W
Will25
New member
If a pre-amp only boosts a signal, what do transparent pre-amps actually do? I mean what's the point in just boosting the signal..?
Steenamaroo
...
If you don't boost it, you can't really use it.
Same as a reference power amplifier. You need the level to be raised for it's intended purpose, but you don't (necessarily) want to alter the characteristics of the sound.
If you're curious, plug a dynamic mic straight into a converter.
Impedance matching is also a part of it if you do that though.
Same as a reference power amplifier. You need the level to be raised for it's intended purpose, but you don't (necessarily) want to alter the characteristics of the sound.
If you're curious, plug a dynamic mic straight into a converter.
Impedance matching is also a part of it if you do that though.
Bristol Posse
Okey Dokey
So the signal is loud enough to be significantly above the noise floor and can be recorded or sent to the PA and be heard
W
Will25
New member
Ah I see, noise floor being the level before you add an input? So with an onboard pre-amp an external one isn't 100% necessary...
Steenamaroo
...
You'd only use one.
External preamps should plug into line inputs, not another preamp.
External preamps should plug into line inputs, not another preamp.
M
moresound
Loud Sun Studios
My transparent pre-amps are there for the purpose of being able to see my lava lamp positioned on the other side of them! 
mshilarious
Banned
When commercial discrete light emitting transistors *finally* become available (coming up on eight years now, I mean the dude's patent is almost half gone, grrrr), then I am gonna build a truly transparent preamp . . . yeah, it could be done with tubes too, but I can't waste that kinda power anymore . . .
I know of transparent capacitors, have to shop around for a transparent resistor though . . .
I know of transparent capacitors, have to shop around for a transparent resistor though . . .
Armistice
Son of Yoda
My transparent pre-amps are there for the purpose of being able to see my lava lamp positioned on the other side of them!
..... this being on the theory that you can warm the sound up if you put the lava lamp near the inputs?
Should wrap the leads round it a couple of times as well there moresound...
Armistice
Son of Yoda
To answer the question, because it's really good, and transaparent... more of what you want (source) less of what you don't want (noise and change to the source)...
There are of course times when you don't want transparent.
There are of course times when you don't want transparent.
John Willett
Circle Sound Services
A microphone has to be increased in level to line level before it can be used.
I really good transparent pre-amp. will boost the signal without colouring the sound at all and retaining all the characteristics of the microphone.
S
snatchman
Member
Also, a clean pre helps in the many, many stack tracks senario..You can choose to "color" a signal by selecting a different mic, compressor,etc.., if needed.If the pre is already " colored", many stacked tracks may ( or may not depending on what you want) may muddy your track...
wheelema
Boner-obo
And they tend to be expensive. I've never used one but I've been told that the M-Audio DMP-3 is remarkably clean for it's price point. Going up from there is the FMR Real Nice Preamp, Appogee Duet, Sound Devices USBPpre 2, John Hardy, Lynx, and the sky is pretty much the limit.
For me the point of diminishing returns is reached at the Duet/USBPre 2. Note that these particular devices also enjoy highly regarded A/D/A converters.
John Willett
Circle Sound Services
Oh - these are the cheapies.
For the good ones I think more about the Grace Design m101, m201, etc. Or the Millennia, the Crookwood PaintPot or the Nagra EMP, etc.....
wheelema
Boner-obo
Lol. Exactly. However as I pointed out for me the point of diminishing returns is reached at the Appogee Duet/Sound Devices USBPre price points. I don't argue that there are better pres out there, they're just not better enough for me personally to invest in. That's how I minimize gear lust.
mshilarious
Banned
The most transparent preamp is no preamp at all--which is free! 
Take a -30dBV/Pa condenser mic with 4dBA self-noise (that's really really quiet); it has a noise floor of -120dBV-A. Find a converter chip with 120dB dynamic range and 0dBV = 0dBFS. No gain is required; the noise will only degrade 3dB-ish (to 7dBA, still pretty quiet).
