DIY-Central.com - Go Create something! - PCB Design, Electronics - Recording

PEQ-503 EQ - 500 Series Equalizer

DIY-Central.com Administrator — Fri, 19 Nov 2010 18:00:52 GMT

Back in July, I showed you how to design an Eagle CAD Library for a switch. After a month or so, I've released a new product. My PEQ-503 EQ, which incorporated this switch library I designed.

Here are some photos:

The FiveFish Studios PEQ-503 is a beautiful, high-quality, single-channel three (3) band Inductor-based equalizer, designed for the popular API VPR500 Rack format.

Each frequency band has two (2) selectable frequencies, and a bypass switch. It also has an overall EQ In/Bypass switch to let you easily make sound comparisons.

The equalizer's smooth broad curves makes tonal adjustments easy and fast. You can go from small, subtle changes to extreme carving or boosting up to +/- 18dB per band. The SUB and AIR frequency bands can give your tracks the chest-thumping punch you want, and that extra sparkle at the top end without sounding harsh. The mid frequencies band takes care of adding that extra bite to your sound to make it pop.

The PEQ-503 Equalizer uses the following:

A balanced line level receiver using InGenius® high-common mode rejection technology.
An ultra-low distortion, low noise, operational amplifier optimized for high performance audio is used in the EQ section, along with imported Carnhill inductors from the UK, to perform the musical tone shaping and sculpting of your sound.
Using OutSmarts technology for the Balanced output driver, thus capable of driving difficult loads, with short-circuit protection.

The PEQ-503 is all about choices. You can outfit the EQ with optional Discrete 2520/990 type op amp*, and an Output Transformer*. You can also request special panels colors*, just email us for availability. There are also on-board jumpers on the EQ that allows you to experiment and change the Low Frequency and Mid Frequency bands from the factory default setting, to better suit your taste or musical style. Output Bypass jumpers also allow you to change between an active balanced direct output, or transformer output coupling.

Join the other professionals that have discovered the PEQ-503 Equalizer's quality performance. The PEQ-503 is equally at home for use in the mix bus, or individual tracks and channels. You will love it!

* Available separately, extra charges may apply.

FiveFish Studios and the PEQ-503 Equalizer is part of the API VPR Alliance.

The VPR Alliance is a program of standardization and consistency guidelines set by API Audio for manufacturers, to make our products physically fit and electronically conform to API's 500 series rack specifications. As stated on API's website, "Customers benefit from the VPR Alliance through the elimination of any confusion as to which products are endorsed for placement in API racks. Customers also benefit from a wider range of module choices for their racks, safety in the knowledge that the specification of the third party unit is correct, and that there is no risk of damage occurring. "

PEQ-503 Features:

3-Band EQ - Inductor Based EQ
Two Frequency Selection switch per band + independent flat/bypass position
12K/AIR HF control +/- 18dB gain
1.1K/3.2K MF control +/- 18dB gain
SUB/120Hz LF control +/- 18dB gain
EQ On/Bypass switch
Relay-controlled Bypass
Electronically Balanced Inputs using inGenius Technology
Electronically Balanced Outputs using OutSmarts Technology
Output Tranformer option
Discrete OpAmp option, or PDIP chip
Using Carnhill/UK VTB inductors for LF and MF control
WIMA caps for EQ filters
1% metal resistors
Bourns Potentiometers
Solid Machined Aluminum Knobs
CNC-milled/engraved/paint-filled front panel
Double-sided, plated through PCBs
Low Noise Equalizer
Jumper settings for experimentation, changing the EQ filter frequencies

You can buy this EQ using this link.
http://fivefishstudios.com/500-series-modules/peq-503-equalizer

IT'S BACK!!! My FIVEFISH STUDIOS CRAZY DEAL SALE again... !!!

DIY-Central.com Administrator — Mon, 01 Feb 2010 20:11:17 GMT

IT'S BACK!!! My FIVEFISH STUDIOS CRAZY DEAL SALE again... !!!

LIMITED QUANTITY OFFER! I have designated a certain number of units for this SALE. LIMITED QUANTITIES AVAILABLE. If my stock runs out in 5 days, or 2 days, that's it. The SALE will be discontinued.

SAVE MONEY!!! $300 for a pre-assembled X-12mk500 preamp.... $300 ready-made (not a kit). Hurry and don't miss out again on this offer!

