Hi Dustin,
Hi Russ and Brian
Bravo for this new board! It really is neat work, layout is impressive! It should be a killer, no doubt!!!
I'll be happy to hear more about the IVY2. What's inside? What's different? What more/Less? When will IVY II be available (I'd like to get a couple channels).
I'd also like to know why you settled for an integrated THS4131, and not use AD797s as ESS did on their demo boards. Is it better, or just cheaper/more compact. As it's an integrated chip for the two channels, there should be less mismatching between the opposite sides of the signal - thus, less 2nd harmonic distortion. Resistor mismatch remain, but you'll of course use thin film precision resistors, so I feel confident about that.
Well, I just want to know more about your new IVY!!!!
(post modified as requested)
I would bet the 2/3rds of the SO8 you see are for power regulation.
Hi Russ and Brian
Bravo for this new board! It really is neat work, layout is impressive! It should be a killer, no doubt!!!
I'll be happy to hear more about the IVY2. What's inside? What's different? What more/Less? When will IVY II be available (I'd like to get a couple channels).
I'd also like to know why you settled for an integrated THS4131, and not use AD797s as ESS did on their demo boards. Is it better, or just cheaper/more compact. As it's an integrated chip for the two channels, there should be less mismatching between the opposite sides of the signal - thus, less 2nd harmonic distortion. Resistor mismatch remain, but you'll of course use thin film precision resistors, so I feel confident about that.
Well, I just want to know more about your new IVY!!!!
(post modified as requested)
sangram said:
I would bet the 2/3rds of the SO8 you see are for power regulation.
A couple of design notes...
Thanks folks for the kind comments.
1) The Buffalo32S is the stereo version. There is an 8 channel version coming (shortly) as well , but with no integrated I/V
.
2) Not everything that looks like an op amp on the board is an op amp.
3) I am now using the OPA1632 not the THS4131 because I found that it actually does perform better.
4) I am using the fully symmetrical op amp in a unique way, at least I have never seen it before. It applies feedback to OCM to make SE output as effective as balanced output. You can use this board SE or balanced with no penalty. You just may need to adjust gain.
I have no problem with the AD797, its just that now that I know how to use it well I prefer the OPA1632 especially because it is so simple to set the common mode voltage. It has a lot going for it.
Some details you can't see in the picture. This is intentional.
AVCC is supplied via the same PS as the I/V stage on each side. And they are separated (unless you choose to use the same supply on both sides).
Cheers!
Russ
Thanks folks for the kind comments.
1) The Buffalo32S is the stereo version. There is an 8 channel version coming (shortly) as well , but with no integrated I/V
.2) Not everything that looks like an op amp on the board is an op amp.
3) I am now using the OPA1632 not the THS4131 because I found that it actually does perform better.
4) I am using the fully symmetrical op amp in a unique way, at least I have never seen it before. It applies feedback to OCM to make SE output as effective as balanced output. You can use this board SE or balanced with no penalty. You just may need to adjust gain.
I have no problem with the AD797, its just that now that I know how to use it well I prefer the OPA1632 especially because it is so simple to set the common mode voltage. It has a lot going for it.
Some details you can't see in the picture. This is intentional.
AVCC is supplied via the same PS as the I/V stage on each side. And they are separated (unless you choose to use the same supply on both sides).
Cheers!
Russ
Brian:
Well, copied the design...
First, I will probably won't have any spare I/V boards, and if I have any, they will probably go to friends.
Second, I can't tell how it compares before having tested it, simply. I was just curious about your "why", and how you improved it. Sorry for making electronic stuff, not just buying DIY kits.
Third, it's a transconductance amplifier, these are simply opamps with one resistor to the negative feedback. Plus the chip removes DC.
I can't really admit it as a ripoff, components around the chip aren't even exactly the same - if I would have copied your design, I wouldn't have added optional pi filters on input and output - just to test things. I would just have copy/pasted it. And If I wanted to rip off a design, why wouldn't I have simply took ESS's guide schematics? There even is a view of the implementation with smd (as I only work with smd), I wouldn't even had to use my brain to find a layout!
I hope you didn't meant I ripped off your design. Probably I don't have your level and asked some incredibly lame questions on this board, but I completed an electronics degree, that -hopefully! gave me more than enough to understand an inverting amplifier.
Anyway, I'll leave this thread. I always stressed I was not competing with you, I even told people that may want my boards to use them with your boards around them - yes, I even said to use... IVY for output.
If you want me to remove any reference to your work from my thread, just ask a moderator to do so as I can't edit the posts.
Russ: Thanks.
Cheers,
Nicolas
Well, copied the design...
First, I will probably won't have any spare I/V boards, and if I have any, they will probably go to friends.
Second, I can't tell how it compares before having tested it, simply. I was just curious about your "why", and how you improved it. Sorry for making electronic stuff, not just buying DIY kits.
Third, it's a transconductance amplifier, these are simply opamps with one resistor to the negative feedback. Plus the chip removes DC.
I can't really admit it as a ripoff, components around the chip aren't even exactly the same - if I would have copied your design, I wouldn't have added optional pi filters on input and output - just to test things. I would just have copy/pasted it. And If I wanted to rip off a design, why wouldn't I have simply took ESS's guide schematics? There even is a view of the implementation with smd (as I only work with smd), I wouldn't even had to use my brain to find a layout!
I hope you didn't meant I ripped off your design. Probably I don't have your level and asked some incredibly lame questions on this board, but I completed an electronics degree, that -hopefully! gave me more than enough to understand an inverting amplifier.
Anyway, I'll leave this thread. I always stressed I was not competing with you, I even told people that may want my boards to use them with your boards around them - yes, I even said to use... IVY for output.
If you want me to remove any reference to your work from my thread, just ask a moderator to do so as I can't edit the posts.
