Orange Dark Terror .... Repair?

[@mikoschannel6413]

Probably the best explanation on how to measure true output watts, RMS. Cheers

[@Ireland831]

Your content is amazing. You are a great amp tech I appreciate your knowledge and your videos. I still crack up when I hear an Aussie accent. I met my good buddy Alex, (fellow guitar player and Aussie) at an international sales meeting for the company I was working for. I am an American baseball player and he was explaining all about cricket and we conversed about the similarities and differences. When I met one of his co-workers who was a cricket bowler....."bowla" I was glad to meet him and was excited to talk to him about his cricket playing. I kept busting out my new Aussie terms that my new pal Alex taught me and with an exaggerated American accent doing an Aussie. I kept saying...."well that must have bean a wicked googley" and something about silly mid on. He turns to me and says....I think you are making fun of me....get away from me before I kick your ass. So funny. I still love to say....."that was a wickid gooogley mate". Sorry for the ramble. You are an awesome amp tech and wonderful video production and content presentation. Thanks so much!

[@BradsGuitarGarage]

Thank you, mate! Sorry for some reason I only stumbled across this comment a year later. Thanks for watching, and as we say: GET A DOG UP YA GUTS!

[@Malarky49]

It's like watching myself when I wrench on motorcycles and have to diagnose electrical issues. Swearing, dropping shit, swearing, calling myself a knob, swearing. So cool seeing how the O scope reads for amplifiers. I watch peak voltage usually when testing ignition coils using the oscilloscope. I ordered an ebay special Dark Terror that blows the HT fuse and I'm going to see how well I adjust to diag for AC voltage rather than DC. Anyway, thanks for the awesome video and hope to use it as reference to my new project.

[@alexfarmer9051]

thank you sir! ive got a troublesome dark terror myself (im on the sunny coast in qld) the bastard keeps dropping volume, glad someone has been a legend and beautifully documented the road ahead of me! hey, epic job donating that acoustic to that little girl too, good deeds make the world turn my friend keep up the bitchin work!

[@BradsGuitarGarage]

I didn't realise that the screen capture didn't come through on the HD recording. Here's the link to the live streamed version (crappy video quality) but at least you can see the screen capture as I'm talking for specific fault locations. facebook.com/bradsguitargarage/videos/2217918378479400/

[@BradsGuitarGarage]

You could always ship it down here, mate.

[@LosTroopos]

Thanks for showing the insides of the dark terror. My Dark Terror gets extremely noisey when the preamp gain gets pushed past 1 o'clock. Little bit of hum in there but also a lot of "white noise". Changed tubes (even upgraded to a few really expensive ones) and nothing changes. I bought it used for a good price (even if it has to go to a tech) but maybe you've got an idea, where to start to look.

[@paulartman1720]

Friend, have you find a reason? I have the same issue with my DH15

[@DanCooz323]

There's a "hum balance" micro pot inside the chassis, and you can adjust it with the amp on. That might alleviate some of your issue. You can see it in this video at 43:10 just above the large capacitor, it's blue and white. Hope this helps!

[@samiraloufa]

I’m facing the same problem here, the only difference was that when a changed tubes the sound get cleaner for a while (~5minutes) and then… got distorted again, even with gain knob in position 0. Any ideias or news my friends?

[@samiraloufa]

@@DanCooz323 Friend, I really appreciate your help. But can’t understand why should I adjust this once I never touched this pot before? I know the component name “hum pot” is very suggestive but I was wondering if you might be able to explain how it works and/or why it can solve the problem. Please, be patient with me, I’m very afraid to make this adjustment as a test.

[@DanCooz323]

@@samiraloufa Being that no 2 tubes are exactly alike, there's always going to be some adjustment needed to get them perfectly balanced. If you take note of your current pot position, you can always revert back to it. Adjust it so you have the least hum coming out of your speakers, you will not harm anything.

[@kengevers8738]

Speaking about watts, it is interesting that most people can't tell the difference between 10 and 15 watts. Like you said of manufacturers, they give you an arbitrary # that is close to what the amp really is putting out, but then at what line voltage. Nice video, cheers.

