I am glad you are still in the loop. There was time you were interested in MOSFETs instead of R100s. Did you abandon this potential changeover? What is is the future direction of diyF6? It seems that dual PSUs are for the time being per the recent threads? The Vbe of a power Darlington is ~ like that for Vgs of R100. Is a Darlington a justifiable way to proceed in light of the scarcity of R100?I am still here, watching for rare pearls of wisdom.
Best regards
Why not use IRFP240? Or Fairchild 16N25 that you can get from buzzforb.
The information on the (minor) changes it takes to use those devices is in this blog post-
http://www.diyaudio.com/forums/blogs/tea-bag/941-f6-clone-convertible-pcb-blog.html
Thanks 6L6. I already have Tea-Bag's PCBs; they are impressive and NASA quality. And I am looking forward to buzzforb's kit for diyF6. Allow me to stir up this pot further. DiyF6, diyF5, and diy BA3 Front End use the familiar SK/SJ pair. Their use is by far the simplest and most elegant /practical approach. But the future of this SK/SJ pair is uncertain, costly and forcing our supplying diyers to match'em up. It is time to consider using other readily available alternatives. BUF634 and LH0002 are potential candidates; plus your choice of others. The future of diyF6 is bleak. Its principal semiconductors can only become scarcier and more expensive. Aside from Mr. Pass, the only diyers who are known to have diyF6 are Zen Mod, lhquam, flochinni, generg, Tea-Bag and buzzforb. Needed are new pcbs for the aforementioned diys amps to flow with this changing world of diy semis.
The Linear J74 is real. It's just not to solid production yields yet.
Although I agree with you concerning the R100, the Jfet input pair is only going to have more availability in the near future. We currently are in the drought before the rain.
Other output devices fork for the F6, and according to the people who have built it, the magic is in to topology, not necessarily the power fets.
That is true, but only because the rest of us are all waiting for transformer group buys.
A fantastic idea! Can we nominate you to spearhead that? I'm sure there are people who know PCB layout who are very willing to help. Just ask.
So far I am only seeing the perils of part extinction.
so you are a chain of pearls......
It is getting away from the original design in some ways, but i thkn mulitple pairs of Exicon laterals would be very interesting. I tried the laterals in my first iteration and continue to like them. You will simply have to parallel them to get the current and gain capability up. THis is assuming that you need it, as I believe they would fit into the FW mold as they are. I am listening to a bjt based amp, the TSSA, that uses them and they sound wonderful. I will probably use them in my M2 attempt. THey have the benefit of having a temp coefficient that allows dumping of the Rs. In this as well as in their tendency towards better linearity, they have similar potential.
Plus,its not the parts. I believe Nelson using mosfets was a bit of a step away from the norm. Heading back to the swine pen for a while.
Plus,its not the parts. I believe Nelson using mosfets was a bit of a step away from the norm. Heading back to the swine pen for a while.
Just a matter of ordering them from Profusion. Little expensive, but great deal less than SS.
Two I would recommend.
ECW20N20-Z
ECW20P20-Z
Two I would recommend.
ECW20N20-Z
ECW20P20-Z
I wrote:Needed are new pcbs for the aforementioned diys amps to flow with this changing world of diy semis.
6L6 replied: A fantastic idea! Can we nominate you to spearhead that? I'm sure there are people who know PCB layout who are very willing to help. Just ask.
Thank you for your confidence in my idea. DIYers practice different types of DIY'ing. My shared ideas are my form of DIY'ing. I also share novel schematics. Still I must leave the future pcbs to the experts like Tea-Bag. lhquam, and others. They have the right stuff.
Best regards
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6L6 replied: A fantastic idea! Can we nominate you to spearhead that? I'm sure there are people who know PCB layout who are very willing to help. Just ask.
Thank you for your confidence in my idea. DIYers practice different types of DIY'ing. My shared ideas are my form of DIY'ing. I also share novel schematics. Still I must leave the future pcbs to the experts like Tea-Bag. lhquam, and others. They have the right stuff.
Best regards
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The main issue with the Cree is the temp coefficient. It wil not allow for low or no Rs on the outptut fets. I ebelieve it may be a better alternative than IRF. It will get closer than the Exicon on the gain/Yfs front, but I personally feel that the dropping of Rs is one of the things that defines the sound of this amp. I am working on an output board for the Vfet's. We will try 2sk82 first.
droppin' or not , look on it as part's transfer curve altering tool ; for SJEP , we don't need it tempco wise , and possibly that we prefer transfer curve without them
for any other part - you either need Rs or not , tempco wise , but what's happening with final transfer curve , is still for test
for any other part - you either need Rs or not , tempco wise , but what's happening with final transfer curve , is still for test