FAQ...

Looking for answers? CLICK the links below and read through the FAQ section first.

Q. What is the length of the warranty period on my UltraSound Amplifier?

Q. How do I use headphones with my UltraSound Amplifier?

Q. What is a ground loop and what causes this problem?

Q. Why does UltraSound only use 15v phantom power instead of 48V ?

Q. What is the "Notch Filter" on my amplifier used for?

Q. Why does the green Power light on my DS2/DS3/DS4 model amplifier turn red sometimes?

Q. What is the "Shape" control on my amplifier used for?

Q. How can I chain my UltraSound Amplifiers together to create more sound?

Q. How do I install my Tilt Hardware?

Q. How do I use my Tilt Hardware?

Troubleshooting Guide...

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Q. What is the length of the warranty period on my UltraSound Amplifier?

A. UltraSound Amplifiers warrants to the original purchaser that this product (exclusive of speakers, tubes, meters, and foot pedals) will be free of defects in material and workmanship for a period of 5 years from the original date of purchase. UltraSound Amplifiers warrants to the original purchaser of this product the (speakers, tubes, meters, and foot pedals for a period of ninety (90) days) from the original date of purchase by the original purchaser; provided however, it is understood that the speaker warranty will be subject to the inspection of any speakers by UltraSound Amplifiers, or any Authorized Dealer. Complete Ultrasound Warranty

Q. How do I use headphones with my UltraSound Amplifier?

A. With the exception of our entry level AG-30 amplifier, there is not a dedicated "Headphone Out" jack on our amplifiers. There has been some controversy in the industry about headphone out signals in recent years because a lot of players like to use this signal to drive a personal monitor. The headphone out will work well for this with one exception, most times when a plug is inserted into a headphone out jack, it will defeat the internal speaker(s) of the amp. While this is great for silent practicing, if you are using the amp on stage and using a personal monitor, you have a dilemma, no sound from your amplifier.

It is very simple to use headphones with your Ultrasound amp for use as a monitor or for silent practicing by using the "Line Out" signal and a dedicated headphone amp such as the Behringer MA400. (The MA400 is available from Musicians Friend for about $20) With this setup you have a lot of flexibility.

1. Since the Line Out and Direct Out signals are "Pre" Master Volume, by turning the Master Volume on the amp to 0, you can practice in silence since there will still be signal available at the Line Out and Direct Out jacks.
2. If you are using a personal monitor with the amp on stage, just turn up the Master Volume control to the desired level for your stage mix. (The setting on the Master Volume will not affect the Line Out or Direct Out signal level)

Q. What is a ground loop and what causes this problem?

A. When 2 pieces of AC powered equipment are connected together there is potential for a ground loop. A ground loop is usually heard as a "hum" through the speakers of the PA or amplifier. For instance, if you connect your amplifier to a mixing board via the XLR Direct Out jack or Line Out jack, there is potential for a ground loop if both pieces of equipment use earth ground as their signal ground. (Earth ground, sometimes called the safety ground is the round prong on the AC power cord, which plugs into the wall outlet.) The cause of this is the resistance of the line cords used on your equipment and sometimes the house wiring, which your equipment is plugged into. Most PA systems and some amplifiers have a Ground Lift switch. What this Ground Lift switch does is floats or separates the earth ground from the signal ground. There are also some Hum Eliminator boxes available which isolate the grounds by using an isolation transformer in line with the signal cables. Ground Loop Tech Tips

Q. Why does UltraSound use only 15v phantom power rather than the 48V?

The main reason we use the DIN 45-596-P12 standard is because it is much less likely to harm your equipment. 48v phantom has been known to cause harm to some equipment that is plugged into it. Given that only a very few "boutique" externally biased condenser mics actually need 48v phantom power we feel it is not worth the risk and expense. Below is an excerpt from our owners manual which has a list of condenser mics which will work very well with our amps.

** PHANTOM POWER - An internal phantom power source (13.6 volts) is provided for use with condenser mics. This power source is on at all times and does not affect the standard operation of the amp, even when a condenser mic is not used.  We use the DIN 45-596-P12 volt standard which will operate virtually all of the live sound reinforcement condenser microphones on the market.  Some "boutique" externally biased condenser mics will not be compatible and will require 48 volt phantom power. We suggest live sound condenser mics by: AKG (C4500B,4000B, etc.), Audio Technica (AT3035, 3032, Pro Series, etc.), CAD, Shure and Crown.

Q. What is the "Notch Filter" on my amplifier used for?

A. The Notch Filter is used to eliminate unwanted acoustic feedback. When amplifying an acoustic guitar there is a great potential for positive feedback from the amplifier to the guitar. Since the acoustic guitar is hollow and usually constructed of fairly thin material it has the potential to resonate at certain frequencies, (usually between 100 - 350 HZ). The Notch Filter is used to eliminate, or filter out, the frequency that will cause the guitar to resonate. The Notch Filter frequency control varies the frequency of the Notch Filter between 100 - 350 HZ to allow you to "sweep" through these frequencies to find the frequency, which is causing any unwanted feedback.

