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.)
_________________
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.
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!
DIY Preamp boards lined up for final assembly  and finally, Burning-in of preamps before shipment... Shown are some SC-1mk500, X-12mk500 and X-72mk500 preamps in 500 Series Lunchbox format. 
This is our new Mic Preamp in the API-500 Series card format. We're
bringing all the quality of the original SC-1 and some more, plus new
additional features in this new form factor. Features:
- Popular 500-form factor
- 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
- or with optional Input Transformer option
- Improved design, improved performance, design refinements.
- DC Servo, Dual Buffered design
- Using uMetal shielded Input Transformer for excellent magnetic shielding
- 6dB gain steps in the lower range, and 4db gain steps in the upper range for more precise control
- Bourns, conductive plastic potentiometers
- 12-position Grayhill gain selector switch
- Input RFI protection
- Input clamping protection
- Output surge protection circuit
- Output RFI protection
- 0.063" thick PCB with 2 oz. copper, Solder mask, silkscreen, plated-through holes, - Lead-free Rohs
- Gold fingers
- 5-LED VU Meter kit
- Relay-controlled Polarity Reverse
- Use of high quality 1% Metal Film resistors, and high-quality ceramic and electrolytic capacitors
- Easy to assemble, easy to troubleshoot design
- Each component carefully labeled, protected and packed in separate zip bags
- Very affordable!!!
http://fivefishstudios.com/index.php/SC-1mk500-Mic-Preamp-Kit.html SC-1mk500 500-Series Mic Preamp Kit Assembly Guide
SC-1mk500 VU Meter More Photos
Click here for Audio Samples http://fivefishstudios.com/index.php/Audio-Samples.html#SC1
This
is the X-12 mic preamp in the API 500 Series lunchbox format. You can
use this preamp module with the API lunchbox rack, or any of the
compatible 500 series racks available out there. Big and beefy with
lots of transformer mojo goodness in a compact form factor.
Using Input and Output Transformers
12-step Gain from 22dB to 68dB, at 4dB/step
-20dB Input Pad
High-quality parts
Option to use Discrete OpAmps with the 990/2520 format
Using high-performance chipsets, currently the best chip around
Using High-speed 2000V/us, video buffer, high-current transformer line driver
Using Grayhill switch - high quality mil-spec
with output trim Bourns potentiometer - so you can overdrive the input trafo and be able to trim the output of the pre.
Null offset trimmer adjustment
LED-lighted push buttons for 48V phantom, pads, and polarity reverse
Relay Controlled Polarity Reverse
Relay Controlled -20dB Pad
Soft-start/Ramp-up 48V Phantom Power
Includes on-board voltage regulators
Professional PCB, Rohs PCB with double-sided, plated-through holes, 2oz. copper
with soldermask, silkscreen layout,
Includes everything... 5-LED VU Meter, spacers, screws, knobs
Download X-12 Mic Preamp Assembly Guide
Don't forget to download too the VU Meter Assembly Guide NOTE: The X-12mk500 Preamp requires an API 500 Series Rack or compatible rack. You can also use discrete opamps with these kits.
Discrete OpAmps not provided with kits. But there are lots of 3rd-party companies making and selling them.
More Photos
Click here for Audio Sampleshttp://fivefishstudios.com/index.php/Audio-Samples.html#X12
What if you could take the best features from different preamps, and combine them into one Super-Frankenstein Hybrid preamp? And that's exactly what I did. Welcome my new X-72mk500 Mic Preamp! http://fivefishstudios.com/index.php/X-72mk500-with-UK/Carnhill-Trafos.html
I
used the latest low-noise modern chipsets, and couple them with big,
hunking, hulky, giant input and output transformers from
UK/Carnhill....
These same transformers are usually used in
Neve-type/clone preamps.
And
not only that, you have the option to use Discrete Op Amps (DOA) like
2520/990 type opamps, like the ones you find in API preamps.
What
about the sound? The sound to me is BIG, PUNCHY, and HUGE. It adds a
deep, nice, WARM coloration to the sound.
Really deep-sounding huge.
And low frequencies come out punchy and TIGHT. I really love it.
Totally unexpected.
I'm
using fast video buffer driver chips (spec'd at 2000V/usec) to drive
this awesome UK/Carnhill Output Transformers. After
the Input
Transformer, the signal is amplfied by modern, low-noise chips capable
of driving 600-ohm loads. Gain is adjusted
by mil-spec Grayhill
Selector Switches, and trimmed using Bourns potentiometer.
The
48Volt Phantom Power circuitry also has a "soft-start/ramp-up"
feature. When you turn ON Phantom Power, 48 Volts is
gradually applied
to your expensive microphone. The result is no more annoying and
bone-jarring "POPPING" sound when
you turn ON or OFF your Phantom
Power. It also protects your monitors from this loud popping sound!
Using Input and Output Transformers
12-step Gain from 22dB to 68dB, at 4dB/step
-20dB Input Pad
High-quality parts
Option to use Discrete OpAmps with the 990/2520 format
Using high-performance chipsets, currently the best chip around
Using High-speed 2000V/us, video buffer, high-current transformer line driver
Using Grayhill switch - high quality mil-spec
with output trim Bourns potentiometer - so you can overdrive the input trafo and be able to trim the output of the pre.
Null offset trimmer adjustment
LED-lighted push buttons for 48V phantom, pads, and polarity reverse
Relay Controlled Polarity Reverse
Relay Controlled -20dB Pad
Soft-start/Ramp-up 48V Phantom Power
Includes on-board voltage regulators
Professional PCB, Rohs PCB with double-sided, plated-through holes, 2oz. copper
with soldermask, silkscreen layout,
Includes everything... 5-LED VU Meter, spacers, screws, knobs
NOTE: The X-72mk500 Preamp requires an API 500 Series Rack or compatible rack. You can also use discrete opamps with these kits. Discrete OpAmps not provided with kits. But there are lots of 3rd-party companies making and selling them.
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