| Russ White |
Ok, so Brian and I have been talking about a source and amp selector for quite a while. Finally it is coming to into existance... even if slowly. :)
The layout is nearly complete, but still has some tweaking. I know many of you guys have been asking me about this for quite a while, and I though it was about time to show some work.
Here are some details:
1) 3 stereo sources.
2) A selectable output buffer.
3) 2 outputs which can operate independantly or together, but from the same input source.
4) PIC MCU controlled with headers which allow for various input devices (switches, Qprox..., etc...)
5) On board PS for easy layout and integration with other projects.
The idea is for this to a be a companion to the Kookaburra preamp and Mauro's "My Ref" amp.
Keep in mind this is a work in progress... Stay tuned!! :)
Well here it is: |
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| Nisbeth |
You should consider moving the in/out pinheaders closer to the relays so that the "ground"-pin has a better connection to the ground plane :)
/U.
EDIT: Nice job, again, of course:D |
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| Russ White |
Thx Nisbeth,
Here is a new PIC which is a lot easier to read, and has your change. ;) |
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| Nisbeth |
Much better ;)
/U. |
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| Russ White |
I added one more change,
I added JAC1, JAC2, and JGND which are simple 0R resistor jumpers which allow you to use one trafo or two for semi-isolated or fully isolated PSs.
Though I am pretty sure JGND should always be in place. |
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| Evilsizer |
| looks good! btw what is the size of the board so far? |
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| Russ White |
Thanks!
Well, its about 4.2" x 3.2" and it won't get any bigger, it may get a little smaller.
Cheers!
Russ |
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| bg40403 |
Hi Russ,
Will there be an option to use off-board PS? |
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| Russ White |
It would be easy enough to do with the PCB, but honestly probably no big gain there.
You would simply omit PS parts up to the REGs and wire your PS to the REG GND and OUT pads. |
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| Russ White |
| Actually I meant including the regs. You would omit them as well. |
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| paulb |
| You've announced quite a few new boards lately. Are you planning to sell any of them via your site? |
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| Russ White |
| quote: | Originally posted by paulb
You've announced quite a few new boards lately. Are you planning to sell any of them via your site? |
Yes,
Absolutely...
Right now Mauro's design the monobloc REV C PCBs are in stock,
And I am just waiting for my shipment of PCBs for the kookaburra.
This PCB is up next.
All of the above will/do have kits as well.
You should be able to order Kookaburra very very soon as a matter of fact.
Cheers!
Russ |
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| jleaman |
| What about a remote or a lcd ? |
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| Russ White |
| quote: | Originally posted by jleaman
What about a remote or a lcd ? |
The interface inputs are TTL for either manual buttons or such or another PCB which could hold an IR/RF reciever and and another PIC to control the selector.
The idea is to create a duaghter add-on PCB which can control this PCB as well as the Kookaburra at the same time, both manually, and by remote.
The board as supplied will work out of the box with manual switches, etc... but it would be very easy to fashon a remote PCB, and simply use the interface header.
I am also working on a 5.1/7.1 pre which will have LCD display + and very likely, remote functionality, built in, but that is simply because its operation is much more complex.
Cheers!
Russ |
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| Evilsizer |
| quote: | Originally posted by Russ White
The interface inputs are TTL for either manual buttons or such or another PCB which could hold an IR/RF reciever and and another PIC to control the selector.
The idea is to create a duaghter add-on PCB which can control this PCB as well as the Kookaburra at the same time, both manually, and by remote.
The board as supplied will work out of the box with manual switches, etc... but it would be very easy to fashon a remote PCB, and simply use the interface header.
I am also working on a 5.1/7.1 pre which will have LCD display + and very likely, remote functionality, built in, but that is simply because its operation is much more complex.
Cheers!
Russ |
any chances it can be configured to also be a 2.1 pre as well? i know i would take a afew of these!! |
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| Russ White |
| quote: | Originally posted by Evilsizer
any chances it can be configured to also be a 2.1 pre as well? i know i would take a afew of these!! |
Well, the 5.1 circuit I am working on would be way overkill for 2.1, but maybe you could be more specific about what you want.
What I think you are asking for is a 2 channel in preamp with a high pass filter on the two channels out plus a summing low pass filter for a subwoofer.
I started designing a PCB like that a while back. If there is enough interest I will bring it forward.