Please allow 3-4 weeks for delivery. We're still waiting for the trafo shipment from the factory. LIMITED QUANTITIES AVAILABLE for this sale. Sale may be discontinued at any time once stock runs out.

Link and BUY button on this page... http://www.fivefishstudios.com

DIY Tube Microphone

DIY-Central.com Administrator — Wed, 02 Dec 2009 14:54:33 GMT

A DIY Tube Microphone.... and yes, it's a KIT! What's even more awesome about this is the microphone body, grille and other stuff is included in the KIT. Anybody that's into building DIY microphones know this is the most hardest thing to DIY... the microphone case. Not the electronics, not the power supply but the mechanical enclosure! So this kit packages everything nicely.

From the writeup:

Beautifully machined (unpainted) brass microphone body and head-grill assembly
Internal mounting cage assembly to mount circuit board, capsule, transformer and connector housings.

Components included

1 - 32mm/1in large diaphragm pressure gradient capsule (assembled)
1 - Plastic capsule mount
1 - Pre-amp circuit PCB
1 - Tube socket PCB
1 - Vacuum tube, 12AX7
1 - 9-pin tube socket
1 - 7-pin XLR male connector
2 - Ceramic insulators for both ends of C4

1 - Film Resistor, 1/2 W 10KΩ
1 - Film Resistor, 2W 100KΩ
2 - Film Resistor, 1/2 W 270KΩ
2 - Resistor, 51M
1 - Resistor, 200M
1 - Film Resistor, RJ 1/2 W 3KΩ
1 - Resistor, 1 KM
3 - Capacitor, 1μ/400V
2 - Capacitor, .022μ/630V
1 - Capacitor, 1000 pF/630V
1 - Capacitor, 100μ/25V
3 - Capacitor, 0.1μ/63V
1 - Capacitor, 1000μ/10V
1 - Ceramic Capacitor, 2pF
1 - Transformer, turns ratio 10:1

1 - Fully assembled power supply
1 - Power cable for power supply
1 - 7-pin microphone cable

Printed documents
Schematic

I bought this kit on eBay and sure hope to find the time to build it. I'll post pictures of my build.

TS-2 Mic Preamp Production

DIY-Central.com Administrator — Thu, 02 Oct 2008 19:33:49 GMT

So I'm starting "production" of the TS-2 Mic Preamp units. Everything will be handbuilt here in "the FiveFish Studios Lab."

Initial run will be 8 units. Sell the 1st (8) and then use the money to fund the next batch of units.

These are (2) channel mic preamps, with DC servo, and internal buffering. Using THAT chips, Burr Brown chips. Output using balanced line driver from THAT. Includes (2) channel VU meter. Polarity switches on both channels, individual 48V phantom power switches, and an ON/OFF switch for the VU meters (to be discrete during taping :). XLR Ins and outputs. Powered by 12VDC from AC wall adapter or portable DVD batteries.

Intro Price: $499

Everything is in a pipeline... panels will need to be manufactured, milled. Cases bought, and everything put together and tested in the coming weeks. Hopefully, I'll have finished units ready before Thanksgiving.

SC-1 Solo Preamp (Prototype) powered by 12VDC wall wart (or battery)

DIY-Central.com Administrator — Wed, 02 Apr 2008 19:22:20 GMT

I'm making CAD measurements of trying to fit an SC-1 preamp plus a Mini-IO module in my extruded aluminum "brick case"... hmmm.. its a tight fit, the TRS jack is almost hitting the top of the case, and the soldered terminals touching the blue trim potentiometer of the SC-1.

I'm concerned about the terminals touching the blue potentiometer. It's plastic so it's non conductive so maybe it's not even an issue. If the case has an extra 0.1" height, it would have been fine. But given this TRS jack is the hi-Z input, I'm afraid it might have side effects.

For sure a VU-meter will fit inside without problems.

Unless I can find a slightly taller case, the SC-1 Solo will probably consist of the SC-1 and a VU meter, plus the PSU board. (at least, for this 1st prototype I'm making.)

My eventual goal is to find a case that will be tall enough to fit an SC-1 plus the IO-module (with input/output transformers)/Mini-IO, and maybe even the VU meter. Now, that would be some hot SC-1 Solo product!

Okay...did the CAD drawings, created the CNC programming then tested it on some .125" scrap aluminum. Looks good.

Loaded the "real" panel and let the program run... X fingers!

Yes... everything fits like a glove! No more manual drilling with a drill press or filing around to make everything fit.