Hook up to a reasonably quiet phantom power source--not too critical so long as the mic has some power supply rejection. It's pretty easily to filter a source with 3k4 supply resistance, so that is not very hard to do.
If you are recording a loud source, use a pad on the mic.
THE END
Take a -30dBV/Pa condenser mic with 4dBA self-noise (that's really really quiet); it has a noise floor of -120dBV-A. Find a converter chip with 120dB dynamic range and 0dBV = 0dBFS. No gain is required; the noise will only degrade 3dB-ish (to 7dBA, still pretty quiet).
Hook up to a reasonably quiet phantom power source--not too critical so long as the mic has some power supply rejection. It's pretty easily to filter a source with 3k4 supply resistance, so that is not very hard to do.
If you are recording a loud source, use a pad on the mic.
THE END
M
moresound
Loud Sun Studios
..... this being on the theory that you can warm the sound up if you put the lava lamp near the inputs?
Should wrap the leads round it a couple of times as well there moresound...
Lava lamp turned volcano! I'm liking this idea David.
M
moresound
Loud Sun Studios
The most transparent preamp is no preamp at all--which is free!
Take a -30dBV/Pa condenser mic with 4dBA self-noise (that's really really quiet); it has a noise floor of -120dBV-A. Find a converter chip with 120dB dynamic range and 0dBV = 0dBFS. No gain is required; the noise will only degrade 3dB-ish (to 7dBA, still pretty quiet).
Hook up to a reasonably quiet phantom power source--not too critical so long as the mic has some power supply rejection. It's pretty easily to filter a source with 3k4 supply resistance, so that is not very hard to do.
If you are recording a loud source, use a pad on the mic.
THE END
But what about all the bells and whistles? Not to mention all of the pretty LED lights!
mshilarious
Banned
You can still have blinky LEDs on the converter box if you like . . .
John Willett
Circle Sound Services
The most transparent preamp is no preamp at all--which is free!
Take a -30dBV/Pa condenser mic with 4dBA self-noise (that's really really quiet); it has a noise floor of -120dBV-A. Find a converter chip with 120dB dynamic range and 0dBV = 0dBFS. No gain is required; the noise will only degrade 3dB-ish (to 7dBA, still pretty quiet).
Hook up to a reasonably quiet phantom power source--not too critical so long as the mic has some power supply rejection. It's pretty easily to filter a source with 3k4 supply resistance, so that is not very hard to do.
If you are recording a loud source, use a pad on the mic.
THE END
That's still too noisy.
Take a microphone capsule, connect it directly to an AES42 module - and BINGO - you have your 24/96 digital audio without any amplifiers or analogue cables at all - and very very very low noise.
Bobbsy
Boring Old Git
A really good, transparent pre amp will get the best out of your really good, clear and natural but still warm microphone.
If you don't have a really good mic, stick with a good, standard pre amp.
That said, even an "ordinary" pre amp is a pretty remarkable piece of equipment. It can add approximately 60dB of gain to the very low signal from a microphone without adding objectionable noise. To put this amount of gain into perspective, if you added 60dB of gain to a 0dBu line level signal, you'd be using a thousand watt amplifier. (To purists, yes, I know I've simplified the math....)
The other thing to say is that very often the choice of a boutique pre amp is not to improve transparency. Rather, a lot of the popular ones are chosen because they're less than transparent and actually add a noticeable "something" to the signal--usually that hard-to-define quality known as "warmth".
If you don't have a really good mic, stick with a good, standard pre amp.
That said, even an "ordinary" pre amp is a pretty remarkable piece of equipment. It can add approximately 60dB of gain to the very low signal from a microphone without adding objectionable noise. To put this amount of gain into perspective, if you added 60dB of gain to a 0dBu line level signal, you'd be using a thousand watt amplifier. (To purists, yes, I know I've simplified the math....)
The other thing to say is that very often the choice of a boutique pre amp is not to improve transparency. Rather, a lot of the popular ones are chosen because they're less than transparent and actually add a noticeable "something" to the signal--usually that hard-to-define quality known as "warmth".