Hi Peranders,
Yes, I did price out some NAIS/Aromat relays. They are indeed very expensive....
Perhaps, I'll post some applicable pricing comparisons.
The problem is that some people want "the best" while most people want very good because of the cost tradeoff. I felt that The cost of the kit was approaching limits of what people would be willing to spend. Adding another $120 to the system seemed a bit excessive.
Best REgards,
Dale
Yes, I did price out some NAIS/Aromat relays. They are indeed very expensive....
Perhaps, I'll post some applicable pricing comparisons.
The problem is that some people want "the best" while most people want very good because of the cost tradeoff. I felt that The cost of the kit was approaching limits of what people would be willing to spend. Adding another $120 to the system seemed a bit excessive.
Best REgards,
Dale
harvardian said:
I'm not concerned much with relays on volume control board, but could we have the option of buying input selector boards without relays? Especially, if somebody has already the relays in his drawer.😉
Hi Peter,
I am sure that we would be amenable to special requests via a private email...
Just make sure that your relays are pinout compatible and possibly drive levels.
Dale
I am sure that we would be amenable to special requests via a private email...
Just make sure that your relays are pinout compatible and possibly drive levels.
Dale
Mercury wetted
Hi,
For the Apox-1, it would probably be worthwhile to consider mercury wetted option for the series pass units, but I presume it would not be worth the effort in shunt mode. Thus, a few bucks could potentially do quite a bit of damage (not that I would know personally) 🙂
When you do go and price these units in Mercury, it would be worth considering that some Mercury wetted units have so much Mercury in them that they splash if not mounted with the right orientation. I am considering mounting my boards vertically due to the large number of channels.
Petter
Hi,
For the Apox-1, it would probably be worthwhile to consider mercury wetted option for the series pass units, but I presume it would not be worth the effort in shunt mode. Thus, a few bucks could potentially do quite a bit of damage (not that I would know personally) 🙂
When you do go and price these units in Mercury, it would be worth considering that some Mercury wetted units have so much Mercury in them that they splash if not mounted with the right orientation. I am considering mounting my boards vertically due to the large number of channels.
Petter
confused
Petter or anyone else,
Can someone explain to me why people think that
the shunt resistors and/or relays are not as important as
the series pass elements.
I really think this is myth!
The shunt elements are just as important as the series pass elements. just develop a simple voltage divider formula,
and you will see that shunt impedance affects the outputs just as much as the series elements do.
-Craig
Petter or anyone else,
Can someone explain to me why people think that
the shunt resistors and/or relays are not as important as
the series pass elements.
I really think this is myth!
The shunt elements are just as important as the series pass elements. just develop a simple voltage divider formula,
and you will see that shunt impedance affects the outputs just as much as the series elements do.
-Craig
Craig,
There is a belief that components in series with the signal can affect the sound characteristics of the audio. The actual mechanism is not really understood, but some types of materials can create non-linearities and other distortions (phase, THD). That is why some resistors/caps are preferred over other ones. It is not because of their tolerance specifications.
So, Petter is not really talking about the difference between 100mOhms and 150mOhms.
Dale
There is a belief that components in series with the signal can affect the sound characteristics of the audio. The actual mechanism is not really understood, but some types of materials can create non-linearities and other distortions (phase, THD). That is why some resistors/caps are preferred over other ones. It is not because of their tolerance specifications.
So, Petter is not really talking about the difference between 100mOhms and 150mOhms.
Dale
Craig,
Adding to what Dale said, there is only one element in series with the input, and on the assumption that the distortion added by each element is cumulative.......
Regards,
Jam
Adding to what Dale said, there is only one element in series with the input, and on the assumption that the distortion added by each element is cumulative.......
Regards,
Jam
shunt vs series
What can I add? 🙂
I believe that if you add inductance or other parasitics, you will get more effect in the next stage because such stages are typically voltage driven. Moreover, the stage is loaded by the shunt elements. The shunt elements themselves are not per se loaded, and with phase shunting there is only one of them as compared with two (and in series!) for the pass elements.
