.
INSTRUCTIONS FOR CHANGING TONE ARM
Locate the handle cover which carries the initials. Slip a screw driver under the end of this cover and snap it off. Remove the two machine screws which hold the handle on. On the opposite side, remove the two rubber feet.
Remove the platter and stand the unit up on edge, handle end up.
On the AC-300 & AC-300A hold the red reset button on the circuit breaker in so that it will clear the case, and gently slide the unit out of the case.
Set the chassis upside down on a soft pad or cushion. Locate the red and black wires which come out of the tone arm. Be sure to mark or sketch the two terminals on the tape playback jack so that you can reconnect the leads from the new tone arm in exactly the same way. Unsolder the red and black leads.
Being careful not to pinch the red and black leads, remove the nut and lock washer from the base of the tone arm, set the unit back up on edge, and remove the tone arm. Install the new arm, making sure that it is in the clip, and lay the unit back down. Reinstall the lock washer and nut, again being careful not to damage the red and black leads. Be sure that the nut is secure. Resolder the red and black leads to the same terminals from which you removed them, and reinstall the unit in the case, again being careful that the reset button clears the case as the chassis slips into place.
TO ADJUST THE ANTI-SKATE SPRING ON THE POST OF THE TONE ARM:
Loosen the set screw in the set collar at the bottom of the post, so that the anti-skate spring is under no tension. Put a 45 RPM record on the platter, allowing the needle to rest on the pickup grooves at the outer rim of the record. Lock the setscrew on the post so that the set collar is about 1/8" above the deck, and so that the spring is still under no tension.
The unit should now be ready for use. Play a record through to make sure that the arm track properly, and check the reset to make sure that it returns properly when the button is pressed.
If you need further assistance or have any questions, please do not hesitate to contact us. We sincerely appreciate your continued support of the Hilton product line.
INSTALLING PRE-AMP BOARDS AC-300A, AC-300B, & AC-300C
Slide a screwdriver under the chrome handle cover and snap it off, exposing the two screws which hold the handle in place. Remove these screws. On the opposite side of the unit, locate the two rubber feet. Remove the screws that hold these two feet in place.
Before removing the amplifier from the case take off the platter and set it off to the side. Also, make sure the tone arm is locked in it's clip. The entire unit will now slide out of the carrying case. Be careful that the circuit breaker does not hang up on the case when removing the amplifier.
Locate the pre-amp board that is defective (the boards are in line behind the control knobs) and unplug it. Insert the new board firmly, being sure that the board is in the same direction as the original. Reverse the directions for opening the amplifier to close.
CHANGING THE TAPE OUT FROM MIC. TO LINE LEVEL AC-300, AC-300A, AC-300B, & AC-300C
REMOVING AMPLIFIER FROM CASE
Slide a screwdriver under the chrome handle cover and snap it off, exposing the two screws which hold the handle in place. Remove these screws. On the opposite side of the unit, locate the two rubber feet. Remove the screws that hold these two feet in place.
Before removing the amplifier from the case take off the platter and set it off to the side. Also, make sure the tone arm is locked in its clip. The entire unit will now slide out of the carrying case. Be careful that the circuit breaker does not hang up on the case when removing the amplifier.
MODIFICATION
Locate the tape out jack on the back of the set near the main speaker output jacks.
Note the location of the ends of the 100k ohm resistor between the speaker jack and the tape out jack.
Remove the 100k ohm resistor and replace it with a 10k ohm resistor.
AC-300, AC-300A, AC-300B, & AC-300C
Slide a screwdriver under the chrome handle cover and snap it off, exposing the two screws which hold the handle in place. Remove these screws. On the opposite side of the unit, locate the two rubber feet. Remove the screws that hold these two feet in place.
Before removing the amplifier from the case take off the platter and set it off to the side. Also, make sure the tone arm is locked in it's clip. The entire unit will now slide out of the carrying case. Be careful that the circuit breaker does not hang up on the case when removing the amplifier.
INSTRUCTIONS FOR CHANGING MOTOR IN AC-300A, AC-300B, OR AC-300C
Slide a screwdriver under the chrome handle cover and snap it off, exposing the two screws which hold the handle in place. Remove these screws. On the opposite side of the unit, locate the two rubber feet. Remove the screws that hold these two feet in place.
