I all ready have the transformer for my build. It's a 600VA Antek.
However, I am getting enough interest in this project from my friends (even before it's built...) that I am sure I will build another. Most likely I will have 2 transformers and 2 PSU boards for the exact reason I mentioned above - being able to tune the amount of capacitance easily. Peter's PSU boards only have room for 2 caps per rail, and as they are really nice boards, I will use them again.
Thanks for the link - their product looks very nice!
However, I am getting enough interest in this project from my friends (even before it's built...) that I am sure I will build another. Most likely I will have 2 transformers and 2 PSU boards for the exact reason I mentioned above - being able to tune the amount of capacitance easily. Peter's PSU boards only have room for 2 caps per rail, and as they are really nice boards, I will use them again.
Thanks for the link - their product looks very nice!
Hmm, this might be an option as well.
Nuvotem | Transformere | Transformere | Toroid Transformers | Ringkerne, kapslet, 230 V? primær, 15 VA til 500 VA |0500P1-2-030K
But then a question pops up, are Nuvotem any good or subpar?
Nuvotem | Transformere | Transformere | Toroid Transformers | Ringkerne, kapslet, 230 V? primær, 15 VA til 500 VA |0500P1-2-030K
But then a question pops up, are Nuvotem any good or subpar?
I am looking at the Toroidy.pl website and see no information on how the epoxy-filled transformer is to be mounted. Are you supposed to drill through the epoxy with a hole to the necessary size? Is that information on the site but not in english?
The Potted transformers (they call 'airtight casing') are very nice...
Mine came with a 6mm hole drilled through the centre. Excellent quality; they even made to suit UK 240v's. We are meant to be on 230v but where I live the mains never drops below 240.
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just a note
potting and epoxy filling doesnt make a good toroid, as such
anyone can do that
hell, they can even make a crappy toroid look fancy that way
the "industrial" feature of it may be that the potting protects it against rough environment
not sure why potting has become a sign of highend quality
the quality of the toroid itself is what matter
core and copper quality
winding precision
impregnating
now, I would like to ask about magnetic/electric shielding, what is it worth
potting and epoxy filling doesnt make a good toroid, as such
anyone can do that
hell, they can even make a crappy toroid look fancy that way
the "industrial" feature of it may be that the potting protects it against rough environment
not sure why potting has become a sign of highend quality
the quality of the toroid itself is what matter
core and copper quality
winding precision
impregnating
now, I would like to ask about magnetic/electric shielding, what is it worth
the quality of the toroid itself is what matter
core and copper quality
winding precision
impregnating
now, I would like to ask about magnetic/electric shielding, what is it worth
It is very important that the core has been properly annealed.
I think electric shielding betwwen primary and secondary windings is worthwhile.
The requirement for magnetic shielding will depend on your chassis lay out, if you place transformer away from small signal wires than that might be enough. If your case is small and cluttered then the magnetic shielding might be worthwhile.
Davide,
Most of the info is in the earlier posts - I've added some to get you started as I'm doing a thread summary plus the various pcbs - slow going. (# = post number, not page)
#97 EUVL (Fet source degen.) #119 N.P (R11/12) #1188 EUVL (Tosh Source Rs for F5) #1417 EUVL (Yfs for k170/j74) #1465 N.P (Trimming Source Rs) #1470 EUVL (trim method) #1480 N.P (Transconductance) #2025/2190 Estman (Toshibas) #2310/2603 EUVL (Toshiba Yfs) .......
Enough to get you started - a few off-subject, but useful.
#1912/3056 Jackj (about the THermostat) #1988/3731 GR/NP (feedback ratios)
There is more info about the need for J74 degeneration to better match the Toshibas Fets in the balanced thread - early on the first page I think.
Incidently, there is quite a bit of useful info in the F5 Blog and the F5 Build thread. - I'm only about # 3752 (May 09) and quite a way to go yet.
Perhaps this may be helpful.