Which brings up another point -- now that we have the opportunity to create more or less the same attenuation at different ranges, what is the optimal switching point. I have (and still do since I have no better ideas) subscribed to the notion of maximum energy transfer into the next stage. Another way to look at it is to use just about the smallest pass element. I think we should consider at what level one decides to move to the next range. The more I think about it, the more I believe the sequence should be something like this:
-30dB range used from zero volume
-20dB range does kicks in at some point after the first possible setting. If it switches immediately, a lot of energy is "lost" in the shunt element at the lowest setting on that range.
-10dB same as -20dB
0dB same as -10dB
Now, the optimal switchover point might vary from system to system depending on input impedance, output impedance etc.
Would it be possible to have a delay setting so people can choose how many dB's past the first possible transition the next range switches in. I would guess that 0, 1.5 and 3dB would be more than adequate. Is this hard to do? Is this something others would be interested in?
Petter
What can I add? 🙂
I believe that if you add inductance or other parasitics, you will get more effect in the next stage because such stages are typically voltage driven. Moreover, the stage is loaded by the shunt elements. The shunt elements themselves are not per se loaded, and with phase shunting there is only one of them as compared with two (and in series!) for the pass elements.
Which brings up another point -- now that we have the opportunity to create more or less the same attenuation at different ranges, what is the optimal switching point. I have (and still do since I have no better ideas) subscribed to the notion of maximum energy transfer into the next stage. Another way to look at it is to use just about the smallest pass element. I think we should consider at what level one decides to move to the next range. The more I think about it, the more I believe the sequence should be something like this:
-30dB range used from zero volume
-20dB range does kicks in at some point after the first possible setting. If it switches immediately, a lot of energy is "lost" in the shunt element at the lowest setting on that range.
-10dB same as -20dB
0dB same as -10dB
Now, the optimal switchover point might vary from system to system depending on input impedance, output impedance etc.
Would it be possible to have a delay setting so people can choose how many dB's past the first possible transition the next range switches in. I would guess that 0, 1.5 and 3dB would be more than adequate. Is this hard to do? Is this something others would be interested in?
Petter
I would like the volume control to have two modes:
Mode 1: A couple turns runs through all the volume positions. for the apox 1, that would be like 300 steps per turn (your encoder may not do that smoothly, but rather have to jump in 10 step steps).
Mode 2: Velocity sensing; turning slowly goes in single or small volume steps, turning more and ore quickly increases the step size for each step.
BTW: how is the remote volume control going to deal with the APOX1 vs. APOX2? The remote should go in single steps for the APOX2, but should cruise pretty fast through the steps for an APOX1.
Sheldon
Mode 1: A couple turns runs through all the volume positions. for the apox 1, that would be like 300 steps per turn (your encoder may not do that smoothly, but rather have to jump in 10 step steps).
Mode 2: Velocity sensing; turning slowly goes in single or small volume steps, turning more and ore quickly increases the step size for each step.
BTW: how is the remote volume control going to deal with the APOX1 vs. APOX2? The remote should go in single steps for the APOX2, but should cruise pretty fast through the steps for an APOX1.
Sheldon
I was planning on implementing mode 1.
I was thinking about mode 2 during my lunchtime jog. I think it can be done. I am just not sure how intuitive the control will be.
The last question is simply answered that we know which volume board is connected, and can make the apropriate changes. I also can detect how many input boards are connected...
Dale
I was thinking about mode 2 during my lunchtime jog. I think it can be done. I am just not sure how intuitive the control will be.
The last question is simply answered that we know which volume board is connected, and can make the apropriate changes. I also can detect how many input boards are connected...
Dale
balance control?
I would like to suggest that a "balance" offset be added so that a constant "db delta" can be set and maintained as the volume control is turned. This would simulate the balance control present in some pre-amps.
