Introducing Our New 3630 Mod Kit (FAQ) January 13, 2016 13:33

We're excited to introduce our first mod kit: the 3630 Parts Upgrade Kit. The Alesis 3630 is a (in)famous, budget compressor/limiter that can be found in either the racks or storage closets of most studios. Our new mod kit cleans up some of the sub-par components that hinder the 3630's sound.

What does this mod do (in plain english)?

Basically, the Alesis 3630 features a solid circuit that's compromised by crappy parts. This mod replaces those parts with truly pro-quality components for better sound and performance. It swaps out ICs and capacitors in the signal path, and also strengthens the power section with fresh diodes and bigger caps. The end result is a more solid low end response, lower noise floor, and a more transparent sound.

How much does this mod improve the sound?

We'll let you decide for yourself from the samples below. Listen especially for the improved bass response in the kick and the transient detail in the acoustic guitar.

For better audio quality, click through to Soundcloud to download .wav files. 

Does the mod make the 3630 sound as good as the soft diminishments of our psyches as we fade away into nothingness?.. or like an LA2A or something?

No probably not. But it will delight your heart and validate your diy spirit, that spirit being what most likely caused you to purchase such a diamond-in-the-rough in the first place.

How much does the 3630 Parts Upgrade Kit cost?

$50 American dollars.

What's in the kit?

Good stuff! Highlights include silver mica capacitors, our all-time favorite Panasonic FR-series electrolytic caps, and THAT Corp. 2180 VCA.

Is this a difficult mod to do?

Nope, not really. I wouldn’t recommend it be the first kit you ever take on, but anyone with intermediate soldering ability should have minimal trouble. The hardest part is desoldering the pre-exising components. But since they’re crap, you don’t need to worry about damaging them!

Check out the step-by-step instructions to see exactly what's involved.

Will doing this mod void my warranty with Alesis?

Most certainly.

Is this mod worth the investment?

If you already own an un-modded 3630, I think it's a no-brainer. For the price of a couple cables, you can give your 3630 a second life as a very usable, high-fidelity compressor.

If you don't own a 3630 yet, you can also get in on this modding action by getting a used 3630. You should be able to find one on eBay for under $100. In which case, you'd be looking at $150 total for a respectable, stereo, hardware compressor. Check out 


Monitor Cube Kit Design Pt. 1 March 12, 2014 12:48 54 Comments

Since their introduction in the 1960s, the Auratone 5C "Super Sound Cube" monitors have been a must-have studio tool for countless engineers. Since Auratone ceased making them, their sticker price on the vintage market has ballooned accordingly. But despite their fame and resale value, the speakers themselves are exceedingly simple. Simple design, inflated price--sounds ripe for the DIY treatment! In 2013 we at DIYRE began working on DIY-friendly monitor cube kit inspired by the 5C. We're "live blogging" our progress to share what we've learned and to get your feedback on the direction of the project.

Quincy Jones with his 5Cs.

Quincy Jones with his 5Cs

Is it a "Clone"?

In short, no. A clone attempts to recreate the sonic characteristics of a vintage piece of gear by replicating its physical attributes. An ideal clone is indistinguishable from the original. There are a few reasons that attempting to clone the Auratone 5C would be a futile exercise:
  • The 5C underwent many revisions during its lifetime, with significant changes such as different drivers and internal volumes between revisions. Which 5C is the "original" that we should clone?
  • None of the drivers for any of the revisions are still in production.
  • According to their website, Auratone will be re-releasing a "5C Super Sound Cube Limited Edition" in the near future. Additionally, Avantone and Behringer currently offer their own versions of the sound cube design.
But, even if these practical limitations were not in place, would there really be a point to strictly cloning the 5C? Unlike, say the Neumann U47 microphone, the 5C is not special for having a certain, well-defined sonic character. The 5C is special because it helps engineers listen in a certain way. Engineers have described the 5C's role in various ways: "putting the mids under a microscope," "replicating real-world listening conditions," "narrowing the sweet spot," "forcing the ear to focus on the mids," etc. Our goal with this project is to create a speaker kit that fulfills the 5C's role in mixing as well as possible, not to create the closest possible physical reproduction.