Cheers!
Russ |
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| MunkeeVegetable |
| quote: | Originally posted by Russ White
...a 2 channel in preamp with a high pass filter on the two channels out plus a summing low pass filter for a subwoofer.
I started designing a PCB like that a while back. If there is enough interest I will bring it forward. |
Yes! :D Sounds like a great idea to me. (I'm assuming the normal stereo boards only do the two channels without subwoofers or whatever?)
--Nathan |
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| Evilsizer |
| quote: | Originally posted by Russ White
Well, the 5.1 circuit I am working on would be way overkill for 2.1, but maybe you could be more specific about what you want.
What I think you are asking for is a 2 channel in preamp with a high pass filter on the two channels out plus a summing low pass filter for a subwoofer.
I started designing a PCB like that a while back. If there is enough interest I will bring it forward.
Cheers!
Russ |
i was thinking 2 channel full range then with a LFE out (150hz) down somthing along those lines... i was asking though if the 5.1 you are working on could be configured to do 2.1... would make it easier on your part... was mainly a thought... |
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| Nisbeth |
| quote: | Originally posted by Russ White
Well, the 5.1 circuit I am working on would be way overkill for 2.1, but maybe you could be more specific about what you want.
What I think you are asking for is a 2 channel in preamp with a high pass filter on the two channels out plus a summing low pass filter for a subwoofer.
I started designing a PCB like that a while back. If there is enough interest I will bring it forward.
Cheers!
Russ |
I'd like to see this as well. Perhaps it could be a modular design where you can simply use more boards depending on if you want 2/5/7 channels :)
/U. |
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| Nordic |
| quote: | | am also working on a 5.1/7.1 pre which will have LCD display + and very likely, remote functionality, built in, but that is simply because its operation is much more complex. |
Come on!!!!!!! You'd be my hero!!!!!!!! |
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| Russ White |
Well I will post other threads for the 2.1 and 5.1 pre ideas, just keep in mind that the 5.1 pre is mainly for things like listening to multichannel SACD or DVDA players that have 5.1 outputs, the circuit will not have any sort of surround decoder. I wouldn't mind doing a decoder if I could find a good one that did DD, but I don't think that sort of thing is accessible to DIY.
Cheers!
Russ |
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| BrianDonegan |
| All the Dolby chips are licensed and tightly controlled by Dolby Labs. You can only get them two ways: buy a license from Dolby or rip apart an existing piece of equiptment. |
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| Russ White |
| quote: | Originally posted by BrianDonegan
All the Dolby chips are licensed and tightly controlled by Dolby Labs. |
Right, which is why they are not DIY friendly. :)
The man is holding us down!! LOL |
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| Russ White |
| BTW I actually have an Analog Devices Sharc Melody evalution kit a good friend sent me which I will likely use in a project soon, and it is way cool, but it is not generally available. |
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| UnixMan |
Hi Russ,
small question: does your selector switches only the signal (with common grounds always connected) or does it switch both signal and ground?
...it would be much better to switch both, i.e. to completely disconnect any unused source(s), to avoid ground loops. |
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| BrianDonegan |
It only switched the signal with common grounds. This cuts the number of relays in half. Plus, I think if you were going to have any ground loops between components becuase of an irregular ground in a particular source, you would still have a loop between that component and the amp.
I think this approach provides a common ground point for all component signal gounds in the system. I could be wrong. |
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| GeWa |
Two days already without a post from Russ, weird..... :scratch2:
Cheers ;) |
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| jleaman |
| quote: | Originally posted by Evilsizer
any chances it can be configured to also be a 2.1 pre as well? i know i would take a afew of these!! |
I have yet to see some one design a pcb for lcd remote etc etc volume inputs all inone or a fewboards that work to make this.. I think it would be a huge seller id buy 3. |
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| GeWa |
| Give it some time, I'm sure Russ will come up with something :D . |
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| BrianDonegan |
| We are working on it... more soon. |
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| metal |
Hello Russ White
Nice work in deed...Could you upload eagle files for .brd & .sch...
