Nice work Marc.🙂
Did you had the chance to test these amplifier with the Cap Multiplayer PS?
If yes how does compare with your regular power supply?
Please let me know, many people say regulated or Cap multiplier power supply does lose (cut the dynamic) the dynamic and the sound all over become much thiner and clinical.
If you already tested please share your result with us
Thank you
Greetings G
Did you had the chance to test these amplifier with the Cap Multiplayer PS?
If yes how does compare with your regular power supply?
Please let me know, many people say regulated or Cap multiplier power supply does lose (cut the dynamic) the dynamic and the sound all over become much thiner and clinical.
If you already tested please share your result with us
Thank you
Greetings G
Idefixes
Why thers no holes between radiators on the bottom? Air must flow through them.
I have one more question to you Borys before I produce my PC boards.
Would you be so kind please take a look at these two circuit and please let me know which one would you use with Toshiba 2SK1531 & 2SJ200 mosfet.
The main difference between the two schematics the parts in the red plus one has BJT heat sensor the other mosfet.
Actually I could use the mosfet with both circuit all do I do not have on hand IRF540, but that is not a problem.
I remember you wrote for power mosfet you would use mosfet sensor.
My main question the parts marked with red, I do not understand 100% their function.😱
One more time if you could take a look please and let me know which one would be better or which one would you pick for the power Toshiba so I can go on and produce my PC boards.
Thank you very much🙂
Greetings Gabor
Would you be so kind please take a look at these two circuit and please let me know which one would you use with Toshiba 2SK1531 & 2SJ200 mosfet.
The main difference between the two schematics the parts in the red plus one has BJT heat sensor the other mosfet.
Actually I could use the mosfet with both circuit all do I do not have on hand IRF540, but that is not a problem.
I remember you wrote for power mosfet you would use mosfet sensor.
My main question the parts marked with red, I do not understand 100% their function.😱
One more time if you could take a look please and let me know which one would be better or which one would you pick for the power Toshiba so I can go on and produce my PC boards.
Thank you very much🙂
Greetings Gabor
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Look better to pictures there hole that cover whole heatsink fines ...
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Not tryed yet as only one capmu is assembled and i am in dual mono configuration.
Marc
The parts marked with red square is boostrap for vas stage - take a look at this topic at the 1-2 pages there are scope diagrams how it works.
With boostrap output swings nearly rail to rail, with no boostrap output is loosing around 7V each supply rail!
Better of to use first schematic with bjt as temperature sensor, the 2sj/2sk toshiba mosfets would be over compensated around 30% in this case.
So You will have to set the bias at 130mA and after 20min you should get around 100mA. Toshiba mosfets and hexfets have different temperature characteristics.
If you do not need super efficient amp do not have to mount boostrap, get transformer with 2x30V ac and you will have around 80W@8R.
Idefixes
I hope You had good hilidays. Now there is ''the amp'' time so have to working hard.
BTW
I am using simple psu with: DC protect, speaker ON delay, fast speaker OFF function. If someone will need I will post rest of the files.
There is movie how it works:
BG psu v1 - YouTube
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Hi,
I am following Marc thread on a French forum.
I think making a VERSATIL 50 amp with BD139/140-16.
The driver MJE15034/35 could be without changing the diagram?
Thanks.
I am following Marc thread on a French forum.
I think making a VERSATIL 50 amp with BD139/140-16.
The driver MJE15034/35 could be without changing the diagram?
Thanks.
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Maybe it is possible to use BD139/140 (16?) for VAS and driver like the ESP P3A amplifier : 60-80W Power Amplifier
The bd139-16 140-16 are doing good job in this circuit and they have gain about 200. Just bare in mind they are only up to 80V.
I just change on my BG1 Saken transistor for MJL4281/4302 to explore ths way. As BYRTT said thay are less airy but seem afetr first listening better balanced in sound stage that win in deepness and better singer/instruments localisation...I will qualify them for more natural. I space to do the tansistor changes i replug my NBIP3 and i can say that this amp is really near to waht présent BG/VSSA familly. At first i deceded to dismantel it but will in final keep it a ending finishing its enclosure.
