- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
Just apply the excellent solution of "dskum" that I am reproducing here:
dskum
I had the same sub and I started hunting down the problem by disabling \'sectional\' parts of the circuit to find out whats causing the problem. The problem was narrowed down to the small \'limiter\' circuit which is soldered vertically on the Pre-Amp. (The wire from power amp connects to it)
As far me, the limiter circuit doesn\'t add much value, if you are careful enough not to push the subwoofer to its peak limits. There is a 7 wire bus which connects the Pre-Amp (top board) to the power amplifier (bottom board). In that 6 wires are just direct connection from pre-to- power amp board. The pre-amp output goes through the limiter. (1st black wire).
To remove the limiter from circuit just physically remove the limiter board by de-soldering the 7 pins through which its connected to pre-amp. Also you may\'ve to clean up the glue around to easily remove it. Disconnect the 7 wire connector from the limiter and solder it directly to the pre-amp board. (Only 6 black wires need to be connected.) Check the picture. Also as part of experiment I replaced the power filter capacitors with slightly bigger capacity. (But its not necessary - the glue on the old capacitors made it look like it was bulged - but its not).
The white wire (limiter feedback) is not necessary and that can be disconnected or cut off for good. All the popup/crackling/thumping it was making is gone and the sub is working great again. (Yes it was doing so even without any inputs).
While de-soldering make sure don\'t apply too much heat. The boards are pretty weak and you might easily damage the solder pads.
WhiWh
Whil Also don\'t use any kind of diode or mess with it the limiter circuit. Just removing the limiter circuit makes it good. If you use diode to directly connect the pre-amp line to power line as suggested earlier you might be damaging it more than its currently since you are almost connecting to the 42 v rails to it. Also if you google you would come across the service manual if you are interested in the circuit diagram.
Just apply the excellent solution of "dskum" that I am reproducing here:
dskum
I had the same sub and I started hunting down the problem by disabling \'sectional\' parts of the circuit to find out whats causing the problem. The problem was narrowed down to the small \'limiter\' circuit which is soldered vertically on the Pre-Amp. (The wire from power amp connects to it)
As far me, the limiter circuit doesn\'t add much value, if you are careful enough not to push the subwoofer to its peak limits. There is a 7 wire bus which connects the Pre-Amp (top board) to the power amplifier (bottom board). In that 6 wires are just direct connection from pre-to- power amp board. The pre-amp output goes through the limiter. (1st black wire).
To remove the limiter from circuit just physically remove the limiter board by de-soldering the 7 pins through which its connected to pre-amp. Also you may\'ve to clean up the glue around to easily remove it. Disconnect the 7 wire connector from the limiter and solder it directly to the pre-amp board. (Only 6 black wires need to be connected.) Check the picture. Also as part of experiment I replaced the power filter capacitors with slightly bigger capacity. (But its not necessary - the glue on the old capacitors made it look like it was bulged - but its not).
The white wire (limiter feedback) is not necessary and that can be disconnected or cut off for good. All the popup/crackling/thumping it was making is gone and the sub is working great again. (Yes it was doing so even without any inputs).
While de-soldering make sure don\'t apply too much heat. The boards are pretty weak and you might easily damage the solder pads.
WhiWh
Whil Also don\'t use any kind of diode or mess with it the limiter circuit. Just removing the limiter circuit makes it good. If you use diode to directly connect the pre-amp line to power line as suggested earlier you might be damaging it more than its currently since you are almost connecting to the 42 v rails to it. Also if you google you would come across the service manual if you are interested in the circuit diagram.
Parts ordering: http://www.searspartsdirect.com/partsdirect/part-model/Craftsman-Parts/Air-compressor-Parts/Model-919167450/0247/0703000/P0040151/00001?blt=06&prst=&shdMod=
If your talking about the thump thump sound thru the sub when in standby mode, here's a fix if your good with a small soldering iron. Remove the amp from the sub. Locate U301 on the limit curcuit. (the small circuit card standing up right)
Replace U301 with a TL074IN (www.alliedelec.com part #248-0012) .35cents +S/H also remove R263 from the preamp board,add a new 1N4148 diode(#935-0242) .05 cents to the pre amp board. Connect the Anode of the new diode to the Anode of D101 and the Cathode of the new diode to the Cathode of D108. Replace amp and test. Thump thump should be gone.
Depending upon the compressor and mixer, there are a couple of options. The compressor should be between the output of the mixer and the input of the power amps. To accomplish this, you can use either an insert cable or 2 audio cables. Some mixers have an insert point for each output. These are usually marked as inserts adn use TRS cables (Tip/Ring/Sleeve). These cables are essentially the same as stereo 1/4" cables. If the compressor can take that, than all you need is a single insert cable. This insert cable will insert the compressor directly so that you still connect the mixer output to the amp as you woud without the compressor. If not, then you will need two 1/4" standard audio cables to connect the mixer output L/R to the amp input L/R.
Our 2 HP Speedaire horizontal tank compressor is rated 115 / 230 volts at 24 / 12 amps, respectively. This means at 115 volts, a 30 amp circuit breaker is the bare minimum. That also means that the wiring should be #10 copper wires for short runs, but the next size up; #8 copper wires would be better connected to a 40 amp circuit breaker. Running at 230 drops the amperage requirement by half, to 12. A #14 copper wire is minimum for short runs with a double pole 15 amp circuit breaker, but #12 copper wires connected to a double pole 20 amp circuit breaker would be better choice.
If the compressor is cord connected (or even directly wired) with the minimum sized wires, it will likely a voltage drop problem unless very close to the panel. This problem is more pronounced as the distance between the circuit breaker and motor increases, or when smaller wires are in the circuit. All the voltage at the circuit breaker does not reach the motor, as it is lost as heat; so the compressor only sees 90 to 105 volts instead of the 115 volts it expects.
If the cords, connections, etc are getting hot, it is a tell tale sign of under-sized wires and /or poor connections. Once you solve these problems, the compressor should run "as advertised " because motors usually don't "go bad" but fail all at once. Unless you have a bearing problem - or there is a problem with the load itself (compressor).
×