Thanks |
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| Mr.Radar |
| quote: | Originally posted by jleaman
I have yet to see some one design a pcb for lcd remote etc etc volume inputs all inone or a fewboards that work to make this.. I think it would be a huge seller id buy 3. |
I'm actually working on something like this using a design based on the one used by this I/O selector and Russ's digital preamp. I won't be selling/making any PCBs though (I'll be making it on a few perfboards). I'll post a thread about it when I'm finished drawing the schematic and prototyping (in a loose sense of the word) the software for the microcontrollers (which should be by the weekend at the pace I'm going, next week at the latest). |
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| jleaman |
| quote: | Originally posted by Mr.Radar
I'm actually working on something like this using a design based on the one used by this I/O selector and Russ's digital preamp. I won't be selling/making any PCBs though (I'll be making it on a few perfboards). I'll post a thread about it when I'm finished drawing the schematic and prototyping (in a loose sense of the word) the software for the microcontrollers (which should be by the weekend at the pace I'm going, next week at the latest). |
I'm not looking to make any money i just want a few. But i could also work up a board for this if i had a schematic.. I use eagle. |
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| Russ White |
I am just about ready to put in an order for these PCBs and they will be available very soon. :) Keep an eye on twistedpearaudio.com site, you will also be able to puchase a full kit with all the relays/opamp/and a preprogrammed PIC. We just got a batch of very high quality silver contact relays in to go with this PCB and you will be able to get the parts in the kit much cheaper then if you sourced the parts yourself.
Meant to post earlier, had a very busy day yesterday. It is my ploicy not to release design IP until after Brian and I have had a chance to liquidate the first round of kits/PCBs since we take a large risk in designing/developing/prototyping/ and ordering parts and PCBs. That being said, I do believe in sharing the PCB design, and I will soon, just not yet. I hope eveyone understands.
Cheers!
Russ |
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| jleaman |
| I'll buy one :D.. |
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| GeWa |
Russ, Brian
What's the status on this little project? ;)
Cheers |
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| Russ White |
We are going to get a couple of prototype PCBs made in the next week or so, and then maybe a couple beta kits will go out, after that we will do a production run.
Cheers!
Russ |
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| jleaman |
| quote: | Originally posted by Russ White
We are going to get a couple of prototype PCBs made in the next week or so, and then maybe a couple beta kits will go out, after that we will do a production run.
Cheers!
Russ |
I'll do some testing :D |
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| maf_au |
Russ,
I have a friend whom I support with some cast-off gear (she's over 90 years old!!) and she is always having issues with source selection because she has so many inputs.
Currently she manages with my old NAD integrated and a tandy switchbox, but it's ugly and easy to get flumoxed.
Her sources are (I'll have to check if I have this correct):
CD
Tuner
Phono
Tape1 Reel to Reel
Tape2 Reel to Reel
Tape3 Cassette
Tape4 4 Track
Could I adapt this project to handle more inputs (use 2 boards?), and still keep it user friendly?
Michael |
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| Russ White |
| quote: | Originally posted by maf_au
CD
Tuner
Phono
Tape1 Reel to Reel
Tape2 Reel to Reel
Tape3 Cassette
Tape4 4 Track
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Wow thats a tall order. :)
The current answer is that with the circuit as it is, no you could not, but let me look at it a little closer. Thats a lot of inputs! :)
Cheers!
Russ |
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| jleaman |
| quote: | Originally posted by Russ White
Wow thats a tall order. :)
The current answer is that with the circuit as it is, no you could not, but let me look at it a little closer. Thats a lot of inputs! :)
Cheers!
Russ |
why some one would use all them inputs is beond me.. thats way to many.. |
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| maf_au |
| quote: | Originally posted by jleaman
why some one would use all them inputs is beond me.. thats way to many.. |
Well, I'm not silly enough to start arguing with an over-90yo :)
She has a lifetime of creativity and enjoyment stored in those sources, can you blame her for wanting to keep using them?
Myself, I have the CD, the tuner and the DVD...
Regards,
Michael |
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| johnnyx |
| Four tape loops:bigeyes: |
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| Cobra2 |
| quote: | Originally posted by Russ White
Wow thats a tall order. :)
The current answer is that with the circuit as it is, no you could not, but let me look at it a little closer. Thats a lot of inputs! :)
Cheers!
Russ |
Not at all...
I too would like MANY inputs, 3 or 4, you can find anywhere...
