High voltage V1 Pin1?

Discuss your builds of MetroAmp Kits.

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Ceeya68
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Joined: Fri Aug 19, 2016 5:29 am
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Re: High voltage V1 Pin1?

Post by Ceeya68 » Thu Sep 15, 2016 2:27 am

Ok, well here's a new vid with the amp going. Please see vid:
(https://youtu.be/4pRD8DSALso).
I did not mention in the video that I put in 0.68 uf 160 volt miniwatt caps on the board. It definitely made a difference in they way the amp sounded. It made the amp a lot more warm sounding. They were and are freaky expensive though. Also I used a 43K resistor for the bias adjustment. The 47K just did not give me the trim pot adjustment that I wanted. It was way to far to one side. The 43K gives me more of a middle ground with the trim pot so I can have plenty of adjustment either way cold or hot. I made all the measurements over again when I finished with the new sockets and all the measurements seemed to be right in line with the tolerance chart on the instructions I followed. So that was a happy for sure. (Lesson learned don't use liquid flux on your tube sockets. Even if it's just a tiny little drop). Thanx for the help. And stay tuned I may be back with MV trouble. I hope not! :scratch:

danman
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Re: High voltage V1 Pin1?

Post by danman » Sat Sep 17, 2016 4:53 pm

Sorry....I just saw your reply. Glad to hear that you got it fixed. You are probably right that the flux was preventing good contact at pin 5, and your tubes were not getting the bias voltage. I like to use a flux pen on occasion because I can paint the flux exactly where I want it.

The amp sounds great! A MV will help to tame it but you may not like the sound when it is turned down to far. A really nice attenuator is another option for taming the beast. Scumback Speakers sells a very nice unit that will preserve the original tone quite well. Let us know if you have any questions with the MV install.

Ceeya68
New Member
Posts: 10
Joined: Fri Aug 19, 2016 5:29 am
Just the numbers in order: 13492

Re: High voltage V1 Pin1?

Post by Ceeya68 » Sun Sep 18, 2016 6:00 pm

Hey Danman, Thanx for the help and guidance. I did install the MV. It did flatten the tone/sound like you stated, just a bit. Is there a remedy for this? The amp is sounding really good through my cabinet of vintage 30's though. Thax again! :thumbsup:

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