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New Kid On The Block
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Registered: 09-2015
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My amp sings to me


Hi I have an Everhardt Tiger 100 amp. It has a high pitched ring to it when keyed up after the relay closes, which by the way increases or decreases when I adjust the ant tune screw in back as the wattage changes also. ( barely puts out more than 15W atm with 3w in),
It uses a single 8417 tube and has two sk3012 transistors in a heat sink out the back.

I picked it up on a lark in an antique mall for 9 bucks and just wanted to play with it a bit so any information would be greatly appreciated.
I assumed this might be good for 50-75W with 4w into it. Initially I tried an 8 amp power supply but the amp cut in and out, so I switched to a large truck battery to make sure I was feeding it enough amps, the cutting in and out has stopped.

The only other tube amp I had used was a Kris Mach 3B back in the day so this is considerably different for me. I was told this high pitched whine was "normal" for this type of amp? Wife said she couldn't hear it when listening on another radio. Before I move ahead and try and solve the low output I wanted to make sure there wasn't more issues. The noise it makes reminds me of the chargers on the old style flash lighting for cameras, they would whine and then stop and you knew you could take a picture (early 80's style flash packs I guess?)

Appreciate any help, thanks!
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15/Sep/2015, 4:57 pm Link to this post Send Email to 2fb069   Send PM to 2fb069 Blog
 
Weak Radio Profile
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New Kid On The Block
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Registered: 06-2015
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Re: My amp sings to me


I Would Say try changing the filter caps, They look a little old. This would help in both cases to help stop the whined and make sure the tube is getting the proper voltage.
24/Sep/2015, 6:05 pm Link to this post Send Email to Weak Radio   Send PM to Weak Radio Blog
 
mslisaj Profile
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New Kid On The Block
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Registered: 11-2015
Location: Klamath Falls, Oregon
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Re: My amp sings to me


Nice pictures and neat amp too.
Good luck.

Lisa
13/Jan/2016, 5:40 am Link to this post Send Email to mslisaj   Send PM to mslisaj Blog
 
Hot Fusion Profile
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Management
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Registered: 03-2008
Location: South West England
Posts: 1372
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Re: My amp sings to me


It looks like this amp uses an inverter to produce the HT voltage for the tube from the low voltage supply, and the whine you are hearing is the sound of the inverter section, the switching being audible through the transformer so I don't think this is a fault.

The low power could be down to many things, but more than likely an output tuning issue. Do you have a circuit diagram?

---
Andy - FB107
8/Oct/2016, 10:39 am Link to this post Send Email to Hot Fusion   Send PM to Hot Fusion
 


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