Navigation

Home
DIY Projects
DIY-Central Blog
Electronics Bookstore
Home Studio Equipment List
Privacy Policy

Search


On this page

TS-2 Rev.B Preamp Redesign Part 3
TS-2 Rev.B Preamp Redesign Part 2
TS-2 Rev.B Preamp Redesign

Archive

September, 2010 (1)
December, 2009 (3)
February, 2007 (2)
January, 2007 (8)
December, 2006 (20)
November, 2006 (11)
January, 2000 (1)

Blogroll

RSS 2.0 | Atom 1.0 | CDF

Send mail to the author(s) E-mail

Total Posts: 47
This Year: 0
This Month: 0
This Week: 0
Comments: 24

SC-1 Mic Preamp NOW ON SALE!!!!

After many months of development, testing, troubleshooting, frustration, problems, and accomplishments... the SC-1 mic preamp kit, PSU-1848 power supply kit and power transformer kits are now available for sale!

Click here to ORDER

Photo of a finished SC-1 mic preamp kit!  (Note: XLR jacks and wires shown on picture not included in the kit.)

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
... read more...

Download PDF file of Assembly Guide/Kit Instructions

Related products like the PSU-1848 Power Supply Kit, Power Transformer Kit, Power Control Kit are also available for sale. Click here.
 Monday, December 28, 2009
TS-2 Rev.B Preamp Redesign Part 3
Monday, December 28, 2009 11:04:05 PM (Central Standard Time, UTC-06:00) (  |  )
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.

Comments [0] | Trackback | # 
TS-2 Rev.B Preamp Redesign Part 2
Monday, December 28, 2009 11:03:22 PM (Central Standard Time, UTC-06:00) (  |  )
My parts arrived for my TS-2 prototype. I ordered the parts so I can judge their quality and size, get dimensions and pin spacings so I can create Eagle part libraries for it.

I Found a 4-LED vertical, PCB mount, Right-Angle part. I think I'll use this for the VU meters for the new TS-2RevB. I wish it was a 5-LED device, but 4 will do.

Also, I'm beefing up the DC-DC converter. It only cost a few dollars more than my previous converter, and a big step up in power, so why not? Plus, I have the real-estate board space for it.

The 48V section DC-DC converter is home-grown, developed here in FFS Lab. That will remain unchanged. I think I'll just add some overvoltage protection.

Larger filtering caps will be added too.... again, thanks to the bigger board space.

I'm thinking of adding relays for polarity reverse functions, but a non-latching relay will be consuming power while engaged, and that will be a drain on the battery. A better solution is to use latching relays (they only consume power when changing states), but controlling those will be more complicated than a simple relay. So this is still up in the air.... or maybe I should just get rid of the polarity switch? < what do you think? >

On the original TS-2, there is a switch to turn on/off the VU meters to conserve battery power. What if this switch is instead used as a High Pass filter? Then again, this will be another relay to control. ... which will affect power consumption, etc... Plus, a single switch will be controlling 2 HPF channels? That doesn't sound right.

The compromise decision making process is driving me nuts.

Comments [0] | Trackback | # 
TS-2 Rev.B Preamp Redesign
Monday, December 28, 2009 11:02:22 PM (Central Standard Time, UTC-06:00) ( )
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!

Comments [0] | Trackback | #