Ripe for DIY

Unlike most vintage-inspired DIY projects, there are no specialized components to source, such as tubes, transformers, etc.; the raw ingredients are wood, wire, connectors, and a speaker driver. And unlike most DIY speaker projects, the woodwork is simple; it's a cube. With that in mind, we're confident that we can release a DIY kit that's incredibly cost effective and beginner friendly.

Beginnings and Inspiration

In 2011, GroupDIY member DaveP created and documented his DIY sound cube project. Dave's speakers turned out beautifully and his documentation was very clear, but since I had no woodworking experience and Dave's chosen driver was not available outside the UK, I decided not to pursue the project. Then last August a fellow engineer contacted me wondering if I could replace a disintegrating driver in late-model Auratone 5Cs. By this time, DIYRE had moved into our co-working space, NextFab studio. Suddenly we had all of the elements required to get started: Dave's initial documentation, a full wood shop, and a genuine article to measure and compare!

DIY auratone speaker DaveP's DIY sound cubes

Since August, we've made some great progress on making the sound cubes DIY-friendly. DIYRE intern and pedal maker has taken the lead on refining the box design and woodworking process. We've evaluated various drivers and connectors and are closing in on having a kit ready for sale.Our most recent box design and kit components.

Our most recent box design and kit components.

Choosing Drivers

As I'll detail in my next post, we have built and verified a final box design that is easy to assemble at home while maintaining the internal dimensions of our reference speaker. However, we have not determined which drivers, if any, to include in the kit. We have discovered at least seven different drivers that meet the rough specs of the 5C's size and sound. We've evaluated two of these so far and found that, while they are very different, it's difficult to make an objective assessment of which better fulfills the monitor cubes' role. So for that reason, it makes sense not to include any drivers in the kit to allow builders experiment and choose their own. We plan to host a blind listening test to compare various drivers, including an original 5C, and compile notes on the sonic qualities of each to help builders make an educated decision.
Some footage of our highly scientific driver testing lab.

However, the issue is complicated by the fact that all of the drivers have different mounting diameters and hole positions. Since there is no one-size-fits-all hole size, builders will have to cut the front panel holes themselves based on the drivers they choose. We can include a guide hole (see image below) to make the process easier, but builders will still need a compass and appropriate saw to cut the hole. This will, of course, limit the number of people who will be able to complete the project at home.

Providing a guide hole makes centering the speaker hole easier.Your Thoughts?

    DIY Project Wiki: If we build it, will you come? March 5, 2014 13:59 14 Comments

    For a while now, we've been struggling to keep the DIY Project Directory accurate and up to date. As we've become busier and busier with our own projects the DIY community has become more and more prolific. Our "to do" list of projects to document has become embarrassingly long, and an increasing amount of entries feature dead links or old information. With that in mind, we're strongly considering converting the Directory into a wiki. The DIYRE Wiki would be like any other: anyone could create an account and start adding or editing content, all of the content would available under a Creative Commons License, and the community as a whole (ourselves included) would be responsible for keeping it healthy and accurate. So, here are my questions for you, dear DIYer:
    • Could you see yourself contributing to the wiki?
    • Do you see any potential problems with turning the Directory into a wiki?
    • Would making a community-based wiki dilute, or otherwise harm, the excellent community that is the GroupDIY forum?
    • Do you have any recommendations for self-hosted wiki scripts? We're currently looking at a WordPress plugin called WordPress Wiki.
    Thanks as always for your thoughts.

