F5X -- the EUVL Approach

[EUVL]

Yes.

Patrick

 

[iiee3602]

hi apex send me calculation of transformer using EI core and toroidal core. thanks! send it to iiee3602@yahoo.com

 

[qusp]

i think you posted in the wrong thread iiee3602

 

[Nikon1975]

I have a question about the BOM:

Is the Idss of the JFET specified at 10V 25C ?

Thanks,

Davide

 

[EUVL]

Depends.

In the standard version, the FET will see about 13V at Idss.
So if you want to be exact, this would be the working condition you need to match at.
(For the P-JFET with 5R degen.)

But room temperature match at 10V is close enough for most.


Patrick

 

[Nikon1975]

Happy New Year to our Chinese and Hong Kong members.

Davide

 

[EUVL]

Davide,

Many thanks on behalf of them, but you are actually one day too early.
Chinese New Years day should be 23 Jan 2012. 😉
But Mark & Co are already not reachable by email till end of January.

Here also picture of a Chinese Dragon, which is a bit different from its European counterpart.


Patrick

 

[EUVL]

For the case subscribers, the cases were actually all packed ready to ship by Thursday.
But the bank transfer from John had not arrived.
So we all agreed that they would be shipped when Mark comes back, which will be 2 Feb.


Patrick

 

[pdhanwada]

EUVL,

Can you point me to the documentation related to F5 bridging.

I am trying to understand if I can use it in my situation.

forgive my ignorance. I see that in the balanced version, we can make it work like bridged amp. Is that true.

If my preamp has output of 3v rms, and has rca outputs, can it be used.

Thanks
pandu

 

[EUVL]

The F5X as described in this thread, in the floating X configuration, is straightly speaking a fully differential amplifier as opposed to a bridged amp using 2x single ended amps. The grounded X configuration, however, can be considered as a bridge amp.

> If my preamp has output of 3v rms, and has rca outputs, can it be used.

Again in theory you can use the floated X configuration with RCA inputs. But for optimum performance, we strongly recommend fully balanced inputs.

RCA inputs however will not work with the Grounded X configuration. You need to use a single ended to balanced converter, such as e.g. a Phase Splitter.

Eventually when fitzfish is ready to start his build & test thread, the issue for using RCA inputs as well as the performance under these conditions would be described in detail.


Patrick

 

[EUVL]

A further update.

The revised protection board has been fully tested, including thermal tests, without issues.
I'll let Alexis give you the details himself.

Give it a few more days, and we'll let you know about GB for the PCBs.
Component GB you need to organise yourselves, I am afraid.

Schematics and BoM of the protection will follow tomorrow (from me).


Patrick

 

[ashaw]

Thanks patrick, Yes it all works as expected, here are some photos to do you guys over until the BOM and schematics are published tomorrow.

I look forward to posting details on a component GB soon if people are interested, also those who have already paid for a component kit, PM me, and I will arrange shipping with you.

Thankyou everyone for this amazing opportunity to serve this amazing community.

------
Alexis

 

[buzzforb]

I do not recall publishing a regulator using 2SJ201 ??

But in any case, you can pretty much use any MOSFET in those positions.
Only two factors need to be consider :

1. The Vgs at operating current will determine the minimum voltage drop.
2. The transconductance will determine the output impedance.


Patrick

I was speaking of the F5x using 2sj201 and its counterpart.

 

[Nikon1975]

We will have some fun in soldering that little chips 😱

D.

 

[ashaw]

Compared to what I am used to. Not that little. There is only one actually hard to solder part on this board. And that too is relatively easy.

Regards

 

[reytnz]

i'll PASS , that's beyond my soldering skills😉

 

[EUVL]

A few years from now, you would have no choice.
The industry will not produce through hole components for hobbists.
And the entire industry, even for prototyping, will move to SMD, because production cost is less.


Patrick

 

[qusp]

not the sot-143? or the soic14? guys you really just gotta give this a go, its really not hard with the proper tools, at least everything here has leads. ashaw, will you be releasing one of these types of boards for the DIYA store version? sorry if youve covered this already. i remember we talked about this some time ago, but not sure how that progressed

its not just production savings, performance is more often than not superior as well

 

[EUVL]

This board is tailored for the F5X case and as such is considered not universal enough by the forum. For them serving 30 case subscribers is not interesting and too much effort, so the protection board will only be available through us in a GB, primarily for case subscribers. We of course welcome all, but there will be a "normal" version later on in the year for general use. Also please bear in mind that these are Beta boards, and there might be a very small change of error or imperfections. So the first GB will receive subsidised prices. The protection board will only be available from us, not from DIYA.

Also just to clarify things, while we thank Alexis wholeheartedly for his excellent work on the board, like many others from this volunteer team that does the F5X work, including John, Greg, Fred, Heinz1, ..... they are NOT part of XEN Audio, and their involvements are limited to the F5X project only. Other than MarkLai & I, all team members of XEN will remain anonymous.

The schematics of the protection board belongs to us (XEN Audio), the layout to Alexis, who has also done all the testing. After the Beta testing, we shall discuss with him to purchase the right of the layout from him also, in which case we have 100% ownership.

Hope this is all clear.


Patrick

 

[EUVL]

As promised the schematics of the protection & control PCB.
All credits to Alexis.


Patrick