NGD - Yamaha bass amp

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laurie
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NGD - Yamaha bass amp

Post by laurie » Thu May 19, 2022 1:04 am

I was given a Yamaha VX55B bass amp today. Not working but it turns out to be blown internal fuse due to aging (40 year old) main filter capacitor.

With a full recap and bit of maintenance (dirty pots, etc.) it should be good as new.

Will post pics when I can.

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Pepe
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Re: NGD - Yamaha bass amp

Post by Pepe » Thu May 19, 2022 5:29 am

Nice! :)
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laurie
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Re: NGD - Yamaha bass amp

Post by laurie » Sat May 21, 2022 11:39 am

VX55B_1.jpg
VX55B_1.jpg (251.5 KiB) Viewed 6250 times
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VX55B_2.jpg
VX55B_2.jpg (202.88 KiB) Viewed 6250 times
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VX55B_3.jpg
VX55B_3.jpg (229.4 KiB) Viewed 6250 times
Last edited by laurie on Sat May 21, 2022 11:42 am, edited 1 time in total.

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laurie
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Re: NGD - Yamaha bass amp

Post by laurie » Sat May 21, 2022 11:40 am

Caps are dated 1986. Clear that it needs a recap just from the sound of it.

Ordered new caps plus a dual primary transformer. $80 total and maybe 3 hours work it will be good as new and usable in Australia when I get there.

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Re: NGD - Yamaha bass amp

Post by Old_Iron » Sun May 22, 2022 12:14 am

laurie wrote:
Sat May 21, 2022 11:40 am
Caps are dated 1986. Clear that it needs a recap just from the sound of it.

Ordered new caps plus a dual primary transformer. $80 total and maybe 3 hours work it will be good as new and usable in Australia when I get there.
In a bass amp fresh caps are very important.

Very nice catch Laurie.

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laurie
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Re: NGD - Yamaha bass amp

Post by laurie » Sat Jun 04, 2022 5:07 pm

Parts for the recap and transformer swap have arrived.

Am out of town on vacation for the next week. Will get this amp up-and-running in a couple of weeks time :D

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Re: NGD - Yamaha bass amp

Post by laurie » Sun Jun 19, 2022 1:37 am

Fixed. It was in fact a failed main filter capacitor. I swapped out all the electrolytics and replaced the power transformer with a dual primary one (230/115).

Sounds pretty good for a 55W amp!
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VX55B finished.jpg
VX55B finished.jpg (187.27 KiB) Viewed 6029 times

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