Switchable Hi-Z input impedance, how ? - Page 61 - diyAudio
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Old 26th June 2013, 08:59 PM   #601
tinitus is offline tinitus  Europe
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Quote:
Originally Posted by shanx View Post
Get some copper tape and line the insides, as well as the cover, and connect to your jack ground.
yes, I have seen pictures of that
strangely its 100% hum free right now
both pots are connected with a wire soldered dirctly on housing
and there is a tin foil on pickguard/cover, connecting to jack plug ground

but I have a little very mild 'white noise/hiss' that might be related to interference


btw, almost all the noise I had before dissappeared when I left the 2 channel setup, and connected only one channel
funny thing
ground from unused channel on 2-channel power amp have to be connected to preamp ground
it connects to a free RCA on preamp, only connected to ground
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Old 26th June 2013, 09:47 PM   #602
shanx is offline shanx  Canada
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From your previous pic I think you have shielded pickup cable, which will help in reducing interference. Yes if you leave one channel of power amp floating open you could get that problem.
If you terminate it's ground to the same point in your preamp, you may have removed a ground loop there.
After I built my guitar preamp, a friend who plays bass asked me to build him something similar.
He plugs in to mixing board and with a passive bass, not enough volume etc..He normally uses a multi effects pedal (commercial, I won't say which), but the sound is noisy and not a lot of output level. So I am thinking a simple fet pre, active tone/eq and unbalanced/balanced line out. Wonder if I should suggest to put an effects loop in there?
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Old 26th June 2013, 10:45 PM   #603
tinitus is offline tinitus  Europe
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Quote:
Originally Posted by shanx View Post
Wonder if I should suggest to put an effects loop in there?
not sure
many effect pedals power on by plugging in the input jack connector
in the effect loop they would be permantly connected, and burn the battery
in such case it might be better to just have two input
with input selector switch
one input for pedals, and one straight

or have I overlooked something ?
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Old 27th June 2013, 03:31 AM   #604
shanx is offline shanx  Canada
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I was just thinking out loud and wondering if it was worth adding it. Could always put it in later. Even the balanced output adds a few parts, need a +/- supply so don't want it to cost too much.
Are you planning on doing the tube section of your preamp? Sounds like you were happy with the fet.
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Old 27th June 2013, 08:44 AM   #605
tinitus is offline tinitus  Europe
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Quote:
Originally Posted by shanx View Post
Are you planning on doing the tube section of your preamp?

Sounds like you were happy with the fet.
yes and yes

waiting for my new bass ... very happy with my 28" kids bass, but time to try a full(long) scale
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Old 27th June 2013, 01:29 PM   #606
shanx is offline shanx  Canada
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Cool! Let us know when you get going on it. And for a new bass that is always fun. What type (just curious)
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Old 27th June 2013, 02:20 PM   #607
tinitus is offline tinitus  Europe
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its a Cort Action Passive 4 Red
cost 200EUR
I liked it right away
easier to play than my short scale
which is a surprice
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Old 28th June 2013, 07:57 AM   #608
AndrewT is offline AndrewT  Scotland
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Can you explain the two sets of pickups?
And why one set is split into staggered sections?
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Old 28th June 2013, 08:40 AM   #609
tinitus is offline tinitus  Europe
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its just ordinary Fender type P-style and J-style pickups
and I suppose it stands for Precisson Bass and Jazz Bass
the two famous Fender models

but this appears to be a silly slapbass
and just I hate slapbass
it all sounds the same to me

it has a pronounced metallick string noise
but since its a slapbass I suppose it meant to
maybe I will be able to 'repair' it
other strings could be needed as well

or I can just keep it as is
not sure what to think about this
for the money it is nicely designed and well built
I especially like the neck with wide string spacing
and it does have this charming chrispy gnarly slapbass sound
quite impressive they are able to do this

I guess its just nice to have as 'optional bass'
its cheap enough for sure
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Old 28th June 2013, 09:29 AM   #610
AndrewT is offline AndrewT  Scotland
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Precision & Jazz bass,
is that different harmonic content?
Why the two sets and why are they different positions?
Why are one set split?
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