Crate Music - Page 6 - Answered Questions & Fixed Issues

Do you happen to have another speaker that you could hook up to speaker output? This would bypass the amps internal speaker and lf you get sound from that setup, it would mean either a jack failure or possible internal speaker problems. Please let me know.

you have either a failing fuse or a failing power transformer. take out the screws on the top of the amp, leave the handle in tact and pull out the chasis. look at your fuse to see if it is in its holder correctly, and see if the fuse is burnt. the correct fuse values will be printed on the circuit board. if the fuse looks good then, it may be the power tranny going south.

its a crate. 60% of all crate amplifiers go back on defects. take the top screws out and slide out the chasis, look at the fuse and determine if its toast. if the fuse is good, get a new amp. if the fuse is bad replace it and you should be good. the circuit board will have the correct fuse to be used printed on the board.
yostamplifier.com

did you change out the fuse? could be a tranny going south. if you change the fuse and you still get no power, then you have a fried power transformer. they are relatively easy to replace. look on ebay . get the numbers off of the existing one and start web searching. something will come up. if not email me on my contacts tab in my website yostamplifier.com we can troubleshoot. you should see the custom blue voodoo i built and gave to my little brother.

Do you have electronics experience? Inspect the amp for broken or cold solder joints and any burned components. Check to see if the fuse blew and that the output IC's or transistors (not sure what Crate used in these) are not bad. Check your speaker wire as well.

You can reach the limiting IRRESPECTIVE of where the volume control is set when you have a guitar or other source that has HIGH output.

Guitars that have battery in them with internal amplifiers are an example of a high output guitar. Plain inductive pickups may require the volume control to be set at say 70% to reach limiting.

Please NOTE that the volume control is NOT linear, but is an "audio taper".

Limiting means you are probably driving it too hard. Many learn the hard way when speakers and thee power amp fail.

When the cone is driven too far beyond the pole pieces of the magnet, then the IMPEDANCE of the speaker becomes relatively low and can damage the power amp. The limiter tries to prevent this by sensing the current and or voltage and will back off the gain internally. This causes distortion when it happens.

Are you getting sufficient power to the amp?

Could be a loose connection inside the amp (such as a wire), a bad component, or a severed ground. Many possibilities here. If you know electronics, take a multimeter and start testing all the components. Look for any burn marks, check for broken solder connections, and continuity test all wires. Be careful since amps can hold a deadly voltage for a good while. Be sure to drain the capacitors before doing anything else inside it. If you do not feel comfortable doing this, you can take it to a electronics repair person. Keep in mind that Crate is one of the harder amps to fix because most of their components are surface mount.

Make sure the "ground lift" option is used on the direct box.

DO NOT UNDER ANY CIRCUMSTANCES use a headphone output jack as the output of this unit. The headphone jack is for HEADPHONES that have no return to ground. Use of this as drive to a sound board is sure to cause problems and in some cases can fry these amps due to the circuitry.

The cable used to go to the direct box should be very short and high quality.

You should source the power for this unit from the SAME source and receptacle as your sound board if at all possible.

Hi

The problem is with the amplifier itself. Crackling is usually capacitor related and you will need to have the amp checked over to properly identify the cause.

Some amps are also prone to pick up static from other electrical items which can also cause these problems. I had a crackling issue with an old Crate amp of mine which turned out it was due to being too near a computer/monitor so it is worth eliminating these things as a possible cause before having the amp checked.

Hope this helps. Thanks for using FixYa.

The switch that is a part of the effects loop jack is making poor contact.

Open the unit and ALSO check the soldering of the jack pins.

MANY of these have a contact as part of the strip that contacts the plug. This spring strip often gets weakened and doesn't contact the metal contact below. The contact "forwards" the preamp to the power amplifier. If the contact doesn't quite make, no power will get to the power amp. If the jack is bad, you MIGHT also try a jumper plug. You MIGHT be able to bend the contact to get moore force as a repair.


If it is a mono 1/4 jack, then use a short jumper from the FX send to the return is another non-invasive fix..

IF it is a TRS type effects loop, plug in a plug that has the Tip and the Ring jumpered in the plug as a quick fix.

In general the jacks in these guitar amps are JUNK !!!

grounding it,and encasing the box in foil and grounding the foil

Hi there. This should work but check it out: pin assignment. It's a 32 watt so won't blow again. http://www.mouser.com/Search/Refine.aspx?Keyword=tda2050
Thanks
Paul

Not good. If you have electronics experience, you can replace the power amp IC to fix it.
Paul

Yes, if you have "line out" from 788. You will need appropriate cables to attach to PC sound card.
Paul

Hi

Go to www.ezrepair.ca and send it to us.
We will diagnose your unit for free and give you an estimate in a 48H maximum period.

If its the input reverb tank wire or output reverb tank wire just reconnect it (if the amp has a reverb tank).

Check the input RCA plug going into the reverb tank (silver box with two wires connected to it). Make sure the amp is off when you do this. Sounds like the output is working fine if hitting the amp does it.

When a piece of equipment causes a fuse to blow or a breaker to trip, it normally means something in the equipment's circuit was shorted. Either because of heat, moisture, a loose screw, loose wire, loose part, a bug, etc. For safety reasons, don't plug it back in and take it to a repair shop.

Hope this helps!

Start easy. You could have a bad power switch. Do you get any kind of indication of any life at all, like tube filiments or front panel indicators? If the fuse is blown you have a fault that is drawing excess current, in which case you can check the rectifiers that create your bias voltages, yank the output tubes to see if they have an internal short, less likely would be a shorted filter capacitor (although I have seen it). You could also have a bias problem on the output tubes that causes them to draw excess current and likely makes the tube(s) glow bright red before popping the fuse. If this is the case, look for shorted or leaky coupling capacitors and burned bias resistors, or maybe just a tube with internal shorts, and you will likely have junk tubes as a bonus (they don't take kindly to glowing bright red- meaning a glow that is far more intense than the soft glow of the filiments). If the fix gets more involved than all of this, give me your email addy and we can get hard core.

Yes.
Are you saying that the only indication that it is running at all is that the fans are running? So the tubes don't light up? No indicators on the front of the amp?
Power supplies that provide multiple voltages, which your amp has, can provide some of the voltages while having a problem that prevents them from providing others, all while not blowing a fuse. If you are not confident in your ability to work on a piece of electronic equipment that has 120VAC coming in and at least 175VDC or more present inside it, bring it to a service center.
The good news is that it is probably not horribly serious. Problems like this can almost always be repaired in a cost effective manner.