[@MikeHanby]

Thanks for the in-depth tear-down of the dark terror. I came here because my DT isn't producing any output on the cabinet, however if I hold my ear to the head I can faintly hear the guitar. Weird. I haven't tested it with another cab yet, but I did verify with a continuity check that the HT fuse is good. Not expecting a reply just wanted to add my notes.

[@BradsGuitarGarage]

That sound you're acoustically hearing from the amp is a big problem. That's magnetostriction in the output transformer or power transformer indicating you either have a short or open circuit on the speaker output. Triple check your speaker cables and connections in both the amp and the cab, and discontinue use of the amp until you or a tech finds the problem. Continuing use in this state may damage the amp, if it hasn't already. Where are you based? I may be able to refer you to a good tech in your area if you haven't worked on amps before.

[@MikeHanby]

@@BradsGuitarGarage Thanks for the feedback. I'm in NE Tennessee, USA. I'll start looking for a tech.

[@BradsGuitarGarage]

@@MikeHanby I'll ask the guys I know in the US for a good contact and get back to you.

[@BradsGuitarGarage]

@@MikeHanby Contact me on the Facebook page and I'll give you a referral.

[@russellesimonetta3835]

Looks like a pedal with tubes!

[@russellesimonetta3835]

Uhhh, if all the tranny wires were twisted maybe the noise floor could be better.

[@scootergreen3]

Hi Brad's Guitar Garage, are there tubes in those 6 metal caps with the springs, if there tubes then I wonder why some are covered and others are not?

[@rianvanrensburg9960]

Those are preamp tubes, they are shielded in those cylinders because they are more prone to interference

[@davidk8735]

My Dark Terror's gain pot gets noisy when rotating up past noon. Would it need a squirt of contact cleaner? How do I get that inside the pot?

[@BradsGuitarGarage]

There's no need to disassemble the pot for cleaning. My preferred cleaner and lubricator is Electrolube EML. A drop on the point where the read casing of the pot and the wafer meet is enough to wick down inside and combined with cycling the pot back and forth several dozens of times, they usually clear up. Sometimes some compressed air is required beforehand.

[@davidk8735]

Thanks. I have not opened the case for access beneath, but was wondering if a “space” on the case allows for easy cleaner squirts. The noise has existed for 5 years, but since the pot is always found at 11:00 o'clock, I never investigated the noise.

[@stevo946]

20:38 how do you remove these?

[@BradsGuitarGarage]

They are soldered from the bottom of the board. The only way to remove them is to desolder from the bottom of the PCB.

[@stevo946]

​@@BradsGuitarGarageDang, I was afraid of that. Thanks for your great reply!

[@KyleSince1986]

Any advice would be helpful… channel A / gain pot on my dual dark 100 is on its way out “have to to constantly rotate the pot to get full volume to come back… any thoughts on what pot you would replace it with? Looks super annoying to the whole thing apart…

[@BradsGuitarGarage]

Looks like a pretty standard Alpha dual gang pot to me. The rest is up to you.

[@Addario13423]

I have a dark terror but mine has no gain control. What could be? Already checked tubes and the gain sounds like half way but the gain knob does nothing.

[@BradsGuitarGarage]

No idea. Take it to a reputable local technician, I'd say.

[@petedazer3381]

You know we can’t see the schematic right?

[@BradsGuitarGarage]

It was a livestream. The schematic didn't show on the recording but did show on the live facebook stream.

[@thefilthygringo9228]

Very interesting

[@pvampman]

Do these amps require rebias?

[@jeremyrebelka]

no - class A

[@pvampman]

@@jeremyrebelka so if I replace the power tubes I'm good? Nothing else to do?

[@YouBunzBro]

​@@pvampman yes

[@HiFiMonki]

Funny you say Sanwa is a funny name but they are actually manufacture very good quality components. Japanese company.

[@BradsGuitarGarage]

Yeah, they're not bad.