Crate GLX-212 combo. cant change DSP. repair??

SOURCE: turned on switch to crate V33-212 and it shorted out

Your amplifier is a solid-state rectified tube amplifier. This means that a tube is NOT used for the power supply. Why is this significant? Because most of the time you have the problem you are describing, it is because of the tube rectifier.
Since this amp does not have a tube rectifier, the problem is likely one or more of the tubes. I have seen in 95% of the amps I repaired that the tubes were the cause, and since the amp is so new, I would suspect tubes first.
Now the hard part: which tube? Without a tube tester, you will have to use the 'firewall' technique. You will need to get a bunch of replacement fuses, as you might go through a few untill you find the problem. Radio Shack is a great place for fuses (make sure they are SLOW BLOW type).
The problem is almost guarenteed to be the power tubes: they are a big failure mode in tube amps (the preamp tubes are not as likely the problem).

This is what I do at a customer site without a tube tester:
(1) Have either a KNOWN TO BE GOOD REPLACEMENT SET OF TUBES or a NEW SET OF TUBES.
(2) Have plenty of fuses.
(3) Start with power tubes: they cause most of these problems. Replace burned out fuse.
(4) Replace all 2 (or 4 in your case) with the good tubes.
(5) Turn on amp and play on it (30 minutes at various volumes and settings). Turn it on and off many times using the on/off procedure your amp requires (like using the standby switch on some models).

* if the amp plays and works, likely you had a bad power tube. If you are blowing fuses, the problem is either the power amp circuitry or the preamp tubes.

* Leave the good power tubes in before going on to the next step. Also: the minor difference in bias wont matter for what we are doing now: the bias being WAY out is almost never the cause.

(6) Check preamp tubes (easy to do, as this does not require us to poke around on the insides).
(7) Replace burned out fuse (atleast number two by this point).
(8) Replace all preamp tubes.
(9) Turn on and repeat step 5.

* Blowing fuses at this point means atleast two types of repairs needed: retention tube sockets or someone to look inside the amp. Either way, this is a serviceman repair (things I do). Since the amp is so new, take the warentee buyout and throw it back to where you got it. Crate is real good about dealing with these issues (if you are the only owner and it is within warantee).

If you need to contact warantee support, you can tell them you have had the amp re-tubed and the problem still persists (meaning they can brush you off with 'just get it retubed and then call us if there is problems'. This is like 'take two asprins and call me in the morning: 95% of all tube amp problems can be fixed by this (retube, not asprins).

If you have to do the warantee route, KEEP YOUR NEW TUBES. The preamp tubes are fine, but the power tubes may be damaged. Wait for what Crate tells you before you use them. This is if you are cheap. I would pitch all of the tubes and consider the 70 bucks as my cheap attempt to bet I am in the 95% solution number (tubes are the cause). Otherwise, the repair will cost shipping at a minumum. Dont you love it: tube amps are expensive and require someone with deep pockets to enjoy the tone. But what can we do: tubes DO sound better and when everything is working, they perform reasonably well.

Good luck on this!
-mike

Posted on Mar 30, 2009

SOURCE: Crate TX50 DB has noisy DSP circuit when rotating the DSP pot!

When you are changing the DSP effect on the fly, static or noise is NORMAL !!! The DSP is changing the data and having to recalculate on the fly and doesn't mute itself while doing so which results in "garbage sounds out".

The bypass setting should NOT get any tone UNLESS you have feedback going on. If your guitar can "hear" the speakers in the amp, the strings can vibrate and get feedback going.

Unplug the guitar and see if high freq tone is still there on bypass. If the tone is in the musical range, then there is a problem if nothing is plugged in. If it is a VERY weak, very high frequency tone, this may be the digitizing noise from the DSP. On bypass, the audio is likely to still go through the DSP, just not be modified by it.

Posted on May 03, 2010

Testimonial: "Concise and timely response to my question...Thanks!"

SOURCE: where can I get copy of owner's manuel for Crate

Download it here:

http://www.crateamps.com/pdf/manuals/BX80_OM.pdf

Posted on Nov 05, 2010

SOURCE: basically i cannot seem to

Norrmally you run the guitar into the pedal and then into the amp. IF you want it behind the built in effects, The look on page 6 of your users manual showing the special cable you will need to do the "insert" of your effects pedal.
If you don't have a manual, download it here:

http://www.crateamps.com/pdf/manuals/FW120H_OM.pdf

Posted on Jan 11, 2011

SOURCE: My crate FW120HS has suddenly

This has a digital reverb unit. The settings are subject to get clobbered I suspect. I don't know if you are using foot switch for the reveb control... You may also have a cable that has come loose...

Here is a link to schematic for your unit:

http://elektrotanya.com/crate_flexwave_guitar_amp.pdf.pdf/download.html

Notice that the reverb is set by DC voltages from teh setting pots that go to the DSP chip. These setting pots receive voltage from a 16 volt ZENER regulated source. First thing is to CHECK that voltage. If the Zener has opened and you find much over that 16 volts, that is your cause of the problem.

The circuitry is on page 1 in the 3B to 3D lower left of the page.

Posted on Feb 14, 2011