Quasi comp is when the P transistor of a regular complementary PP is replaced with a CFP having a PNP as an input.
The C has nothing in common with the traditional topology: the OP transistors need to be of the same polarity, otherwise it cannot work.
For practical reasons, I opted for two CFP's as output, but it can work with two darlingtons or MOSFETs, and if you search the thread, you will see that members have implemented such versions, often "inverted" to be able to use N OP devices.
"Circlo" in the name refers to the similarity with the Circlotron topology, but without the folklore and inconvenience of floating supplies, etc.
The C has nothing in common with the traditional topology: the OP transistors need to be of the same polarity, otherwise it cannot work.
For practical reasons, I opted for two CFP's as output, but it can work with two darlingtons or MOSFETs, and if you search the thread, you will see that members have implemented such versions, often "inverted" to be able to use N OP devices.
"Circlo" in the name refers to the similarity with the Circlotron topology, but without the folklore and inconvenience of floating supplies, etc.
Hi Katiyar
Hey Rajesh,
Hope you all are doing well - as per you’re advice I got CDIL mostly ..
BC546B - CDIL
BC556B - CDIL or PHILIPs
2N3051 - CDIL
2N5551 - kE brand
KSC1845 -
BD140 - CDIL
MJL21194 - ONSEMI ( RSComp )
All resistors mfr
Caps will be mostly cog(npo) and input cap philips bipolar or Muse ( if I get it )
Hope this is all ok - will be assembling board
Hey Rajesh,
Hope you all are doing well - as per you’re advice I got CDIL mostly ..
BC546B - CDIL
BC556B - CDIL or PHILIPs
2N3051 - CDIL
2N5551 - kE brand
KSC1845 -
BD140 - CDIL
MJL21194 - ONSEMI ( RSComp )
All resistors mfr
Caps will be mostly cog(npo) and input cap philips bipolar or Muse ( if I get it )
Hope this is all ok - will be assembling board
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Mr Aditya,
Why are you using 2N3051. Its Vce is only 20V. It will fail in VAS. You should use 2N3019 in VAS up to 25v Rail. Use KSC3503 in VAS if rail voltage is higher. Other selection is perfect.
You will love Circlophone with its audio quality and stability. My MOSFET version of Circlophone stereo is powered on for more than two months and all parameters are within its limit. Quiescent current is well maintained at 160ma. Offset is ~5mv.
Best wishes for your build.
Why are you using 2N3051. Its Vce is only 20V. It will fail in VAS. You should use 2N3019 in VAS up to 25v Rail. Use KSC3503 in VAS if rail voltage is higher. Other selection is perfect.
You will love Circlophone with its audio quality and stability. My MOSFET version of Circlophone stereo is powered on for more than two months and all parameters are within its limit. Quiescent current is well maintained at 160ma. Offset is ~5mv.
Best wishes for your build.
Hi Katiyar
hey thank you for the catch, ( my dyslexia ) But i correct my self and have bought 2N3019, about 45/- each. was looking for KSC3503 but didnt find it.
i got the boards from Prasi, so the board part is sorted - now is input selection board and cabinet and sweet labour of love... going to use my exisitng transformer that used to give me around 21 or 22 volts dc so lets see " will take TIME "
will keep posted, is there something i need to keep in mind
hey thank you for the catch, ( my dyslexia ) But i correct my self and have bought 2N3019, about 45/- each. was looking for KSC3503 but didnt find it.
i got the boards from Prasi, so the board part is sorted - now is input selection board and cabinet and sweet labour of love... going to use my exisitng transformer that used to give me around 21 or 22 volts dc so lets see " will take TIME "
will keep posted, is there something i need to keep in mind
Yes I am aware of those sold by DAC, but it depends brand to brand and on element 14 there is one from multicomp I think it’s sold for 113/-
And there are mil stand ones sold for 1000/- made by Microchip ( they make microcontrollers - “pic16F, 18F” series and also recently acquired atmel )
Thank you Gouthma, so future need would only be transformer change. If I decide to.
I think I will follow the suggestion from post 1864 by Terri.
But do let me know if something has changed
Thank you in advance
In this case, stay on the safe side: use 820pF. It is safe and proven with countless device types, and the published specs apply to this case.
Using a lower cap will improve the dynamic performances with suitable devices, but refrain from using one until you have the means to check its viability: you certainly do not want to fry your tweeters
Using a lower cap will improve the dynamic performances with suitable devices, but refrain from using one until you have the means to check its viability: you certainly do not want to fry your tweeters
Hi Aditya,
The price of CDIL 2N3019 is quite reasonable. Is this vendor also sells online?. Please share address.
I have also build prototype one channel with BJT in past and experimented with 2N3055 and 2N3773 transistors as op device with CDIL BC546, BC556 and BD140 transistors at 35-0-35V DC Rail with excellent results. I also found no difference in audio quality between BJT and MOSFET versions.
The price of CDIL 2N3019 is quite reasonable. Is this vendor also sells online?. Please share address.
I have also build prototype one channel with BJT in past and experimented with 2N3055 and 2N3773 transistors as op device with CDIL BC546, BC556 and BD140 transistors at 35-0-35V DC Rail with excellent results. I also found no difference in audio quality between BJT and MOSFET versions.