F5X -- the EUVL Approach

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nope not the first or last, most all ackos pcbs are curvy and where important they will probably continue to be, its second nature to rf engineers, but possibly not quite as important for analogue audio anyway. great work Fitzfish, i love curvy pcbs!! look forward to it and thanks for all your hard work!!. they look sweet and are for sure built for speed

bold added, because i'm speaking out my ***, wouldnt personally know anything much about rf, perhaps it helps with eddie currents? i also didnt know it was so much hard work. i look forward to hearing more about the build so i can start planning for it. i'll have to shoot dave a pm, where should we direct posts about making the build work with other cases? will this take the form of another thread when the time comes? or wil we still try to keep info on this pcb set central? just so i know where the line is
 
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First we need to make the PCB available. And then we'll publish the Bill of Material for the standard circuit, as well as dimensions of the PCB mounting. You can start collecting parts then. The dissipation of the amplifier is well known. So you can order the right heat sinks.

The rest is internal layout inside the case, which is all personal taste. I am only going to illustrate one example here according to my taste. There are many ways to do the same, but that topic does not belong to this thread. You are of course welcome to start a new thread like "Internal Layout of a Dual-Mono Class A Amplifier" ...

The testing and evaluation / comparison of further circuit configurations will be done one at a time and published sequentially when the results are available and mature. So we will not publish diaries of the tests.


Patrick
 
ok no problems, will wait for the published layout and proto results and direct any questions that relate to the building, operation of the amplifier circuit and set up if i have any to the build thread when its started, but mechanical issues really arent too much concern, because the same parameters and concerns apply for pretty much any build. i'm mainly meaning biasing intricacies that may be peculiar to this version of the amp and certain parts choices and values that may assist in gaining the best performance
 
you didnt specify that, you just said on the forum and the first designs published or rather shared that i saw using them were well before he had a website. please do not make this into something it wasnt, it was simply me mentioning that you statement as read was incorrect, just as you would have done. it was not one upping anyone, i think its excellent that the pcbs are like this and kudos to anyone who can produce such a thing
 
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A member asked me a few questions that I thought might be of interest to others.
I hope he would not mind me putting his questions here without asking.

1) why choose the F5 to balanced it? Why not the Aleph J?

I have both. So how should I answer your question....
I have both a Porsche and a Ferrari. I like both.
They are different, but also nice in their own way.

2)Is the meaning of F5X 'balanced' the same as 'symetrical' as in Nelson's 'X' amps series (SuSi)?

Yes, it has a cross-coupled feedback.
But Nelson did mention once that he believes the distortion cancellation mechanism is different.

3) What is the main benefit in balancing this F5?

More power, less distortion.

4) I am sure you are capable of designing an amp which would be very good or may even rival Nelson's amp, why not choose to do your amp and make the schematic available and benefit us forum members?

It was a project I did in 2008. Some people kept asking me for PCBs by PM. In the end I gave up and promised to make it available to all.

The next projects I shall be publishing would be my own design.
But they are difficult projects and not for beginners.

And BTW, I have published many of my designs already.
Like the DAO headphone amp loved by all who cared to build it, a 2-stage Xed-circlotron, Xed JLH Class A, .....
But then I am not Nelson. So people don't think much of those designs.

:)

5) Will you show us step by step in working out this F5X amp until the amp is fully complete and in working condition or will you just leave after all the GB is complete? In other words, will you help us in completing this F5x amp?

I have promised to help 3 selected (very experienced and very well equipped) members to build all configurations (6 at least) of prototypes. They will then be reporting their experiences and impressions, and answer questions. I don't make a living from audio, so I cannot possibly have the time to answer all your questions to your satisfaction. That is why there are the 3 of them to relief me of that burden. I shall only jump in when they also need help.


Hope you find the answers satisfactory,
Patrick

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Regulator MOSFET GB

According to information from AndrewT, the MOSFETs are on their way back to Zhoufang in Singapore. Although they are insured against loss, the claim has to be done by the sender (Zhou). Since we have not heard from him for quite some time now, I have made a post at his sales thread.

Hopefully we can have a response before too long.

http://www.diyaudio.com/forums/vend...ted-but-hard-get-they-here-5.html#post2548260


Patrick
 
For regulator GB'ers :

I have heard from Zhou. Instead of paying him 25USD extra for sending the MOSFETs to UK again, and run through the same ordeal with the Royal Mail, I made the decision to have them sent to Mark Lai (together with other stuff we ordered from him private, so no extra cost other than a few USD insurance).

That means Mark Lai will have to take over the matching and then distribute later to you direct.
Hope you are OK with this decision, Andrew.


I shall keep you informed when I have more,
Patrick
 
I am about to pull the trigger on a pair of Sumr Toroids. I really don't know what the specs are to even try to find alternative vendors, but after looking through the thread and asking fitzfish I contacted Sumr and they gave me a quote of $333 shipped for 2 of RC0600 915 5. If this is the ones correct for this build, let me know.
Thanks,
Bryan
 
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