Before removing the amplifier from the case take off the platter and set it off to the side. Also, make sure the tone arm is locked in it's clip. The entire unit will now slide out of the carrying case. Be careful that the circuit breaker does not hang up on the case when removing the amplifier.
Locate the tension spring which provides the spring tension to hold the motor assembly up so that the drive wheel contacts the underside of the platter. Remove the nuts and washer from this bolt, remove the spring and the motor assembly will swing out so that you can get at it.
Unsolder the three leads, the two going to the motor and the one ground lead. Remove one of the hex bolts holding the motor mount to the bracket, slide the grommet off the other bolt and the motor will come out. Remove the two bolts holding the bracket to the motor.
Install the replacement motor by following above instructions in reverse order.
Please return the old motor to us for inspection.
TO RECALIBRATE AC-300C FROM 50 TO 60 HZ
Lift off the turntable platter and set it off to the side.
To remove the chassis from the case: stick a screwdriver under the chrome handle cover and snap it off. Remove the 2 screws holding the handle, and the 2 rubber feet on the opposite side. Tilt the unit on its side and slide the AC-300C out of the case.
Turn the AC-300C chassis up side down, control panel away from you, on a pillow or soft foam to protect the tone arm. Locate the speed control transport, the throwout (which disengages the motor in the off position), and the microswitch that turns off the motor when the speed control is in the off position (see drawing below).
Before actually adjusting the speed do the following two procedures. First, loosen the screw on the fiberglass plate holding the microswitch (see drawing) and pivot it to the rear of the amplifier so that it is out of the way. Second, loosen the two 1/4 inch hex nuts holding the throwout and slide it all the way toward you, out of the way.
Set the unit on its side, so you can see and reach both the top and underside of the system. Move the speed control so that the knob is pointing at 38 R.P.M. (This should be the speed at which you currently have to set the system in order to play 45 R.P.M. records). Note the position of the motor and speed control transport; this is the position you want the motor and speed control transport to be in when the knob is pointing at 45 R.P.M.
Holding the motor in place, loosen the 2 screws on the speed control transport and move the knob to 45 R.P.M. and then lightly retighten the 2 screws.
Now you can plug in the power cord, put on the platter, and check if the speed is set correctly. If more adjusting is necessary be sure to unplug the power cord before readjusting the 2 screws on the speed control transport. Do this as many times as necessary to get the speed set correctly. Only when the speed is correct should you firmly tighten these 2 screws.
BE SURE THE SPEED IS ADJUSTED CORRECTLY BEFORE PROCEEDING!
Now that the speed is set correctly unplug the unit, move the knob to the off position, and turn it over again on the pillow or foam. Loosen the screw on the fiberglass plate (see drawing) and rotate the brown microswitch until there is about 1/16 inch of clearance between the leaf and the body of the switch. Retighten the screw.
Loosen the two 1/4 inch hex nuts holding the throwout (see drawing) so that it can be repositioned. Keep the speed control in the off position, and lift the motor slightly so that you can slide the throwout back under the motor mount (metal piece) so it rests on the ledge shown in the drawing. This holds the drive wheel away from the platter in the off position. Retighten the nuts so that they are firm but not extremely tight. If you over tighten them the speed control can bind and not move freely.
Turn the unit right side up, plug in the power cord, and turn it on. Check to be sure that the turntable strobes correctly; that the motor turns off when the speed control knob is in the off position, that the speed control moves freely, and that the drive wheel disengages from the platter when the speed control knob is in the off position.
Reinstall the chassis in the case and the job is finished.
TO RECALIBRATE AC-300C FROM 60 TO 50 HZ
Lift off the turntable platter and set it off to the side.
To remove the chassis from the case: stick a screwdriver under the chrome handle cover and snap it off. Remove the 2 screws holding the handle, and the 2 rubber feet on the opposite side. Tilt the unit on its side and slide the AC-300C out of the case.
