Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Group Buys Members group buys

Maya R2R Advanced Volume controller
Maya R2R Advanced Volume controller
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
Reply
 
Thread Tools Search this Thread
Old 30th April 2016, 05:36 AM   #41
tvicol is offline tvicol  Europe
diyAudio Member
 
tvicol's Avatar
 
Join Date: Jan 2005
Location: Bucharest
Maya R2R Advanced Volume controller Maya R2R Advanced Volume controller
Quote:
Originally Posted by Hans Polak View Post
If you want to use more BPBP boards playing at the same time at different levels, you will need just as many Maya controllers and ´Hans`boards as you have BPBP boards.
Tibi, do you agree?

Hans
Such feature can be implemented still with a single Maya controller by adapting firmware and changing R-2R board to allow PCF addressing via I2C bus.
So, it is possible with some effort.
I wonder how many people are interested in such function.

Regards,
Tibi
__________________
https://evotronix.eu
  Reply With Quote
Old 30th April 2016, 12:46 PM   #42
Hans Polak is offline Hans Polak  Netherlands
diyAudio Member
 
Join Date: Mar 2005
Location: Blaricum
Tibi,

I see no provision for setting different I2C addresses on the circuit diagram of the R2R board that I have, needed when using more that 4 input channels.

Schematic MAYA 3.2.pdf

Volume Control has address 0 and Channel Select address 4 in this diagram.
But there is a connector Aux1 that leads P3 to P7 from the channel select PCF to the outside world.
So I suspect, in case of extending the amount of channels to 8 or 12, you need a different type of R-2R board that can input P3 to P7 as it's address?

The reason I'm asking has to do with the question whether a slight change to the Hans board can facilitate the use of more BPBP amps, without having to change anything at all to the software of the Maya CPU control.
Since this "Hans" board isn't yet in production, I could still easily make a new set of Gerbers.

Hans
  Reply With Quote
Old 1st May 2016, 06:38 AM   #43
tvicol is offline tvicol  Europe
diyAudio Member
 
tvicol's Avatar
 
Join Date: Jan 2005
Location: Bucharest
Maya R2R Advanced Volume controller Maya R2R Advanced Volume controller
Hi Hans,

Addressing can be provisioned via A0,A1,A3 for each PCF/PCA8574. A 6 position switch or some pcb soldering bulbs must be added to set each board slave addressing.

For further expanding can be used drop in replacement PCA9674.
Maya will interrogate via i2c and "detect" how many slave boards are attached.

Regards,
Tibi
__________________
https://evotronix.eu
  Reply With Quote
Old 1st May 2016, 06:52 AM   #44
aradan is offline aradan  Singapore
diyAudio Member
 
Join Date: Apr 2015
Location: Born in Russia, living in Singapore
Hi Tibi,

Is native maya logarithmic or linear?

I guess Hans board should be linear right?

Sent from my ONE A2003 using Tapatalk
  Reply With Quote
Old 1st May 2016, 07:08 AM   #45
tvicol is offline tvicol  Europe
diyAudio Member
 
tvicol's Avatar
 
Join Date: Jan 2005
Location: Bucharest
Maya R2R Advanced Volume controller Maya R2R Advanced Volume controller
Native Maya is logarithmic with constant 10K output impedance. Maya was designed to offer an ideal attenuator between a source/preamplifier and an power amplifier.

Hans R-2R board is also logarithmic, but with 2K constant input impedance and address another application.

Regards,
Tibi
__________________
https://evotronix.eu
  Reply With Quote
Old 1st May 2016, 12:50 PM   #46
NATDBERG is offline NATDBERG  United Kingdom
diyAudio Member
 
Join Date: Nov 2006
Quote:
Originally Posted by aradan View Post
Hi Tibi,

Is native maya logarithmic or linear?

I guess Hans board should be linear right?

Sent from my ONE A2003 using Tapatalk
Linearity as set out in Bruno Putzey's design ONLY applies to using a potentiometer and how, as a potential divider, this is important in the feedback loop (where the pot is used) to prevent distortion. Hans gave a good explanation of this on the main BPPBP thread a couple of days ago.

If you're using an R2R ladder, or a scheme using fixed resistors rather than a continuous track, one can go back to using logarithmic for convenience of use. It's added expense though for no sonic gain, only certain conveniences.