(my collection; Tape, RIAA1, RIAA2, Tuner, MD, CD-R, CD1, CD2, DAC1, DAC2, TV, VCR, DVD, Satelite, Cable = 15) ... and then it would be nice to have a test-input, or two, so I did not need to rewire everytime I wanted to test new-made equipment ;-)
Arne K |
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| maf_au |
| quote: | Originally posted by johnnyx
Four tape loops:bigeyes: |
Actually, I think one tape loop would do, I'd just make up a RCA patch panel to handle the others, I think only one of the tapes is used to record these days... |
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| SheldonD |
I would like to "chip" in here,
I would like to see say 8
cassette tape,
reel to reel,
tuner
Phono,
CD
2 tape loops
Aux
possible AUx2 or test |
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| GeWa |
Russ, Brian
Any chance I can put o' these under the Christmas tree? :angel:
Regards |
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| Russ White |
| Regrettably, no. :( But hopefully within the next couple of months. |
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| GeWa |
| MONTH'S!!!! :bawling: |
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| Byrd |
| Prod Prod - Poke Poke - Peek Peek ;) Hows it comming? |
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| Russ White |
Actually very well, I should have a prototype in the next couple weeks. :D Not too much longer I promise. :up:
It has changes quite a bit (for the better) and I will post a lot of details soon,
Cheers!
Russ |
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| maxw |
Any news on this? ;)
What will you use to control the input? a rotary encoder? or buttons? or a rotary switch? |
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| maf_au |
C'mon Russ,
I'm needing motivation to get into a project. Renovating the workshop and building a garage has kept me busy, and I'm doing a woodwork course, so the electronics is missing out... (no not a 'powertool' ww course, one where darkside tools are learned, chisels, planes, that sort of thing)
and my ancient friend is still alive, it would make her day... I can see a source selector built into a redgum box...
Michael |
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| Russ White |
| quote: | Originally posted by maf_au
C'mon Russ,
I'm needing motivation to get into a project. Renovating the workshop and building a garage has kept me busy, and I'm doing a woodwork course, so the electronics is missing out... (no not a 'powertool' ww course, one where darkside tools are learned, chisels, planes, that sort of thing)
and my ancient friend is still alive, it would make her day... I can see a source selector built into a redgum box...
Michael |
Hi Michael,
I always try to remember my Australian mates. Keep your ears to the ground. Darwin is coming. :D
So many projects, so little time..... Real work always gets in the way. :cool:
Cheers!
Russ |
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| Russ White |
Darwin is a 6 in 2 out with loop selector which can be controlled very easily with two switches or three, or a microcontroller, or whatever. It is very flexible. It is designed to very small(1.5" x 4" x .625") and easy to mount even to the back plate of a preamp/amp. The idea is that the source/output switching happens very close to in/out jacks so cable runs for signal can be quite short. The switching relays are very good signal relays (G6K)
The interface wires (to switches or controller PCB) can be as long as you need them without penalty to your audio signal. This makes case wire routing much more practical and easy.
There is an output loop on the PCB so that the signal can pass through a preamp, EQ, or whatever prior to coming out the outputs if you desire. This loop can be jumpered I will use this loop to run the signal through my XBOSOZ/Joshua tree prior to outputs.
The source selector PCB consists of two channels with a common ground trace for all inputs and outputs. So with one PCB you can do stereo single ended with a shared GND. With two relay PCBs stacked and using a common control you could do stereo single ended with distinct switched GNDs or balanced inputs/outputs.
This relay PCB is the exact same size and has the same hole patterns as my attanuator which you can read about here:
http://www.diyaudio.com/forums/show...&threadid=74224
So it is designed to stack with it. And can easily be integrated with the attenuator or the kookaburra (although the kooka will not stack).
Here are some options
A very simple control (no micro controller necessary) just need a +5VDC supply (could easily piggy back off the attenuator PS).
For input a simple 6 position rotary switch , and quality is not very important here as it is not in the signal path.
For output you could do:
A) A 3 position rotory with position A being output 1 position B being output 2 and position C being both.
B) two SPST switched one for each output.
There is also the option of using a microcontroller for remote control and display and such, but there is no such controller yet, but one is coming. For now the relay PCB will be available in about 2 weeks or so.
Cheers!