Russ: Thanks.
Cheers,
Nicolas
Nicolas, Don't worry. Everything is fine.
I expected people to start investigating and using some of the ideas I have laid out or I would not have done it in a public forum.
I don't claim to be doing anything that could not be done by spending a few minutes with a datasheet or a book or two.
I am fine with your DIY project and in fact encourage it.
What I think Brian was reacting to was just that you chose to talk about it on our vendor thread. Maybe the more generic ESS thread would have been more appropriate.
In any case I really hope your project works out well for you.
Cheers!
Russ
I expected people to start investigating and using some of the ideas I have laid out or I would not have done it in a public forum.
I don't claim to be doing anything that could not be done by spending a few minutes with a datasheet or a book or two.
I am fine with your DIY project and in fact encourage it.
What I think Brian was reacting to was just that you chose to talk about it on our vendor thread. Maybe the more generic ESS thread would have been more appropriate.
In any case I really hope your project works out well for you.
Cheers!
Russ
Really, let's not go there. My post sounded a little terse as I posted it before my morning coffee. Sorry about that. I assumed it was a copy of the Ivy because you refer to it as "basically the same thing, some slightly different stuff." I can be a little grumpy first thing in the morning, and should know better than to post so early, it always comes out wrong.
Your boards look nice. Honestly, even if it were an exact copy of something we did (it is not), I wouldn't have a problem with it, as you did it for yourself. That's what DIY is all about.
That said, our Vendor thread is probably not the best place to offer your extras for sale, but NO BIG DEAL. Really.
Thanks Russ.
Boy, that was a fast reply. Actually I was planning on editing the question and You had already answered. I went back to the older pages and rossl had reported having used these.
Panasonic ECQ-P(Z) polypropylene film caps at DigiKey.
http://dkc3.digikey.com/PDF/T083/P1686.pdf
WIMA FKP2 at Mouser.
http://www.mouser.com/catalog/636/835.pdf
Dinesh
Boy, that was a fast reply. Actually I was planning on editing the question and You had already answered. I went back to the older pages and rossl had reported having used these.
Panasonic ECQ-P(Z) polypropylene film caps at DigiKey.
http://dkc3.digikey.com/PDF/T083/P1686.pdf
WIMA FKP2 at Mouser.
http://www.mouser.com/catalog/636/835.pdf
Dinesh
khundude said:
No...
We are still debating what to include on this board, and what to leave off. The I/V stage will definitely not be on it.
But, for example, do we include vregs (less flexible), or leave them off (more user work required), or include them but make them bypassable (possibly wasted, less ideal routing), etc.
These are the kind of thing we are working through. Make it flexible, but still functional, and vice-versa.
mikelm said:
Hi Mike,
That's good question. It is a prototype of the new IVY. Basically it is an old Ivy reconfigured to test my ideas for the new IVY II. It not exactly the same as the new IVY II. In a lot of ways the IVY II should be better. Especially the integrated version as everything will be very tight.
Cheers!
Russ
compromise
I have an idea that would probably satisfy Russ/Brian and some customers.
The most difficult part to on the board is the ESS chip. I think it is not possible to solder it with a normal iron.
I would be happy if I could buy an old buffalo board with just the new chip and the programming chip on it, nothing else. This is no work for you, because you could simply order old boards.
This solution came into my mind, when I removed all the parts I don't want on my present board:
I replaced the smd condensers with Rubycons, removed the opamp and reg1 because of a battery supply (report is yet to come).
All the other parts are not difficult to solder.
I would like to stress that the reason for my request is not to save money. I just don't like to remove parts that have just been put on the board.
Thank you
Andre
BrianDonegan said:
I have an idea that would probably satisfy Russ/Brian and some customers.
The most difficult part to on the board is the ESS chip. I think it is not possible to solder it with a normal iron.
I would be happy if I could buy an old buffalo board with just the new chip and the programming chip on it, nothing else. This is no work for you, because you could simply order old boards.
This solution came into my mind, when I removed all the parts I don't want on my present board:
I replaced the smd condensers with Rubycons, removed the opamp and reg1 because of a battery supply (report is yet to come).
All the other parts are not difficult to solder.
I would like to stress that the reason for my request is not to save money. I just don't like to remove parts that have just been put on the board.
Thank you
Andre
khundude said:
1) That's a given. The "Tweakers" board will allow all input and output options.
2) That's tricky. Because you truly need to plan for good voltage regulation. You cannot add it as an after thought. The best approach in my opinion is to apply a proven practical approach that proves performance within specification.
3) That's also tricky because as I have learned through the "school of hard knocks" you absolutely must take care of the routing of the current out of the DAC and into the I/V stage. I have an excellent solution, but it does not lend itself to tweaking.
4) define "best".
5) What should it do?
6) define "best"
7) Those who want to leverage my experience will be glad I took the time to add one.
But as we said there will be a tweakers board without one.8) Agreed. One overriding concern has to be practicality. Some things simply can't be done as well off the PCB. This I have learned the hard way.
We value your input. We strive to provide a platforms for both experimenting (read DIY fun) and full on performance. What you get out of it is completely up to you.
Cheers!
Russ
Re: Buffala32 thoughts and design considerations
I am interested in both but would probably opt for #2 with external IVY IIs on 2x2 channels and a more simple output stage on remaining 4 channels that could be bypassable and default on all channels.
Any news on those FIR-functions that may be used for XO-design, will it be feasable to do 80 Hz?
Russ White said:
I am interested in both but would probably opt for #2 with external IVY IIs on 2x2 channels and a more simple output stage on remaining 4 channels that could be bypassable and default on all channels.
Any news on those FIR-functions that may be used for XO-design, will it be feasable to do 80 Hz?
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