Hello
I did started the PC boards stuffing, it took me a while because I needed to select the left over resisters from another projects.
Also I ordered the Toshiba 2SA1360/2SC3423 bipolar from Europe. I still need few resister, the diodes and trimmers.
I hope in March I will start to test the amp.
Slowly but soon I be there so I can report the result for those who interested on these project.
Greetings Gabor
I did started the PC boards stuffing, it took me a while because I needed to select the left over resisters from another projects.
Also I ordered the Toshiba 2SA1360/2SC3423 bipolar from Europe. I still need few resister, the diodes and trimmers.
I hope in March I will start to test the amp.
Slowly but soon I be there so I can report the result for those who interested on these project.
Greetings Gabor
Attachments
Hi Gabor ,
Great to see that this amp is going its way.
As pointed , no need of costly passive components , provided
they are of good quality there wont be any difference compared
to exotic brands.
The transistors are the real sound shapers but not all have the same
importance , the most criticals are the 2SA992/2SC1845 wich can be
valuably replaced by BC560C/550C as well as the 2SC3423 that is used
in the side of the current mirror that drive the lateral Pfets.
If you have trouble finding some of the small signal transistors or if they
are excessively expensive just post about it , i ll provide a list of replacements
that should yield the expected perfs.
Great to see that this amp is going its way.
As pointed , no need of costly passive components , provided
they are of good quality there wont be any difference compared
to exotic brands.
The transistors are the real sound shapers but not all have the same
importance , the most criticals are the 2SA992/2SC1845 wich can be
valuably replaced by BC560C/550C as well as the 2SC3423 that is used
in the side of the current mirror that drive the lateral Pfets.
If you have trouble finding some of the small signal transistors or if they
are excessively expensive just post about it , i ll provide a list of replacements
that should yield the expected perfs.
Thank you Wahab
Just to be clear I do not have 2SC1845 in the circuit or that is a mistake?
Right what I do not have and needed the 2SA992 but I didn't check the local store yet.
I'll go soon when the weather will be better because I need the diodes, some clad board etc.
In case if I do not get I will ask some quality replacement all do I have some Hitachi 2SB716 and complementary.
I think has same pin out.. if That is OK.
Greetings G
Just to be clear I do not have 2SC1845 in the circuit or that is a mistake?
Right what I do not have and needed the 2SA992 but I didn't check the local store yet.
I'll go soon when the weather will be better because I need the diodes, some clad board etc.
In case if I do not get I will ask some quality replacement all do I have some Hitachi 2SB716 and complementary.
I think has same pin out.. if That is OK.
Greetings G
Attachments
My bad , there s no 2SC1845...
Ok, a first possible cheap replacements :
Q3/Q4/Q9 can be 2N5551 if from reputable manufacturer.
Q11 can be BF469/471 if they are from Phillips/NXP or eventualy
a renowed brand as Fairchild but second rates manufacturers are
to be discarded.
Q5/Q6 can be 2SA872/BC560C/BC416C.
Q10 is extremely important and the 2SC3423 is to be used preferably ,
there s not other devices that are possible and easily available.
I see that you have populated Q18/Q19 , these can be whatever
small signal transistors.
The 2SB716 are exceptionnal devices and should be spared
to be used where their huge gain can be advantageous.
Ok, a first possible cheap replacements :
Q3/Q4/Q9 can be 2N5551 if from reputable manufacturer.
Q11 can be BF469/471 if they are from Phillips/NXP or eventualy
a renowed brand as Fairchild but second rates manufacturers are
to be discarded.
Q5/Q6 can be 2SA872/BC560C/BC416C.
Q10 is extremely important and the 2SC3423 is to be used preferably ,
there s not other devices that are possible and easily available.
I see that you have populated Q18/Q19 , these can be whatever
small signal transistors.
The 2SB716 are exceptionnal devices and should be spared
to be used where their huge gain can be advantageous.
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Hello
For Q5 & Q6 I have at home a lot of Hitachi 2SA872A E grade Hfe400-450...
