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ADA Power Amps => Microtube 200 MT-200 => Topic started by: HerlonGuitar on August 24, 2021, 07:20:19 AM

Title: Microtube 200 Yellow Leds
Post by: HerlonGuitar on August 24, 2021, 07:20:19 AM
Hi Guys!

There are two yellow LEDs inside the MT200 one near each tube. Do they light up? I've never seen an MT200 with those leds working. In mine they don't light up either.

Title: Re: Microtube 200 Yellow Leds
Post by: HerlonGuitar on July 06, 2022, 09:08:18 AM
guys??
Title: Re: Microtube 200 Yellow Leds
Post by: Kim on July 06, 2022, 10:09:52 AM
Not sure how your post got missed; sorry about that.

I believe those LEDs are there to be used as just an actual diode (because they are indeed diodes after all) and not as a source of light.  It's common to see these yellow LEDs used in this manner in other amps.  Marshall JCM900 to name just one.
Title: Re: Microtube 200 Yellow Leds
Post by: HerlonGuitar on July 29, 2022, 10:38:02 AM
Thanks man! I understand.

But, why does it say: "Real power amp glow in the dark". The photo looks like with the bright yellow leds.


Title: Re: Microtube 200 Yellow Leds
Post by: Harley Hexxe on July 29, 2022, 01:43:13 PM
That was just ADA's ad back in the day.

    You were supposed to be able to see the tubes in the power amp through the vent grill on the front. Maybe the yellow LED's were supposed to help illuminate them since they don't glow very bright in there :dunno:
    As long as the amp is working, it's all good.
Title: Re: Microtube 200 Yellow Leds
Post by: HerlonGuitar on July 29, 2022, 06:22:24 PM
you are right man. it sounds great.  I'm just curious about the LEDs.  Do they light up or not?? Thats the question.🤔
Title: Re: Microtube 200 Yellow Leds
Post by: rnolan on July 29, 2022, 08:55:14 PM
Well it seems they are supposed to light up  :dunno: .  Does the amp still work?
Title: Re: Microtube 200 Yellow Leds
Post by: HerlonGuitar on July 29, 2022, 11:14:49 PM
Yes. The amp works.
Title: Re: Microtube 200 Yellow Leds
Post by: Harley Hexxe on July 31, 2022, 06:01:04 AM
Yes. The amp works.

If it's not broke, don't fix it
Title: Re: Microtube 200 Yellow Leds
Post by: rnolan on August 01, 2022, 01:52:41 AM
Sure, but he'd like to see the yellow glow like the add says it's supposed to  >:D . 

@MJMP, are these leds supposed to glow (seems they are)? And if they are and they aren't glowing, is that an issue? or are they just there for looks?
Title: Re: Microtube 200 Yellow Leds
Post by: HerlonGuitar on August 01, 2022, 09:40:23 AM
Here's a better photo.





the truth is only one. There are two yellow LEDs next to each valve, in the Ad the LEDs appear glowing and they still say it glows. but I've never seen them lit on any MT200 in pictures
Title: Re: Microtube 200 Yellow Leds
Post by: MarshallJMP on August 01, 2022, 01:58:36 PM
I don't think they are supposed to glow, looks more like a clamping circuit between the gate and cathode. I think the glow you see is a marketing thing. That led is not supposed to make the tubes glow yellow.
Title: Re: Microtube 200 Yellow Leds
Post by: Dante on August 01, 2022, 04:22:56 PM
I don't think they are supposed to glow, looks more like a clamping circuit between the gate and cathode. I think the glow you see is a marketing thing. That led is not supposed to make the tubes glow yellow.
]

I'm pretty sure that was an enhanced photo, I've never seen one glow that bright and the tubes are only orange...no yellow

I can see why you'd think it's the yellow LEDs showing through, that makes sense if they line up (do they?). I flipped mine on just now, I see no yeller lights inside behind the tubes and my amp works great. I'm with Harley on this - don't fix what ain't broke