Russ |
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| Russ White |
| Here is the Darwin Schematic: |
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| Duck-Twacy |
| quote: | Originally posted by Russ White
Darwin is a 6 in 2 out with loop selector which can be controlled very easily with two switches or three, or a microcontroller, or whatever. It is very flexible. It is designed to very small(1.5" x 4" x .625") and easy to mount even to the back plate of a preamp/amp. The idea is that the source/output switching happens very close to in/out jacks so cable runs for signal can be quite short. The switching relays are very good signal relays (G6K)
...
Cheers!
Russ |
perfect!! |
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| rabstg |
| quote: | Originally posted by Russ White
Here is the Darwin Schematic: |
I don't see a "Buy now" button on the web site... ;) |
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| jleaman |
| quote: | Originally posted by rabstg
I don't see a "Buy now" button on the web site... ;) |
He would not be sleeping if he had that button :) I like the work you are doing on all these project's keep up the good work Brian & Russ. |
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| BrianDonegan |
| quote: | | I don't see a "Buy now" button on the web site... |
I'm actually trying to add it to the NEW website and get that out the door, instead of updating both the old site and the new site. Check again tomorrow (depending on how late I can stay up tonight ;) ). |
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| jam |
Russ,
I am trying to understand the reason for the resistors on the pcb, they would always be across the input to ground except for the input that that was active adding to load presented to the source. They are probably not needed or were they ment to be in series with the input.
Regards,
Jam |
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| Russ White |
| quote: | Originally posted by jam
Russ,
I am trying to understand the reason for the resistors on the pcb, they would always be across the input to ground except for the input that that was active adding to load presented to the source. They are probably not needed or were they ment to be in series with the input.
Regards,
Jam |
They are there simply to provide a high impedance (100K or so) GND reference for unused sources and ouputs. They are only active when a source/output is "off". Some sources don't like "open" loads, and most amplifiers don't like open inputs. So really I am just keeping any inactive input/outputs from floating.
They can of course be omitted.
Cheers!
Russ |
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| jam |
Russ,
I understand your reasoning but to me then the switches need to be redrawn or the resistors tied directly to the inputs..............or maybe I am missing something?
Regards,
Jam |
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| Russ White |
| quote: | Originally posted by jam
Russ,
I understand your reasoning but to me then the switches need to be redrawn or the resistors tied directly to the inputs..............or maybe I am missing something?
Regards,
Jam |
You are correct. It has been fixed thanks!!! |
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| Russ White |
| here is the fixed version. :) |
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| jam |
Russ,
Works for me................just a thought but you could rewire the unused pin on the relay to short non-active inputs to ground thus eleminating a potential source of cross talk...........but then again some sources might not like their outputs shorted........;)
Regards,
Jam |
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| Russ White |
| quote: | Originally posted by jam
Russ,
but then again some sources might not like their outputs shorted........;)
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Hi Jam,
Thank you very much for your input. I think the layout is safest the way it is. I don't want to have explain to every person who builds one of these which sources can be shorted and which can't. I think I will leave it as is and if some want to they can very easily throw on a jumper or a resistor from that pin to GND.
Cheers!
Russ |
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| jam |
Russ,
Could you e-mail me. I have ideas and I would like to discuss them with you.
Regards,
Jam |
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| Russ White |
| email sent. :) |
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| Hawaii |
When will the kit be ready for shipping?
Can't wait to build it... :D |
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| Russ White |
| quote: | Originally posted by Hawaii
When will the kit be ready for shipping?
Can't wait to build it... :D |
Soon. Very soon. :) |
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| moreismore |
| I was at your site yesterday, prepaid for a kit and returned later that day and noticed another relay board has been added. What is the function of the second relay board? |
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| jleaman |
| quote: | Originally posted by moreismore
I was at your site yesterday, prepaid for a kit and returned later that day and noticed another relay board has been added. What is the function of the second relay board? |
Are you talking about the input selector one or the volume relay board ?
Jase |
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| moreismore |
| Yes, the Darwin input selector. |
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| jleaman |
| quote: | Originally posted by moreismore
Yes, the Darwin input selector. |
I don't want to assume but i would think the extra board is so you can use it in balanced mode. :) |
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| BrianDonegan |
The second relay board is for balanced operation. With one relay board, you can do single-ended (R+, GND, L+). With two boards, one would switch R+, GND, R-, the other L+, GND, L-.