    Coming Soon: Micro "Circuit Building Block" Kits August 23, 2013 13:39 8 Comments

    While I wait for yet another round of Colour prototypes to arrive from the PCB fab house, I've been keeping myself busy laying out little PCBs to perform common "housekeeping" tasks in audio circuits. The idea here is to provide a set of cheap and simple shortcuts to make building, modifying, and prototyping audio gear more painless. These PCBs will also enable DIYers with only a circuit block level of understanding to put together their own circuits.

    differential receiver 

    The first two off the bench are balanced input and output boards. Both boards are based around THAT Corp's state-of-the-art integrated circuits (but also pin compatible with offerings from TI and Analog Devices) and include noise filtering, DC-offset protection, and power supply bypassing. At a tiny 1.4" x 1" (25 x 36mm), the boards are also intended to be small enough to retrofit into your consumer-level, unbalanced gear.

    balanced output pcb

    Balanced Line Driver PCB[/caption] Once I have received and tested the boards, PCBs and parts kits will be available from the store. Full kits for each will be around $20.

    balanced line receiver pcb 

    balanced line driver schematic 

    Introducing the Passive Pickup Emulator (PPE) June 5, 2013 17:45 6 Comments

    Your pedal board and amp collection are a potential playground for manipulating non-guitar signals. Yet, if you've spent some time reamping pre-recorded tracks, patching synths into fuzz pedals, or sending samples through amps, you know that the results are often disappointing compared to the magic of a well-paired guitar and amp. The Passive Pickup Emulator (PPE) is a little, four-component box that attempts to bring that magical guitar/amp interaction to any output device by simulating the sound and behavior of a classic single-coil guitar pickup.PPE Top view

    What does it do?

    The PPE makes connecting your non-guitar gear to guitar amps and pedals sound "right." Like everything we do here at DIYRE, the PPE draws its magic from the dynamic, interdependent nature of analog electronics. When you connect two pieces of analog gear, they interact. Unlike a digital system in which data is transferred from one stage to the next unaffected, the signal passed between two analog devices is a unique result of the characteristics of both stages. So, one can't substitute one type of device for another and expect the same results.
    The PPE makes any output "look like" a passive pickup to the following input, making for a more authentic interaction with guitar amp and pedal inputs.

    What's impedance got to do with it?

    One of the most important characteristics of analog inputs and outputs is their impedance, often shortened as "Z." Modern gear is typically designed to minimize the sonic effects of impedance. Most guitar gear, on the other hand, takes a vintage approach (if it's not vintage to begin with) and embraces the effects of impedance. Guitar gear expects to see the wildly variable and complex output Z of a passive pickup and tone control. So it's no surprise that your guitar gear may sound a little flat or unnatural when fed a "modern" signal with a low, linear output Z.

    How does it work?

    The PPE recreates the dynamic, interactive system of a guitar output using only four components. Looking at each of these in turn will provide a fairly complete explanation of how the circuit works.

    NOS Inductor L1 - 1 Henry Inductor
    In a guitar pickup, the inductor converts the vibration of the strings into an electrical current. There are no vibrating strings in our emulator, but we use an inductor to recreate the pickup's phase and frequency non-linearities. In conjunction with the capacitor and resistors, the inductor creates a resonant low-pass filter.

    Carbon Comp ResistorR1 - 15k Ohm Resistor The resistor replicates the impedance of a volume control without the volume attenuation. The resistor's value sets the PPE's output impedance as well as the damping ratio of the resonant filter.
    250k Tone Pot250k Ohm Linear Pot
    Just like a Fender guitar, we use one leg of a potentiometer as the resistive element of our tone control. The rotation of the pot controls how much of the high frequency signal is thrown away by being shunted to ground.
    Ceramic Cap100nF/.1uF Capacitor A capacitor makes up the second half of the tone control circuit. The relatively-large .1uF capacitor sets the initial rolloff frequency around 6kHz; smaller capacitors will yield a brighter tone with a higher rolloff frequency.

    How do I build it?

    Full kits, including hard-to-source NOS 1H inductors, are available from the Store or you may choose to source your own parts. Either way, you can follow the step-by-step instructions in the PPE Assembly Manual. Estimated build time is 30 minutes to one hour.

