Thanks for the answer OS. I will definitely look at trying this once I am at that point. In the tests that Pavel did the distortion was significantly reduced with this method. The major conclusion was that current driving the speaker does reduce distortion compared to using purely voltage drive of the speakers.
I can't understand why guys don't try first time with one pair only😕
In all my test this G2 connection is on power supply STAR GND.
In all my test this G2 connection is on power supply STAR GND.
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Hi,
I would like to use MJL4281A/4302 for 2P slewmaster outputstage and 2SC3503 for VAS stage (Kypton C, Infidel etc.)
what can you recommend as driver? is it necessary to use MJL4302 as driver, when something smaller can be used?
Would it be okay to use 2SC3503 as predriver?
I would like to use MJL4281A/4302 for 2P slewmaster outputstage and 2SC3503 for VAS stage (Kypton C, Infidel etc.)
what can you recommend as driver? is it necessary to use MJL4302 as driver, when something smaller can be used?
Would it be okay to use 2SC3503 as predriver?
Which part? Jason had a large group buy for most of the boards. I think it is pretty much over but he released his gerbers. He may have some boards left.
Well... I guess that one went pass me! All OPS are sold. I'll wait and be patient, not in a rush at all, got many projects on the way.
Do
Do
2SK1530 &20J200 to be replaced with 2SK1529 & 2SJ200 any necessary mode
Guy
Please someone take a look - I'm ready to heat up the iron to make some boards but before that I need some help🙂
Do these circuit will work with Toshiba 2SJ200 & 2SK1529.
I do have a few spare parts of those Toshiba (original) I want to put those in good use.
The circuit was design to the more rugged Toshiba 2SK1530 & 2SJ201.
These later one I only has a matched set only. To buy them now is a task because even some large distributors sale counterfeit the bigger Toshiba.
Please take a look and advise what do I change to compensate the differences between the two type of Toshiba fets.
Again the 2SK1529 & 2SJ200 I have several matched pair of them.
Also I made the layout ready for these circuit. In case I need to mode something it is a good time to do it before I do the PC boards.
Thank for the help🙂
Greetings
Guy
Please someone take a look - I'm ready to heat up the iron to make some boards but before that I need some help🙂
Do these circuit will work with Toshiba 2SJ200 & 2SK1529.
I do have a few spare parts of those Toshiba (original) I want to put those in good use.
The circuit was design to the more rugged Toshiba 2SK1530 & 2SJ201.
These later one I only has a matched set only. To buy them now is a task because even some large distributors sale counterfeit the bigger Toshiba.
Please take a look and advise what do I change to compensate the differences between the two type of Toshiba fets.
Again the 2SK1529 & 2SJ200 I have several matched pair of them.
Also I made the layout ready for these circuit. In case I need to mode something it is a good time to do it before I do the PC boards.
Thank for the help🙂
Greetings
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Other request
Someone started a Cordel type of circuit mode to HEX Fet a few moths back now I don't find it. I did search several days on the forum and no result came up.
I think OS or Jason did it.
Can someone point to that thread the above layout is for that circuit.
It was these circuit with HEX-Fet.
Thanks
Someone started a Cordel type of circuit mode to HEX Fet a few moths back now I don't find it. I did search several days on the forum and no result came up.
I think OS or Jason did it.
Can someone point to that thread the above layout is for that circuit.
It was these circuit with HEX-Fet.
Thanks
Attachments
I did originally test this with one pair months ago with a lower voltage supply. All my problems started when I went high voltage and added output devices.
I originally had G2 to the star ground too but was told that was wrong.
G2 can go to the chassis main star. I deviated from the PCB , too.
My G2/G1 goes to the chassis star , but my speaker grounds also go to the chassis
star - NOT back to the PCB speaker ground fast-on.
Where G2 is soldered to G1 , don't solder it to the G1 pad - instead , solder it
right to the G1 fast-on pad. Right at this point (halfway between the OPS decoupling
caps) ,OPS current pulses cancel each other out fully.
Sort of like a twisted wire "triplet" ....
To determine if the OPS is working absolutely properly , R115 and R111 are your friends. (I use 10R here - easy calculating)
Here , you can calculate the total driver/predriver/IPS current draw.
For example , I get 290mv/210mv on a wolverine (65V rails). I add this 29ma
to the 210ma of my 3 MT-200's bias current (@240ma).
I have another 10R at negative rail input. This reads a 2.4V drop - it adds up perfectly.
No milliamp's are "unaccounted for" .... any defect or oscillation would make
for "missing" currents !!
PS - also , compare with a simulation set to 65V rails .... LT says 30ma/22ma
for the wolverine across the OPS 10R's (R115/111).
On an OPS with the cap multiplier ... about 1 extra ma per rail. Spooky / and Kypton C
draw much more current for the zener shunt regulators (50ma per rail).
OS
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Hi,
For the most economic setup (Kypton C, Slewmaster 2P, +-50V PSU, can I use:
2SC3601 as VAS
MJE350 as predriver
MJE15032 as driver
MJL4302 as output
instead of (a bit expensive):
2SC3503 as VAS
2SC3503 as predriver
2SC4793 as driver
MJL4302 as output
??
I have also ordered 5 PCB´s Kypton C and 2 pair Slewmaster boards from PCBway, maybe I can sell the not used boards if anything goes well🙂
For the most economic setup (Kypton C, Slewmaster 2P, +-50V PSU, can I use:
2SC3601 as VAS
MJE350 as predriver
MJE15032 as driver
MJL4302 as output
instead of (a bit expensive):
2SC3503 as VAS
2SC3503 as predriver
2SC4793 as driver
MJL4302 as output
??
I have also ordered 5 PCB´s Kypton C and 2 pair Slewmaster boards from PCBway, maybe I can sell the not used boards if anything goes well🙂
340/350 should work for VAS's. 15032/33 will work for the 5 pair, but a bigger
TO-3P like my C3263/A1294 will be better for difficult loads and will have less
heat.
The original HK680 EF3 had the 2sc4793/a1837 ... but only drove 2 pair
MT-100 sanken. "Slewbaby" is nearly an exact clone of this with to-220 drivers.
Most economical would be mje340/350 - njw0281/0302 - njw0281/0302 as
pre - driver - output.
Most ideal would be like mine .... c3503/a1381 - C3263/A1294 - njw0281/0302.
There is a better driver - Sanken 2SC2837/2SA1186 , fastest TO-3p in the west -
110pF Cob - 60-80mhz Ft ... wish I had those !!
OS
I never designed any FET OPS's , you might want to ask someone who did ??
😕
PS - I have no connection to any of these modifications.
OS
Sanken 2sc2837 1186 sold by electronics-salon
but i don't know if it is a fake one.
somebody having experience with this seller?
but i don't know if it is a fake one.
somebody having experience with this seller?
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I have try 3503 as predriver and 1387 driver 2sc3264 out without any issue.
It seems stable even with uncompensated driver
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