I started work on the chassis for the EQ, but its on hold until the custom transformers and custom inductors arrive from Cinemag.  Meanwhile I decided to go through my paper in oil capacitor collection to see if I had enough variety to build the Flux Bender.  Not even close.  I spent the better part of this morning scouring the internet for my vintage cap needs, with a good deal of success. Unfortunately, I now realize I'll have to charge a hell of a lot more for this EQ.

I'm sure it will blow minds when its complete, but getting there has been the hard part due to the massive self-funded built cost.  I've been gathering parts for this endeavor for about 6 months and I have almost everything.  Its over budget because I refuse to settle for less than the best components, even if it costs a lot more than I expected.  The Flux Bender will be the most complex wiring feat I've ever attempted, so I don't want to cut any corners anywhere.

In the past week I accidentally figured out a way to cancel nearly all noise from my line/mic amps.  Using a pair of rectifier tubes wired up in an unconventional manner and combined with a pair of neon regulator tubes I was able to build an ultra low noise regulated tube power supply, which exceeds the performance of any audio gear in my studio racks.  The new power supply combined with how the preamp tubes are wired up cancels out all of the heater filament hum (which was never more than subtle in the past) and also most noise that might be on the B+, which was in the past also very subtle. This means an overall reduction of about 6dB of noise.  6dB is very significant in this game of inches.  I was considering going the more expensive route of solid state tube heaters, but that idea was thrown right out the window after testing the noiseless double rectifier double regulator power supply ("DRDR" - a Lightning Boy invention).  

I have several projects on the bench, but today I'm starting work on a new version of the 1401 Stereo Mic Amp.  I did some prototyping first and the new version will have a lot of really impressive things to offer.  First off, some changes were made to the amplifier design that allowed me to coax 5 more dB of gain out of the amp.  The only trade off is a slightly warmer sound.  Win+Win!  Also, a new feature is getting added to the preamp.  Based on user feedback, there is now going to be a mic/line input switch on both channels.  Another new feature is the treble control bypass, which is incorporated into the treble knob itself.  A switch is built into the knob... turn it down all the way and then a little more until it clicks.  Bypassing the treble control will allow for a couple more dB of gain and a gentle touch of brightness.  Finally, it of course will incorporate the new LBA noiseless DRDR tube power supply.  

New stats (based on prototype):
Noise Floor:  -86dB
Gain:  +45dB per channel or +47dB with treble bypassed.  

Actual stats will be presented on the 1401 Preamp's product page after the completion of this first production version of Revision A.  

The past 3 days were devoted almost entirely to R&D.  It started accidentally and lead down a long rabbit hole which ended in my complete amazement. The R&D pertains mostly to the Flux Bender EQ's amplifier stage, but also pertains to the LBA 1401 Stereo Microphone amp because the two amplifiers are essentially the same.  Basically, there is a revision to the 1401 Stereo Microphone Amp, which will be coming out mid August.  

Working on personal project, I found that by wiring up a matched pair of 6X4 rectifier tubes in a push/pull configuration I was able to increase the B+ voltage, while also doubling the mA output and creating a more regulated voltage.  This revelation led me to bust open my prototype passive EQ and work out a more perfected version of this twin rectifier supply.  I decided to change some power filter caps for different values and tweak some resistor values to get the most out of the twin rectifiers. Then I added on a pair of NE-2 neon regulators to get a perfectly rock solid 343v B+.  The changes to the power supply resulted in an increased voltage of about 5v and more B+ amperage than the EQ would ever need.  The changes to the B+ supply made me want to re-bias the EQ's amplifier tube... a change I will never regret!  I mounted a pot on the front panel of the EQ so I could adjust the bias by ear, while simultaneously recording before/after changes into Pro Tools.  I found the magic sweet spot, which was actually sweeter than ever before!!!  

Previously with the EQ bypassed and audio running through the amp things sounded fairly transparent, with some coloration - but essentially no significant changes to the sound quality.  The noise floor was measured at -76dB.   After the power supply and bias changes the EQ's amplifier (eq bypassed) sounded AMAZING!  It blew my mind, but it actually made the original audio sound more "real."  I could hear subtle details in the source material that I didn't even realize was there.  After listening to the original source material again I struggled to hear those subtle intricacies in the sound of the music... in fact it seemed like they weren't there.  This amplifier was able to extract something from the music that was clearly there, but hidden from sight.  That's the magic, folks!  Well, as excited as I was about the sound, I decided to test the S/N ratio.  The new noise floor was measured to be -85dB!!!  Woah!  Where did 9dB of noise go?  Amazing.  

To end this long rant of discovery, I will be building a new 1401 Stereo Mic Amp for LBA Studios in a couple weeks and all future builds will get the same. It will incorporate twin rectifiers, the new bias settings, and the front panel indicator lamp will be replaced by a more functional regulator tube glowing behind a clear jewel.  What does this mean for the 1401 Preamp?  More headroom for one, but also a richer, more detailed tone.  It will also get the back panel branding, "Rev A."    

