#175150  by Darkstar860
 
Ok i gotta ask if you all know anyone who builds Twin Reverb cabs out of Birch. Ive found a couple but i feel like there has got to be some more options other than the 3 places i found. If any of you can help me out in finding a head cab for the amp, that would ROCK! :-)

Many thanks
 #175191  by Darkstar860
 
I did want to ask if any of you folks know of any way to lower the noise floor. The amp has a hiss. You dont hear it when your playing, but you hear it when you stop playing. Ive tried turning the volume and eq on the regular channel down. I have the vib knobs turn all the way off. Ive tried turning the reverb knob all the way off. The sound is there with or without a guitar plugged in. I had a 68 Twin that made a simalar noise but not as drastic as this.

If anyone knows any good ways of quieting down this noise please let me know. Ive tried tube swapping and that did NOTHING to change the floor noise. Its not a hum, its just a SSSSSSSSS...... in the background.
 #175194  by Chocol8
 
Hisssss is most likely caused by the carbon comp resistors, especially early in the circuit.

Bad or failing electrolytic filter caps would give you hum and ghosting, and bad bypass caps would impact the tone response and gain.

Bad coupling caps can show up as scratchy pots.
 #175195  by franklins_timmy
 
What would most of you consider an acceptable amount of hum & hiss? Bought an amp from a small builder a few years ago. The amp sounds good and the builder is a great guy... very nice, generous with his time, and above & beyond customer service. The amp is just too noisy to me though and wanted to see if maybe I was nitpicking. Have done a number of things to try and help but still feel it is too noisy.
 #175196  by Chocol8
 
It's very hard to say without being there. A real tube amp is a noisy organic beast, especially when you turn them up and let them sing, but there are things you can do to clean them up, with tradeoffs.
 #175198  by Darkstar860
 
The amp sounds great but just has high floor noise hiss. I will check the dog house and see if the caps have been replaced. I have the caps so it isnt that difficult for me to replace. If its not those caps causing it ill have to do some more digging around. Thanks yall :-)
 #175200  by Darkstar860
 
Recap worked ! :-) Thanks again for everyones advice. I put in 100uf and 22uf caps. I didnt have 80 or 20 uf. But im within 20% which is fine. Amp sounds just as good as it did, but with no LOUD hiss. I do need to find a FS so i can turn on the Vib.

Anyone know of an easy hack to switch on the trem/vib effect on these. ?

So happy just jammed to Dire Straits for 2 hours and this amp is the bees knees :-)
 #175201  by Gr8fulCadi
 
Take an old rca plug. Cut it about an inch or two from the plug. Strip the wire and twist the the ground insulation and wire together and plug it into the Vibrato foot switch
 #175202  by Darkstar860
 
Well i got something else to fix. The plug thing worked but the effect has a ticking sound. So i gotta go thru and see whats causing this. :-(