MATAMP GT120 Troubleshooting and How to Bias

Музыка

I had a cool amp come through the shop with some strange noise issues. The first two preamp tubes were generating noises. I did a lot of troubleshooting to find out why the amp was eating tubes and the cause had nothing to do with the amp at all. It wasn't until the customer brought me another amplifier with the same issue. It was then I asked him detailed questions about his setup and found out they were running the incorrect high output send from a digital modeler into the input of the amps. The too-large signal was frying the input grids on the first stage preamp tube and them swapping tubes would just fry the next ones too.
I have that repair documented as well and will include a link and update this video with the new information when I can. I repair a lot of amps and tour around the world so it didn't dawn on me to revisit this video.
In the process of service I make sure to clean the sockets with Deoxit and check all the voltages throughout the amp and make sure there are no shorts or partial shorts when things get warmed up.
I get the amp biased up for the client and make sure it can handle being played on 10 before sending it out the door!

Пікірлер: 20

  • @azzazelo
    @azzazelo Жыл бұрын

    Man that's some neat insides

  • @danielkosmider8715
    @danielkosmider8715 Жыл бұрын

    Just discovered your channel . This is exactly what I was looking for. Subscribed. Will be watching these the rest of the night. Thanks and cheers!

  • @russiangoose7053
    @russiangoose7053 Жыл бұрын

    Garret from Windhand uses one of these or at least he used to, ever since I started listening to them it's been one of my bucket list amps. It's cool seeing the guts of one and watching it get worked on. As always my favorite part is when you just riff out and jam through the amp, sounds great with your playing and it's refreshing to hear one playing some rock and not slathered in fuzz even though I do love that. Great video!

  • @purgasound

    @purgasound

    Жыл бұрын

    I opted not to do any sludge or doom riffs because there's a ton of those videos out there. This amp definitely gets that stoner doom sound when the volume is dimed. Windhand is also from here in Richmond. Thanks!

  • @SKY_DWELLER333

    @SKY_DWELLER333

    3 ай бұрын

    @@purgasound really glad I found this video because while one of these and or a GT1 are becoming bucket list amps for me I really wanted to hear somebody just play in standard tuning straight through the amp so I appreciate you for doing that. Also you mentioned how it doesn't have a master volume, all of these are custom built to order so you can totally get a version with a master volume as well. but make no mistake if I got one of these it would be stoner doom filth all day every day.

  • @futureprojektor798
    @futureprojektor798 Жыл бұрын

    👊👊 great video and explanation

  • @TheSafetysheep
    @TheSafetysheep Жыл бұрын

    I love your videos man!

  • @TheAxe4Ever
    @TheAxe4Ever Жыл бұрын

    I have a Ceriatone Chupacabra 100 amp. Basically a José modded Marshall clone. Great amp. Sounds fantastic and the wiring on the turret board is very clean. For biasing, it!s set up the same as this amp. 4 test points and bias pot for each individual tube. I really like that set up but man! Those pots are so touchy! All you have to do is think about turning the pot and it will jump 2 to 3 numbers.

  • @MarkEagleton
    @MarkEagleton Жыл бұрын

    Really interesting to see how good and bad a design can be. Thanks for posting this one. Nice to have you back, too!

  • @purgasound

    @purgasound

    Жыл бұрын

    This one was definitely interesting. At first glance it looks really well made but the longer you look at it the more you will say "why?". A majority of the solder joints are just lap joints so there's no mechanical connection backing it up. I am not really a fan of that and it's everywhere. The turrets don't make sense either since it's already on a PCB so it's just for looks. I will say the wiring and soldering are still done very well and with care despite the joining method. I don't foresee any problems coming from the design/construction.

  • @MarkEagleton

    @MarkEagleton

    Жыл бұрын

    @@purgasound I could see how the turrets would make changing out components easier. Everything is right on the surface, so you wouldn’t need to pull the board. Pretty weird, though.

  • @michaelmitchell5909
    @michaelmitchell5909 Жыл бұрын

    Damn I thought the matamps were pretty good. That is who built the first orange amps. Great channel man I missed watching, glad to see ya back

  • @DemonKingOFFICIAL
    @DemonKingOFFICIAL Жыл бұрын

    4:15 Good correction there lol. Most would have just gone on and said “made pretty good.”

  • @thefilthygringo9228
    @thefilthygringo9228 Жыл бұрын

    Killer video , you fkn shred man. What pick-ups are in that sweet les Paul . I have a 50’s standard gold top with the burstbucker 1 and 2 . I was thinking about swapping them out but I’m not sure about high or low output. For classic rock, punk. Just all around rock shredding lol. Just curious because that les paul sounds killer

  • @1peanut
    @1peanut Жыл бұрын

    11:40 "Running Wild" Judas Priest.

  • @tonya4157
    @tonya41575 ай бұрын

    Im not am amp tech or repair person but I can sure identify with, fucking bullshit. Sorry man but I had to laugh, it was like listening to myself.

  • @DamnDealDone
    @DamnDealDone9 ай бұрын

    You didn't find "anything else wrong with the amp". Correction, you didn't find anything wrong with the amp to begin with. Two preamp valves went bad. Could have been replaced by the owner. Proceeds to shit on Matamp for nothing being wrong with the amp.

  • @purgasound

    @purgasound

    9 ай бұрын

    I critiqued the few things I didn't like. I didn't "shit on Matamp". The amp build is fine, way better than most actually. To wrap up this story the customer brought me a second amp a few months later with the same issue. It wasn't until then I asked detailed questions about their specific setup and found out they were running a high output send from a popular digital modeler and the too-large signal voltage was frying the input grid of the first stage. The owner did replace those tubes and fried the new ones too because they continued to run it the same way. After obtaining that information it was only then we could point to an exact cause for the fault. I didn't think to post a follow up because I no longer had this amp in my possession and I think I addressed during the repair of the other amp, which was also a Matamp and did have burned out components due to a failed output tube. I'll update the video at some point to highlight what the cause was. In any case, any tech will have to troubleshoot the issue as preamp tube failures are not common. We have meters, diagnostic tools and intuition, not a crystal ball. Have a good one.

  • @rikkydavidson1762
    @rikkydavidson176210 ай бұрын

    ❤cool ampman😮nice work.😇😎😇✌️🌎✌️🎳🙉🙈🙊🌡️💲🙄💲🏜️🌄🏜️👌👁️👌😮 wow learning to amp🤗

Келесі