I recently got back from a week in the tropics for my honeymoon.  My hands needed the vacation and where very thankful to finally have a break from working metal and building circuits.  Now that we're all healed up its time to dig in to some long awaited projects.  I spent my first few days back building some acoustic upgrades to the live room at LBA Studios and this week I'm living in the studio recording an album for a band called Molten Wax (you can meet a couple members in the new Gravitone 30 video).  As soon as we're finished tracking I'm planning to build a new plate reverb for the studio so we have the ultimate reverb for Mixing their album.  I'm still using my version 1.0 plate reverb at LBA Studios, but in a week or two we'll be upgraded to the new 1401 Plate Reverb (with remote-auto dampening panel upgrade)... and you can expect an impressive new demo video.

As soon as the reverb is done I intend to start working on the very long awaited production model stereo tube eq... The Flux Bender.  It will be done this year.  I'm making a promise to myself and to the world.  There, its official.      

Slated for release sometime mid July, we've been hustling to put together demos, product photos and lots of real world testing before the big day. Initially, the first testing was conducted with the Gravitone 30 configured as a guitar amp.  When running as a guitar amp, it runs a 12AX7 preamp tube, a KT88 power tube and a 5U4 rectifier tube to deliver more than 30 watts of creamy warm tone.  Its a very tasty guitar amp, designed to be versatile for studio applications.  One of several very nice studio features is the built-in reamping box.  However, the EQ is what makes it extremely versatile.  3 band passive EQ with 4 selectable mid frequencies.  

Over the past week I've been experimenting with the Gravitone 30 as the 1401 Analog Plate Reverb driver amp - its intended application.  As the reverb driver amp, the tube compliment is a 12AU7 preamp tube, a 6V6 power tube, and a 5AR4 rectifier tube to deliver ultra clean, highly detailed amplification.  As an ultra-linear single ended tube amp, its pretty much designed to be extremely detailed and ultra clean sounding, with a tasteful amount of that beautiful single ended tone.  The low gain, wide bandwidth 12AU7 ensures clean tone throughout the first 2/3rds rotation of the input gain knob.  Beyond 2/3 a mild amount of tube saturation can be heard with a subtle, but noticeable amount of breakup happening when wide open.  The 3 band EQ is extremely useful for plate reverb driver amp duties.  Yesterday I started Mixing a Folk-ish type acoustic record for a client at www.lbastudios.com.  The EQ on the Gravitone 30 proved to be more valuable than expected.  Having the ability to shape the sound before it hits the plate can drastically affect how well the reverb sits in the overall Mix.  The Mid section of the eq was particularly special in that it allowed me to find and suck out a little bit of a mid frequency that was competing for authority with the lead vocal.  By bringing back that mid frequency on the Gravitone 30 (pre-reverb) it allowed the lead vocal to stand out in the foreground, while still having reverb on it.  I rolled off some highs on the Gravitone 30 as well, because there was some minor sibilance on the lead vocal and the highs in the lead guitar tracks were a tad bright - both of which were going through the plate reverb.  That helped those tracks stand out tremendously.  Then the next step was setting up the plate reverb output amplifier, the 1401 Stereo Microphone Amp.  I rolled back the highs on this about 80% to make the reverb sound very dark.  It helped put the reverb further into the background, regardless of how much reverb was being used. With the treble all the way up, the reverb is more easily heard, but I think most people will probably want it to sound more in the background in general. Regardless of that, the most obvious thing I heard was the immense size of the reverb.  By size I'm not talking about quantity of reverb, I'm talking about stereo width.  I didn't know my speakers could put out something sounding that wide.  But, lets get back to functionality in the Mix.  When turning the treble knobs on the Stereo Mic Amp I began to see with clarity how amazing this reverb truly is.  Between the pre and post EQ, the ability to dial in pre-thickness, and the reverb decay time adjustment on the plate, the possibilities are ENDLESS!  It can be made to work perfectly in any Mix situation.  I'm sure there has never been a better sounding plate reverb and I think it can go without saying that even the best software based reverb doesn't even come remotely close to the sonic beauty created by the LBA 1401 Analog Plate Reverb system. This summer I plan to do a new Plate Reverb demo video to demonstrate the awesome abilities of this masterpiece of spacial enhancement.               

Keep an eye on www.digitalrecordingarts.com for a review of the 1401 Stereo Microphone Amp and the Ghost Box.  They have both units are in the process of reviewing.  Expect some real world details published on their website in the coming weeks.

I've seen some European review interest in the combo, which has caused me to plan a revision to the Ghost Box.  After I finish up the current build queue I'll be building a new version of the Ghost Box that offers the option of 120v or 240v operation so that our friends in Europe can experience ghost power.  The only thing I don't like about this is that I'll have to raise the price of the Ghost Box by about $75 to cover the cost of the power transformer and the additional labor to implement it.  

Few know my long term goals, but the main one is to build a large format 32 channel vacuum tube Mixing console, code named "The Big One."   Its literally going to cost a fortune in parts and it will take many years to complete... unless of course an Angel investor drops into my lap.  