It was my mistake in not posting it correctly the first time. If you need balanced operation and already ordered, send me an email and we can work something out. |
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| jleaman |
| quote: | Originally posted by BrianDonegan
The second relay board is for balanced operation. With one relay board, you can do single-ended (R+, GND, L+). With two boards, one would switch R+, GND, R-, the other L+, GND, L-.
It was my mistake in not posting it correctly the first time. If you need balanced operation and already ordered, send me an email and we can work something out. |
And this is a perfect example of how Brian / Russ are ding such a good job.
Keep it up guy's.
Jase |
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| BrianDonegan |
Here's a pic of the relay board with kit parts:
Not shown in the pic are the two rotary switches (6-pos, 2-deck and 3-pos 4-deck) and the IDC wiring connector. |
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| jleaman |
| quote: | Originally posted by BrianDonegan
Here's a pic of the relay board with kit parts:
Not shown in the pic are the two rotary switches (6-pos, 2-deck and 3-pos 4-deck) and the IDC wiring connector. |
Yet another nice kit.. Look for my order soon :) |
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| karma |
| brian u have mail;) |
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| bramht |
i think i have found an excellent remote control kit which would control the darwin and 2 motorpots ( to control the volume of the master and subwoofer channel of you multi kook perch and power supply)
have a look:remote kit |
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| jleaman |
| quote: | Originally posted by bramht
i think i have found an excellent remote control kit which would control the darwin and 2 motorpots ( to control the volume of the master and subwoofer channel of you multi kook perch and power supply)
have a look:remote kit |
Good Idea. |
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| sklimek |
And there is also the touch sensors, Qprox or Q-touch that Brian talked about a few months back that senses your touch for triggering. Can be used for glass as well.
http://www.qprox.com/products/qtouch.php |
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| kestrel200 |
From looking at the wiring diagram I assume I am suppose to connect the the grounds of the Left & right channel together and the run a single wire from them tto the board. Is that right?
Something like this?? |
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| maxlorenz |
Hi :D
I'm upgrading the speakers for my DIY system nș2 (activelly biamped) and they are so efficient that I needed a preamp (formerly using active crossover's attenuator as pre) plus a source selector. I added a Kookaburra and a Darwin inside the CX' box. After a few inconvenients due to my lack of study of the diagrams...:guilty: I managed to make it work, but, I got an annoying buzz that made me separate preamp+source selector from active CX: now I got a silent, fully functional unit :cool: and I can listen at lower level and avoid spouse's recrimination :cannotbe:
As all tweastedpearaudio's units, they came brilliantly packaged and labeled. Building of Kooka (my second) was a breeze. I had a few troubles with Darwin connections due to lack of expertize and care, as I confessed before...anyway, it took me a day or two to build the preamp-selector into a complete, one box unit.
Want to see my "little" new speakers?:
[IMG] [/IMG]
Russ and Brian, you are spoiling us :mad:
Cheers
M |
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| khaho |
Russ, I was thinking to use the output section of Darwin for switched outputs after Xbosoz and Joshua Tree (with the input section before Xbosoz).
But it seems that it would make a ground loop in Darwin board (inputs and outputs have common ground according to shematic), so maybe it should not be used that way ?
Even otherwise the ground would be quite same, but can be arranged as star ground. Maybe there is no problem, I am quite a beginnger in DIY. |
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| Russ White |
| quote: | Originally posted by khaho
Russ, I was thinking to use the output section of Darwin for switched outputs after Xbosoz and Joshua Tree (with the input section before Xbosoz).
But it seems that it would make a ground loop in Darwin board (inputs and outputs have common ground according to shematic), so maybe it should not be used that way ?
Even otherwise the ground would be quite same, but can be arranged as star ground. Maybe there is no problem, I am quite a beginnger in DIY. |
Hi,
It is a good question.
The Darwin is designed to be used with common GND (a very common technique for source selectors) if you use one PCB for both channels.
It is also designed to you can use one PCB per channel and switch GND as well as hot. This would be the same as when using the Darwin for balanced operation, but GND would be connected where the inverted signal would be, and you would not connect GND to the normal GND location.
Cheers!
Russ |
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| maxw |
This input selector uses a 6-way rotary switch to select the input but I really want to use momentary switch(es).
Does anyone know a circuit/IC that could enable me to use a single momentary switch to cycle through the inputs in a loop fasion?
