This is great forum and has been very helpful. I just order some W204011ASH1
W61084ASN2_juma cap multi boards from PCBway! I am planing to modify one of the boards by adding a TL431 to add regulation and compensate for the difference in the Vgs of the mosfets.
I have one question about the original design. Do the diodes D1, D2, D4 and D5 eliminate the need for zener clamp between gate and source of the MOSFETs?
In case of a short circuit, C2 is going to discharge through the reference pin of TL431 and maybe destroy the IC
A tweak worth trying is adding bypass cap to 220uf cap.
I had already added a selection of film caps from 1 uf down after the Mx.
It helped tame the ''fatness'' of adding what seemed like too many large electrolytics, keeping the full, smooth sound but tightening it up and adding some air. There was good synergy there.
increasing 220uf Mx cap to 1000uf seemed to have similar effect to the large lytics after the Mx, it was easier to solder a bypass cap the legs than desolder them again and surprisingly this also helped in the same way.
The Mx cap seems to influence sound nearly as much as the Mx output caps
also the Mx caps were silmics, which I believe are low ESR, A general purpose cap might benefit even more from a bypass cap here.
I had already added a selection of film caps from 1 uf down after the Mx.
It helped tame the ''fatness'' of adding what seemed like too many large electrolytics, keeping the full, smooth sound but tightening it up and adding some air. There was good synergy there.
increasing 220uf Mx cap to 1000uf seemed to have similar effect to the large lytics after the Mx, it was easier to solder a bypass cap the legs than desolder them again and surprisingly this also helped in the same way.
The Mx cap seems to influence sound nearly as much as the Mx output caps
also the Mx caps were silmics, which I believe are low ESR, A general purpose cap might benefit even more from a bypass cap here.
Last edited:
Hello Shawn,
Is it the Juma Cap MX?
In that case try estimate the heat dissipated per mosfet by current through a given mosfet x 4.5V approx.
This will allow to estimate the heatsink size required.
Anyway there is BJT Cap MX by M. Johnson/ Gtose that has much lower voltage drop.
regards
Prasi
Is it the Juma Cap MX?
In that case try estimate the heat dissipated per mosfet by current through a given mosfet x 4.5V approx.
This will allow to estimate the heatsink size required.
Anyway there is BJT Cap MX by M. Johnson/ Gtose that has much lower voltage drop.
regards
Prasi
Hi,
Are there gerbers for the BJT Cap MX by M. Johnson/Gtose without the rectifier bridge and input caps ?
so I can use a LT4320 based bridge and other caps ?
Regards,
Danny
I think what you want is the SLB. LT4320 bridge plus CRC plus CFP cap Mx for sub mVrms ripple under Class A load of 4A.
The SLB (Smooth Like Butter) Active Rect/CRC/Cap Mx Class A Power Supply GB
Here is data for the measured ripple under 4A load (yellow trace):
yes just use IRFP240 and caps with sufficient voltage rating
Will I need to use a zener in place of the diode?
Last edited:
- Home
- Amplifiers
- Power Supplies
- Juma's Easy-Peasy Capacitance Multiplier