Hi,

Could someone please help with the following problem? I need to know if this is serious enough to return the head.

I’ve had my DT25HD and DT25112 cab for just over a week. All has been well and the amp has performed brilliantly until I powered it up this morning and there was a very noticeable hum coming from the speaker.

The amp was set up as follows: Channel A – Triode – Voice Switching I – Class A/B – Master and Volume at hallway position.

I spent an hour changing the setup in various ways but came up with the following problem combinations:

• Whenever the amp is in Triode mode there is a very noticeable hum. Changing to Pentode kills the hum completely.



• With Class A and Triode set the hum gets much much louder.  Again changing back to Pentode kills the hum completely.

I’ve owned tube amps for twenty years and recognise the sounds that you can expect and this is definitely not normal. Closest experience I can come up with was a problem with the power tube on a Fender amp I owned. The noise I’m experiencing on the DT25 is similar but louder.

Any help would be appreciated.

Thanks in advance.

Martin

Extra note -changing volume or master does not change the level of hum and it is present with or without a guitar.