    May Giveaway: Hairball Audio Lola Mic Preamp Full Kit May 11, 2012 16:11 2 Comments

    To learn more about the Lola, check out my conversation with the designer Mike Mabie. If you'd rather not leave things to fate, you can buy Lola kits today at Bonus Second Place Prize: The second winner will receive a sharp new Hairball Audio hoodie. The winner can choose their size. They can also choose any color they want, as long as it's black!

    New Feature: Pre-Orders for Old Projects! August 30, 2011 14:33

    Have you ever discovered an awesome project only to find that PCBs and kits haven't been offered for years? I get comments and emails weekly from people trying to track down products that are no longer in production. I also hear from designers who would be more than willing to do another run of kits, pcbs, front panels, etc. if they could be sure the interest was there to make back their investment. So today I'm introducing a new feature that will connect interested builders with those who can offer kits and pcbs. If you're interested in a new run of kits or pcbs for a certain project, simply navigate to the page for that project and enter your info in the pre-order form. Once enough people have expressed interest in that project, the designer will contact you about prices, shipping, etc. Of course there's no guarantee that PCB files, front panel art, etc. will be available to fulfill a pre-order for every project, but by that same token, you are not obligated to buy anything by simply leaving your contact info.

    LAZ EQN (Neve 1084 500-series EQ) Available for One More Week March 5, 2011 21:40

    Peter Purpose of LAZ has announced a 3rd run of his popular EQN project, a DIY Neve 1084 equalizer clone for the 500-series. But he's only taking pre-orders for one more week! If you want to get your hands on these, check out the LAZ website ( and send an email with your order to the address on the page. "Mr. Purpose" is placing his order for PCBs and components on the 12th, so make sure to get your order in by next Friday, the 11th.

    Hamptone Unveils New, Low-Cost DIY Kits March 1, 2011 15:51

    Scott Hampton, designer of such juicy preamps as the JFET HJFP2 and the tube HVTP2, has begun to release his long-promised low-cost kits for the Hamptone line. The new kits make the HJFP circuit available in more flexible and affordable options.
    • The first is the HJFP1 which adapts the HJFP mic preamp circuit to a one channel board.
    • Second is the HJFA multi-purpose preamp kit. The HJFA can amplify any HI-Z signal, such as an instrument, plate reverb pickup, etc. It runs off an included wallwart, according to Hampton, is at least as quiet as the preamp power supplies.
    • Finally, there's the new active HPDI that also incorporates the JFET amplifier circuit.
    Fans of the Hamptone sound (myself included) will appreciate being able choose our own housing and power options for these amps. Each kit comes with mechanical layouts for putting together a chassis and Hampton is also planning a series of PSUs designed to power up to six HJFP1 modules. See more about the new kits at

    One New Project for Every Day in February January 31, 2011 14:29 26 Comments

    DIYRecordingEquipment will turn 5 months old tomorrow, and it's come a long way since last September. So far I've compiled just over 125 DIY recording equipment projects, but I know there are a lot more out there with new ones cropping up every week. But as you may have noticed, new projects have been showing up in the directory at an embarrassingly slow rate lately. This is partially due to some new features for the site I've been working on (keep an eye out for these later this month), but I know I could be doing more to make the database more complete. That's why I've decided to add at least one new project to the directory every day next month. I decided to make this goal public so I would be sure to stick to it!

    DIY Ribbon Mics Hit the Front Page of WIRED January 12, 2011 22:01 1 Comment

    Today the San Francisco-based technology magazine WIRED posted a photo essay about ribbon microphones and the people who love and make them. The writer, Matthew Shechmeister, covers the progression from revered vintage rarities such as the RCA 44 and Coles 4038 ribbons, to the influx of Chinese-made cheapies, to the DIY scene which (as we all know) combines quality components with a lower price tag.

