Official Release: Heider FD312 Preamp from classicapi.com

Aren't you always one or two clicks away from it?

Hey, I reached 100 posts, cool!

My analogy is this, I can shift my car into reverse flying 80mph down the highway but I don't do it. The Heider FD312 is my first offering in a fully built unit. From my viewpoint, the 500 series is a no-brainer. There is no UL or CE certification to deal with and stocking all the parts/fully built units takes up way less space. I would never say never but I really don't ever see myself manufacturing this pre in a 1RU. If you checked one out, I'd like to think you'd say this is a great reason to go 500, even though you are not a fan of the format.

500 series pieces were originally units pulled from api consoles, these and new designs are tremendously attractive space saving, high end pieces, that are meant to be chained to other high end pieces, the idea that these are a compromise is a serious misjudgment. It's quite the opposite in fact, trying to acquire a single piece to do a bunch of stuff at a price point, is a compromise. If you wanted, or could get a pre as versatile as a vp28, with tone shaping as powerful as a LC53a, with a good DI, it would cost $3k to get it.

IMV, Any channel strip type combo unit at a low price point, is indeed a compromise.

Sorry Jeff, I didn't see your post.  I guess it's just me, thinking of some of the stupid things I've done in my studio.  Pressing a wrong button on a pre would be something that I would probably be even more prone to do than shifting my car into reverse on the highway.

I do believe your stuff is amazing, and maybe one day I will take up John's previous suggestion and get an EL500 and try a pair of these.

I'm glad you're getting into fully built units.  I have no problem with soldering, but given my day job, I have too little time for music as it is.  I'd rather be spending that time recording than soldering, even if I have to pay more.

 This web site shows -110 db EIN with a 300k measurement bandwidth and an unknown gain setting. That is confusing to most readers as many don't understand how noise is measured.

Typically, audio noise measurements are done with a 20~22k hz measurement bandwidth to remove out of band noise (inaudible) from the readings. This is how Audio Precision, Rode and Schwartz and Prism audio test analysers do it. EIN means equivalent input noise, it's a sum of the gain plus the signal to noise ratio.

60 db of gain is also where mic preamps are measured, simply to equalise the test perameters for easy comparisons. Measureing EIN at higher gains does not improve the specs as preamp self noise begins to wash out the differences. Typically, a 150 ohm source impedance is also used to emulate the output impedance of many microphones and the source impedance of most mic input transformers. When I test EIN of mic preamps, I also test at 50 ohms input impedance to emulate active condenser mics. That will lower the EIN to below the -129.6 db EIN of a 150 ohm resistor and it's load, IF the preamp has less noise as well. Some designs will do -133 db EIN at 50 ohms.

"A" weighting is also to be avoided as it skews the real readings and gives those devices that choose to use A weighting filters a gain in specs without showing the actual noise.

I have seen in the last 15 years or so a complete lack of standardised audio tests and a lot of skewed, mis-applied test proceedures in order to either confuse the end user or to bump up their gear test measurements.

I also realize many do not share my concepts of honest audio reproduction, but we are not talking about any of that, this is noise. Noise has nothing to do with sound or any audio influenced colors, it's noise, plain and simple. Either you accept a certain amount or flavor of noise or you do not. I'm in the second catagory as I find any sort or type of noise unacceptable. With modern design techniques and carefully choosen components and designs, very low noise specs are achievable.

As I mentioned, an API opamp coupled to a proper turns ratio mic input transformer at +60 db of gain with a 20~22k measurement bandwidth will yield a -127 db EIN spec at 150 ohms impedance, as long as the DUT (device under test) is properly screened and the power supply is clean. Anything less than that is either a mistake or a problem.

Many won't notice this problem using high output condenser mics, but connect a low output dynamic or ribbon mic and that hiss will eat you up.

It's 2013 and there is no valid reason to print excess noise to your converters anymore, unless it is to be used as an effect, like emulating tape hiss. As long as buyers do not challenge the manufacturer's to present honest test results, don't expect them to suddenly become honest on their own. We have the manufacturers we deserve, sort of like government. It's up to the end users to demand honesty.

lets not forget the Heider is a 2 stage pre/channel fader, if your comparing apples to apples? Jeffs designs stand alone in this regard, i don't know of another pre/channel fader combo?

Jim is a super smart guy - I'm sure he makes ver valid points here...they are just a little above my layman's knowledge, and I'm not sure they effect anything in practical use. Or, at least, my practical use. Maybe these are noisier if you're cranking these up to 75db with an ancient ribbon mic - I just don't see that as an everyday application - and I don't want someone to get the idea that these are "noisy" preamps.

I appreciate Jim posting here too!

We have more clips in the works. Scott is cutting up a long file into 3 segments now of Randy Kohrs melting a resonator gtr, which is far more interesting to my ears than an acoustic. It was stereo mic'ed with some Peluso's. We did the same 3 HiZ-Pad combination settings as we did with the JK vox.

I am also near to posting some elec crunch gtr and female vox files. Clint Lagerberg on gtr and the talented Whitney Duncan on vox.

Hopefully before the weekend on the above mentioned clips. We have video that accompanies both sessions but that will not be up for a little bit yet. Rack-N-Roll Rob and Tom are still collecting more vid around Nashville. Our very own JK will make a rare video appearance too!

exciting news! will JK be smoking the pipe? he's a sophisticated white haired gentleman of course, but the pipe is what gives him his strength 8) hope to see a more svelte version of Steiger in the vids also.