I do not have almost any use of them since the complementary unavaleble.. I will used here.
For the other BJT I did ordered 16 pair 2SA1360Y & 2SC3423Y Toshiba.
The 16 pair must be enough for these project.
I have some Toshiba 2SA1930 & 2SC5171 at hand, may be I can use (in case for cascode) Q3/Q4 if the 16 pair would be not enough because the matching..
Greetings Gabor
For Q5 & Q6 I have at home a lot of Hitachi 2SA872A E grade Hfe400-450...
I do not have almost any use of them since the complementary unavaleble.. I will used here.
For the other BJT I did ordered 16 pair 2SA1360Y & 2SC3423Y Toshiba.
The 16 pair must be enough for these project.
I have some Toshiba 2SA1930 & 2SC5171 at hand, may be I can use (in case for cascode) Q3/Q4 if the 16 pair would be not enough because the matching..
Greetings Gabor
Yes , they are both adequate , the 2SC3953 being the better.
Great, they are even better than the 2SA992...
2SA1930/SC5171 are not adequate , they are excellent drivers
for use with usual bipolar power transistors though.
hi Gabor,
we are waiting to hear from you about the sound of the amp.
Hi alex MM,
The vizzard of PCB design, have you anything to say about the comparrison of the sound of this circuit to the famous Goldmund Memasis you did some time back.
I am awaiting eagerly torn between the two amps to start building one of them.
I would value a lot, the feed back received from you people.
At the moment I listen to Hitachi LOD HMA 4500 and Sony TA 4650 both
Vfet amps but with only 50 watts of power.
Since Wahab cct and Goldmund circuit can give in excess of 100 watts of
Vfet power, I am power hungry and waiting to select one to build.
At this moment I should also mention here that the very simple
Old Maplin 2SJ49 /2SK134 which I built 15 years ago is also a very good
contender second to none of the two commercial amps mentioned above.
Let there be Vfet sound,
srian.
we are waiting to hear from you about the sound of the amp.
Hi alex MM,
The vizzard of PCB design, have you anything to say about the comparrison of the sound of this circuit to the famous Goldmund Memasis you did some time back.
I am awaiting eagerly torn between the two amps to start building one of them.
I would value a lot, the feed back received from you people.
At the moment I listen to Hitachi LOD HMA 4500 and Sony TA 4650 both
Vfet amps but with only 50 watts of power.
Since Wahab cct and Goldmund circuit can give in excess of 100 watts of
Vfet power, I am power hungry and waiting to select one to build.
At this moment I should also mention here that the very simple
Old Maplin 2SJ49 /2SK134 which I built 15 years ago is also a very good
contender second to none of the two commercial amps mentioned above.
Let there be Vfet sound,
srian.
Hello
I did some more work.
Now I have to visit the local store to get the missing 5PC resisters, diodes and trimmers.
I didn't mounted the heatsink on the VAS transistors until I'm not finished populating 100% the board.
Also very exited to power up the amp so I can give some feed back to those who interested on these project.
I ordered twice from Ebay the trimmers and never received them, almost I waited 3 months in vain...
Greetings Gabor
I did some more work.
Now I have to visit the local store to get the missing 5PC resisters, diodes and trimmers.
I didn't mounted the heatsink on the VAS transistors until I'm not finished populating 100% the board.
Also very exited to power up the amp so I can give some feed back to those who interested on these project.
I ordered twice from Ebay the trimmers and never received them, almost I waited 3 months in vain...
Greetings Gabor
Attachments
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Hello wahab
I have a question
Can I use 1.5nF for C12 with out running in to any problem.The Q20 was added on the end (my lay out was 99% ready) so I used a small place what I had.
I do have Philips 1nF foil cap but to tall and it will block to mount the heatsink on Q20.
I do have some Audio cap 1.5nF if I can use that...
I have to see what the have at the store, I do like to avoid ceramic layer capacitors (many people say those are to noisy)
Usually they carry those cheap stuff.
What would you advise?
Please let me know.