Turn the AC-300C chassis up side down, control panel away from you, on a pillow or soft foam to protect the tone arm. Locate the speed control transport, the throwout (which disengages the motor in the off position), and the microswitch that turns off the motor when the speed control is in the off position (see drawing below). Loosen the 2 nuts holding the throwout and slide it all the way toward you, out of the way.
Set the unit on its side, so you can see and reach both the top and underside of the system. Move the speed control so that the knob is pointing at 52 R.P.M. (This should be the speed at which you currently have to set the system in order to play 45 R.P.M. records). Note the position of the motor and speed control transport; this is the position you want the motor and speed control transport to be in when the knob is pointing at 45 R.P.M.
Holding the motor in place, loosen the 2 screws on the sped control transport and move the knob to 45 R.P.M. and then lightly retighten the 2 screws.
Now you can plug in the power cord, put on the platter, and check if the speed is set correctly. If more adjusting is necessary be sure to unplug the power cord before readjusting the 2 screws on the speed control transport. Do this as many times as necessary to get the speed set correctly. Only when the speed is correct should you firmly tighten these 2 screws.
BE SURE THE SPEED IS ADJUSTED CORRECTLY BEFORE PROCEEDING!
Note: When properly recalibrated a 45 R.P.M. record will play correctly at "39" on the speed control when using 60 Hz AC power.
Now that the speed is set correctly unplug the unit, move the knob to the off position, and turn it over again on the pillow or foam. Loosen the screw on the fiberglass plate (see drawing) and rotate the brown microswitch until there is about 1/16 inch of clearance between the leaf and the body of the switch. Retighten the screw.
Keep the speed control in the off position, and lift the motor so that you can slide the throwout back under the motor mount (metal piece) so it rests on the ledge shown in the drawing. This holds the drive wheel away from the platter in the off position. Retighten the nuts so that they are firm but not extremely tight. If you overtighten them the speed control will bind and not move freely.
Turn the unit right side up, plug in the power cord, and turn it on. Check to be sure that the turntable strobes correctly; that the motor turns off when the speed control knob is in the off position, that the speed control moves freely, and that the drive wheel disengages from the platter when the speed control knob is in the off position.
Reinstall the chassis in the case and the job is finished.
INSTRUCTIONS FOR REMOVING AMPLIFIER FROM CASE and REPLACE THE DIODE PACK. AC-300, AC-300A, AC-300B, & AC-300C
Slide a screwdriver under the chrome handle cover and snap it off, exposing the two screws which hold the handle in place. Remove these screws. On the opposite side of the unit, locate the two rubber feet. Remove the screws that hold these two feet in place.
Before removing the amplifier from the case take off the platter and set it off to the side. Also, make sure the tone arm is locked in it's clip. The entire unit will now slide out of the carrying case. Be careful that the circuit breaker does not hang up on the case when removing the amplifier.
The diode pack is located near the heavy black power transformer near the rear of the amplifier. Make note of how the diode pack is oriented in the machine and then unplug it. Plug in the one sent to you.
You are now ready to put the amplifier back in its case and check it out.
Please contact us immediately if this did not fix the problem with your system. If your system is now back in working order please return the defective diode pack to us.
VOICE & MUSIC
How to record your voice on one track and the music on the other track using an older Hilton AC-300 or AC-200. The instructions also work for the AC-300A, AC-300B, and AC-300C.
These instructions will work with any MiniDisc recorder. They will also work most Computers and CD recorders as long as they have a “Line” level input.
You will need Hilton “Stereo Recording Isolation” cord. These sell for $28.50. You will need to tell us if you are using a “Walkman” or a larger “Shelf” type MiniDisc Player/Recorder. The small Walkman type systems use a Stereo 3.5mm connection while the Shelf type units have Dual RCA input connections. The Hilton “Stereo Recording Isolation” cord allows you to safely connect your MiniDisc to the ¼” speaker jacks on the back of your Hilton sound system.
You will want to decide right at the start if you want the Music on the Left or the Right channel of your recordings. Whichever way you decide *** Be Consistent *** so your recordings are always the same.
