Preamp differences

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Member Since: Dec 10, 2005

What is the differences between bass, e. guitar, e. acoustic and mic preamp (exluding the warm and tone). Can I use it interchangeable without damaging the equipment? I mean in electronic sense. Thanks in advance.

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Member
Since: Dec 10, 2005


Dec 12, 2005 09:43 am

Fuyo, nobody want to answer my qeustion kah? Nevermind I keep it in my pocket lol...

Prince CZAR-ming
Member
Since: Apr 08, 2004


Dec 12, 2005 10:24 am

I just saw this piyan, lots of people don't check at home, and only get in on monday to work, to check up on the forums.

Anyhoo, I believe there's small amount of difference from, say mic level signal to guitar level signal (passive) but it's so small of a difference, that it wouldn't be a problem in either's preamp. Active is a different story, as active pickups will probably overdrive a mic preamp.

As for higher end devices, they will offer mic inputs, in addition, they'll offer instrument level inputs. Both are preamped. So it would seem that some equipment will take different levels, and act accordingly, so this is something to consider too.

Now, for consumer type stuff, say a guitar processor, I'm sure that you could plug passive, active or mic into it's input without problem.

hope that helps. someone else will probably chime in.

ps: what's fuyo?

Answer:On a good day, lipstick.
Member
Since: Jun 24, 2004


Dec 12, 2005 10:37 am

Hey there Piyan. You catch more flies with honey than you do with vinegar. Patience.....

I use a Behringer MIC100 (with a nice little tube in it) for EVERYTHING. Bass, Guitar, Vocals, Keyboards...It adds just what I need, and gets a nice hot signal to the mixer. It has both 1/4" in/out, and XLR in/out - plus phantom power. $50!!!!

You might find that a bass dedicated preamp won't give you very much clarity, as the frequency response is set lower than a guitar preamp would be.


formerly known as 'dB Masters'
Administrator
Since: Apr 03, 2002


Dec 12, 2005 10:39 am

Most preamps for different used have their EQ's shelved differently, to work best for the expected instrument...or, that is one difference...

Member
Since: Dec 10, 2005


Dec 12, 2005 11:46 pm

Hey guys thanks for the input. I think I understand a little bit.

pjk - Correct me if I'm wrong what I have understand you were saying. A passive pickup requires no power to operate such as most e. guitar & e. bass on the market and so you can plugged into to any type of preamp without damage and their impedance are low and most preamp are high impedance so it fits in. An active pickup requires external power like e.acoustic requires baterry thus are not suitable for preamps and can cause distortion if used and it too have a high impendance output. Hope I got correct on this one.

Oh yaa about the fuyoo thing. Is the same as "WOW" expression. It's a word that my brother use to say and I think it came from chinese people (I may be wrong about this) to express thier wow thing. haiya is another word.

TallChap - Well, I grow up in the invironment that is so sour, I can't change unless I reborn again lol..
I'm eyeing on this preamp too but not now. I'm looking for solid state base such as V Tone GD121, AD121, BD121 and I need more view from other people about this 3-1 preamp as it too a DI Box and then should I decided to buy it or not.

DB Master - Does it mean that a preamp too have to own frequency response? So thinking of that, preamp too have different characteristic much like mics so that there is no such as generic/multipurpose preamp. I hope you can give me some input on this. Thanks.

Member
Since: Nov 28, 2005


Dec 13, 2005 09:22 am

Quote:
pjk - Correct me if I'm wrong what I have understand you were saying. A passive pickup requires no power to operate such as most e. guitar & e. bass on the market and so you can plugged into to any type of preamp without damage and their impedance are low and most preamp are high impedance so it fits in. An active pickup requires external power like e.acoustic requires baterry thus are not suitable for preamps and can cause distortion if used and it too have a high impendance output. Hope I got correct on this one.


Let's try again.

Passive pickup & acitve pickup -> preamp

Line level (keyboard, hardware sampler) NO preamp


TO the preamp:

Cables with 3 conductors (mic or Tip/Ring/Sleeve 1/4") = Low Impeadance.