Of course, it takes hours of prep work on the CAD/CAM, testing and final setup... and only about 3 minutes of actual CNC time on the router.

Some photos:

Did the rear panel CAD/CAM/CNC today... I goofed up making measurements on where the DCJack holes should be... so had to do some fudging with a manual file. It's okay... this is just a prototype. But I fixed the CAD drawings to reflect the proper dimensions.

Some photos:

The DC-DC Power Supply installed on the rear panel.

XLR jacks installed

I do have one concern here and that is... with the XLR jacks so near to the DC-DC PSU, will it affect the preamp's performance? From my limited bench testing, it doesn't seem to be... but the proof is in the pudding... so we'll see how this prototype performs.

I have seen one preamp though (and I'm not naming names) and they have a DC-DC PSU, and a microprocessor, and it's associated crystal clock, and 2 preamps crammed into one small case.

By comparsion, what I have is "roomy" compared to what's inside this other preamp.

And finally... a preview of things to come. Rear View of the SC-1 Solo case.

Arghhh... those XLR bolts are too shiny! Will have to replace them in the final prototype with stainless steel bolts to cut down the bling factor.

I'm also using a flat head stainless steel screws to attach the plate to the main case... but I can't properly chamfer the hole openings because the plate is only .036". If it was thicker, I can get away with it. So the (4) corner screws will have to be replaced with pan head screws (also stainless steel)

All these "minor" fixes will be done as the very last step.

SC-1 Solo Preamp

Features:
- Low-Noise, transformerless, High-Quality Mic Preamp
- All solid-state design, using chipsets from THAT Corp and Burr-Brown
- Soft-start, slow ramp-on +48V phantom power
- Crystal clear Red LED indicator for phantom power
- Electronically balanced input and output stages
- 12-position Grayhill gain selector switch
- Gain range from +6 to +72dB, in 6dB increments
- Input RFI protection
- Input clamping protection
- Output surge protection circuit
- Output RFI protection
- Powered by a linear, regulated 18-0-18 Volts supply, with +48VDC for clean power delivery
- Reduced clicking and popping when changing gains
- High quality Bourns, sealed, conductive plastic potentiometer for volume control
- High quality C&K PCB Mounted switch
- Gold-plated, machined, low-profile IC sockets
- Use of high quality 1% Metal Film resistors, and high-quality ceramic and electrolytic capacitors
- With 5-LED VU Meter
- Neutrik XLR input and output jacks
- Powered by 12VDC wall wart

Yamaha PM1000 Rack Project

DIY-Central.com Administrator — Tue, 06 Mar 2007 23:10:44 GMT

I just gutted the guts of a Yamaha PM1000 channel strip. I will try to rack them in a standard 19" rack case. I'll be adding a custom power supply, and the usual XLR/TRS input and output jacks, phase, phantom switch, filter cutoff low-pass, hi-pass, etc...

So far, I'm successful in my testing after ripping and soldering everything together and adding a few modifications (i.e. using simple DPDT switches instead of 3Pole selector switches).

The Yamaha PM1000 are usually called Japanese "Neves" because of a similar approach in design. Just like the Neves, this is all discrete transistor and uses an input transformer and output transformer.

The EQ section is especially sweet because there is not a single IC on this preamp. The EQ section uses inductors and capacitors... totally analog manipulation and shaping of your frequency. (circa 1974)

I've tested them on drums and vocals and they really make the sound FAT. The EQ section shapes your sound anywhere from slight barely noticeable to extreme gain/reduction. Bass frequencies are solid. Of course, being an analog EQ, it is not as precise in shaping the sound as IC chip Equalizers. But the curve is smoother I would think.

This is what a PM1000 mixer looks like (circa 1975). Note, I did not use my fully operational 16 channel vintage mixer for this project. I have a few (8) spare PM1000 modules I got from eBay. I also have 2 master strips.

What's inside a passive direct box?

DIY-Central.com Administrator — Wed, 27 Dec 2006 22:04:45 GMT

On a previous post, I posted a schematic of a passive direct box using Jensen Transformers.

I have a ROLLS DB25 passive direct box in my studio so I decided to open it up to see it's "guts".

The ROLLS DB25 is an inexpensive direct box using all passive components. That's right, no need for a 9V battery or wall wart to use this thing. Plus, it's got a transformer inside that takes care of converting from an unbalanced Hi-Z connection (from a guitar) to a balanced Lo-Z connection for connection to your mixer or preamp via XLR jacks.

