Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Mick-Dee on June 04, 2015, 09:42:24 pm
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Hi I am new to this forum and this will be my first post.your help will be immeasurable because this problem is the reason I joined after being very highly recommend by a good friend.I was recently gifted an old vox ac50 by a friend of mine,it had been unused for quite a long time,many many years I believe.He has told me the valves are practically brand new and they do look undamaged and unaffected in any way.whenever I plug it into a cab I get no noise coming from the speakers just this sqwerking and unusual noise from the head itself and I have no idea what it could be.I've already gained knowledge and a minimal understanding of how valve amps work after just browsing through the tubes for dummies article but this is way out of my league at this stage.any knowledge to what this could be or any help in any way would be so highly appreciated as I cannot wait to get using the amp.below I will include four pictures in case it could give anyone a better understanding,when I figure out how to make them smaller.Thank you for any help in advance.
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Welcome Mick-Dee!
1st that amp has hi-voltages in it! We don't know if you are experienced with safely working with hi-voltage circuits?
Here's a couple of links on how to add attachment's and how to re-size pictures;
http://el34world.com/Forum/index.php?topic=4207.0 (http://el34world.com/Forum/index.php?topic=4207.0)
http://el34world.com/Forum/index.php?topic=464.0 (http://el34world.com/Forum/index.php?topic=464.0)
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You can also use a free image host to upload the images without resizing
and post here the link
here a free image host very simple to use
http://imgur.com (http://imgur.com)
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Have you previous experience with electronics circuit ? are you able to recognize components and use a soldering iron ?
Ciao
K
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Thanks guys :)http://i.imgur.com/NLLwaHs.jpg
http://i.imgur.com/yajU12W.jpg (http://i.imgur.com/yajU12W.jpg) http://imgur.com/OJWlLZahttp://i.imgur.com/B3ysWPf.jpg (http://imgur.com/OJWlLZahttp://i.imgur.com/B3ysWPf.jpg) http://imgur.com/cNtOrfT (http://imgur.com/cNtOrfT)
http://imgur.com/UD9Bt9w (http://imgur.com/UD9Bt9w)
http://imgur.com/iXqY6LK (http://imgur.com/iXqY6LK)
http://imgur.com/6aaRYhf (http://imgur.com/6aaRYhf) http://imgur.com/NuWofkm (http://imgur.com/NuWofkm)
http://imgur.com/ZhZpc2j (http://imgur.com/ZhZpc2j)
As you can see it looks old :)and also the inputs for a cab have been changed from the originals judging by what I've seen from looking at pictures of other ac50s.and to answer a previous question
I don't have any experience working with high voltage circuit just with foot pedals really but my friend who advised me to use this site would have experience with them.
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Seems that the amp is really in bad shape, may be it was exposed to rain for some time
But anyway it is an original Vox and for me it's worth to completely restore it
it is a very big job to do, it is to disassemble everything and rebuild
but this has not completely to do with High Voltages, it implies a lot of mechanical work
that chassis must be disassembled and brought to zincify
and transformers must also be restored
do you feel able to deal with it ? If the answer is yes
here you can find all the necessary info for a successful restoration job
http://www.backfromthesixties.co.uk/Pages/Vox_AC50.aspx (http://www.backfromthesixties.co.uk/Pages/Vox_AC50.aspx)
Ciao
Franco