Just a few more lines of code, I would say, ;-)
I would like to suggest that a "balance" offset be added so that a constant "db delta" can be set and maintained as the volume control is turned. This would simulate the balance control present in some pre-amps.
Just a few more lines of code, I would say, ;-)
harvardian said:
I am currently using code that is speed dependent, so that when I turn the RPG faster, based on a defined threshhold, I have it increment my change variable (DELPRG) again if it was. This could easily be changed to make it increment more then 2 when turned fast. The threshold can be changed also.
The RateRPG is run every 10ms, and Volume += DELRPG....
--
Brian
PRICES ARE RISING!
Ahhh we need more orders!!
After Dale and I have actually gone out and started to
order all of the parts, boards, shipping costs, etc. we noticed that we underestimated some costs and are barely making any profit at all.
So to encourage more short term orders
starting May 1st, the introductory pricing will be ending.
Thanks for all of your support.
Dale and I are planning a nice surprise board to go with
the current APOX kit.
-Craig Beiferman
Ahhh we need more orders!!
After Dale and I have actually gone out and started to
order all of the parts, boards, shipping costs, etc. we noticed that we underestimated some costs and are barely making any profit at all.
So to encourage more short term orders
starting May 1st, the introductory pricing will be ending.
Thanks for all of your support.
Dale and I are planning a nice surprise board to go with
the current APOX kit.
-Craig Beiferman
Hey everyone,
Dale informed me that this is where all the discussions of
the APOX are. It took me a long time to read through all the
posts to catch up last night
I happen to live very close by to Dale, and got to take
a look at the APOX last weekend. 😎
I will definitley be buying one (APOX-2)!
It is very cool looking, silent switching, and has a nice feel
to it (remote and manual). The PCB layout is nice and clean.
Dale showed me how to type in text
(ex. CD PLAYER, INPUT2, etc) and navigate the control
knobs. Piece of cake!
Being a kit, any resistor curve you want can be used.
Oh yeah, it did sound good too! I didn't do any critical listening on Dale's or in my system yet, so I won't think about doing a review until I finish the kit. Poor Dale was trying to finish up some work and I was asking him all about cd player-volume control impedance matching, reed relay theory, etc etc so I had to give him a break!
😉
I am looking forward to building the kit and contributing with this group.
Regards,
Vinnie
Dale informed me that this is where all the discussions of
the APOX are. It took me a long time to read through all the
posts to catch up last night
I happen to live very close by to Dale, and got to take
a look at the APOX last weekend. 😎
I will definitley be buying one (APOX-2)!
It is very cool looking, silent switching, and has a nice feel
to it (remote and manual). The PCB layout is nice and clean.
Dale showed me how to type in text
(ex. CD PLAYER, INPUT2, etc) and navigate the control
knobs. Piece of cake!
Being a kit, any resistor curve you want can be used.
Oh yeah, it did sound good too! I didn't do any critical listening on Dale's or in my system yet, so I won't think about doing a review until I finish the kit. Poor Dale was trying to finish up some work and I was asking him all about cd player-volume control impedance matching, reed relay theory, etc etc so I had to give him a break!
😉
I am looking forward to building the kit and contributing with this group.
Regards,
Vinnie
Hi Vinnie,
Thanks for the good plug. Where do you want me to send your check? Just kidding. Actually, Vinnie has agreed to let me document his build. This will greatly help with the instruction manual.
Dale
Thanks for the good plug. Where do you want me to send your check? Just kidding. Actually, Vinnie has agreed to let me document his build. This will greatly help with the instruction manual.
Dale
Shameless plug on Pass forum
http://www.diyaudio.com/forums/showthread.php?postid=162654#post162654
Some readers here might get some ideas on how this thing can be used.
Petter
http://www.diyaudio.com/forums/showthread.php?postid=162654#post162654
Some readers here might get some ideas on how this thing can be used.