In addition, it has a -20dB and -40dB pad, and a ground lift switch for "stubborn hum" reduction.

How to build your own stereo microphone for less than $10

DIY-Central.com Administrator — Sun, 03 Dec 2006 21:50:11 GMT

I've seen the new Zoom H4 Handy Recorder. I think it's a neat little thing! And best of all, it's "cheap" at $299. Of course, "cheap" is a relative word, but compared to other gear out there, this seems to be one of the low priced new entry. It looks good too!

While reading the H4 specs, this caught my eye... "The H4 features 2 studio-quality electret condenser microphones configured in an X/Y pattern for true stereo recording." The keyword here is "electret microphone." And the picture seems to confirm that it's really just an electret mic.

So I'm thinking, maybe I can DIY my own stereo mic.

I've used an electret microphone on a non-audio project. I made a sound-triggered flash sync for my Canon EOS30D camera. In this case, I just used the audio output from the mic to trigger an SCR, which then triggered the camera flash.

Can we used the same electret mic to create a good enough sounding stereo mic? I think we can.

So I begin adapting my sound-triggered flash sync and while doing some Googling around, I came across this product.
Stereo Super Ear Amplifier Kit

It's a kit made by Velleman and it uses 2 electret mics, and a headphone output jack. Hmmmm.... interesting. So I ordered a kit (hey, it's less than $10 so if it didn't work, it's not too much of a loss). You can use the link above to order your own kit.

The circuit is simple... the Left and Right channel is the same, so the operation of the circuit is identical. Basically, an electret condenser microphone is biased for operation using a single resistor and capacitor. The output of the microphone goes to a potentiometer which acts as the volume control. This is then amplified by the NE5532 opamp, which is then routed to a headphone jack. Since the whole circuit operates from a single supply voltage (4.5Volts), the opamp uses a virtual ground by the use of 2 resistors in it's input pin. This of course, means that each leg of the split power supply will be only Vcc/2, where Vcc=4.5Volts.

I built this kit in less than an hour... while watching TV. And construction isn't hard and it's very simple. So if you're ready to jump into this Electronics hobby and looking for your first audio project, why not try this stereo mic kit? It's only less than $10.

Here are some pics during construction... enjoy.

There are assembly instructions and schematics on the box. Very easy to follow.

2006 Gift Guide for the Musician, Producer, Engineer

DIY-Central.com Administrator — Sat, 02 Dec 2006 00:26:03 GMT

It's that time of the year... here are some gift ideas for your home studio.

Furman PL8II Rackmount Power Conditioner with Lights
So you have thousands of dollars in gear and you're plugging it "naked" to your wall outlet or with a $5 Walmart power strip? I recommend you buy this power conditioner that will give you added protection to your gear. All your gear plugs to the back and you have a single switch to turn on all your gear. The lights are very handy too illuminating your rack gear so you can see what you're doing.

Korg MA-30 Metronome
Keeping time is important. And this little device from KORG packs a lot of sophisticated features at a small size. You can do rythms such as triplets and quadruplets with inner beats removed.

MIDI Drums using DIY triggers

DIY-Central.com Administrator — Sun, 26 Nov 2006 22:37:47 GMT

Want to have your own electronic drum set but can't afford a Roland set? This guy built his own drum kit using Radio Shack Piezo transducers, some jacks, and a few wires. Of course, you'd still need the drum machine like a TD-7, but this will save you hundreds by making your own drum pads.

And the finished drum set...

More information can be found here.

How to calibrate your recording levels

DIY-Central.com Administrator — Fri, 24 Nov 2006 03:10:28 GMT

A few years ago, the common wisdom was to "record as hot as you can." By HOT, I don't mean temperature wise. The wisdom at that time was to record your signal (from your guitar, keyboard, mic, etc.) so that the on-screen digital VU meters on your ProTools, Logic, DP, or Sonar is just hitting 0 dB, but not going over. Everybody knows that as soon as the red light turns on, you'll get clipping and digital clipping sounds nasty... like a fingernail scratching on a blackboard. ... The above argument sounds LOGICAL. There was even talk "you must use all of the bits as much as possible, so 0dB must be 1111111111111111 and that's good since we used up all the bits, nothing got wasted."

But something got forgotten along the way by the people who advised you to record close to 0dB in your DAW (Digital Audio Workstation... just a fancy name for a fast computer optimized for audio recording).