DT25 Head Voicing Switch does what it wants

[Cobar]

Hi there,

I've been looking through a few topics here, but found nothing tha could help me out with my actual problems.

 

My Setup:

- DT25 Head

- DT50 412 Cabinet

- POD HD300

 

I've never had any problems since I purchased the stuff about 5 years ago, but now I noticed something that confuses me:

While I was playing, I heard some quiet "pop" sounds without switching amp modes or something. I would descripe the sound like a chicken ("bugg" "bugg" "bugg"), time intervall between the sound is close to a second, maybe a bit shorter.
Then I took a look at the knobs of my DT25 Head and saw, that the voicing switch was doing his own thing.

 

After a few tests, I recognised a pattern, which is as mentioned below:

Voicing Switch is I, then it pops over to II, then again to I

Voicing Switch is II, stays at II

Voicing Switch is III, pops over to II, then again to III

Voicing Switch is IV, pops over to II, then again to IV

 

So I think maybe there is a problem with the Voicing switch, but it could also be an electrinical part.

Does anyone of you had made the same experiences or could help me out with that problem?

 

Many thanks in advance :-)

Sven

 

 

[MartinDorr]

Check how old your tubes are and and consider replacing. They may no longer work reliably in all modes and it appears as if the mode switch is broken.

[psarkissian]

What Martin said. And make sure your speaker is plugged into the correct speaker output

for the impedance of the speakers you're using. Impedance mis-match can pull down voltages.

 

[Cobar]

Hi,

Thank you very much.

 

I visually checked the electronics, but could nothing determine.

I've tested the Modeswitch, it seems to be ok. The switch is wired onto the frontplane and that one is plugged into the cpu-board. 

I will check the tubes next and replace if neccessary.

If I have any results, I will write a post.

[Cobar]

Hi everybody,

 

a little late, but I want to give you a feedback about your suggestions.

I replaced the tubes and now everything works fine.

 

Thank you very much for your help!