Sorry, I just could not sit idle while being accused of caring more about making money than making good gear. Below you can see how cold hearted and deceitful many other companies are, too. These are pages directly from their respective owner's manuals. I like to think of us as being as open and helpful as possible. There is no conspiracy here. We don't keep secrets and really do care about everyone who owns any of our stuff. I find it interesting (strange) that offering useful information in our manuals and Technotes (at egnateramps.com) is viewed by some as somehow covering our butts by coming right out and admitting we make junk that we know will fail. I recently did a number of training sessions for Guitar Center employees so that they could better understand our products. At those sessions, I was told more than once that our owner's manuals are viewed as the defacto" amp manuals that other companies should follow because of all the useful information we provide. Please note that many amps do not have a separate fuse for the power tubes. Consequently, if a power tube does blow, it can often damage other things inside because the SloBlo Main fuse needs to blow to protect the amp. Notice the term SLoBLo, which means that fuse can hold for quite a long time before it blows, even when a tube is severly shorted. Having the additional low current fuse clearly helps protect the amp against a shorted tube quicker and more efficiently than waiting for the Main fuse to blow even though it may seem like a nuisance to some folks.
Mesa Boogie
: There are two main types of tube faults: shorts and noise. Both large and small tubes may fall prey to either of these problems but diagnosis and remedy is usually simple.If a fuse blows, the problem is most likely a shorted power tube and shorts can either be mild or severe. In a mildly shorted tube the electron flow has overcome the control grid and excess current flows to the plate. You will usually hear the amp become distorted and begin to hum slightly. If this occurs, quickly look at the power tubes as you switch the amp to STANDBY and try to identify one as glowing red hot. It is likely that two of a pair will be glowing since the “shorted” tube will pull down the bias for its adjacent mates, but one tube may be glowing hotter — and that one is the culprit. The other two are often fine — unless they’ve been glowing bright red for several minutes.
Because there is no physical short inside the tube (just electrons rioting out of control) merely switching to STANDBY for a few moments then back to ON will usually cure the problem...at least temporarily. Watch the tubes carefully now. Should the problem recur, the intermittent tube will visibly start to over heat before the others and thus it can be identified. It should be replaced with one from the same color batch, shown on its label. Call us and we will send one out to you. The severe short is not nearly so benign. In the worst cases, a major arcing short occurs between the plate and the cathode with visible lightning inside the glass and a major noise through the speaker. If this is seen to happen, IMMEDIATELY turn the amp to STANDBY. By this time the fuse probably will have blown. Such a short is usually caused by a physical breakdown inside the tube including contaminate coming loose or physical contact (or near contact) between the elements. Replace it and the fuse with the proper type and power up the amp using the power up procedure as we described earlier in this manual.TU Often caused by contamination within in a tube, the culprit can usually be identified, and by lightly tapping on the glass, you will probably hear the noise change. Hearing some noise through the speakers while tapping on the 12AX7’s is normal however. And the one nearer the INPUT will always sound louder because its output is being further amplified by the second 12AX7. The power tubes should be all but quiet when they are tapped. If crackling or hissing changes with the tapping, you have probably found the problem. To confirm a noisy power tube, merely put the RECTO on Standby, remove it from its socket and turn it back on. It will cause no damage to run the RECTO briefly with one power tube missing. You may notice a slight background hum, however, as the push-pull becomes unbalanced. Whenever you are trying to diagnose a suspect tube, keep your other hand on the POWER and STANDBY switches ready to shut them off instantly in the unlikely case you provoke a major short. If you think you’ve located a problem tube but aren’t sure, we recommend substituting the suspect with a new one just to be sure of your diagnoses. You will be doing yourself and us a big favor by just following the simple guidelines previously mentioned regarding tube replacement. You’ll probably be successful with much less effort than is required to disconnect everything and haul the unit to a technician who will basically perform the same simple tests. If the tubes are still within their six-month warranty period, we will happily send you a replacement. Just note the color designation on the tube label so that we can send you the appropriate match.
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D: Because your amplifier is an all tube design, it is quite possible that you will at some point experience minor pre-amp tube noise. Rest assured - this is no cause for alarm and you can take care of the problem yourself in a matter of minutes by simply swapping tubes.
