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Old 10th June 2013, 10:37 AM   #11
wineds is offline wineds  Australia
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Rudi is there any way one of the inputs could be configured as a home theatre (ht) bypass input? Or fourth input added with this functionality?

Mute could possibly also be implemented using software to wind the pot down and then later back to the same position? This might allow the existing mute relay to be used for ht bypass perhaps?

Nice work BTW!

Last edited by wineds; 10th June 2013 at 11:02 AM.
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Old 10th June 2013, 10:50 AM   #12
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Definitely interested as well
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Old 10th June 2013, 03:21 PM   #13
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@Wineds, Wirehead.be: I hope that I understand correctly, what you want.
I am not a "multimedia-man" !

You have access to the un-attenuated and the attenuated audio-signals as shown in the image below.
As I understand you, you want to bypass the attenuation and feed the signal directly to your AMP, in case you select "Home Theatre" as source.

I will not offer this feature on the standard VCPre-PCB for these 2 reasons:
- it is very (!) hard to insert an additional relay on current VCPre-PCB version
- I (myself) do not like to put another strain / load (relay) on the audio-signal

But I will offer you an additional PCB that will fulfill your needs:

Being driven from the VCPre-PCB, this small enhancement will let you switch between attenuated and non-attenuated audio signals.

I hope that this solution will suit you.

Best regards - Rudi_Ratlos
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File Type: png Image4.png (13.9 KB, 573 views)

Last edited by Rudi_Ratlos; 10th June 2013 at 03:23 PM.
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Old 10th June 2013, 03:54 PM   #14
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Hello Rudi, well this is exactly what I need in it's present form. I was thinking of building an Arduino-based LDR attentuator, with relay input channel selector. But this fits the bill 100%
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Old 10th June 2013, 04:12 PM   #15
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@WireHead.be: to layout the supplementary PCB takes me 5 minutes.
Here it is:

Best regards - Rudi_Ratlos
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Old 10th June 2013, 06:14 PM   #16
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Quote:
Originally Posted by Rudi_Ratlos View Post
Goldkenn, Bill: I have added two 2-pole connectors in front of the mute-relay.
Does it suit you?

Best regards - Rudi_Ratlos
It seems great!
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Old 11th June 2013, 11:55 AM   #17
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@Wineds, Wirehead.be: find attached the current layout of the VCPre - PCB.

I put the HTBypass-connector on the bottom right side.
It has 3 pins: VCC, GND and a µProcessor output-pin that will connect to the small HTBypass-PCB.

Best regards - Rudi_Ratlos
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File Type: png VCPre.png (239.1 KB, 552 views)
File Type: png HTByp.png (73.3 KB, 518 views)
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Old 11th June 2013, 01:17 PM   #18
wineds is offline wineds  Australia
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nice job RudI. are you going to post the schematics?
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Old 11th June 2013, 01:29 PM   #19
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Thumbs up I am also interested

Quote:
Originally Posted by Rudi_Ratlos View Post
Gentlemen,

my DIY-friend METAL and I have been working for quite a while on a passive pre-amp that shall be versatile (give us all the functionality
that we need) and comfortable, so we can sit in our armchair and control everything per remote-control-unit.

This is the current result of our project:

Click the image to open in full size.
http://abload.de/img/display012a0xwe.jpg

This PCB (I call it VCPre hereafter) has the following functionality:

- Source selection of up to 3 input sources
- Mute function
- Attenuation, either based on a LDR - solution or a traditional AUDIO potentiometer
- Support of motorized potentiometers
- Display of attenuation
- Display of current temperature of your heatsinks
- Implementation of a Standby / Resume-from-Standby function for your amplifier
- Status-display on a 1x16chars LCD module
- Every function can be controlled by an infrared remote-control unit

The functionality of the VCPre is accomplished by the use of a PIC 16F886 µProcessor.

I myself am using the current VCPre PCB-version in the build of my FC-100 amplifier, it works flawlessly, and I did not yet receive any complaint
from any of the German DIYers, who have already installed the PCB.

Click the image to open in full size.
http://abload.de/img/neverbeforehavelisten5hzwb.jpg

If there is some interest, I will start a group-buy offering the PCB(s), documentation, pre-programmed µProcessor, hard-to-get components (if any), ...

Best regards - Rudi_Ratlos
Hi Rudi,

I am interested in this project if ever convert to group buy, I will participate. Thanks for your great work.

Regards,

Jorge
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Old 11th June 2013, 02:05 PM   #20
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I might do as well. I would like to integrate it with dac in one Box. Do you Think it is doable?
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