Connect the Hilton “Stereo Recording Isolation” cord with one of the ¼” plugs into a Main Channel speaker jack and the other ¼” plug into a Monitor Channel speaker jack. Connect the other end to the record input of your MiniDisc system. Connect a speaker into the other Main speaker jack so you can hear the music while making the recording. At this point you are properly connected to make a voice on one track, music on the other track recording. It will take a little experimenting the first time to get the level adjusted using the Main Music volume control and the Monitor Voice volume control. You want MUSIC ONLY turned up on the Main Channel of your Hilton and VOICE ONLY turned up on the Monitor Channel. When making your first recordings remember to use the tone controls for your voice and the music for the best recording – this will take a little practice and experimenting! In most cases you will want to decrease the Bass of the music and increase the Treble. Make sure your voice has enough treble to be clear and crisp when played back.
For the best playback on older Hilton systems you will need 2 items. One, a Stereo Signal Booster – this allows you to increase the level coming out of the MiniDisc to match the input of older Hilton systems “Tape Playback” jack. Second, a “playback attenuator” -- this device allows you to connect the voice side of your recording directly into the ¼” Microphone input on any Hilton system. The last of the Hilton AC-300 systems, the AC-300C, does not need the Stereo Signal Booster for playing back your recordings.
It takes a little work and few gadgets to make and playback your Voice and Music recordings but it can be done and work very successfully with older Hilton sound systems. Once you have the recordings and the Signal Booster and Playback Attenuator” you can also play your recordings into smaller single channel Hiltons like the Micro-75A.
CHANGING OUTPUT BOARD AC-300A, AC300B, and AC300C
Slide a screwdriver under the chrome handle cover and snap it off, exposing the two bolts which hold the handle in place. Remove these bolts. On the opposite side of the unit, locate the two rubber feet. Remove the bolts that hold these feet in place.
Make sure the tone arm is locked in it's clip. Lift out the platter, and set it aside. Slide the chassis out of the case, depressing the reset button to clear the case as the chassis slides out.
Turn the unit bottom side up on a soft pad and orient it so that the front panel is nearest you and the speaker jacks are farthest away from you. The main channel output board will be on your left and the monitor board on your right, nearest the speed control arm.
After determining which channel is malfunctioning, unsolder the two wires which are connected to the little round thermal cut off. Remove the four screws which hold the board to the heat sink and then unplug the edge connector. Re-connect the edge connector to the new board before re-installing it on the heat sink. Put a drop of silicone cement or glue where the edge connector meets the board to keep it from working loose. Use GE clear silicone seal or equivalent; do not use any material which is a conductor. If you have further problems, call us.
TO CHANGE MOTOR START CAPACITOR
Slide a screwdriver under the chrome handle cover and snap it off, exposing the two bolts which hold the handle in place. Remove these two bolts. On the opposite side of the unit, locate the two rubber feet. Remove the screws holding these two feet in place. The unit is now unbolted from the case.
Make sure the tone arm is locked in it's clip. Lift out the platter and set it aside. Slide the chassis out of the case being careful nothing hangs up on the back side of the case (where the speaker connections are).
NOTE: Replacement capacitor must be rated at 400 Volt or higher.
The motor capacitor is soldered onto a terminal block as part of the motor assembly. The terminal block will most likely have to be bent slightly away from the motor to get at the capacitor. Carefully remove the old capacitor and install the new one. See the sketch below to locate the proper solder points.
Reverse the above procedures to reinstall the set into the case.
If you have any questions, please call us immediately.
CHANGING OUTPUT SELECTOR SWITCH AC-300, 300A, AC300B, & AC300C
Slide a screwdriver under the chrome handle cover and snap it off, exposing the two bolts which hold the handle in place. Remove these bolts. On the opposite side of the unit, locate the two rubber feet. Remove the bolts that hold these feet in place. Make sure the tone arm is locked in it's clip. Lift out the platter, and set it aside. Slide the chassis out of the case, some models have a reset button on the rear panel, depress this button to clear the case as the chassis slides out.
On the model AC-300 the pre-amp board has to be removed. Remove all of the knobs from the controls on the front panel. Remove the small grounding springs underneath each knob. Remove the hex nuts from each of the control shafts. Stand the unit up so that you have access to the underneath side. Remove the bottom heat plate. Remove the plug-in connector at the end of the pre-amp board, it will be necessary to loosen the spot of clear plastic that holds the connector in place. The entire pre-amp assembly will come out now.
