Thanks for that I had thought it was coming up with min order for 500! but it seems to have worked Thanks
I posted this in the wrong spot (F6 build). I have CineMag CMOQ-4 (150 x 4), could this be used instead of edcor?
nope
what you need is 600:15K (nominally) , which gives you voltage ratio of 1:5
with classic repeater (150 x 4 ,usually connected as 600ct:600ct ) , you can get max voltage ratio of 1:3 , if you use one 150R winding as primary , rest connected in series as secondary ...... with drekload of resulting problems
what you need is 600:15K (nominally) , which gives you voltage ratio of 1:5
with classic repeater (150 x 4 ,usually connected as 600ct:600ct ) , you can get max voltage ratio of 1:3 , if you use one 150R winding as primary , rest connected in series as secondary ...... with drekload of resulting problems
yup , I stand corrected - 1:4 , not 1:3 , as I wrote
however , regarding easiness of driving and inductivity (read - frequency transfer) , it need to be verified is there any step back or not , vs. originally intended 600:15K
however , regarding easiness of driving and inductivity (read - frequency transfer) , it need to be verified is there any step back or not , vs. originally intended 600:15K
OK thanks for the clarification. I thought the Cinemag was not quite right for this job...but had to ask, since I have them laying around.
İ used them thanks to ZM in the F6, they had the best sound, so old, so good!
But I am afraid there are not much left.
But I am afraid there are not much left.
I am gathering parts in preparation for this build. I have read several different PSU capacitor ratings so far. Will a 22,000uF + qnty 2 x 4700uF (~31,000uF) per rail be enough for two channels, or will I need double this and make two mono PSU's?
I will use 400VA 18vac trafo for both channels.
I will use 400VA 18vac trafo for both channels.
Standard FW power supply uses 60,000uF total per rail with CRC filter and gives ~150mV ripple according to Duncan's PSU Designer. Personally, I wouldn't want to go any lower than that on the capacitance.
Teabag's M2 - First Sound
This amp was a joy to build. Simple simple simple compared to many of the class AB amps I have worked on.
Completed pair of Teabag M2's:
It seems to be running at 1.3A bias current, and the neat thing was to see it start low, and rise fairly quickly once warmed up. I guess had I been listening I would have heard it go through class B, then class AB, then class A 🙂
Even with the 52.3k resistor on R7, I could not get the DC offset to zero out. It's bottoming out at -95mV. However, that's not going to stop me from listening.
I am using my existing PSU but with a new 400VA 18vac trafo which makes exactly 25.0vdc rails. Ripple is 56mV with CRCLC filter ending with 20mF of small 1k cap bank and about 29mF total per rail.
This amp puts out some heat on these slightly undersized heatsinks.
Still listening to it but sounds very good so far. Wish it had more gain 😀
This amp was a joy to build. Simple simple simple compared to many of the class AB amps I have worked on.
Completed pair of Teabag M2's:
It seems to be running at 1.3A bias current, and the neat thing was to see it start low, and rise fairly quickly once warmed up. I guess had I been listening I would have heard it go through class B, then class AB, then class A 🙂
Even with the 52.3k resistor on R7, I could not get the DC offset to zero out. It's bottoming out at -95mV. However, that's not going to stop me from listening.
I am using my existing PSU but with a new 400VA 18vac trafo which makes exactly 25.0vdc rails. Ripple is 56mV with CRCLC filter ending with 20mF of small 1k cap bank and about 29mF total per rail.
This amp puts out some heat on these slightly undersized heatsinks.
Still listening to it but sounds very good so far. Wish it had more gain 😀
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I wish I can get a pair of those Edcore tranies here in Canada so I could start build my own. Blue PC boards...
is this your first FW clone build? for sure it wont be the last 😀 Opposite way that I never build class ab due to its complicated schematic.
I use 2 paralel 100k for R6 and R7, default DC after soldering around +400mV but after trimming multiturn trimpot, I can get close to 1mV, even down to -30mV on my testing
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The Edcor's are not expensive and shipping to Canada shouldn't be more than $15 for something like this. Have you tried ordering direct from Edcor's website?
Funny you mention word "Furnace" because I was quite unprepared for how much heat a pair of little IRFP's can put out when running pure class A. 😱