Most of the info is in the earlier posts - I've added some to get you started as I'm doing a thread summary plus the various pcbs - slow going. (# = post number, not page)
#97 EUVL (Fet source degen.) #119 N.P (R11/12) #1188 EUVL (Tosh Source Rs for F5) #1417 EUVL (Yfs for k170/j74) #1465 N.P (Trimming Source Rs) #1470 EUVL (trim method) #1480 N.P (Transconductance) #2025/2190 Estman (Toshibas) #2310/2603 EUVL (Toshiba Yfs) .......
Enough to get you started - a few off-subject, but useful.
#1912/3056 Jackj (about the THermostat) #1988/3731 GR/NP (feedback ratios)
There is more info about the need for J74 degeneration to better match the Toshibas Fets in the balanced thread - early on the first page I think.
Incidently, there is quite a bit of useful info in the F5 Blog and the F5 Build thread. - I'm only about # 3752 (May 09) and quite a way to go yet.
Perhaps this may be helpful.
Congratulations and many thanks! I attempted something similar when I built my F-5...didnt get very far....since I was using Peter Daniels boards, I mainly used his group buy thread, which had quite a bit of info in it, and was considerably smaller.
Your project sounds more in depth, I just skimmed the material taking time to note the post number and topic of anything that seemed interesting or useful.
I look forward to your results, as I am sure Many, many other readers/builders would.
The thread has really grown to say the least!
Russellc
Glad to help - Andrew's tip might actually be quite a bit quicker, and more specific - I've never had much success with the threads search system but .... lot's of info buried in this one - the other threads are more specific, thank goodness.
I was thinking of adapting one of the many pcb designs to add those input variations of jack'j, a bit of flexibility around the R1,R2 source resistors, and CMultiplier/Regulator rails, fan cooling to maintain precise Fet die temperature, etc.
Looking forward to see how the work on the Toshiba balanced version comes together - there's lot's of small things about this "so-called" simple amplifier ....
I was thinking of adapting one of the many pcb designs to add those input variations of jack'j, a bit of flexibility around the R1,R2 source resistors, and CMultiplier/Regulator rails, fan cooling to maintain precise Fet die temperature, etc.
Looking forward to see how the work on the Toshiba balanced version comes together - there's lot's of small things about this "so-called" simple amplifier ....
NO TRUER WORDS HAVE EVER BEEN SPOKEN!!!
R11 needs to change to get the bias value more to the center of the pot. With the stock value of R11, you might run out of turns on the bias pot before getting to the bias you want.
Some people think the Toshiba FETs sound better than the other manufacturers. Other people think the inverse is true...
I haven't the foggiest. Hopefully someone else can point you in the right direction.
I would drill a hole, from the back of the panel, through the panel to the front. The diameter of this hole should be smaller than the diameter of the LED. This hole will be the one you will see the light through.
Then, from the back, drill into the first hole with a bigger bit. Hopefully this bit will be the same diameter as the outside of the LED. Drill until the back of the hole is big enough to put the LED into, and ONLY deep enough to hold the LED in place. With luck the LED will stay in place. If not, use a drop of white glue/Elmer's/PVA glue to hold it there.
Does this make sense? I can draw a simple diagram if it's not clear.
I drill a nice big hole, say abut 15-20mm.
Then I fill the hole with hot (white) glue with the front face of the panel pressed on a sheet of butter paper.
While the glue is setting, I insert an LED into the still-liquid muck so it sets in the glue but does not poke all the way through. Remove the butter paper from the front after the glue has hardened, it should peel right off having left its texture on the glue.
Result - a nice soft glow, won't take your eyes out. Lovely in blue or white.
Then I fill the hole with hot (white) glue with the front face of the panel pressed on a sheet of butter paper.
While the glue is setting, I insert an LED into the still-liquid muck so it sets in the glue but does not poke all the way through. Remove the butter paper from the front after the glue has hardened, it should peel right off having left its texture on the glue.
Result - a nice soft glow, won't take your eyes out. Lovely in blue or white.