    In the DIY world, Shechmeister covers Rick Wilkinson who sells kits and instructions for his DIY Austin ribbon mic. The Austin ribbon kit receives some very kind words from Michael Joly of OktavaMod, who claims that a mic built from Wilkinson's plans could go up against his own Apex 205 mod, which he in turn compares to the Coles 4038.

    Not everyone holds their peace, however, at the supposed union of thrift and quality provided by modded and DIY mics. John Vanderslice, producer of many awesome records, has this to say: ""There’s no bargains in audio. You have to bleed to get a good microphone. It’s going to be expensive."

    While I agree with Vanderslice up to a point (how many "bargain" pieces of gear end up costing us dearly through down time and premature repairs?), I've used modded and DIY mics myself that outperform competitors far out of their price range. I suppose, however, that the time spent modding or building could count as "bleeding"--in which case I would have to agree that one doesn't get a great mic without spilling some blood. But that's the beauty of DIY: the time spent on a project isn't a cost, it's part of the reward.

    You can read the full article on WIRED's websiteCongrats to everyone from the DIY and recording communities who were featured!

    SB-3A (DIY LA-3A) now taking pre-orders November 13, 2010 03:19 5 Comments

    Last month we reported that Mike Pildis, creator of the SB4000 buss comp. project, was creating a new clone of the classic UREI LA-3A optical compressor. Pildis has now announced that he is taking pre-orders for kits and front panels.

    SA-3A DIY optical comp

    Prices and options:

    • Stereo PCB/transformer bundle, $300: contains two PCBs and 6 transformers (input, interstage, and output for each channel). Transformers are from Cinemag and Ed Anderson.
    • Front panel for 2RU stereo unit, $55
    • Stereo matched pair of transistors, $20
    • Power transformer, $25
    • Stereo component kit, $165: All of the electronic components needed to complete the build (does not include wire, VU meters, T4B optical cells)

    Igor (I.J. Research) Announces Neve/Pultec Combo November 5, 2010 06:07 3 Comments

    DIY's greatest overachiever is back already with a new concoction. This month, Igor has cooked up a new variation on the passive EQ theme with a Pultec-like EQ circuit and Neve-ish makeup gain. The EQ uses stepped potentiometers for recall and a stereo set can be operated in MS (mid-side) mode!

    Igor estimates a stereo PCB bundle will be under $160.

    DIT Neve, Pultec EQ

    I.J. Research now taking pre-orders for F76 October 21, 2010 04:49

    I.J. Research (or "Igor" on the GroupDIY forum) is now taking orders for the F76, 1176-style compressor for the 500-series and 51x Alliance formats.  There are options for PCB-only or a partial kit with metal work.


    DIY 1176 compressor

    Drip Announces Fairchild 670 PCB October 13, 2010 02:21 4 Comments

    Drip Electronics, maker of boutique PCBs for tube projects, released a PCB for a clone of the Fairchild 670 last month. The Fairchild 670 is the stereo version of perhaps the most lusted after piece of gear ever. According to Drip, the 670 is a 100% accurate reproduction of the original, with all 20 tubes and 13 transformers (count em!). PCBs are $400 for the first two weeks of production, and $600 after.

    DIY tube compressor, Fairchild 670

    Two LA-3A Projects Announced October 12, 2010 03:43

    October 4, 2010 shall henceforth be remembered as "The Day of the LA-3As" within the DIY community. On Monday both Peter Purpose, creator of such wonders as a full-featured 1084 for the 500-series, and Mike Pildis, of SB4000 fame, announced plans for LA-3A clone projects.

    The UREI LA-3A is the solid-state sibling of the more famous LA-2A optical compressor. It might be called a hybrid of the LA-2A and 1176.

    Check them out here:

    Currently sourcing components... August 29, 2010 22:36 3 Comments

    Welcome to! The goal of this site is to build a comprehensive and concise directory for all of the DIY recording equipment projects currently floating around the internet.You can also check out the ever-growing project directory to see what we've got so far. If you know of something you don't see, let us know!