dmp
Well-known member
How did you wire the input? Did you replace the vactrol with a pot & use a jumper in place of 82K?
If you ground the transformer side of C2, is it quiet?
If you ground the transformer side of C2, is it quiet?
dmp said:How did you wire the input? Did you replace the vactrol with a pot & use a jumper in place of 82K?
If you ground the transformer side of C2, is it quiet?
Sounds like you found the smoking gun. Reviewing and cleaning up the ground scheme will probably get you quiet performance.An enormous amount of hum disappeared after grounding the pot with a heavier gauge grounding wire and doing the same for my 0v tap.
mnats said:That value is from the Waltzing Bear schematic linked earlier - and it appears whoever re-drew that schematic was from the "bigger is better" school of device "mods".
waltzingbear said:mnats said:That value is from the Waltzing Bear schematic linked earlier - and it appears whoever re-drew that schematic was from the "bigger is better" school of device "mods".
nope, when I drew that up I couldn't find the schematic anywhere. That is a draw up from existing module in front of me, "as delivered". Have no idea if it was stock, been repaired or what. Fortunately we have the original schematic available now.
Alan
Damn these don't look too involved!Stagefright13 said:
Damn these don't look too involved!
has anyone tried building them?
Just completed a pair, looking forward to putting them to use. I'm getting 43dB of gain out of these two feeding them 26v from the PSU. Only thing I'd like to improve is the 1meg pot response. Any tips?
Let me know if I'm hijacking this thread.....dmp said:Damn these don't look too involved!
has anyone tried building them?
The hard part is figuring out the inductors and making them.
I haven't ever tried them, but I would love to build a pair of (because I'm the eq type of junkie!). Just a guess, but they're probably more of a sweetening eq than a problem solver, and could sound really nice on the mix bus. It'd probably be pretty cheap to build and it's always nice to have a different flavor at your disposel. As far as measuring inductance, you'd have to remove it from the circuit to measure it. Then trace out a schematic and values. And considering all the excitment a few pages back, I'd be willing to bet the communtiy would help make it happen.duantro said:Let me know if I'm hijacking this thread.....
Has anyone used the 508 eq's? I know they are pretty limited, but do they sound good? Any clue on how to find a compatable inductor? I've just bought a 508, and am in the process of racking up 2 original 1108's, and 2 original 1008's. I can't decide what to do about my lack of eq for the other 3 UA channels.
tomas1808 said:Need some help! :'(
I finished building my 1108 a few days ago, but I am going crazy with the high amount of hiss. With gain maxed out I get a noise floor of around -65dbFS when terminating the input with 150ohm metal film resistor.
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