|
Home | Forums | Rules | Articles | diyAudio Store | Blogs | Gallery | Wiki | Register | Donations | FAQ | Calendar | Mark Forums Read |
Analog Line Level Preamplifiers , Passive Pre-amps, Crossovers, etc. |
|
Please consider donating to help us continue to serve you.
Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving |
![]() |
|
Thread Tools |
![]() |
#71 |
diyAudio Member
Join Date: Jan 2008
Location: Calgary
|
that chip looks really good. Arduino control is great. My setup is not well suited as I am using a twin triode 6922 setup with the first stage driving the 100k pot with loudness function. The second 6922 drives the tone stack which then drives the SS amp.
Great looking preamp!! input LEDS or LCD in the centre of wheel would indicate which input is selected and volume level expressed as -Db Last edited by stocktrader200; 1st October 2019 at 02:06 AM. |
![]() |
![]() |
#72 |
diyAudio Member
Join Date: Nov 2016
Location: Barcelona
|
Hi Max, again pretty nice project. I'm about to request the BOM to complete the input selector board, and have a (stupid) question.
I understand the MCP23S17 serves as a SPI expander, so we can use the SPI line between an Arduino and more than one sensor or IC. What I'm not so clear about is the ULN2003V12DR relay load drivers. Since these support 3.3V to 5V CMOS logic input interface, wouldn't it be possible to send those signals from the MCP23S17 or Arduino directly? I mean, the latching relays just need a pulse, right? Sorry, I know these are stupid questions, but would love to learn more. Thank you |
![]() |
![]() |
#73 | |||
diyAudio Member
Join Date: Jun 2004
Location: Berlin
|
Quote:
![]() Quote:
Quote:
> Internal Free-Wheeling Diodes for Inductive Kick-Back Protection If you don't have these then you will need a diode across each relay coil. Sure but then you need many free pins on the micro controller. 2 per relay. And depending on what controller you are using, you might not have that many free pins. That's why IMO it's nicer to use SPI. |
|||
![]() |
![]() |
#74 | |
diyAudio Member
Join Date: Nov 2016
Location: Barcelona
|
cool
![]() Quote:
Now, a not-stupid, just maybe weird scenario/question. Would it be possible to use the input selector to switch audio signals and also close/open power circuits? Changing the arduino code, maybe even changing the pcb design, that is. Example situation: relay 1 for phono audio, relay 2 for phono amp power circuit, relay 3 for dac audio, relay 4 for dac power circuit, relay 5 for aux audio. If this is conceptually possible, i would be able to only power the phone amp or the dac when i select those specific audio signals |
|
![]() |
![]() |
#75 |
diyAudio Member
Join Date: Nov 2016
Location: Barcelona
|
As for the last question, maybe if switching power circuits is not supported by this design (even if modified), then I need to look into "triggers", i.e. Signal Detecting Auto Power-On Unit (project 38) by Rod Elliott (ESP), but will obviously do some more research.
|
![]() |
![]() |
#76 | |
diyAudio Member
Join Date: Jun 2004
Location: Berlin
|
Quote:
Personally I would look for another solution. You can get cheap relays that you can control with an Arduino from Aliexpess. |
|
![]() |
![]() |
#77 | |
diyAudio Member
Join Date: Nov 2016
Location: Barcelona
|
Quote:
Hadn't thought of cheap relays, it's a nice idea. Thank you |
|
![]() |
![]() |
#78 |
diyAudio Member
Join Date: Jun 2004
Location: Berlin
|
|
![]() |
![]() |
#79 |
diyAudio Member
Join Date: Jan 2008
|
Max you are a Genius
|
![]() |
![]() |
#80 |
diyAudio Member
Join Date: Aug 2011
Location: Slovenia
|
Wow Max. This project came a long way since your first version.
Looking at your new implementation and code I am tempted to redesign it for MCU running python. Last edited by zoidbergslo; 31st December 2020 at 05:04 PM. |
![]() |
![]() |
Thread Tools | |
|
|
![]() |
||||
Thread | Thread Starter | Forum | Replies | Last Post |
PCBs: Dual TPS7A330 PSU, 6 input relay selector, MDAC attenuator, 6 way RCA board | maxw | Swap Meet | 13 | 8th January 2017 02:52 PM |
My Preamp Project: Arduino, I2C, relay selector+attenuator, tube stage | maxw | Analog Line Level | 63 | 31st March 2015 07:33 PM |
Relay Attenautor, Input selector and Arduino £35 | maxw | Swap Meet | 4 | 10th December 2013 12:38 PM |
Arduino based Input Selector for preamp | _atari_ | Analog Line Level | 5 | 30th June 2010 03:42 PM |
Lightspeed Attenuator + Input selector | zristic | Solid State | 21 | 11th January 2010 03:17 AM |
New To Site? | Need Help? |