MicPreampKit.com - Build Your Own Mic Preamp

FiveFish Studios Equalizer - PEQ-503 Carnhill Inductor-based EQ 500 Series

DIY Guru — Sat, 21 Aug 2010 03:27:37 GMT

The FiveFish Studios Passive Equalizer, using Carnhill Inductors, for 500 Series racks. -- Model PEQ-503

Very smooth sculpting of sound, no setting is bad. Silky Low Freq and Mid Freq control.... thanks to those huge Carnhill/UK inductors (same kinds used in Neve EQs). High Freq filter also outfitted with additional inductor for better control and shaping of the high frequencies.

3-Band EQ - Inductor Based EQ
Two Frequency Selection switch per band + independent flat/bypass position
12K/AIR HF control +/- 18dB gain
1.0K/3.5K MF control +/- 12dB 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

Estimated Introductory Price (assembled)... $395.00
10 units available at this special introductory pricing
Pre-order your unit today. Email diy@fivefishstudios.com
Estimated availability... Fall 2010

SC-1mk3 Mic Preamp Kit with VU Meter, Polarity Reverse, Pad, Phantom Power, Input Transformer

DIY Guru — Tue, 27 Jul 2010 01:10:58 GMT

SC-1mk3 Mic Preamp

3rd Generation! SC-1mk3 Mic Preamp Kit

The SC-1mk3 Mic Preamp is a clean, "fast", clear, low-noise, high-gain preamp. It's sound is very transparent, offering a flat response, smooth highs and well-defined mids.

Features:

Legend:

            None – this feature was introduced in the original SC-1 preamp (mk1 version)

            MK2 – this feature was first introduced in the SC-1mk2 version, and also avaialble in the mk3 version

            MK3 – this feature is new for the SC-1mk3 version

-        Low-Noise, High-Quality Mic Preamp

-        All solid-state design, using chipsets from THAT Corp and Burr-Brown

-        Soft-start, slow ramp-on +48V phantom power

-        Mk2: Option to use input transformer for added sound “flavor”

-        Mk2: Gain range from +12 to +72dB, in 6dB increments from +12db to +42dB; 4dB increments from 46dB to 72dB.

-        Mk2: Onboard Power Supply Regulation, adjustable +/- voltage rails

-        Mk2: Reduced clicking and popping when changing gains

-        MK3: Further reduced clicking and popping when changing gains

-        Mk3: Robust 48Volt short circuit protection (from accidental phantom power shorts)

-        Mk3: LED-lighted push buttons for phantom power, -20dB pad and polarity reverse

-        MK3: VU Meter, 5-LED bargraph

-        MK3: Relay controlled Pads

-        MK3: Relay controlled Polarity Reverse

-        MK3: Bigger PCB area, more room to work with

-        MK3: Hole locations compatible with our X-12 Mic Preamp. Now you can have (1) X-12 Mic Preamp and (1) SC-1mk3 Mic Preamp in the same 1u Rack Case

-        Electronically balanced input and output stages (option to use input transformer for transformer balancing)

-        12-position Grayhill gain selector switch

-        Input RFI protection

-        Input clamping protection

-        Output surge protection circuit

-        Output RFI protection

-        High quality Bourns, sealed, conductive plastic potentiometer for volume control

-        Gold-plated, machined, low-profile IC sockets

-        Use of high quality 1% Metal Film resistors, and high-quality ceramic and electrolytic capacitors

-        Solder pads for optional INSERT jacks

-        On-board jumper terminals

-        Easy to assemble, easy to troubleshoot design

-        Each component carefully labeled, protected and packed in separate zip bags

-        Thick PCB board with 2oz. copper

-        Very affordable!!! No, this is not “cheap junk” but a high quality product that is reasonably affordable! (i.e. because there are no middlemen, and we don’t do expensive glossy magazine advertising! )

Listen to Audio/Demo Sound clips!

Download PDF file of Assembly Guide/Kit Instructions

SC-1mk3 Mic Preamp WITHOUT Input Transformers

For USA Buyers

For INTL Buyers

$325 - 2 channel kits + PSU + Power Transformer BEST DEAL!!!