Let us begin by saying; It is a “very good” idea to keep at least a couple of spare pre-amp tubes on hand at all times to insure uninterrupted performance. These minor pre-amp tube problems can take many forms but can generally be described in two categories: Noise and Microphonics. Noise can be in the form of crackling, sputtering, white noise/hiss and/or hum. Microphonic
problems usually appear in the form of a ringing or high pitched squealing that gets worse as the gain or volume is increased thus are more noticeable in the higher gain “HI” modes. Microphonic problems are easily identified because the problem is still present even with the instruments’ volume off or unplugged altogether - unlike pick-up feedback which ceases as the instrument is turned down. Microphonic noise is caused by mechanical vibration and shock: think of banging a microphone around and you’ll understand where the word came from.
The best way to approach a pre-amp tube problem is to see if it occurs only in one specific mode or channel. This should lead you to the tube needing replacement. Then all that remains is to swap the suspect tube for a known good performer. If you cannot narrow down the trouble to a specific mode or channel, the problem may be the small tube that drives the power tubes
which is operational in all modes and channels. Though rare, a problem with the driver tube would show up in all aspects of performance - so if you can’t narrow the problem down to being mode or channel specific, you may want to try replacing the driver tube. Driver problems generally show themselves in the form of crackling or hum in all modes of performance and/or weak overall output from the amplifier. Occasionally an anemic driver tube will cause the amplifier to sound flat and lifeless, but this is somewhat uncommon, as worn power tubes are a more likely suspect for this type of problem. Sometimes making the diagnosis is more trouble than it’s worth and it’s faster and easier to merely replace the small pre-amp tubes ONE AT A TIME with a replacement known to be good. But MAKE SURE you keep returning the tubes to their original socket until you hit the one that cures the problem. You’ll notice that tubes located nearer to the INPUT jack always sound noisier...but this is because they are at the start of the chain and their noise gets amplified over and over by the tubes that follow. The tube that goes into this “input socket” (usually labeled V1) needs to be the least noisy of the bunch. The tube that goes at the end of the preamp chain - just ahead of the power tubes - can be quite noisy without causing any problem at all. The tubes in your amp have already been
located in the most appropriate sockets and this is why you should NEVER pull them all out at once and ALWAYS swap them one at a time. ALWAYS return a perfectly good tube to its original socket. Also it’s a good idea to put the amp on STANDBY when swapping tubes to reduce the heat build up in the tubes themselves and to prevent explosive noises (which can still occur even if you are pulling the tubes away from their sockets gently) from coming through the speaker.
Remember, take your time, be patient and chances are real good that you can fix your amp yourself by finding and replacing the bad tube. It kills us to see someone who has shipped their amp back to us...and all it needed was a simple tube replacement! If you must send back your amp, unplug the power cord, speaker and reverb cables then remove the chassis from the cabinet by unscrewing the four mounting bolts on top. The chassis then slides back like a drawer and comes out. Remove the big power tubes and mark them according to their location from left to right 1, 2 etc. They need to be wrapped separately with plenty of wadded up newspaper around them and put in a smaller box within the larger carton. To wrap the chassis, use plenty of tightly wadded up newspaper so there is at least six inches of “crush space” between the chassis and the cardboard box. Bubble wrap also works well, but please DON’T use styrene peanuts - they will shift during transit and get lodged inside your electronics as well as allowing your amp to end up at the bottom of the box unprotected and possibly damaged.
Pre-amp tubes don’t normally wear out as a rule. Therefore, it is not a good idea to change them just for the sake of changing them. If there isn’t a problem - don’t fix it. If there is no
result from your substitutions, it may be possible that you have more than one problematic tube. Though rare, this does happen and though it makes the troubleshooting process a little more intimidating, it is still possible to cure the problem yourself. NOTE: It is normal to hear a slight metallic ringing sound when tapping on the preamp tubes. As long as the tube does not break intooscillation or start crackling or any other form of bizzare noise, it is considered normal and functional.
