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It's time for me to invest in a decent mic preamp. I'm looking at The Brick and the Aphex 107 with 12AT7 Tubes installed. I've been reading praise about both around here.

So, to help me out in my decision, I'd like to hear from any of you that have experience with either one (preferably both). I know there are some guys on here that are EXTREMELY knowledgeable on this stuff, and I'm sure I could use their help.

Thanks in advance


moonbaby Fri, 10/09/2009 - 04:34

I own both of these. They are 2 very different beasts. Both have tubes in their circuit, but beyond that...
What type of material and sources are you going to be dealing with? The Brick makes a great DI for bass and some keys, and offers some coloration when used with used with dynamic and some ribbon mics. It is a "true" high-voltage tube pre, but its' lack of output level control can make for problems down the line when connected to an interface or mixer.
All that gain-GOBS of it- can be a problem sometimes.
The 107 is much more refined. Less raunch, a smoother sheen, maybe a bit quieter. 2 channels vs. single, with polarity reversing and better gain and level control. Not a "true" high-voltage tube circuit, let the techies work that out (eh, Link?). And I've even found a use for the remote muting feature. The negatives? A wall wart power supply, no DI provisions, and of course, it is out of production. You can still find these at a bargain price on CL and e-Bay, many times around $100...

Link555 Fri, 10/09/2009 - 06:22

The Aphex 107 used a new(at the time) idea, they called tubessence or RPA (Reflected Plate Amplifier).

Basically its a circuit that operates tubes plate at a constant low DC potential. However they use a current mirror to extract the proper plate current. This way there is very little plate voltage swing, so they can operate from a low DC plate voltage.

This is not extactly a starved plate amp though. Typically a starved plate amp limits the current though a large value dropping ressitor (5-10 meg or so). This causes a big voltage drop at the plate, and little current. The 107 doesn't do that.

This starved plate idea is what you find the Tubedriver distortion least the smaller version seen at the link below:

Anyway, they are as Moonbaby said- different.

What you you mainly using it for?

Link555 Fri, 10/09/2009 - 10:30

I don't have a brick. But the aphex 107 will be able to handle all of those applications and add some warmth, its subtle though...The problem with 107 are noise at high gain settings. Its a bit noisy but the construction is decent and the parts selection for the time was also very good. For $100 bucks you can't go wrong.

JesterMasque Fri, 10/09/2009 - 13:48

moonbaby wrote: The 107 was designed to use the 12AT7, but ended p shipping with a 12AX7 in it instead. Replacing that with a 12AT7 is the main upgrade.

That would probably clean up some the noise that was being spoken of, correct? I know that even the smallest upset in biasing a tube amp can dirty up the sound and quality quite a bit for power tubes. Same deal with pre-amp tubes?

Link555 Fri, 10/09/2009 - 14:47

Well my goal with the 107 was to make cleaner, quieter pre. The interesting thing about the circuit in the 107 is the changing the tube to 12AX7 actually provides lower gain than a 12AT7.

This is odd because a 12AT7 tube has lower gain than a 12AX7. Its a bit complicated to explain but in a nutshell the Aphex 107 was designed for a 12At7 not an 12Ax7.

The most common mod I see is people swaping the tube. I bought a used 107 off ebay with 12AX7 in it.

I intially swapped the tube thinking I was going to lower the gain, and reduce some of the distortion.
What I found was the pre had more gain and it was cleaner. A few months latter I read a report by Aphex stating it was designed for AT7 and it would not have more gain with a AX7.

Anyway... just my 2 cents.

Link555 Fri, 10/09/2009 - 18:26

I have a clip of the 107 up:

The acu gtr was recorded with a QTC50 pair at 4 feet through a apex 107 into a lynxl22 into nuendo 3.0.

Edit: I should say this a track by Signal and Sound. I had the pleasure of recording them a few times now.

It was actually recorded in a empty living room, I was moving and all my gear was in boxes. All except my PC, Earthworks mics, and 107. The verb you hear in the hardwoods floors and the 12' high ceiling.

Mauisnow13 Fri, 10/09/2009 - 18:59

I understand that. Just complimenting a great sound. :D

So would you say that this pre makes a noticeable difference? Lets say compared to going completely digital. If you add this pre to a digital setup, how much difference will you really hear?

Maybe someone could record a straight through digital track then add the pre and post the two as a comparison. I'm sure it would help a lot of people in the future too. :D

I'll keep searching for something similar on the boards too.

Link555 Fri, 10/09/2009 - 20:42

Thanks. I am sorry but when you say go completely digital, do you mean use a "transparent" pre-amp? The Aphex unit does add subtle harmonics. On one track alone it would not be very obvious but if all tracks went through it might become too much.

Again the main problem with this pre is the noise level, across to many tracks it might raise your noise floor.

Would I buy a second one? Sure its a decent pre.

I am not one to buy into the price indicates the quality. However usually a higher price means they spent longer hours perfecting a unit and want to get paid for their time.
Aphex may be a bit of an exception to this rule.

How you record and what you record should dictate the type of pre's to buy.

If you record only Rock, the API 3124+ is for you. If you want a more transparent pre, maybe Buzz is a better choice.

Personally I want more transparent Pre's at this point.

Mauisnow13 Fri, 10/09/2009 - 21:04

I record a lot of acoustic stuff, and some rock. I find I want a little more warmth and coloration in my sound. There were threads around here on the Brick that claimed it accomplished this, which is what got me looking into pre's. I don't want something that has too much noise, but I do want some warmth.

I'm using the presonus firepod's pre's, which aren't bad. I may end up sticking with them till i find exactly what i want.

Mauisnow13 Mon, 01/25/2010 - 12:43

For reference to those looking for info on the Aphex 107 mic pre, I found the cause of the extremely high levels of low and mid range. There was a large absence of treble and it sounded almost muted. The problem wasn't with the 107. In fact, It SEEMS i have a problem with one of my direct inputs on my recently purchased used Firepod. I swapped the preamp to the 3rd and 4th channels in the Firepod and it sounds much cleaner.

I still haven't had much time to play around with the preamp, try everything out, and listen to the differences. I recently moved and unfortunately my gear isn't here yet! So far though, I like the 107. I'm sure the more I use it and get to know it, the more I'll like it.

CoyoteTrax Tue, 01/26/2010 - 06:32

Mauisnow13, post: 298458 wrote: I swapped the preamp to the 3rd and 4th channels in the Firepod and it sounds much cleaner.

Funny how this happens, and more often than we read in the forums. I've had the same experience (with a different box) where I swapped the input channels on my interface and got a much higher quality input signal from the outboard pre's. It's not always the pre's.