Q. Why does the green Power light on my DS2/DS3/DS4 model amplifier turn red sometimes?

A. The power light serves a dual function on the DS2/DS3/DS4 amplifiers. First, a green light indicates that the amplifier is turned on. Secondly, this light will turn red when the power amplifier reaches full power output. Our DS2/DS3/DS4 model amplifiers are equipped with a voltage limiter on the power amplifier, which will prevent the power amplifier from being overdriven. Once full power is achieved, the voltage limiter is actuated and the power light will turn red indicating that full power has been reached.

Q. What is the "Shape" control on my amplifier used for?

A. The Shape control is a mid dip control. When in the "ON" position, the mid frequencies will be cut and the high and low frequencies will be boosted. This gives the amplifier another complete voice, or flavor allowing the amplifier to be much more versatile and useful for many different instruments.

Q. How can I chain my UltraSound Amplifiers together for more sound?

If the amps you want to connect are "DS" (not DS3 or DS4), you can chain them fairly easily. The best way to do this is via the Effects loop. You can run an "instrument" cable from the EFX "Send" jack of the "Master" amp, (the amp you have your guitar plugged into), into the effects return jack of the "slave" amp. If your amps are DS models, you will need to insert a plug into the instrument input of the slave amp to disable the auto mute circuit. (For the DS3 or DS4 models you will not need to do this)

In this configuration, the volume control on the "Master" amp will control both amps. The tone controls and digital efx will still be active on the slave amp.

Q. How do I install my Tilt Hardware?

A. To install the tilt hardware option on your Ultrasound amplifier please refer to the following:

1. The first step is to locate the middle of the cabinet from left to right. (For the AG-50DS2/DSD3/DS4 this center point is approximately 9" from either side.

2. Step 2 is to measure 2" from the front of the cabinet to this mid point and make a mark. This is the point at which you will install the center mounting screw for the tilt hardware.

3. Position the tilt hardware so that the center mounting hole is above the mark you just made. Place one of the enclosed wood screws through the center mounting hole in the tilt hardware and screw it into the cabinet at the position marked. The wood screw can be screwed directly into the cabinet without drilling a pilot hole. If you wish to drill a small pilot hole, (1/16" - 3/32") in the cabinet this is OK. There is nothing in the bottom of the cabinet, which can be harmed if the drill bit goes into the cabinet. Don't tighten this center screw down all the way.

4. Once you have the center screw located, you will need to position the tilt hardware so that it is straight and oriented properly. The proper orientation is so that the rubber pad is towards the back of the cabinet. Once properly oriented and straight, tighten the middle mounting screw.

5. Install the remaining 2 mounting screws into the mounting holes on the tilt hardware and the installation is complete.

Q. How do I use my Tilt Hardware?

A. To use the tilt hardware feature, tilt the amplifier back and fold the tilt back handle down. Tilt the amp forward until it is resting on the tilt hardware's rubber pad. You are ready to play. Since the tilt hardware is spring loaded, when the amp is pickup up to transport to a different location, the tilt hardware automatically folds back against the cabinet.

Troubleshooting Guide

Quick Checks

. Is the power cord properly plugged into an electrical outlet?

. Is there power at the outlet?

. Are the control knobs, Volume, Master Volume, turned up?

. Are the batteries in your guitar pickup system fresh?

. Are the control knobs on your external equipment turned above 1?

. Is the power cord on your external equipment properly plugged into an electrical outlet?

. Are the batteries in your external equipment fresh?

. Are any cords cut, frayed, or damaged?

. Is the instrument properly plugged into the amplifier?

If you've checked the Quick Checks, and your amp is still not working properly, please review the Common Problems below:

Problem: No pilot light.

1. Check to make sure the power cord is properly plugged into the amplifier and into the electrical outlet.

2. Make sure there is power at the outlet.

3. Check the fuse. The fuse is located within the AC power receptacle on the back of the amp. The fuse compartment can be accessed with a small slotted screwdriver. (Be sure to replace the fuse with the same value and style fuse)

Problem: There is a pilot light but not sound from the amplifier.

1. Make sure the control knobs, Volume and Master Volume, are turned up. ("5" is a normal setting for most pickup systems.)

2. Make sure the batteries in your guitar pickup system are fresh.

3. Make sure the control knobs on any external equipment you may be using are turned up.

4. Make sure the power cord on any external equipment you may be using is properly plugged into an electrical outlet.

5. Make sure the batteries in any external equipment you may be using are fresh.

6. Check all of the signal cords you are using. If any cords are cut, frayed, or damaged replace these with a known "good" cord and try your setup again.

Problem: The GUITAR CHANNEL works but the MIC CHANNEL doesn't work.

1. When using the MIC CHANNEL on the AG-50DS2 and AG-100DS2, there must be a plug inserted into the GUITAR INPUT jack to disable the auto mute function.

Problem: The amplifier makes a "squeaking noise" when I turn it on or off.

1. This noise is caused by the Digital Effects processor powering up or down. This is normal and will not harm the amplifier. To eliminate this, make sure there is not a plug inserted into the GUITAR INPUT jack when turning the amplifier on or off. This will enable the auto mute function of the amplifier and no sound will be heard from the speakers when turning the amplifier on or off.