In Sanken/MJL duel i have impression that onsemi parts have a better (more detailed) lower end frequency, that could be the reason that they seems more airy to as whole equilibrium is displaced. I lower bias with onsemi configuration from 50 to 30mA and win a bit more air in sound. I will lat play this configartion a time to confirm impression. Nbip is just located under BG1 so i can swap to him to have more possibility...
Marc
In Sanken/MJL duel i have impression that onsemi parts have a better (more detailed) lower end frequency, that could be the reason that they seems more airy to as whole equilibrium is displaced. I lower bias with onsemi configuration from 50 to 30mA and win a bit more air in sound. I will lat play this configartion a time to confirm impression. Nbip is just located under BG1 so i can swap to him to have more possibility...
Marc
Hi boris, I know that the bd139-16 140-16 are good for VAS, but do you think that they could be use as Driver like the ESP P3A amplifier ?
sound.westhost.com/project3a.htm
Marc, do you have match your MJL ? I only have 4 each
thanks
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Idefixes
The more air in sound can be obtained by increasing slightly harmonic distortion, lower the bias further and take a listening session, than set the bias at 100mA per device and repeat the listening session - the result can be really suprising sometimes.
The more air in sound can be obtained by increasing slightly harmonic distortion, lower the bias further and take a listening session, than set the bias at 100mA per device and repeat the listening session - the result can be really suprising sometimes.
1. Set bias around 10mA per o/p transistor
2. Do listening session - 3-5 songs that you know very well
3. Increase bias up to 100mA per o/p transistor
4. Do listening session - the same 3-5 songs
I found amps with high performance on the ''paper'' very clear, like sound is just going threw them without any modyfication, but character of te charmonics is adding small bit to the output (even if THD measurement is low). I do not know how to explain so I will give an example.
Bellow is BG3 amp with 3 modulated signals, products of the signals are visible on the left and on the right of them.
I just have changed one resistor pair for reducing bias in input diamond stage, resul can be measured and can be heared! (yes I know that it sounds supid cause thd 0.1 - 0.001% doesnt make any difference).
I think no level of distortion but characteristisc of them is creating the amp 'sounding'.
The amp on the left: very soft base, I think is going deeper than it really is, top end very delicate and bitt hidden.
The amp on the right: bass is less deep but bit improved dynamics, there is more top end or looks like the high's are more acurate.
I do not know if it will make any sense but I was listening amp on the left and on the right for whole week and difference between them are only 2 resistors.
So conclusion is: change the bias setting (haracteristics of harmonics will change a bit) and listen to it to compare.
2. Do listening session - 3-5 songs that you know very well
3. Increase bias up to 100mA per o/p transistor
4. Do listening session - the same 3-5 songs
I found amps with high performance on the ''paper'' very clear, like sound is just going threw them without any modyfication, but character of te charmonics is adding small bit to the output (even if THD measurement is low). I do not know how to explain so I will give an example.
Bellow is BG3 amp with 3 modulated signals, products of the signals are visible on the left and on the right of them.
I just have changed one resistor pair for reducing bias in input diamond stage, resul can be measured and can be heared! (yes I know that it sounds supid cause thd 0.1 - 0.001% doesnt make any difference).
I think no level of distortion but characteristisc of them is creating the amp 'sounding'.
The amp on the left: very soft base, I think is going deeper than it really is, top end very delicate and bitt hidden.
The amp on the right: bass is less deep but bit improved dynamics, there is more top end or looks like the high's are more acurate.
I do not know if it will make any sense but I was listening amp on the left and on the right for whole week and difference between them are only 2 resistors.
So conclusion is: change the bias setting (haracteristics of harmonics will change a bit) and listen to it to compare.
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Sorry to bother again Boris, I already have paired transistor 2N2340/2N5416 (50 each)
Marc knows them well because having used for the Zenquito with 2SK1058
What is the bias VAS ?
Thanks
Marc knows them well because having used for the Zenquito with 2SK1058
What is the bias VAS ?
Thanks
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Marc if you run the MJL-s for a while 50-100 hours to get some burn in also probably will get a bit more air into the sound.
Those MJL my favorite compare to the similar Toshiba or other MJL type.
I never had the chance to test these large Sankens for that reason these comparison is very valuable to me.
Thank for the test report!🙂
Greetings Gabor
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