• TalkBass has been independent since 1998. Add your voice.
    Create a free account to reply to discussions, view embedded media, and browse with fewer display ads.
    Join free Log in
    Want zero display ads or expanded classifieds tools? Compare plans.

Double Bass Idiot ohm question?

Basschair

Basschair

..............
Supporting Member
Feb 5, 2004
2,523
24
Stockton, Ca
#1
Hey guys,

How many ohms in a Mohm? I ask because my new Schertler STAT-B has a 100 ohm impedance, and I'm trying to decide which input to run it to in my AI Contra (Low, Hi-low at 1 Mohm or Hi-Hi at 10 Mohm).

My head hurts.
 
#2
Actually, I should probably just ask this:

According to Wiki-p, one Mohm is 10 to the 6th power ohms. So this probably means that my Stat-b with it's 100 ohm impedance would be considered "low" impedance.

I'll keep it plugged in to the "low" input. Do I have this right?
 
#3
At 100 ohms, it's quite low impedance, and it won't make any difference whichever input you use on the Contra.
100 ohms could be the output impedance of a preamp.
Maybe the STAT-B already has its own preamp?
In that case, make sure you don't overload the Contra's input.
Overloading causes distorsion and fuzziness.
 
#4
Basschair said:
Hey guys,

How many ohms in a Mohm? I ask because my new Schertler STAT-B has a 100 ohm impedance, and I'm trying to decide which input to run it to in my AI Contra (Low, Hi-low at 1 Mohm or Hi-Hi at 10 Mohm).

My head hurts.
Click to expand...
Mohm is short for megohm or 1 million ohms.

In the case of the Schertler STAT-B, the integral preamp's output impedance is 100 ohms. Connecting your Schertler preamp to an input impedance of 1000 ohms (1K) or higher should be fine, and it probably won't make any difference which input you use with your Contra.

Edit: Oops sorry, didn't see Francois' reply before I posted mine. The Schertler Stat-B does indeed have it's own preamp. I'm pretty sure the AI Contra can handle the signal level just fine though.
 
#5
Without preamp: In general, you want the input impedance to be higher than the pickup impedance. This is particularly important with piezos, otherwise you lose all the bottom end. Piezos need input impedance of 1 M-Ohm or greater; 10 M Ohm is typical.

With preamp: Input impedance becomes irrelevant because the preamp will buffer the pickup. Preamps typically have very high input impedance to avoid loading down the pickup, and very low output impedance so they can drive long cables.
 
#13
Basschair said:
The last thing I need is to tell my pregnant wife that I just blew my DB amp and need to get a new one.
Click to expand...
Hardly the last thing.

  1. I just lost my job
  2. I'm tired of our relationship and want to see other people
  3. have you though more about an open marriage
  4. I'm having a midlife crisis with a short asian woman and a $70,000 car
  5. I think we should consider moving to a commune and living naked with other parents and their children
Did I leave anything out?
 
#14
Uncletoad said:
Hardly the last thing.

  1. I just lost my job
  2. I'm tired of our relationship and want to see other people
  3. have you though more about an open marriage
  4. I'm having a midlife crisis with a short asian woman and a $70,000 car
  5. I think we should consider moving to a commune and living naked with other parents and their children
Did I leave anything out?
Click to expand...

How about, "Hmm, that's not how your sister does it."
 
#15
Sorry to get back on topic for a moment, but I thought I'd point out that the Stat-B is not a typical piezo pickup but instead works on the electrostatic principle. The Stat-B system uses an integral preamp with a line level output that can easily drive lower impedance inputs, so it really doesn't matter what the amp's input impedance is. Now back to our regularly scheduled program...
 

Latest posts

Top Bottom
Back