Hi Piersma,
please count me in (my nephew, actually) for a stereo pair of boards.
Thanks
Nicola
please count me in (my nephew, actually) for a stereo pair of boards.
Thanks
Nicola
Piersma, is this also a new version board of the Inverted J-Fet Circlophone?Latest measurements and revision V.1.2
Added:
Degeneration resistors front-end.
Zobel network.
Measurements:
30W@ 8 Ohms BW: 80kHz

Curious to see some pictures of the new boards! 🙂
Version 1.2
Your version is the 1.2 version, the previous one had no degeneration resistors in the LPT, and no Zobel network. There are no other hardware changes made to the board except for the corrected silkscreen errors.
regards,
Piersma
Your version is the 1.2 version, the previous one had no degeneration resistors in the LPT, and no Zobel network. There are no other hardware changes made to the board except for the corrected silkscreen errors.
regards,
Piersma
Update
For all members who subscribed to the Inverted J-FET PCB order list:
If have confirmation that the boards are produced, I am waiting for the boards to arrive in the Netherlands. It may take up to another 10 days.
For anyone who is interested: i have two spare and fully populated boards available. Version 1.0. (See: post #1212)
Leave me a PM for the populated boards.
For all members who subscribed to the Inverted J-FET PCB order list:
If have confirmation that the boards are produced, I am waiting for the boards to arrive in the Netherlands. It may take up to another 10 days.
For anyone who is interested: i have two spare and fully populated boards available. Version 1.0. (See: post #1212)
Leave me a PM for the populated boards.
If you are talking about the amplifier PCB for the amplifier, then count me in for 2 PCBs, Price?
Any pictures of the PCB?
Any pictures of the PCB?
PCB's
hi Cresnet,
The orderlist is already closed, put i will put you on the spare list. Take a look a post # 1477 for the Inverted J-FET PCB.
I will keep you, and others updated.
hi Cresnet,
The orderlist is already closed, put i will put you on the spare list. Take a look a post # 1477 for the Inverted J-FET PCB.
I will keep you, and others updated.
Be sure and let us know when it is time to pay the bill.For all members who subscribed to the Inverted J-FET PCB order list:
If have confirmation that the boards are produced, I am waiting for the boards to arrive in the Netherlands. It may take up to another 10 days.
I sure would like to have the performance of a Circlophone with the negative noise floor and big dynamics, And, I would like one that has a different sonic signature than the one that I have built previously.
Piersma,
Can you post bill of materials for this? I want to use what has actually been measured. I tried that other way and have determined that it is entirely worth the price to buy the correct parts. Don't worry--I can find them.
Can you post bill of materials for this? I want to use what has actually been measured. I tried that other way and have determined that it is entirely worth the price to buy the correct parts. Don't worry--I can find them.
what is the difference between circlo and quasi, i prefer circlo because quasi drives 2 npns with 1 npn and one pnp.
Mosfet54; the answers to your questions can be found in post #1212
Daniel; I will update the B.O.M. and make it available for all who ordered the PCB.
If you looking for a complete Digi-key orderlist for the inverted J-FET Circlophone: member Karl vd Berg has this list available. I think he is willing to provide this orderlist.
Daniel; I will update the B.O.M. and make it available for all who ordered the PCB.
If you looking for a complete Digi-key orderlist for the inverted J-FET Circlophone: member Karl vd Berg has this list available. I think he is willing to provide this orderlist.
Piersma, there is nothing at #1212 😀Mosfet54; the answers to your questions can be found in post #1212
Daniel; I will update the B.O.M. and make it available for all who ordered the PCB.
If you looking for a complete Digi-key orderlist for the inverted J-FET Circlophone: member Karl vd Berg has this list available. I think he is willing to provide this orderlist.
nothing compares it with quasi. Maybe its better as i think. 😛
Evaquad
dear Elvee!
some time ago Eva published a schematic of mosfet amp (IRF540/9540 if I remember correct...) with her input quad
but now there is no sign of it...
do you remember her design or do you have that schematic?
Rule N°1: never misunderestimate Eva, she is smarter than you, me, and a good part of the forum's members put together.😎
Look at the first pic: with an input of 700mV^, a saturation occurs, but the EvaQuad shows no phase reversal, unlike the standard circuit.
In the standard quad, Q1's collector waveform is in phase with the base voltage: this means that any feedback caused by a combination of input resistance and Ccb capacitance will be positive, increasing instabilities.
In the Evaquad, Q5's collector has 0V AC potential, and this couldn't happen.
Moreover, should Q6 be used as an input, voltages at out2 and tp1 will be antiphase, meaning that Q9's capacitance will play its normal role of Miller and contribute to stabilize the thing.
Rule N°2: do not misunderestimate me too much either. 😀
The second pic compares the linearity of the two versions: the raw Xquad is superior, because the cancellation effects are more accurate.
dear Elvee!
some time ago Eva published a schematic of mosfet amp (IRF540/9540 if I remember correct...) with her input quad
but now there is no sign of it...
do you remember her design or do you have that schematic?
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