Thank you
Greetings Gabor
I have a question
Can I use 1.5nF for C12 with out running in to any problem.The Q20 was added on the end (my lay out was 99% ready) so I used a small place what I had.
I do have Philips 1nF foil cap but to tall and it will block to mount the heatsink on Q20.
I do have some Audio cap 1.5nF if I can use that...
I have to see what the have at the store, I do like to avoid ceramic layer capacitors (many people say those are to noisy)
Usually they carry those cheap stuff.
What would you advise?
Please let me know.
Thank you
Greetings Gabor
Attachments
Hi , Gabor
The exact value of this cap is not important provided it is more than 0.3nF ,
so your 1.5nF perfectly fits the purpose assuming that it can withold 65V DC
permanently , i guess that 200V is a cautious enough rating.
Whatever model can be used , but as you point it ceramics are to be discarded.
At the risk of repeating myself , i ll point that so called audiophile
components are not necessary , the essential is in the transistors ,
the rest must simply be of industrial quality , no need of expensive
passive parts.
What values are you using for the supply electrolytics in the PCB ?..
Nice work , anyway , that is a well done compact PCB.
The exact value of this cap is not important provided it is more than 0.3nF ,
so your 1.5nF perfectly fits the purpose assuming that it can withold 65V DC
permanently , i guess that 200V is a cautious enough rating.
Whatever model can be used , but as you point it ceramics are to be discarded.
At the risk of repeating myself , i ll point that so called audiophile
components are not necessary , the essential is in the transistors ,
the rest must simply be of industrial quality , no need of expensive
passive parts.
What values are you using for the supply electrolytics in the PCB ?..
Nice work , anyway , that is a well done compact PCB.
Hello Wahab
Thank you very much!
That so called audio capacitor already had those, min. 100V I can't see the first number, is a left over from other project.
The front end electrolytic are 220uF 100V Nichicon KG type, I had those
The high power caps are 470uF 63V orig (red) Elna Cerafine. I took those out from the Grand Mos PC boards.
I hope not to much the 470uF. The size Cerafine a bit to big but I just could feet those..Bigger than the regular 1000V caps or any exotic same size caps.
I do have some (10PC) STD type 65V 560uF Black Gate capacitors to but those are brand new and may be I'll sell those.
To expensive to use those and they are not as good people do think or write about..
I do try use what I got.. All those resisters , caps etc in the PC boards I already had them.
I just need some resistor 5 or 6 piece for each side and the diodes & LED.
Thank you one more time.
Greetings Gabor
Thank you very much!
That so called audio capacitor already had those, min. 100V I can't see the first number, is a left over from other project.
The front end electrolytic are 220uF 100V Nichicon KG type, I had those
The high power caps are 470uF 63V orig (red) Elna Cerafine. I took those out from the Grand Mos PC boards.
I hope not to much the 470uF. The size Cerafine a bit to big but I just could feet those..Bigger than the regular 1000V caps or any exotic same size caps.
I do have some (10PC) STD type 65V 560uF Black Gate capacitors to but those are brand new and may be I'll sell those.
To expensive to use those and they are not as good people do think or write about..
I do try use what I got.. All those resisters , caps etc in the PC boards I already had them.
I just need some resistor 5 or 6 piece for each side and the diodes & LED.
Thank you one more time.
Greetings Gabor
Non availability of transistors in 2020
Hi Guys,
It is 2020 and even for this day, I think this amplifier would sound among the best.
I am curious to build this amplifier as I have the required mosfets.
But I am unable to get the following transistors.
1. 2SK170 or LSK170 not available. Please suggest substitution.
2. 2SC3423 and 2SA1360 are not available. Can I use MJE 340 and MJE 350 instead?
Thanks
Ganesh
Hi Guys,
It is 2020 and even for this day, I think this amplifier would sound among the best.
I am curious to build this amplifier as I have the required mosfets.
But I am unable to get the following transistors.
1. 2SK170 or LSK170 not available. Please suggest substitution.
2. 2SC3423 and 2SA1360 are not available. Can I use MJE 340 and MJE 350 instead?
Thanks
Ganesh
