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some stuff here too, you may have another supporter for this approach: http://www.diyaudio.com/forums/solid-state/133189-my-first-diy-amplifier-20-years-go.html
High borys,
due to the top not hearing results from versatil iplaned to build "bodybuild version", probably +/-50V rail with 2 or 3 output pair, have you experimented some instability under comparable conditions in your work? For memory i use ksc3505/ksa1381 for VAS, 2sc4793/2sa1837 for driver, and MJL4281/4302 or NJW3281/1302
Marc
Hi Marc
To which sch (post nr.) this amp is related? Maybe I can look to propose some improvements, you never know hehe
Congratulations on nice built, enjoy
Hi Marc
To which sch (post nr.) this amp is related? Maybe I can look to propose some improvements, you never know hehe
Congratulations on nice built, enjoy
Hi LC
Here the version that'running with one smps300re pro chanel and next the 3 pair version (don't pay attention to rail voltage indication, caps voltage rating and BC type for input stage BC560/550c wil be swap to BC556/546C)
Marc
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Last edited:
Idefixes
I have some idea If you are interested for tests. I will draw a schematic with cascoded vas, on the symulations there is visible improvement so maybe You can inplement 2 more transistors and few more components ?
The other amp I have tested with different o/p stages and got quicker basss response on that voltage stage.
Regards
I have some idea If you are interested for tests. I will draw a schematic with cascoded vas, on the symulations there is visible improvement so maybe You can inplement 2 more transistors and few more components ?
The other amp I have tested with different o/p stages and got quicker basss response on that voltage stage.
Regards
For sure you propose...The improvement i'd like if it is possible is the tampco for VAS transistor as they are on main heatsink (TLVH431 like).
Bass response actually is quite impressive in density, speed and details...i can't see how it could significantly better...
Marc
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nalimko33
Nice job. I have putted cascode too but it would be recommended to put set of the drivers just behind the cascode.
The cascode biassed from the emiters ''likes'' the ground reference so it would be prapobly better to use two diodes and two resistors with GND connection in the middle.
If you are going to use single biasing resistor for cascode --> use biasing from rail voltages.
Nice job. I have putted cascode too but it would be recommended to put set of the drivers just behind the cascode.
The cascode biassed from the emiters ''likes'' the ground reference so it would be prapobly better to use two diodes and two resistors with GND connection in the middle.
If you are going to use single biasing resistor for cascode --> use biasing from rail voltages.
I used Hawksford cascode
http://www.diyaudio.com/forums/atta...ord-cascode-experiences-please-hawksford.jpeg
http://www.diyaudio.com/forums/atta...ord-cascode-experiences-please-hawksford.jpeg
Versatil 50 - PCB
Bonjour Marc!
J'ai actuellement un DX Super A qui fonctionne à merveille mais j'aimerai bien me lancer dans la construction de l'amplificateur décrit sur ce fil en version bjt. J'hésite encore entre votre version avec les Sanken et la version "Versatil 50" et je me demandais s'il vous était possible de diffuser votre .pdf du circuit imprimé pour cette version (Versatil 50).
Merci!
__________________________________
Hello Mark!
I currently have a DX Super A that works wonders but I would love to get into the construction of the amplifier described on this thread version bjt. I still hesitate between your version with Sanken and "Versatile 50" version and I was wondering if you could broadcast your pdf. Printed for this release (Versatile 50) circuit.
Thank you!
Bonjour Marc!
J'ai actuellement un DX Super A qui fonctionne à merveille mais j'aimerai bien me lancer dans la construction de l'amplificateur décrit sur ce fil en version bjt. J'hésite encore entre votre version avec les Sanken et la version "Versatil 50" et je me demandais s'il vous était possible de diffuser votre .pdf du circuit imprimé pour cette version (Versatil 50).
Merci!
__________________________________
Hello Mark!
I currently have a DX Super A that works wonders but I would love to get into the construction of the amplifier described on this thread version bjt. I still hesitate between your version with Sanken and "Versatile 50" version and I was wondering if you could broadcast your pdf. Printed for this release (Versatile 50) circuit.
Thank you!
Hi you could send me a email through forum to discus It. I think that if you have original thank you can try it, but my though is that MJL version is more reliable and soubd like a charm.
Marc
The pair irfp240/9140 is the best matching pair from the irfpxxxxx range transistors - but only up to +/-50V (the 9140 is 100V max). If you are goning to build amp wih higher supply fitt irfp240/9240 instead. My amp is running at approx +-50V, my friend has +-77V supply and 4 pairs at output, there are only small changes in amp circuit for that high psu.
You can think about double bootstrapped version where output is swinging nearly rail to rail.
Regards
You can think about double bootstrapped version where output is swinging nearly rail to rail.
Regards
Thanks for quick reply.
I see there's many people sellling matched pairs
,even in this forum http://www.diyaudio.com/forums/swap...fets-your-f1-f4-f5-aleph-j-6.html#post2853398 ,but they match only N to N , not N to P.
After search, somes says matching is important for input FET ,somes says also important for output...
So,maybe it's better to buy 50 pieces of each IRFP for match by myself (84€ and 90€ from Mouser).
It's possible to have to files from the +-77V version ?
I see there's many people sellling matched pairs
,even in this forum http://www.diyaudio.com/forums/swap...fets-your-f1-f4-f5-aleph-j-6.html#post2853398 ,but they match only N to N , not N to P.
After search, somes says matching is important for input FET ,somes says also important for output...
So,maybe it's better to buy 50 pieces of each IRFP for match by myself (84€ and 90€ from Mouser).
It's possible to have to files from the +-77V version ?
