I have PCBs, have built one channel, and am bench testing the design. The cascoded LU1014D behaves very differently from the Tokin SITs and I am finding that some design changes will be needed to obtain the desired goal. The OS stage rail voltages will need to be around 25V for 20W output into 8R without clipping.
Bottom line: The LuX25 will not be a simple modification to the SIT3X design, but it should be simpler to build.
Bottom line: The LuX25 will not be a simple modification to the SIT3X design, but it should be simpler to build.
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I have mostly been tending to farm chores; irrigating hay fields, weed management, fence repairs, ... This is fairly normal this time of year.
My prototype SIT3X, with Tokin 2SK182ES SITs and the +44V/-44V power supply is running just fine. I have yet not built the version with a single -88V (or lower) supply for the OS and a small +45/-45V supply for the FCFE.
I have the LuX25 prototype sitting on my test bench waiting for more testing after making a few circuit changes. At this time I do not know it I can achieve the desired behavior with the LU1014D. With suitable adjustments I expected to get a behavior similar to ZM's LuDEF, but so far both 2nd and 3rd harmonics have been too high.
My prototype SIT3X, with Tokin 2SK182ES SITs and the +44V/-44V power supply is running just fine. I have yet not built the version with a single -88V (or lower) supply for the OS and a small +45/-45V supply for the FCFE.
I have the LuX25 prototype sitting on my test bench waiting for more testing after making a few circuit changes. At this time I do not know it I can achieve the desired behavior with the LU1014D. With suitable adjustments I expected to get a behavior similar to ZM's LuDEF, but so far both 2nd and 3rd harmonics have been too high.
I am very happy that I managed to finish SIT3X.
I used the FCFE balanced version, with a regulated power supply - / + 48 VDC. The OS has a power supply with a voltage of -70VDC.
The amplifier is very stable, with zero noise in the speakers.
The bias is set to 1.8A.
The radiators heat up after 3 hours at 55 degrees.
The sound - very very special from what I've had so far, I really like it.
I want to thank Lynn for the wonderful scheme and for patience in guiding me for an exceptional end result!
I used the FCFE balanced version, with a regulated power supply - / + 48 VDC. The OS has a power supply with a voltage of -70VDC.
The amplifier is very stable, with zero noise in the speakers.
The bias is set to 1.8A.
The radiators heat up after 3 hours at 55 degrees.
The sound - very very special from what I've had so far, I really like it.
I want to thank Lynn for the wonderful scheme and for patience in guiding me for an exceptional end result!
Attachments
I will second that. Totally professional looking packaging. Was the chassis off-the-shelf or custom?
Vă mulțumesc foarte mult pentru cuvintele frumoase. Și chiar nu-mi pasă de greutatea lor atâta timp cât sunetul este grozav. Lynn a proiectat un amplificator excepțional și aș dori să-i mulțumesc din nou pentru tot sprijinul acordat în realizarea SIT-3X. Și nu pot să nu observ cât de bine reproduce basul acest amplificator. Niciun amplificator de-al meu din clasa A nu merge atât de bine.
If you have the FCFE PCBs with the date of 20200815 then there is no provision for that capacitor (220uF). I fabricated a limited run (6x) of FCFE PCBs dated 20210408 which include that capacitor, but it is not really necessary.
Hello lhquam,
From F7 topics to here
I'm completed to investigate F7 and well done it. Thanks for your many topics .
Now, I got one pair THF51s and BA-3 stage. Do you think I can get 100W RMS with this OS design ? with un-balance input
my speakers are 6R 82dB/W(1m) . (4R at 200Hz)
Thank you.
From F7 topics to here
I'm completed to investigate F7 and well done it. Thanks for your many topics .
Now, I got one pair THF51s and BA-3 stage. Do you think I can get 100W RMS with this OS design ? with un-balance input
my speakers are 6R 82dB/W(1m) . (4R at 200Hz)
Thank you.
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