On models AC-300A, AC-300B, and AC-300C remove only the selector knob and the hex nut from the control shaft. Turn the unit bottom side up on a soft pad and orient it so that the front panel is nearest you and the speaker jacks are farthest away from you.
The new switches are slightly different in appearance and how they are connected. The drawings below will help you identify the wires. Locate the selector switch and mark the wires with tape as shown in the drawing below. Unsolder the wires marked "A", "B", "C", and "D". Install the new switch in the position shown in the drawing. Solder the wires you previously marked with tape, to the switch using the drawing as a guide.
Reassemble the unit by reversing the above procedure. If you have any difficulty please do not hesitate to contact us.
INSTRUCTIONS FOR CHANGING TONE ARM
Locate the handle cover which carries the initials. Slip a screw driver under the end of this cover and snap it off. Remove the two machine screws which hold the handle on. On the opposite side, remove the two rubber feet.
Remove the platter and stand the unit up on edge, handle end up.
On the AC-300 & AC-300A hold the red reset button on the circuit breaker in so that it will clear the case, and gently slide the unit out of the case.
Set the chassis upside down on a soft pad or cushion. Locate the red and black wires which come out of the tone arm. Be sure to mark or sketch the two terminals on the tape playback jack so that you can reconnect the leads from the new tone arm in exactly the same way. Unsolder the red and black leads.
Being careful not to pinch the red and black leads, remove the nut and lock washer from the base of the tone arm, set the unit back up on edge, and remove the tone arm. Install the new arm, making sure that it is in the clip, and lay the unit back down. Reinstall the lock washer and nut, again being careful not to damage the red and black leads. Be sure that the nut is secure. Resolder the red and black leads to the same terminals from which you removed them, and reinstall the unit in the case, again being careful that the reset button clears the case as the chassis slips into place.
TO ADJUST THE ANTI-SKATE SPRING ON THE POST OF THE TONE ARM:
Loosen the set screw in the set collar at the bottom of the post, so that the anti-skate spring is under no tension. Put a 45 RPM record on the platter, allowing the needle to rest on the pickup grooves at the outer rim of the record. Lock the setscrew on the post so that the set collar is about 1/8" above the deck, and so that the spring is still under no tension.
The unit should now be ready for use. Play a record through to make sure that the arm track properly, and check the reset to make sure that it returns properly when the button is pressed.
If you need further assistance or have any questions, please do not hesitate to contact us. We sincerely appreciate your continued support of the Hilton product line.
INSTALLING PRE-AMP BOARDS AC-300A, AC-300B, & AC-300C
Slide a screwdriver under the chrome handle cover and snap it off, exposing the two screws which hold the handle in place. Remove these screws. On the opposite side of the unit, locate the two rubber feet. Remove the screws that hold these two feet in place.
Before removing the amplifier from the case take off the platter and set it off to the side. Also, make sure the tone arm is locked in it's clip. The entire unit will now slide out of the carrying case. Be careful that the circuit breaker does not hang up on the case when removing the amplifier.
Locate the pre-amp board that is defective (the boards are in line behind the control knobs) and unplug it. Insert the new board firmly, being sure that the board is in the same direction as the original. Reverse the directions for opening the amplifier to close.
CHANGING THE TAPE OUT FROM MIC. TO LINE LEVEL AC-300, AC-300A, AC-300B, & AC-300C
REMOVING AMPLIFIER FROM CASE
Slide a screwdriver under the chrome handle cover and snap it off, exposing the two screws which hold the handle in place. Remove these screws. On the opposite side of the unit, locate the two rubber feet. Remove the screws that hold these two feet in place.
Before removing the amplifier from the case take off the platter and set it off to the side. Also, make sure the tone arm is locked in its clip. The entire unit will now slide out of the carrying case. Be careful that the circuit breaker does not hang up on the case when removing the amplifier.
MODIFICATION
Locate the tape out jack on the back of the set near the main speaker output jacks.
Note the location of the ends of the 100k ohm resistor between the speaker jack and the tape out jack.
Remove the 100k ohm resistor and replace it with a 10k ohm resistor.
