Author Topic: Noob looking for simple bass guitar preamp  (Read 382 times)

yapper

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Noob looking for simple bass guitar preamp
« on: December 09, 2017, 10:53:31 PM »
I'm looking for a straightforward 'flat' preamp for my passive p-bass clone. Ideally something with 10dB gain. Is there a cheap-ish kit out that that would do this? I've seen various things on ebay but they all seem to be embellished with tone adjustments.

Thanks in advance for any pointers,

Mark

jimilee

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Re: Noob looking for simple bass guitar preamp
« Reply #1 on: December 10, 2017, 09:31:54 AM »
What context are you using it? As a bassist myself for most of my 46 years, an external preamp is not anything Iíve ever actively looked for.


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yapper

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Re: Noob looking for simple bass guitar preamp
« Reply #2 on: December 10, 2017, 11:37:13 AM »
Primarily to improve noise. Somewhere I'm picking up noise and I found by using an old headphone amp between the bass and the cable to the (main) amp the signal to noise levels are much better. I'm not necessarily looking for an external amp - today I've come across some circuits based on a J201 FET that look promising and it's simple enough to fit inside the bass.

jimilee

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Re: Noob looking for simple bass guitar preamp
« Reply #3 on: December 10, 2017, 02:07:16 PM »
Like just a basic boost or something then? Thatís really strange youíre getting noise that filters out that easily. Is it like a 60 cycle hum?


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soldersqueeze

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Re: Noob looking for simple bass guitar preamp
« Reply #4 on: December 10, 2017, 02:12:47 PM »
 Is there a chance your bass isn't grounded properly? The headphone amp could be sorting a grounding issue between your bass and amplifier?
 Just a thought, but as jimilee says it's a strange situation

yapper

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Re: Noob looking for simple bass guitar preamp
« Reply #5 on: December 10, 2017, 02:38:43 PM »
I suspect it's either my cheap guitar cable, or the amp that's picking up the noise so simply (pre) amplifying the guitar signal means it's now xdB louder than the noise.

The bass appears to be grounded properly. I've got the cavities lined with good quality copper tape with overlapping seams and the bridge is grounded back to the pots.

Changing the focus from amps to cable, can you recommend a good cable (either a ready made cord or a brand/type of cable) that is well screened?

jimilee

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Noob looking for simple bass guitar preamp
« Reply #6 on: December 10, 2017, 04:37:23 PM »
I use Hotwire. Cheapish but never an issue.is where itís plugged in grounded? Is the headphone amp battery or plug in?


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yapper

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Re: Noob looking for simple bass guitar preamp
« Reply #7 on: December 10, 2017, 04:49:48 PM »
I've located the source of my noise. It was the 9V DC PSU for a pedal. Running the pedal off a batteries got rid of the noise!

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Re: Noob looking for simple bass guitar preamp
« Reply #8 on: December 10, 2017, 06:39:34 PM »
I've located the source of my noise. It was the 9V DC PSU for a pedal. Running the pedal off a batteries got rid of the noise!
Excellent! Bad psu or house wiring is acting wonky? The latter happens from time to time.


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yapper

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Re: Noob looking for simple bass guitar preamp
« Reply #9 on: December 10, 2017, 06:48:19 PM »
It's a bad PSU I think. The output smoothing capacitor looks like it's leaking.

jimilee

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Re: Noob looking for simple bass guitar preamp
« Reply #10 on: December 10, 2017, 07:00:21 PM »
Ahhh. Glad thatís all it was.


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