Loud clicking noise

[dcribbs1412]

Hi guys
got the parts decided to get my Dlite conversion to HRM
up and making some noise. Started up with bulb limiter
everything was fine...tubed it and there was a building buzz sound
and I shut it down.
Now I have a clicking noise(loud and fast) when I hit the power switch...sounds like its coming from the switch area, checked grounds, connections, replaced switch no go...any suggestions are
greatly appreciated

Darin

[boldaslove6789]

Post some gut shots, maybe we can help you better.

[dcribbs1412]

Thanks bold
here's a link to some shots I did when I started
https://tubeamparchive.com/viewtopic.php?t=17691
until I can get some better shots

Thanks
Darin

[Structo]

Could it be something arcing?

[dcribbs1412]

Could it be something arcing?

Hi Tom
it sounds like that but I don't see any arcs...
sounds like its coming from the switch...replaced it and its still happening.
I'm using 2 220uf 300V F&T caps..replaced 1 both check around 225uf
could a bad cap cause this...this is a new problem I haven't run into.
I hope its something simple and not the PT.

Darin

[67plexi]

The Belton tube socket lugs crack easy, check the heater wire look close.

[dcribbs1412]

The Belton tube socket lugs crack easy, check the heater wire look close.

Will do
Thanks
Darin

[talbany]

Darin
Yes I have had caps arc internally and make a clicking sound however rare .Double check your grounds on the caps first and try not to run the amp for very long or stand directly over it (Be Careful).After checking your grounds if it's still there turn out all the lights in the room and see if you can spot the arc to make sure it's not coming from a socket or a bad solder joint or tube etc..etc..Also make sure you have a load on the amp while doing this!!

Good Luck!!

Tony

[dcribbs1412]

Darin
Yes I have had caps arc internally and make a clicking sound however rare .Double check your grounds on the caps first and try not to run the amp for very long or stand directly over it (Be Careful).After checking your grounds if it's still there turn out all the lights in the room and see if you can spot the arc to make sure it's not coming from a socket or a bad solder joint or tube etc..etc..Also make sure you have a load on the amp while doing this!!

Good Luck!!

Tony

Thanks Tony
will do ASAP

Darin

[wjdunham]

Also make sure to check the ground connection between the power and standby switches and the chassis, remove any paint/powder coat on the chassis. Charge can build up on the switch bodies and arc to the chassis. It's usually not enough to create a spark, just an annoying tick.
Bill

www.sebagosound.com

[dcribbs1412]

Also make sure to check the ground connection between the power and standby switches and the chassis, remove any paint/powder coat on the chassis. Charge can build up on the switch bodies and arc to the chassis. It's usually not enough to create a spark, just an annoying tick.
Bill

www.sebagosound.com

Bill
I did not know this...I know there is paint between the chassis and switch I just changed out..I will remove/sand these areas
Thanks
Darin

[dcribbs1412]

Update
had to work late
removed paint from switch area
checked grounds again and heater wiring
then decided to check bias supply...seemed like where the popping was coming from...changed cap and redid ground...not sure which one did it..but powered up with bulb limiter and no popping.Tubed it, then threw the standby and a few seconds later I got a motorboat sound...

Darin

[Structo]

Check your negative feedback/ presence.

Make sure you have it wired the Dumble way, not D'lite.
What size feedback resistor are you using and what tap on the OT is it connected to?

Also check your preamp filters and how they are grounded.

Inadequate filtering can cause motorboating.

How are the preamp voltages?

[talbany]

Darin
Is this the initial smoke test? If it's a fast type of loud motor boating when you first fire the amp up could be you have the output transformer primary's reversed.. This type of positive feedback can give you either a loud squeellll!!
or a rather fast type of motor boating..

BTW I never hook up the wire from the speaker jack to the NFB resistor until after install and bias up the output tubes and make sure the amp is functioning as it should.I'll usually connect it with an alligator clip to check it..This way if say your primary's are reversed your not trying to bias up your output tubes with + feedback taking place..Sometimes I like to play the amp first to see how it responds with no negative feedback before I decide on the exact value for the NFB resistor..


Tony

[Structo]

Good practice Tony.

That makes a lot of sense.