I'm not even sure how to google for such a thing... |
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| khaho |
| quote: | Originally posted by Russ White
It is also designed to you can use one PCB per channel and switch GND as well as hot. This would be the same as when using the Darwin for balanced operation, but GND would be connected where the inverted signal would be, and you would not connect GND to the normal GND location.
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Yes I understand that but in the schematic all input/ouput header pins number 2 are connected even without the loop jumpers ? I think that the problem is this direct connection between input and output sections and a loop comes by going from loop jumpers to xbosoz and jt and back again.
I will use balanced operation, one board per channel. Well, I really dont need the switched outputs, I will just leave the output section unused.
One more question: in Control Wiring Diagram there is "Ground from Power Source" in the switches, but "+5V from Power Source" in the IDC connector, is one of those wrong ? |
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| Russ White |
| quote: | Originally posted by maxw
This input selector uses a 6-way rotary switch to select the input but I really want to use momentary switch(es).
Does anyone know a circuit/IC that could enable me to use a single momentary switch to cycle through the inputs in a loop fasion?
I'm not even sure how to google for such a thing... |
The switch is only one way to control the Dawrin. Darwin is meant to be a building block PCB which will be used later with a more in depth controller.
We thought many people would like to try to build their own controllers. You could use an 18 - 20 pin PIC to control the Darwin pretty easily. Even without driver transistors. I would look at the PIC 16F690 or something similar. The PCB would be pretty simple, but you could really do such a circuit on protoboard without much problem.
If I ever get to were I can build something again here soon (after my move) I will be developing an "uber controller" that will control the Darwin and the JT with rotory encoder and remote control, as well as have some other options.
Have fun!
Cheers!
Russ |
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| Russ White |
| quote: | Originally posted by khaho
Yes I understand that but in the schematic all input/ouput header pins number 2 are connected even without the loop jumpers ? I think that the problem is this direct connection between input and output sections and a loop comes by going from loop jumpers to xbosoz and jt and back again. |
The "loop" is there to inject something like a preamp. The outputs are there to go so some other amp (like power amps) that would share exactly one source and the loop.
The loop can simply be a jumper in which case the two outputs will be direct connected to a single selected source. The two outputs can either be on or off, but they must in order to share input be tied to a single signal(s) since they are sharring a common source.
The best place to put your preamp is in the "loop". Connect the side of the loop coming from the input to your preamp(with JT), then the output of the premp to the side of the loop connected to the two outputs. You can then switch between power amps or run two at the same time (say for biamping or multi room).
I hope that makes it more clear. :)
Cheers!
Russ |
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| Russ White |
More directly, there is no way I can see to avoid connecting with a common GND for balanced circuits unless you use three pole relays :xeye: or three single pole relays, which would be a lot of relays....
As an example I am using the Darwin to select between balanced sources with a balanced preamp (twisted sibling) and two balanced power amps (LM3886 SuSy, and a super secret SuSy chipamp ;)) with no problems at all. Certainly no humm or anything that would indicate a problem with the shared GND.
Cheers!
Russ |
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| khaho |
| quote: | Originally posted by Russ White
More directly, there is no way I can see to avoid connecting with a common GND for balanced circuits unless you use three pole relays :xeye: or three single pole relays, which would be a lot of relays....
As an example I am using the Darwin to select between balanced sources with a balanced preamp (twisted sibling) and two balanced power amps (LM3886 SuSy, and a super secret SuSy chipamp ;)) with no problems at all. Certainly no humm or anything that would indicate a problem with the shared GND.
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Ok, thanks! Maybe newcomers just become afraid ot grounding issues in forums like this, nearly always problems seem to be humming and nearly always grounding is suspected to be the problem.
About my other question: can the IDC connector +5V used in the switches (even said to be ground in the diagram) or do I have to do separate ground wires and leave the +5V unconnected ? |
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| Russ White |
| quote: | Originally posted by khaho
About my other question: can the IDC connector +5V used in the switches (even said to be ground in the diagram) or do I have to do separate ground wires and leave the +5V unconnected ? |
The +V should come from some power supply. It is common to all the relay coils. Each relay's negative pin goes to a control pin on the IDC connector, which in turn is switched to power GND (not signal GND) via the rotary switches. You don't connect +5V to anything else but the +5V pins on the IDC connector. :) The key here is that the +5V is common and the switches switch to GND.
Cheers!
Russ |
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