Diezel VH4
2.3.3 Causes for Faulty Tubes
There are different reasons for failing tubes. Often tubes fail prematurely due to strong
vibrations. Tubes are very sensitive to mechanical impacts and vibrations, such as happen when transporting an amplifier or unloading/loading etc. The inside filaments of a tube deform easily and will cause a short inside the tube, resulting in it’s early demise. This is why we cannot extend our warranty to the tubes. A relatively new, but defective tube can be replaced by a matching unit, no need to replace the entire set. (Unless you want to, which is always a good solution) This is not age or wear related, but accidental damage. Tube Failure due to normal wear and old age is also a common cause. If this is the case, then it makes more sense to replace the entire tube set with a matched quartet. Testing has proven that matched sets last longer and are more reliable than mismatched sets. Also, if one tube of a matched set fails after a few years, then the general status of the remaining tubes is no longer a secret, because the tubes in a matched set will wear evenly, and at the same rate. Yes - this means that the
remaining tubes are likely to fail very soon and it is time for a new set of matched tubes.
The aging process is a slow depletion of the anode’s coating (Wolfram). The more power the tube has to produce, the quicker this coating wears off.
Soldano
Most of the problems that we hear about with amps are due to the tubes—and are pretty straightforward to fix. Close to 90% of the problems that people call us about are due to tubes—or tube sockets. Sometimes they get dirty and mucked up. (Tubes get very hot and can burn you, of course; don’t touch them when they are hot.)
With the amp on, wiggle the tubes a little to alter the contact points. If this recreates or stops the noise, you have isolated the problem tube (or socket). If it doesn’t, turn the amp off and let the tubes cool. Then pull and reinsert each tube several times to try to establish better contact. Test the amp after you adjust each tube to see if you have found the problem.
Hopefully, this will fix the problem or determine the tube that needs to be replaced. If you have pinpointed a problem tube, but not fixed it, you probably need to replace the faulty tube.
How do I determine if my preamp tubes or my output tubes need to be changed?
If you're experiencing a lack of bottom end and power, it's probably your output tubes. If you're hearing strange sounds coming from your amplifier, turn your gain section up in volume, and slowly turn the master volume down. If the noises persist after the master volume has been turned down, it's an output tube. If the noises go away after turning the master volume down, it's an input tube.
How often should I change my tubes?
Tubes are like light bulbs—they could go out at any time. Generally, if you're playing hard, tube life can be anywhere from six months to a year, although we've seen tubes last much longer than that. Preamp tubes can last indefinitely. Good quality tubes are the key to keeping your amplifier working great. Should you start to experience strange noises, microphonic squealing, hiss, or other strange and unwanted phenomena, check your preamp tubes. One of them may need replacement.
If strange noises do appear, unplug your guitar cord from the input to help isolate the problem and switch to the Overdrive Channel. Then, turn the Overdrive Channel’s Volume Control to ‘0.’ If the noises go away, it is likely that a preamp tube is at fault. If the noises persist, you probably have an Output tube that needs to be replaced.
What kind of tubes are in my Soldano amp?
We use 12AX7preamp tubes and 5881 power tubes.
What should I do to be prepared for tube problems?
You should keep a couple of good spare 12AX7 preamp tubes around at all times for any tube amplifier. This will save you a lot of trouble when you do need them. If you suspect that one of the tubes in your amp may be faulty, replace it with a known good tube and see if that alleviates the problem. If not, replace the original tube and try swapping out the next 12AX7 in the signal chain.
As with the preamp tubes, it is important to always keep a spare 5881 output tubes on hand. This will save you much time and frustration when replacement is needed.
Beware! In certain instances, you may actually run into two microphonic tubes and have to replace them both so do not overlook this possibility. Also, just because you purchased a brand new 12AX7 does not mean that it is not microphonic. Make sure you test the tube to make sure that it is in fact good. The best way to do this—presuming you don’t have access to a tube tester—is to swap out your tubes with spares when your amp is working fine. That way, if one of the spares is faulty, you will know it immediately.
I need to, I know. But I do carry spare fuses, and if one side blows, I always have another side to get me through the gig.
My current rig as good as it sounds is overkill for going back to pub gigs, a Cornford MK50, two Cornford 2x12's and a G System.