$269 - 2 channel kits (without power supply)

$199 - 1 channel kit + PSU + Power Transformer

$139 - 1 channel kit (without power supply)

SC-1mk3 Mic Preamp WITH Input Transformers

$445 - 2 channel kits + PSU + Power Transformer + Input Transformers BEST DEAL!!!

$389 - 2 channel kits (without power supply) + Input Transformers

$259 - 1 channel kit + PSU + Power Transformer + Input Transformer

$199 - 1 channel kit (without power supply) + Input Transformer

More Photos

Click here for Audio Samples

http://fivefishstudios.com/index.php/Audio-Samples.html#SC1

TS-2 Rev.B Switchboard, DC-DC Converter for 48V Phantom Power, Battery Powered Preamp

DIY Guru — Thu, 29 Apr 2010 21:53:09 GMT

I assembled the first prototype switchboard PCB, powered it up and.... nothing. No output voltage... well, there is... about 2.0 Volts.

And not only that, the IC chip, inductor, and even the regulator were all getting HOT... very HOT!

I couldn't understand why...

At first I thought maybe I made a mistake when I redesigned the PCB and moved parts around.

So I opened up my CAD software and checking my schematic and PCB design...

Then I noticed the IC chip was facing south on my CAD layout! I build the prototype with the IC facing north! (which is what I usually do... I always design with the IC notch facing north.)

So I went back to my workbench and removed the IC chip and re-inserted it in the proper way.

Power up again, and nothing.

Hmmmm.... maybe I fried the IC chip.

So I got a new one from my tube and insert it, making sure the IC notch is facing south.

Power up and VOILA!... we have power! The DC-DC converter is working!

Adjusted the trimmer for a 48V output and so far, looking good. No "frying bacon" noise, nothing getting hot or warm.... everything fine and dandy.

Some pics.

It will do 48V output for as little as 7.5V input.

Feed it 5.0V DC, and it will do 35V output.

Not bad.

Next time is marrying the switchboard and the main preamp board.
_________________

TS-2 Rev.B redesign Mic Preamp Battery Powered Prototype Working!

DIY Guru — Mon, 01 Mar 2010 13:57:51 GMT

It's alive! Works on the first power-up! I'm very pleased.

As for the sound, initial impressions:
A bit punchy on the bass.
Tighter low end.
Smooth high freq response.

It could run on 3 Volts!!!

TS-2 Rev.B redesign Mic Preamp Battery Powered Prototype

DIY Guru — Sun, 28 Feb 2010 13:57:08 GMT

I forced myself to build the TS2 prototype last night, even though there are still some pending orders.

Happy to say the TS2 redesign is a much better improvement in the build time. Finished assembling this board in about 2 hours time!

I haven't powered up this baby yet, so don't know yet how it sounds.

I don't have the new TS-2 switchboard ready for this, so I think I'll just jury-rig the wiring for the phantom power, polarity reverse switches.

TS-2 Rev.B redesign Mic Preamp Battery Powered PCB

DIY Guru — Mon, 25 Jan 2010 13:56:19 GMT

We have prototype PCBs!!!

from this...

to this...

Haven't built it yet... too busy with other stuff.

TS-2 Rev.B redesign Mic Preamp Battery Powered

DIY Guru — Mon, 11 Jan 2010 13:55:44 GMT

Sent the prototype PCB Gerber files to the factory.

Now we wait... and wait... about a week before we get the finished boards back.

This is just the motherboard. When I get this back, I'll rework the switchboard. (I want to make sure all the holes and dimensions are aligned.)
_________________

TS-2 Rev.B redesign Mic Preamp Battery Powered

DIY Guru — Mon, 28 Dec 2009 13:54:02 GMT

A flash of inspiration... I found a smaller footprint output transformer I can use... so I created an Eagle part library for that. (Tip: use a digital caliper when creating part libraries)

After some creative rearranging of parts, and I made this.

This is just the motherboard. Measuring about 6" x 6".

Ch-check it out!

2 Input Transformers - NEW FEATURE
2 Output Transformers - NEW FEATURE
Gain and Trim knob for each channel
2 VU Meters
4 Full size XLRs
Relay Controlled switching - NEW FEATURE
Bigger DC Converters - NEW FEATURE
... and better PCB layout by re-arranging parts.

