Need everyones help Diezel vh4

[Lexothphi]

Bought a diezel vh4, it sounded immese for 2-3 days turned it on this morning channel 1-2 seem the same but channel 3 (the high gain territory) seems to be lacking in.. well the high gain, i used to have it around 1oclock and it was loads now it needs to be near enough full to get near what i had before? im confused as when tubes are dieing u get background noise, and hum this is still as if i have a decimator infront of it.... Ive tried different cables, maybe its Caparisons shitty jack socket on its way out ?

[Trypios]

What kind of background noise? If it's microphonics, one of the gain stage tubes is malfunctioning. If it's crackling noise, it could be a plate resistor or a capacitor. If channels 1,2 are ok then it can't be Caparison's socket, but try another guitar as well...and no other gear.

Whatever they tell you in forums though, it probably needs a tech. (Unless its a microphonic tube, that's an easy fix)

[Xykhron]

In ordeer to know if its microphonics as Trypios said you can do a very simple and quick test: with the amp turned on an working (not in standby mode) hit the amp case (not the chasis) with your fist. Not very very hard but not soft. When hitting if you hear like a whistle or a very high frequency sound, you know you have microphonic poweramp tubes.

Its simple and won't damage the amp. All the REAL tech I know do that way.

[Xykhron]

Forgot to mention: you should do this test without pluging in the guitar or instrument cable but with master volume up to 1 to hear the sound the amp head delivrs when hitting

[Trypios]

When hitting if you hear like a whistle or a very high frequency sound, you know you have microphonic poweramp tubes.

I was thinking of a microphonic preamp tube, since channels 1+2 are still fine. If that's the case, you have to open the chassis and lightly hit each preamp tube with a pencil or other object that won't harm the glass. It's better to let someone else troubleshoot the amp first, 'till you learn the basics yourself. DIY for the first time with no experiences or references is quite dangerous

[Xykhron]

yes, I ws thinking of being preamp, but the on the channels 1&2 of the VH4 is quite more difficult to know if its preamp. The poweramp microphonic test needs no tech skills or even use an screwdriver, so its the first attempt he can do to discard the poweramp failure. Then if its ok, he should start thinking on the preamp tubes.

[Loiss]

Tubes for sure. These days the quality of the Tubes isn't there anymore. Change them.

[fireheart82]

i can buy the diezel. its broken some of your Preamp tubes are bad, it was the same when i got my rig.

[ntroulis]

Hey Lexothphi, how sound the diezel low volumes, you have a engl SE before think
Also somebody nows the difference vh4 vh4stereo?
is only in stereo plug or something else?