| MMicke |
Hello!
I must thank you all at whis forum. I really enjoy reading must of the stuff her. Well after reading about the GainClone I decided to build one of my own and so have I done now.
I have only used 5 components. A 220k resistor from pin 8 to pin 3 and another at 10k from pin 3 to a 4,7 uF cap that is connected to the volym pot and of course a LM3805.
Everything works great, but if I disconnect the input and start turning upp the volume the GC starts to hum a litle bit, is this normal or is it some kind of disturbence or osiolation?
If this is normal, then there is no point in trying to get rid of it, but if this isn't normal then I have a little chalange ahead.
/MMicke |
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| ronc |
You need some resistance network on the input to ground,i use a 100ohm resistor.
ron |
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| MMicke |
Where am I supose to connect the resistance?
I have attached a drawing of my circet. |
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| ronc |
Between the input and the 4.7Uf.
ron |
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| ronc |
I didnt think you were using an input pot?If you dont have an input pot then you need to have a reference to ground.
ron |
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| ronc |
OK re read your post, you are using a pot @ input.I would check the grounding wires and if the hum (no input ) isint too great then it should be ok. Sounds like a stability problem with the inputs not connected, so just dont turn up the volume with no inputs.
ron |
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| zygibajt |
[/QUOTE]Everything works great, but if I disconnect the input
So what are you disconnect it for? You usually have some source connected to the amp,so if there is no hum when the source is connected why bother?
My gain clone is dead quiet on 95db speakers,even when I put my ear into the speaker,but I always care about proper earthing and grounding.
Bartek |
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| ronc |
Yea , proper method should be to power off anyway before you connect or disconnect inputs.I am using battery power and hear nothing when connected but nothing going into inputs till about 5 o clock on the input pot then a very very faint hum.
ron |
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| zygibajt |
I don't use input pot.I put some 47K resistor to ground instead,what means I'm using it as a power amp.And even when the preamp is all the way up there is no even slight hum.
Bartek |
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