I'd think curve matching parts would be far more beneficial than simply matching with a meter. But nobody's really equipped to do that.
I think the basic idea for the F6 was to use exactly the same parts for both output devices,
and use a transformer for the necessary polarity inversion.
Well the project is on hold; wanted to order the PCB + transformer but that was already sold out before I woke up (took somewhat longer than blinking,. . )
Anyway - yes I have closely matched K55's. (four pairs).
And I have the matched FETs.
And I have the chassis from my F5.
Jensen is unobtainium in Europe.
What Lundahl transformer is advised?
Anyway - yes I have closely matched K55's. (four pairs).
And I have the matched FETs.
And I have the chassis from my F5.
Jensen is unobtainium in Europe.
What Lundahl transformer is advised?
I was thinking about ordering these Vishay 1.3W 100mA units:
1N4739A-TAP Vishay Semiconductors | Mouser
Thank you .. Was intending Dual mono.
Whilst Dithering the last few boards/txs sold out.
No matter ..I can wait, as if there was choice 😉
Questions; What were those alternate 'cheaper' tx's that Nelson suggested wayyy so many posts past (and I can't relocate)
What's the purpose of buying Matched Jfets then.. If any?
No one has considered relocating their Torroids to a seperate Box(s)??
The diyAudio board only works with the Jensen transformer.
You can also buy them direct, with either pcb or leaded termination.
Do you have a Model # for those Cinemag transformers (post #228)
OK found it:
CineMag cmoq-4hpc (which is pcb mount/ special order, Leads version is in stock)
No idea on pricings.. yet.
Considering a point to point build of this rascal... clever or not.
Easier than waiting 🙂
Hmm.. dual outboard..Smps's (or PSU's for that matter) allows for an inexpensive Bespoke Box of markedly smaller volume, with 'pretty' Folded Copper Sheet heatsinks,
lotsa imaginary notions.
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Are there any available that are more than 100mV? I am collecting parts now.😀
Russellc
Order PCB+ Jensen when they return to the store. The PCB only fits Jensen.
There will be 60 more PCB+Jensen kits to the store in about 2 weeks. And then that's it for awhile, until PCB production arrives, in 6-8 weeks.
Russel,
Buy this one. Save your time for the expensive decisions. 😉
1N4739A Fairchild Semiconductor | Mouser
Buy this one. Save your time for the expensive decisions. 😉
1N4739A Fairchild Semiconductor | Mouser
It's 100mA, not mV.
A quick search at Mouser turned up this 200mA device, though they are out of stock.
1N4739A-B Rectron | Mouser
Is there any particular reason(s) why the Vishay diode, I linked to in post 784, will not work?
Are 200mA diodes really required for this amp?
That one's only 28mA.
Perhaps someone smarter than myself can chime in on what will or will not work.
boys , 100mW part will work perfectly fine
little analysis can't harm
current through it is here : (Urail - Uzenner)/10K
so , say , 14V/10K=1.4mA , resulting in bloody 1.4mAx9V1=12.74mW of dissipation
that's what one can call power de-rating factor
all that according to schm in attached file , or schm in post #1 on this very thread
little analysis can't harm
current through it is here : (Urail - Uzenner)/10K
so , say , 14V/10K=1.4mA , resulting in bloody 1.4mAx9V1=12.74mW of dissipation
that's what one can call power de-rating factor
all that according to schm in attached file , or schm in post #1 on this very thread
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I have no idea (well do now that Zen mod cleared it up) he just said "at a minimum" so I assumed there may be stronger choice is all.
Russellc
Russellc
Remember that Zener diodes are noisy and less stable if operated at too low a bias current. You need at least
around 5% or more of the maximum current (Pd max/Vz) to begin to get away from those problems.
A 400mW diode may not work as well for this purpose as the 100mW diode.