The whole idea of Bruno's clever volume scheme using the cheap linear pot is to negate the whole compromise/distortion of using a fancy and expensive pot / stepped attenuator in the conventional way. In his own circuit build he accidentally used a log pot and it worked ok, just there was more distortion measured than there should have been (than with the linear pot). If you can live with the idiosyncrisies of a linear pot's volume position, a cheap one will perform (sonically - maybe not absolute longevity) as good as any other type.
  Reply With Quote
Old 1st May 2016, 01:50 PM   #47
Hans Polak is offline Hans Polak  Netherlands
diyAudio Member
 
Join Date: Mar 2005
Location: Blaricum
Quote:
Originally Posted by tvicol View Post
Hi Hans,

Addressing can be provisioned via A0,A1,A3 for each PCF/PCA8574. A 6 position switch or some pcb soldering bulbs must be added to set each board slave addressing.

For further expanding can be used drop in replacement PCA9674.
Maya will interrogate via i2c and "detect" how many slave boards are attached.

Regards,
Tibi
Hi Tibi,

Thanks for your response.
Sorry for all the trouble, but your answer brings me to the following 4 Questions:

1) When you say "for each PCF", does that mean selectable addresses for the Volume Select PCF and for Channel Select PCF?

2) And if dual addresses per board are used, in case of using THREE R-2R MAYA boards, are the addresses for the two PCF,s set to resp 0/4 (board1), 1/5 (board2) and 2/6 (board3) ?

3) Which PCF's are interrogated to detect how many boards are used, the Volume PCF or the Channel Select PCF?

4) When each Volume PCF has a different address per R-2R board, what happens to its volume setting after switching to another R-2R board. Will it remain in its last used position or not.

Could you please be as specific as possible in answering these questions.
It might open the door to enable extra features to the use of multiple BPBP boards, without you having to change anything at all to the CPU software.

Regards,
Hans
  Reply With Quote
Old 1st May 2016, 07:23 PM   #48
tvicol is offline tvicol  Europe
diyAudio Member
 
tvicol's Avatar
 
Join Date: Jan 2005
Location: Bucharest
Maya R2R Advanced Volume controller Maya R2R Advanced Volume controller
Hi Hans,

1. Controller will scan for all I2C bus addresses, this way perform a pre-check.
2. Yes, you figured correctly, as per table 5.
3. Both
4. Maya will keep in memory only volume per channel. This allow different volume for each input.

What are the features BPBP users are looking for ?
If requests are coherent we may adapt Maya firmware for this specific project.

Regards,
Tibi
__________________
https://evotronix.eu
  Reply With Quote
Old 1st May 2016, 08:31 PM   #49
Hans Polak is offline Hans Polak  Netherlands
diyAudio Member
 
Join Date: Mar 2005
Location: Blaricum
Quote:
Originally Posted by tvicol View Post
Hi Hans,

What are the features BPBP users are looking for ?
If requests are coherent we may adapt Maya firmware for this specific project.

Regards,
Tibi
O.K., I am getting more detailed idea now.

But the more I go into detail, the more I doubt what to enable and what not.

So let me think it over again, before bombarding you with further questions.

Hans.
  Reply With Quote
Old 2nd May 2016, 08:25 AM   #50
Hans Polak is offline Hans Polak  Netherlands
diyAudio Member
 
Join Date: Mar 2005
Location: Blaricum
Hi Tibi,

Of all the possible options, I see only one thing as being useful, all the others can be solved in different ways.

Let me explain first that the BPBP has only one relay for selecting channel one or channel two. It is thus not possible to deselect both channels.

In case of using more BPBP's at the same time, this means that on every preamp one of the two input channels is always active.

But this is exactly that you want when playing a Multichannel Surround System or a Multichannel Loudspeaker System for low/mid/high.

For the PCF's this would imply all Volume PCF's addresses set to zero and all Channel Select PCF's addresses set to 4 to get the proper synchronisation between the pre-amps.

However when reading PCF's this would mean that the SDA lines are driven by more than one PCF. But since they carry the same information, I do not see any problem.
Do you agree?

In that case nothing has to be changed to the "Hans" board at all and your software can also stay as it is.

If we agree, we can close the books, and I will explain to the BPBP Forum what they can expect.

Hans
  Reply With Quote

Reply


Maya R2R Advanced Volume controllerHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Interest check on Vicol Audio Maya R2R Volume controller aradan Group Buys 222 12th November 2018 09:55 AM
R2R Shunt Volume with 3 selectable sources quanghao Quanghao Audio Design 13 2nd August 2016 04:30 PM
Vicol Audio R2R Volume controller Builds aradan Analog Line Level 13 18th April 2016 02:06 PM
R2R/Shunt volume controller; Quasar amplifier; Silver-Gold interconnect tvicol Vendor's Bazaar 3 27th June 2011 06:40 AM
Samsung 1602VFD For CDROM Controller & Remote Volume Controller slowgay Swap Meet 2 22nd November 2008 02:44 PM


New To Site? Need Help?

All times are GMT. The time now is 10:55 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki