@ vacuphile
You may use MUSES chip even in a passive preamp, but you should be aware that its resistance tolerances from 14-20 kOhms will vary its predictable output impedance a little bit too much. IMHO it needs a high impedance active load like a buffer or gain device.
@ ilardi
If you ever will have luck to buy a single chip: you must be very skilled with SMD-soldering because pin distance is only 0,65 mm = 25,59 mil !!
You may use MUSES chip even in a passive preamp, but you should be aware that its resistance tolerances from 14-20 kOhms will vary its predictable output impedance a little bit too much. IMHO it needs a high impedance active load like a buffer or gain device.
@ ilardi
If you ever will have luck to buy a single chip: you must be very skilled with SMD-soldering because pin distance is only 0,65 mm = 25,59 mil !!
yes, but if they are a full blown and obvious commercial project, not a development by the community, they are rightfully, supposed to be … in the vendors section where they can have a free thread to advertise their wares, which is pretty sweet if you ask me. this part of the open forum is not a free advertising space. whether you see a problem with it or not, it is against the rules of the forum.
some start out as an amateur diy project, are contributed to by the community, PCBs offered at cheap prices etc and when they become popular and more commercial, they are moved to the vendors section. some commercial products/modules are bought by members of the forum and considered a suitable or worthy design for discussion, or utilisation/modification by diyers. if they are mentioned by others, threads started etc by customers who do not have a stake in the sales, fair enough.
others, like this, are already products for sale at a profit, not a community project, design decisions are already made, rather than being discussed and developed openly and critiqued by the community and the designer sneaks in a free advertisement.
this is not the place for the latter and that is not my opinion, its the rules.
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Till today I could not see any price offers, therefore I wonder about your consistent comments in this direction.
E.g. in thread (it started in “Digital Line Level”-forum as announcement for a Group Buy)
http://www.diyaudio.com/forums/quan...dac-end-r-es9018-full-assembled-board-21.html
you have obviously a different meaning, at least untill your comments #157 & #170 ( I am to lazy to go through whole thread).
Now this DAC-thread is moved to Vendour Forums – who ever did this.
But if a moderator will shift MUSES-thread to Vendour Forums, it’s up to him to do so.
E.g. in thread (it started in “Digital Line Level”-forum as announcement for a Group Buy)
http://www.diyaudio.com/forums/quan...dac-end-r-es9018-full-assembled-board-21.html
you have obviously a different meaning, at least untill your comments #157 & #170 ( I am to lazy to go through whole thread).
Now this DAC-thread is moved to Vendour Forums – who ever did this.
But if a moderator will shift MUSES-thread to Vendour Forums, it’s up to him to do so.
no, I do NOT have a different meaning. there are no price offers, because its free to have a thread in the vendors forum (1 thread), so there is not even that excuse.
yes, his board is in the vendors forum where it should be, he broke the rules of the forum also and it was moved there when reported. (he already knew the rules, or had at least been made aware of them more than once previously, but paid no attention) using him as an example is not doing you any favours … he sometimes seems easily confused ...
read the rules and please comply with them, dont expect to just break them until found out and make the moderators clean up after you, comply with them and in the spirit of the forum, do not use it for free commercial advertising.
yes, his board is in the vendors forum where it should be, he broke the rules of the forum also and it was moved there when reported. (he already knew the rules, or had at least been made aware of them more than once previously, but paid no attention) using him as an example is not doing you any favours … he sometimes seems easily confused ...
read the rules and please comply with them, dont expect to just break them until found out and make the moderators clean up after you, comply with them and in the spirit of the forum, do not use it for free commercial advertising.
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There's now a thread in Vendors,
http://www.diyaudio.com/forums/vendors-bazaar/239997-akouo-muses-adda-module-diy.html#post3577662
http://www.diyaudio.com/forums/vendors-bazaar/239997-akouo-muses-adda-module-diy.html#post3577662
I am looking at settings, and it seems you can set independently gain and attenuation.
However I don't understand if signal still passes through an op amp or not.
Block diagram doesn't even show the internal gain-stage.
Moreover I can see two section of wipers, one is 10K and the other 20K.
I don't understand why two different set of attenuators.
BTW wayne...I meant to do it before but then I forgot....I wanted to compliment you and Nelson for the new XS design.
It is pretty awesome line of products!!!
Good job you guys!
I see!
The block diagram won't show any internal opamp! However if you can set a positive gain that means there must be some sort of active circuitry.
But maybe the positive gain set is related to the test circuit 4 where resistors are connected in a non inverting configuration with external opamp..that would make some sort of sense!!!
JCX, I don't like some usual claims and I suspect you might agree with me in this case. The best opamps are baked on a sliver of silicon, although discrete designs can be very good as well (has the SWOPA been built and evaluated already? Scott's measurements of the prototype looked impressive).
In this case there is the added complexity of impedance matching between inverting and non inverting inputs. The on board opamp of the Ti chip will be optimized to work with inbalanced plus and minus; an add on opamp likely to be used behind the MUSES chip is not of that variety; I only know the OPA211 as an opamp that explicitely mentions in the specsheet that it is internally compensated for input impedance mismatches. And then there are the issues of thermal tracking and that the best connecting wire is the shortest one. Just three good reasons why I would generally like the opamp in a PGA to be integrated in the package.
B.t.w., the Ti chip with opamp has better specs than the MUSES chips without, where the required buffer stage will always add some further artifacts.
Anyways, the point I originally wanted to make is that MUSES starts with the 'M' of marketing for a reason. It caters to all of those who are sensible to the boutique value of parts.