Cables with 2 conductors (guitar or Tip/Sleeve) = High Impedance.

Impedance should always be matched, not opposite.

In other words, if your preamp ONLY has XLR (mic cable) inputs and you use an adapter instead of an impedance converter to plug your guitar in you will hear hum.

From the preamp

Everything is line level.






edit0r
Member
Since: Aug 17, 2004


Dec 13, 2005 02:06 pm

Erm, TRS are still high impedance.

And active outputs are line level.

Correct me if I'm wrong somebody.

Member
Since: Nov 28, 2005


Dec 13, 2005 03:22 pm

[quote]Erm, TRS are still high impedance.

And active outputs are line level.

Correct me if I'm wrong somebody.
[/quote]

I could be wrong ;) but what would be the point of a TRS cable (aside from stereo) if not to be a balanced, therefore, lo-Z, lead.

I am thinkin' the impedance (being the AC equivalent of DC resistance) has more to do with the way in which the signal is transmited than what kind of plugs they put on the end, provided they are 3 conductor plugs & cables.

Honestly, I am not even sure where it would be applicable because I am always using XLR cables into the pre and TRS after.

As far as the active outputs, I know they're hotter but are you sure they put out -10/+4?

I've never heard of anyone plugging a bass or guitar into a console insert/input without a DI and a pre.

Definitely merits some research on my part. Of course I'm no pro either.

edit0r
Member
Since: Aug 17, 2004


Dec 13, 2005 04:43 pm

But balanced does not mean Lo Z. XLR cables are Lo z and are made to carry low level singals from microphones without great singal loss with distance. TRS is a TS with one more conductor. In a TS cables the sheild shares the negative, but in TRS The sheild is also the ground me thinks. Exactly the same cables, just one more conductor.

People don't plug their basses directlt into the mixer because the leads would have to freaking long. With an unbalanced TS lead, signal loss and noise induction begins to be noticable at about 5 meters in length. In theory it would be alright to plug a passive pick up into the pre amp in, and an active pick up into the line in.


Member
Since: Dec 10, 2005


Dec 13, 2005 09:32 pm

Wowwowooo guys!! hold on, you left the questioner far behind.

netstat - Thanks for clear explanation. BUt one thing I'm not sure about
"impedance should always be matched, not opposite."
I read somewhere in the net that say, line in impendance matching is not require anymore but the rules that must be followed is output impendance should be lower than input impendance ( he also mentioned that in 60's they do require matching impendance that fixed at 600ohm, I guess something to do with vacumm tube component). I may wrong about this, maybe the writer refering to home audio equip. not related to music equip.

Colonel Sanders - Thanks for extra info. I've tried plucking active pickup (piezo type) to line-in -10 (TS). It does't work, no sound. I've read somewhere that piezo pickup has it own buffer preamp and its output impedance
is about 10 Megaohm, is it right? Where can I get an input that accept/match for that value? Do buffer preamp generate unbal or bal?

So this my idea for correct setup for my active pickup, hope someone agree with me.

Piezo pickup/buffer preamp -> DI Box -> Mic preamp

2nd setup (if the buffer preamp line out balance)

Piezo pickup/buffer preamp -> TRS cable -> line in +4 bal

3rd setup
Buy special adapter for buffer preamp (I dont know whether it exist or not and looking help on this one).


edit0r
Member
Since: Aug 17, 2004


Dec 14, 2005 01:46 am

Hmmm. There should be some signal shouldn't there? Even if the impedances were mismatched, there would be a little bit of signal. I've tried it before as well. When I was in my first band we didn't have amps, so all our guitars (acoustic and electric guitar, and active bass) went directly into line ins on the powered mixer.

I would say buffer pre amps generate unbal. because the level is so high it does not need extra noise reduction. Cheaper to make.

No idea on the 10 mega ohm thang lol.

Member
Since: Dec 10, 2005


Dec 15, 2005 06:33 am

I guess I have a bad cable.
Emm...I read somewhere on the net about the 10Mohm, well never mind.
Ok, I just read somewhere recently about DI BOX setup and its the best option so far and I go for it. Topic closed.

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