Quantcast
do I need a preamp for this - Gearspace.com
The No.1 Website for Pro Audio
do I need a preamp for this
Old 27th January 2013
  #1
Here for the gear
 
🎧 5 years
do I need a preamp for this

New Mac mini being set up for hobbyist music production, I have some Alesis M1 mk II monitors and a colleague is giving me an Apogee Duet he doesn't use (!). Will I need a pre-amp between them? If so, any suggestions?
Thanks from a gear newb.
Old 27th January 2013
  #2
Gear Addict
 
skinnypete's Avatar
 
🎧 5 years
The Duet has pres built into it. Don't let anyone on Gearsluz tell you the Apogee pres suck!

They are pretty good.

Sent from my Droid
Old 28th January 2013
  #3
Lives for gear
 
🎧 10 years
If the question is about hooking up the monitors to the Duet answer's no.
The Alesis are active monitors which means the amp is built in, you can plug them direct to the Duet's outs.
Have fun!
A.
Old 28th January 2013
  #4
Here for the gear
 
🎧 5 years
Thanks guys. Whenever I see the Duet's preamps mentioned, it seems like they're talking about input preamps used to boost a microphone level etc. before conversion. SkinnyPete is this what you're talking about?

Andy_bt, yes that's what I meant, between the Duet and the monitors. Is that always the case, that powered speakers don't need pre-amplification?
Old 28th January 2013
  #5
Gear Addict
 
skinnypete's Avatar
 
🎧 5 years
Quote:
Originally Posted by montagular ➑️
Thanks guys. Whenever I see the Duet's preamps mentioned, it seems like they're talking about input preamps used to boost a microphone level etc. before conversion. SkinnyPete is this what you're talking about?

Andy_bt, yes that's what I meant, between the Duet and the monitors. Is that always the case, that powered speakers don't need pre-amplification?
You are using the word "preamp" wrong. You are talking about a power amp. That has nothing to do with the Duet.

Anyways, have fun the Duet is a great piece of gear.

Sent from my Droid
Old 28th January 2013 | Show parent
  #6
Lives for gear
 
🎧 10 years
Quote:
Originally Posted by montagular ➑️
Thanks guys. Whenever I see the Duet's preamps mentioned, it seems like they're talking about input preamps used to boost a microphone level etc. before conversion. SkinnyPete is this what you're talking about?

Andy_bt, yes that's what I meant, between the Duet and the monitors. Is that always the case, that powered speakers don't need pre-amplification?
Yep, no need for preamp with actives, that's the point
In pro audio preamp usually refers to a microphone preamp which you plug the mic into in order to get the very low voltage recorded signal back to line level, the Duet has that also.
A.
Old 28th January 2013
  #7
Lives for gear
 
Lotus 7's Avatar
As Andy bt and skinnypete have already said, you are confusing a preamplifier with a power amplifier.

A preamplifier. commonly called a "mic pre" around here, but may also be a amplifier used to increase the signal level of a phono cartridge for us vinyl-age dinosaurs. That sort of amplifier may have a signal gain of 40 dB to as much as 85 dB and works at input signal levels of less then millivolts (1/1000 of a volt) and is used to bring the signal up to "line-levels" (several volts). It's basically a simple voltage amplifier, and a mic pre will usually have a "balanced input" and may also provide "phantom power" at its input to provide power for microphones that require it. Some mic pres are designed to provide only gain with no change in the "character" of the signal (sound), while some mic pres are designed to modify the sound to "enhance" the signal in specific ways. The mic pres in your Apogee Duet are of the "clean" type and don't modify the sound the way a transformer-coupled, vacuum-tube mic pre might.

A power amplifier is used to drive "passive" speakers. A power amplifier typically has fairly low voltage gain, often less then 20dB, but provides very high power gain. That means it can generate the high output current that is required to drive the low impedance load of a passive speaker. A power amplifier takes a line level signal (such as that coming from a interface or mixer "monitor" output, usually a few volts (at a current of 0.1 milliamp) to something like 20 volts at 2.5 amperes (which is a power level of 50 watts when connected to an 8-ohm speaker) to drive a loudspeaker. Audio power amplifiers are available in output power ratings of a few watts to thousands of watts.

An "active monitor" or "active speaker" is simply a speaker system with a built-in power amplifier, or more likely several built-in power amplifiers. Usually, any contemporary active monitor will actually have separate power amplifiers for each of the drivers. There will be an amplifier for only the low frequencies that's connected to only the low frequency speaker (the "woofer") and a separate amplifier for the high-frequencies connected to only the high-frequency speaker (the "tweeter"). The signal frequencies are separated in an electronic "crossover" that is also included in the "active monitor". Having the amplifiers "matched" to the speaker drivers in active monitors usually provides design advantages over having a speaker used with an unknown external power amplifier, so is becoming the "norm" in professional audio these days.

Your Alesis M-1 Mk-II active monitors each contain a 75 watt low-frequency power amplifier and a 25 watt high-frequency power amplifier, as well as a 2kHz crossover, so you actually already own (4) power amplifiers!

The input for any contemporary "active monitor"can be easily driven from the "line-level" output from your Duet interface.

Hope this helps define the differences between pre amps and power amps for you.

Please ignore the automatic links that Gearslutz adds to these posts. They are usually unrelated to the true post content and just try to route you to a sales outlet to sell a product.
Old 28th January 2013
  #8
Here for the gear
 
🎧 5 years
Lotus 7, thank you for an extremely clear explanation. You're right I was confused about the terminology. Regards - Montagular
Old 28th January 2013
  #9
Lives for gear
 
🎧 10 years
@ Lotus 7:
Great post
In the hi-fi world some systems use both a preamp and a power amp thus the possible confusion I guess
A.
Old 28th January 2013 | Show parent
  #10
Lives for gear
 
Lotus 7's Avatar
Quote:
Originally Posted by Andy_bt ➑️
@ Lotus 7:
Great post
In the hi-fi world some systems use both a preamp and a power amp thus the possible confusion I guess
A.
Good point, although sadly in the modern digital age it's becoming pretty rare to see an Integrated amplifier (incorporating a pre amplifier (usually for a phono cartridge) and a power amplifier. The most common version in the home hi-fi world used to be the common Audio Receiver (phono pre amplifier, radio tuner and a stereo power amplifier, with inputs/outputs for one or more tape decks), but these days the Video Receiver seems to be more popular and may have as many as 7 audio power amplifier channels for surround sound for video movies, and of course, video routing and switching circuitry.

Fortunately, the pro-audio world is usually separated into simpler "blocks", although we still have the specialized "variants" such as guitar and bass amplifiers, and headphone amplifiers, etc.
πŸ“ Reply
Topic:
Post Reply

Welcome to the Gearspace Pro Audio Community!

Registration benefits include:
  • The ability to reply to and create new discussions
  • Access to members-only giveaways & competitions
  • Interact with VIP industry experts in our guest Q&As
  • Access to members-only sub forum discussions
  • Access to members-only Chat Room
  • Get INSTANT ACCESS to the world's best private pro audio Classifieds for only USD $20/year
  • Promote your eBay auctions and Reverb.com listings for free
  • Remove this message!
You need an account to post a reply. Create a username and password below and an account will be created and your post entered.


 
 
Slide to join now Processing…

Forum Jump
Forum Jump