Petter
Re: PRICES ARE RISING!
Hi Craig,
I will definitely buy the User Interface Board!
I already sent email to your support address.
There you can find my email address.
I´m back in the office on wednesday.
Uli
PS: my 2cts:
maybe you add an independant tape out loop?
(-> 2nd set of input switch outputted before volume)
dipchip said:Ahhh we need more orders!!
After Dale and I have actually gone out and started to
order all of the parts, boards, shipping costs, etc. we noticed that we underestimated some costs and are barely making any profit at all.
So to encourage more short term orders
starting May 1st, the introductory pricing will be ending.
Thanks for all of your support.
Dale and I are planning a nice surprise board to go with
the current APOX kit.
-Craig Beiferman
Hi Craig,
I will definitely buy the User Interface Board!
I already sent email to your support address.
There you can find my email address.
I´m back in the office on wednesday.
Uli
PS: my 2cts:
maybe you add an independant tape out loop?
(-> 2nd set of input switch outputted before volume)
There is a new excel spreadsheet
for the APOX-1 rev. 3 😉
This spreadsheet is a little simpler, just change the resistors
and watch the graphs change right before your eyes.
You'll see the 4 seperate attenuation curves based on which
pass resistors you have switched in.
The values I currently have in the spreadsheet are just made up, with no attempt to optimize anything.
If someone would like to come up with an ideal set of resistors
please go ahead! The only 'gotcha' is the minimum input impedance. So basically when all of the pass resistors are in parallel, and the shunt resistors are muted. Make sure the input impedance is high enough for your system to handle it.
(You would probably want to stay above 5K Ohms)
I am still trying to think of the best scheme to use to have a smooth transition from 1 curve to the other. Unfortunately, I think this will be highly dependant on what resistors people choose. I may choose to have three jump values in the eeprom.
When you have exhausted the 1st graph, the controller will jump to the next curve with a binary offset stored in the EEPROM.
(Did I just confuse people
)
This offset could then be programmable from the front panel.
Another neat idea might be to somehow download all of the
resistor values to the APOX-1. Then this board could decide how
to switch in the relays for a much smoother dB steps.
-Craig Beiferman
for the APOX-1 rev. 3 😉
This spreadsheet is a little simpler, just change the resistors
and watch the graphs change right before your eyes.
You'll see the 4 seperate attenuation curves based on which
pass resistors you have switched in.
The values I currently have in the spreadsheet are just made up, with no attempt to optimize anything.
If someone would like to come up with an ideal set of resistors
please go ahead! The only 'gotcha' is the minimum input impedance. So basically when all of the pass resistors are in parallel, and the shunt resistors are muted. Make sure the input impedance is high enough for your system to handle it.
(You would probably want to stay above 5K Ohms)
I am still trying to think of the best scheme to use to have a smooth transition from 1 curve to the other. Unfortunately, I think this will be highly dependant on what resistors people choose. I may choose to have three jump values in the eeprom.
When you have exhausted the 1st graph, the controller will jump to the next curve with a binary offset stored in the EEPROM.
(Did I just confuse people
)This offset could then be programmable from the front panel.
Another neat idea might be to somehow download all of the
resistor values to the APOX-1. Then this board could decide how
to switch in the relays for a much smoother dB steps.
-Craig Beiferman
APOX-3 schematic rollout
The APOX-3 schematic is now available to the general public.
Please tell me what you guys think?
I am now also working on a X-BOSOZ board with optional active or passive current source, and optional X circuit to complement
the APOX boards with a matching power supply. Is this something people would want?
Thanks,
Craig Beiferman
The APOX-3 schematic is now available to the general public.
Please tell me what you guys think?
I am now also working on a X-BOSOZ board with optional active or passive current source, and optional X circuit to complement
the APOX boards with a matching power supply. Is this something people would want?
Thanks,
Craig Beiferman
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