The goal is lofty, so I thought the best way to get there is with baby steps.  Its such a massive undertaking that I'll only get one shot at this (Recording equipment parallel to Nasa's landing on the Moon).  So, to make prototyping possible I plan to start small.  Yesterday I built a small active tube powered splitter, which takes one signal and splits it into two outputs with independent volume controls.  I couldn't do this passively without the volume knobs interacting with each other, so a single 12AU7 tube is on both channels for isolation purposes.  The 12AU7 also adds some overall volume to each channel.  The sound is not 100% transparent, but its very close and the subtle coloration is very pleasing.  How could this be used in "The Big One?"  Using this circuit (or a modification of it) I could implement several FX sends on each channel of the board.  Being able to route a channel to various external effects with controls of the send volumes is absolutely critical for a Mixing board.  I would be happy with 2 sends, which is exactly what this prototype box is capable of.     

I really hope to create a small 4 channel tube mixer later this year.  What I'd like to build is something relatively simple and rack mount friendly.  I'm thinking per channel it would have volume, pan, phase invert, and low cut switches + VU meters for the stereo output.  It wouldn't be cheap, but it could be priced in the realm of obtainable for project studios.  It could be used to combine the outputs of 2 summing boxes or it could be used for sub-mixing, which is how I intend to use it.  

This is the first post about The Big One, but I'll be writing more in the future as things develop.  

Since my last post about the 1401, minor alterations were made to the layout to lower the noise floor and raise the output level capability.  It is now complete and available for purchase here on the site.  Details about the 1401 Stereo Microphone Amp can be found here. 

The Ghost Box (pictured above the 1401 Preamp) was built as an add-on to give the 1401 all the typical features commonly associated with mic preamps. Its main feature is phantom power, but it also provides switches for phase invert and low cut.  The Ghost Box is stereo to compliment the 1401 Preamp, but it can be used with any mic preamp as a sonic alternative to on-board phantom power.
  
There's a few interesting things to note about the Ghost Box.  First off, its 100% valve state (like everything made by Lightning Boy Audio).  That might not sound too strange unless you're familiar with phantom power enough to know devices that deliver phantom power are traditionally powered by solid state power supplies.  Usually with phantom power, it needs to be well regulated so that the microphones being powered by it can operate with low noise.  The use of solid state voltage regulators is common in the industry.   Furthermore, phantom power was first introduced when solid state condenser mics came about.  I doubt anyone considered building a tube based phantom power supply because few people are as crazy as I am and its considerably more expensive to do... not to mention the design challenges involved.      
The Ghost Box departs from traditional phantom power by deriving its 48vDC from a vacuum tube rectifier and a neon voltage regulator tube.  

What's so special about that you might ask?  Well aside from it being a new concept, there is an obvious sonic difference between using a solid state phantom power supply and the all-tube Ghost Box.  Check out this demo video with some decent speakers or headphones to hear the difference yourself!  

As you'll see from looking around the site, I've been busy incorporating my studio into the folds of Lightning Boy Audio.  I renamed the studio and have a new sign on the way... "LBA Studios."  Keep an eye on the site as new gear rolls out and the studio section of the site comes together.  BTW, check out the super killer 1401 preamp and Ghost Box!  There's some tasty demos up, with more on the way!!!

My prototype passive EQ was first put into service in January of 2010, which means I probably started building it in December of 2009.  In the beginning it was a passive EQ filter with no amplifier for makeup gain, no output transformer and the incorrect input transformer, but even then it sounded great.  Since then I have occasionally modified, tweaked, added on and taken away from it, until 2013.  In '13 I stared hitting it hard with lots of R&D time of which the most was conducted in the first few months of 2014.  Yesterday I finally got the EQ sounding so great its breathtaking, which means I'm done.  The actual production model will be somewhat different, but it will be strongly based on the prototype.

• The prototype features Carnhill input and output transformers, a Jensen interstage transformer and an Edcor power transformer.  With 3 transformers in the audio path per channel, its clearly a tone machine.  
  
• The prototype filter section is a modification of the Pultec EQP1-A program equalizer.  It features independent controls for low boost, low attenuate, high boost, high attenuate and a Q control for the high boost.  The prototype has more than twice as many EQ frequency choices as a pultec and with the combination of overlapping frequencies and independent controls, its vastly more versatile.  All of the filter caps are paper in oil (of course) and the inductors are my very own hand-wound creations.  I even managed to make some of the paper in oil caps by hand.  
  
• The amplifier section uses a single 12AT7 per channel in zero-negative feedback push/pull configuration.  I tried many tubes before settling on the 12AT7, which I favored for its wide frequency response and warm "single-ended sounding" tone.  Plus, the 12AT7 has just the right amount of gain for this circuit.  
• The power supply is onboard in the prototype, but will be external with the production model, due to limited space.  The supply puts out 500v through a 6X4 rectifier tube and some very big audio-grade filter caps for DC smoothing.