Also, reduced the number of molex connectors from the original (7) to a single 10-pin Molex! That will be a big time-saver.... plus the use of PCB mounted XLR Neutrik Jacks.

I also have a smaller daughterboard that contains the 48VDC converter and soft-start phantom power, plus all the switches. I haven't re-worked on that yet.

TS-2 Mic Preamp Revision B

DIY Guru — Sat, 12 Dec 2009 08:44:43 GMT

The TS-2 has been getting some traction recently... and I'm thinking maybe it's time to revisit this product again and do a Revision B.

The first TS-2 design was very good, and I love the sound of it! (Of course, it's based on the SC-1mk500 and SC-1mk2 preamps, but in a smaller form factor.)

But assembling a single TS-2 unit takes up a lot of time/manpower and with the small profit I have on each unit, it's a losing proposition. I'd come out ahead if I DON'T build a TS-2!

So to fix this problem, I'd need to raise TS-2 prices, or reduce my production cost, or a little bit of both. For now, I'm going to concentrate on reducing production cost. With today's economy, it may not be smart to raise prices (unless that price increase brings with it additional features that the original TS-2 didn't have.)

Question: So what can I do to reduce production cost?
Answer: Reduce the time/manpower to build a TS-2 unit.

Question: How can I reduce time to build a TS-2 unit?
Answer: Good question...

I'm thinking of several possibilities.
1. Through automation. Using SMD parts and pick and place machines. Ask a manufacturer to build the boards for me.

Cons: A little on the expensive side, and requires a lot of capital. I think 100 boards is the minimum. Assuming it will cost $50 per board assembly fee, 100pcs is a staggering $5000!

And I doubt it will cost only $50 per board... maybe closer to $100. And that's just the labor. The cost of parts for 100 boards is not included yet.

2. Minimize "wiring". Yes, soldering wires to the PCB board and connectors, and jacks take a lot of time. So if we can get rid of "flying wires", then that will reduce a lot of time and labor. So as much as possible, use PCB mounted jacks, switches, LEDs, etc... everything should be soldered to the PCB. No more hookup wires, if I can avoid it!

3. Reduce the number of PCBs. Right now, the original TS-2 preamp has 4 PCBs. A motherboard and a switchboard, and 2 VU meter PCBs.
That's a lot! And of course, there are hookup wires to connect all 4 PCBs to each other (see #2 above). So I need to reduce the number of boards required to build a TS-2.

I've upgraded my PCB design software last year, to allow me to make the bigger boards. Unfortunately, the TS-2 board design was prior to my software upgrade.

Now, with the ability to make bigger boards, I think I'll be able to combine more functions in a single board.

We've got plenty of real estate space FREE!

What else...

Revision B will also give the user the option to have INPUT TRANSFORMERS! So that will be cool! Maybe even add a switch to bypass Input Transformer. Hmmm... I'm getting too far ahead here.

So that's my goal.... redesign the TS-2 preamp to minimize wiring, combine more functionality in a single board, and add some new features.

Wish me luck!

MicPreampKit.com - Build Your Own Mic Preamp

FiveFish Studios Equalizer - PEQ-503 Carnhill Inductor-based EQ 500 Series

SC-1mk3 Mic Preamp Kit with VU Meter, Polarity Reverse, Pad, Phantom Power, Input Transformer

3rd Generation! SC-1mk3 Mic Preamp Kit

More Photos

Click here for Audio Samples

Customers also bought:

PSU-2448mk2 Power Supply Kit - $40

1u Power Transformer Kit - $39

TS-2 Rev.B Switchboard, DC-DC Converter for 48V Phantom Power, Battery Powered Preamp

TS-2 Rev.B redesign Mic Preamp Battery Powered Prototype Working!

TS-2 Rev.B redesign Mic Preamp Battery Powered Prototype

TS-2 Rev.B redesign Mic Preamp Battery Powered PCB

TS-2 Rev.B redesign Mic Preamp Battery Powered

TS-2 Rev.B redesign Mic Preamp Battery Powered

TS-2 Mic Preamp Revision B