VAS bias is high - 10-15mA, so for thermal stability it is important to put them on the main heatsink (this would be the best).
Hi Gabor i have no intention for moment to change output devices on this board so they have time to burn in. Next work will be on vesatil that will use at first sanken devices. have some hard finishing work on versatil case and will direct compare BG1-MJL to Versatil-Sanken even if one is with simple PSU and other with Capmu.
Marc
In case anyone is interested, more 'warmth' can be obtained by lowering one of the two 100R feedback resistors to say 82R with very little effect on bias and offset.
For illustration, some quick simulation furriers...
Attachments
Thank you Marc
I do have at least 40-45 pair of these MJL-s from ON semi, good to know they aren't bad compare to the Sankens.
I do have some Sankens but I'm not sure if they orig or counterfeit.
I did use them once and for some reason they blew up at first power up in a amplifier circuit (DoGC) more than 35 guys successfully built before me.🙄
All do I got those here in Toronto local store not from Ebay I do had the luck😀 they sold me fake semis several times.
Of course they do not refund even if they aren't soldered or used.
Not even the day of purchase.
I do want to start with the Toshiba power mosfet.
When you test your Capmu PS please let us know how these amplifier it perform that.
I used mine from ESP Capmu. PS with Hiraga Class A.
The performance very much depend on the quality of the transistors used, and is for Class A.
It has some strength over the regular PS but also has some weakness to.
I would like to find something better for Class A/B (low) biased amps.
Many guy wrote the similar result from regulated or Capmu PS
the sound of the amp become thin and lose some of the dynamics, bass😱
Greetings Gabor
I don't be sure my sanken aren't counterfeit...MJL are more then just "not so bad compare to Sanken". The sound has a more clean presentation and the less airy they have is less and less disturbing while listening session progress, as the the sound is more well balance in sound stage "large versus deep". I am surprising me more to close eyes during music to sink into...really sweet sensation...Music seems to flow without make up...as for women...the fisrt you see is the one with a execess make up and final you heart balaced to more natural/balanced presentation😀😀😀...wil doing more hearing session and will try may be the NJW3281/1302...
Marc
In case anyone is interested, more 'warmth' can be obtained by lowering one of the two 100R feedback resistors to say 82R with very little effect on bias and offset.
For illustration, some quick simulation furriers...
Hi Shaan !
Thanks for you suggestion and graphs !
Your 100R/82R graph results very close to so called `waterfall`THD sprectrum , where many people sense that sound same as you say as `warm` , less fatiguing for listening and preferable , regardless for increased THD % .
Best Regards !
Last edited:
Hi Borys,
Thank you for your posting of PSU. Could you post the pdf laylout of bg psu7.jpg? I like it. TIA.
Regards,
Boyet
Attachments
I continue to play with MJL4281/4302 bias alternating with listening session => first 50mA, than 30mA, after return to 50mA.
-50mA was little to Dark for me
-30mA was little "metal bow sounded" with singer center but...wide back of the stage
Than i test 40mA (8.8mV over 0R22 emitter resistor), and that it, the right sweet spot that out perform Sanken configuration : more clean sound, more equilibrate sound stage (wide versus deep), more define and deep bottom end and greater impact in this area too...so for me i can clam Onsemi MJL4281/4302 as winner in BG1-BJT...next step is to test NJW3281/1302 and MJL3281/1302...
One fact is sure listening session bring me a whole amount of pleasure...do you know when "Foot tapping" come in action...
Marc
-50mA was little to Dark for me
-30mA was little "metal bow sounded" with singer center but...wide back of the stage
Than i test 40mA (8.8mV over 0R22 emitter resistor), and that it, the right sweet spot that out perform Sanken configuration : more clean sound, more equilibrate sound stage (wide versus deep), more define and deep bottom end and greater impact in this area too...so for me i can clam Onsemi MJL4281/4302 as winner in BG1-BJT...next step is to test NJW3281/1302 and MJL3281/1302...
One fact is sure listening session bring me a whole amount of pleasure...do you know when "Foot tapping" come in action...
Marc
shaan
Thanks a lot for your sim plots. There is defenetly a way to do a very small tweek to create amp ''signature'' in sound spectrum, but definetley it requires some time to spend on it.
boyet0173
Bellow you have both supply boards for caps diameter 25mm and 35mm.
In both versions You can put power resistors under the board. I have used 1W 1R smd resistors.
Thanks a lot for your sim plots. There is defenetly a way to do a very small tweek to create amp ''signature'' in sound spectrum, but definetley it requires some time to spend on it.
boyet0173
Bellow you have both supply boards for caps diameter 25mm and 35mm.
In both versions You can put power resistors under the board. I have used 1W 1R smd resistors.
Boban thanks for compliment. According to latest listening results i decided to forgive MT200 versions to TO264/TO3P versions.
Marc
Here VERSATIL 50 : one output pair devices and +/-35Vdc rail. Board size 105x88mm
Attachments
Last edited:
Here VERSATIL 100 : 2 output pair devices and more than +/-45Vdc rail with BC556C/BC546C as input pair. Board size 125x88mm
Attachments
Last edited:
Hi Marc,
so the MT200 version is not so good compared to TO264/TO3P version?
I have a lot of MT200 like you use, they are very rugged 🙂
John for my MT200 the decision is clear, but yet are mine original or fake. If some one wants/need MT200 layout it is on my HD plate, but due to listening results and output devices availability and relaybility the better things to do is going for TO264/TO3P configuration.
Marc