Have you tried altering the noise reduction settings? I've found it can help. I'm not sure how you do it on the VT30, i've only had amps from the older and newer series.
This is a good point. You could have accidentally disabled the noise reduction or changed its setting without knowing it. The VT30 has a very nice feature set.
If you don't have the manual I'm sure you can download it by doing a search on google or going to the Vox site. It tells how to do the manual reset, etc.
I strongly recommend that you go to the valvetronix.net site and register and post your problem there. Those guys definitely will be able to help you out. They have "been there, done that". Also there are resources there that are essential to keeping your "Chromie" working right. Such as the instructions on how to effectively clean "all" of the jacks on the amp, which seems to be needed to be done regualarly to these amps, due to the cheap jacks. These are great amps but they cut corners on using cheap jacks and this is well documented with solutions. There are even instructions and kits to replace all the jacks on the amp with high quality ones. A lot of people actually do that. I have not replaced the jacks on my VT30 and have not had a problem with it.
One note: you should use the "right" electrical contact cleaner to clean the jacks, not WD40 by any means. I use de-oxit and spray some in the jack with the amp off and then push a plug in and out several times. You need to do this to all the jacks. Even the headphone jack could be causing a problem.
Also, did you do the "manual reset"? You will lose your presets. They recommend writing down your presets so you can put them back in later. They have a bunch of presets on the valvetronix.net site that you can put into your amp and you can share your presets there. They say that it gets to the point with these valvetronix amps that you "have to do a manual reset", just like re-booting your computer. They are so computerized that things just get messed up and a reboot (manual reset) is necessary once in a while. The manual reset is reported to clear up almost all problems with the amp, not related to the "oxidized jacks" problem.
I'm fairly sure that if you post on the valvetronix.net forum that you will get the feedback you need to get your amp back up running right; at least there is a high probability that they will be able to help you completely solve the problem. Evidently, outside of a few correctable problems, the "Chromies" are very reliable amps, contrary to the uninformed opinions of some. The (+) series is still fairly new but they have a lot of information on the site regarding those too. Evidently the "plus" series has had some amps exhibit a new phenomenon called the "snare drum sizzle". I'm not sure if they found a solution to this problem or if Vox corrected the problem in the latest production runs of the amp.
I have "some" natural hiss coming from my VT30, but it is on a high gain setting. It isn't hissing any more than my other amps, so I don't see it as a problem. Most amps are going to hiss a little, especially at higher gain settings or volume settings. Still, there are a lot of things you can do and check.
I have a Peavey 6505+ combo high gain amp. Heavy metal type amp. It has six preamp tubes, plus two power tube and is sixty loud watts. It has a "lot" of gain. When you crank the gain and volume up on this amp is shakes the house. However, when you have the gain and volume turned up like this, it hisses probably a "lot" louder than you would expect. It is really fun to play thru and even fun to crank up to "chest pounding" volume sometimes.
In the end, it might be a good idea to look at the manufacturer's warranty period before buying an amp. Vox has one year. Fender has 5 years on the Super Champ X2, and you can upload different amp models and effects from that site that the Mustangs use. Plus the Super Champ X2 is a great amp. But the thing I'm mentioning here is that Fender has the 5 year warranty. That suggests that they have "confidence" that the amp will last 5 years without them having to do a lot of repairs/exchanges, etc. I don't think Vox has that same confidence.
I like my VT30 a lot. Always wanted a "Chromie". If it gets squirrely after a while I don't know what route I'll go. I got a super great deal on a NOS one, so I'll probably just get a new one or one of the plus ones, I'm not sure. I like the protective chrome grill. I don't know if I'd sell my SCXD, but the new SCX2's definitely seem like they would be great, especially in that you can upload some presumably awesome amp models and effects, and it has a real power tube section.
I hope you get to the bottom of this and get it working right. It is definitely a neat amp.
