Thank you Zen Mod. If I use the attached schematic, again do the two 15K resistors also get connected to 0V? I understand that both are effectively at 0V, but not sure what the proper thing to do is here. Do the resistor values look ok? Can I run this up to the CSX2 rail voltages, with the BJT cascode?
Attachments
I think I'm going to just leave a spot for a small daughterboard. I added some SMD bridges just because there was some space. The five-pin regulators can be two of these:
TI TPS7A4700 Ultralow Noise 4?VRMS Low Dropout Linear Regulators 5 3pin Config | eBay
or just two positive fixed voltage regulators. A bit of flexibility.
The relay allows for removing the buffer and there are two jumpers to configure the primaries. I added some zobels on the outputs as well.
Thoughts?
TI TPS7A4700 Ultralow Noise 4?VRMS Low Dropout Linear Regulators 5 3pin Config | eBay
or just two positive fixed voltage regulators. A bit of flexibility.
The relay allows for removing the buffer and there are two jumpers to configure the primaries. I added some zobels on the outputs as well.
Thoughts?
Attachments
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Cinemag CMOQ-4.
Hi partner, do you have the pinout of the Cinemag transformer? PB model.
Best Regards
Hi partner, do you have the pinout of the Cinemag transformer? PB model.
Best Regards
Has anyone tried using the Silicon in VFETs, I have some and was wondering but using them instead of the other VFETs.
Balanced connection in out for CSX idea?
Dear partners of this Pass Labs threads.
Few months ago I started with the CSX1 project. Then, I got from Acroman several pieces of the pairs 82/28 and with another pieces of another friend and member, jama, we found carefully their curves envelope and matching to obtain four identical pairs.
Then looking for more damping I planned in parallel them.
I tried they and they are matched fine, with a DC of 0.01volt and a difference in the polarization of 0.2volt between the negative and positive rail.
Yesterday I start to think in the project again and trial several drawings of symmetrical connection between the devices, finally I found a schema that I will show with the object of be judged for more experienced members. Please I need your counsel if is possible to make it without troubles.
Best Regards in advance and thank for your opinion.
🙂
Dear partners of this Pass Labs threads.
Few months ago I started with the CSX1 project. Then, I got from Acroman several pieces of the pairs 82/28 and with another pieces of another friend and member, jama, we found carefully their curves envelope and matching to obtain four identical pairs.
Then looking for more damping I planned in parallel them.
I tried they and they are matched fine, with a DC of 0.01volt and a difference in the polarization of 0.2volt between the negative and positive rail.
Yesterday I start to think in the project again and trial several drawings of symmetrical connection between the devices, finally I found a schema that I will show with the object of be judged for more experienced members. Please I need your counsel if is possible to make it without troubles.
Best Regards in advance and thank for your opinion.
🙂
Attachments
While we are at it, I have a question. Will Sansui 2sk70/2sj20 vfets work in a CSX1 (with some mods of course)? I am saving all my 2sk82/j28 pairs for Version 2 and have left with some spare CSX1 boards (R.I.P Permander) from the group buy.
TIA
TIA
I guess is possible, modifying the polarization, I guess listen Tim he measured the yamahas 70-20 and find transconductanceless than sonys
Is a member of Diyaudio. cwtim01
There are a confusion between the Vfet, he tried the 2SK76 and 2SJ26 from Yamaha.
The 2SK70 and 2SJ20 are from NEC and I could see some in the chinnese market.
Take care because there are plenty of fake Vfets, I got 20 pairs of 2SJ18/2SK60 and they was all fakes.
There are a confusion between the Vfet, he tried the 2SK76 and 2SJ26 from Yamaha.
The 2SK70 and 2SJ20 are from NEC and I could see some in the chinnese market.
Take care because there are plenty of fake Vfets, I got 20 pairs of 2SJ18/2SK60 and they was all fakes.
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New try today with the symetrical CSX
Yesterday, I tried in the workshop at the basement the voltages and the currents, the DC in the out is more difficult in stabilize, 0,2volt.
This afternoon I put in my living room, I was intrigued and I tried with one channel. The sound, very good. The loudspeakers are full range 15ohm EX4Lowther in a DIY back loaded horn (Mauhorn). I tried with bach solo cello sonata, something with King Crimson, and a little of Mahler with bestial symphonic passage. Suddenly the SMPS died,
But the sound was amazing, coherent and dynamic.
I guess I have to stabilize the DC, put a fan in the SMPS. Anybody of the people here could give an idea about the improvement?
Yesterday, I tried in the workshop at the basement the voltages and the currents, the DC in the out is more difficult in stabilize, 0,2volt.
This afternoon I put in my living room, I was intrigued and I tried with one channel. The sound, very good. The loudspeakers are full range 15ohm EX4Lowther in a DIY back loaded horn (Mauhorn). I tried with bach solo cello sonata, something with King Crimson, and a little of Mahler with bestial symphonic passage. Suddenly the SMPS died,
But the sound was amazing, coherent and dynamic.
I guess I have to stabilize the DC, put a fan in the SMPS. Anybody of the people here could give an idea about the improvement?
Attachments
Today I rise the current until 1.5A with 23,5 Volt.
45ºC, I trying in calculate the input capacitance...😕
Before I tried with parallel windings on the primary of the transformer with louder sound.
Today I attached and preamp but the windings in series gave better sound.
Exploring one channel with different music today, after 3 hours the DC rise a little, the SMPS with a 12 volt fan working with 4,5 gave enough air for maintain under good temperature.
The clue? somebody can counsel to me. Mr Aleksandar ZEN?
Mr Mode?
Best Regards Gentlemen
45ºC, I trying in calculate the input capacitance...😕
Before I tried with parallel windings on the primary of the transformer with louder sound.
Today I attached and preamp but the windings in series gave better sound.
Exploring one channel with different music today, after 3 hours the DC rise a little, the SMPS with a 12 volt fan working with 4,5 gave enough air for maintain under good temperature.
The clue? somebody can counsel to me. Mr Aleksandar ZEN?
Mr Mode?
Best Regards Gentlemen
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