Thanks both of you.
If i do some math, it look like i have to draw near 6A, if using only one psu.
My onechannel AlephJ mini draws 1,3-1,4A, so two channels will be double (2,8A)
This is meassured on the +19vdc supply rail, so the same amount will be drawn on -19vdc rail i guess.
This will be all together 5,6A; so near the limit of 6A.
Will that work?
Jesper.
Btw.: If we can discuss this in my thread it would be better. I dont want to spoil youre thread Juma.
My thread is in my signature. And i will post youre PSU schm. there Juma shortly!
If i do some math, it look like i have to draw near 6A, if using only one psu.
My onechannel AlephJ mini draws 1,3-1,4A, so two channels will be double (2,8A)
This is meassured on the +19vdc supply rail, so the same amount will be drawn on -19vdc rail i guess.
This will be all together 5,6A; so near the limit of 6A.
Will that work?
Jesper.
Btw.: If we can discuss this in my thread it would be better. I dont want to spoil youre thread Juma.
My thread is in my signature. And i will post youre PSU schm. there Juma shortly!
Google "class A amplifier". You'll find a lot of reading material on this subject at Nelson Pass' websites - DIY and FirstWatt.
As an ultimate experience I recommend to build this amp and see for yourself what's the sound and measurement difference between the class A and 40mA bias (I did it long ago).
As an ultimate experience I recommend to build this amp and see for yourself what's the sound and measurement difference between the class A and 40mA bias (I did it long ago).
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Hello, could you please share your measurements results? I like very much the F5 simplicity. I have a F5 v3 board assembled, I need to check but I think I can adapt my board to a cubie ... but I'm very interested on a low bias .
Thanks
Sorry Bruno, but it seems that I don't have those notes with me. When I made this amp I lived in Belgrade and later that year I moved to Berlin, so I must have left them at my house in Belgrade.
Anyway, I remember that although THD was not spectacular (about 0.01) it consisted of low order harmonics only (H2 & H3), adjustable by usual tricks ("P3", small source resistor for output MOSFETs, etc...).
You'll find square wave response (90kHz at pure resistive and highly reactive load) in post #1. The amp is very fast and stable.
What I remember too is that it was very pleasant to listen with my Canton ct-1000 speakers (overall impression more on the "gentle" side) but later, on my Epos M5 (I brought them with me to Berlin because they are smaller) it sounded a bit too "gentle" so I moved on to Cubie2, 3 etc...
Have in mind that Cubie is a 10W amp so if you need more power you'll have to look somewhere else or redesign it a bit (few small interventions will turn it into F7 - all the info needed is in the F7 thread).
Anyway, I remember that although THD was not spectacular (about 0.01) it consisted of low order harmonics only (H2 & H3), adjustable by usual tricks ("P3", small source resistor for output MOSFETs, etc...).
You'll find square wave response (90kHz at pure resistive and highly reactive load) in post #1. The amp is very fast and stable.
What I remember too is that it was very pleasant to listen with my Canton ct-1000 speakers (overall impression more on the "gentle" side) but later, on my Epos M5 (I brought them with me to Berlin because they are smaller) it sounded a bit too "gentle" so I moved on to Cubie2, 3 etc...
Have in mind that Cubie is a 10W amp so if you need more power you'll have to look somewhere else or redesign it a bit (few small interventions will turn it into F7 - all the info needed is in the F7 thread).
Hello Juma. 0.01 % is a very good distortion, you know speaker drivers and room acoustics will distort the overall sound much ... much more then that. with a very good speaker driver will you maybe get 0.4-2% distortion.
I read the whole thread with great interest and I was tempted to try this little amp. My speakers have a sensitivity of 96dB, so I think there will be no problem for Cubie to drive them.
I wonder whether I could use current production lateral MOSFETs, namely the Exicon EXC10N20 and EXC10P20. I think that they come in matched pairs by the manufacturer.
I wonder whether I could use current production lateral MOSFETs, namely the Exicon EXC10N20 and EXC10P20. I think that they come in matched pairs by the manufacturer.
Giasou Kenev,
Cubie ia a nice little amp indeed, but Cubie 2 is better and it isn't much more complicated.
Also, if you look at the F7 thread you'll see that it's easy to turn a Cubie into F7.
Exicons are practically the same thing as 2sk1058/2sj162 (which are current production too and there is a groupbuy for them gong on now:
http://www.diyaudio.com/forums/group-buys/307426-sj162-sk1058-groupsbuy.html ).
You can also buy k1058/j162 on many sites (reichelt.de for example).
I don't really know if Exicons come as matched pairs from manufacturer but I doubt it...
Na'sai kala !
Cubie ia a nice little amp indeed, but Cubie 2 is better and it isn't much more complicated.
Also, if you look at the F7 thread you'll see that it's easy to turn a Cubie into F7.
Exicons are practically the same thing as 2sk1058/2sj162 (which are current production too and there is a groupbuy for them gong on now:
http://www.diyaudio.com/forums/group-buys/307426-sj162-sk1058-groupsbuy.html ).
You can also buy k1058/j162 on many sites (reichelt.de for example).
I don't really know if Exicons come as matched pairs from manufacturer but I doubt it...
Na'sai kala !
Geia sou juma,
Thank you for your immediate response! I hadn't notice the emergence of Cubie 2. Now, I will have to read the Cubie 2 thread and decide. But, since you suggest that ver. 2 is better, I have no reason not to follow your recommendations.
Regarding the lateral MOSFETs, I saw the gb thread and I might order a couple (if I'm not too late), but I quote from the last message by touchdown in that thread:
"Since the price difference is low (3.97 vs 4.19E) I vote for Exicon selected ones ...
Matched MosFets, no issues on P channel behavior, right price ... I think you can't get better Laterals in the market!
Just my opinion, though 🙂"
So, maybe I should order from Exicon.
Thank you again,
Na' sai kala kai sy!
Vagelis
Thank you for your immediate response! I hadn't notice the emergence of Cubie 2. Now, I will have to read the Cubie 2 thread and decide. But, since you suggest that ver. 2 is better, I have no reason not to follow your recommendations.
Regarding the lateral MOSFETs, I saw the gb thread and I might order a couple (if I'm not too late), but I quote from the last message by touchdown in that thread:
"Since the price difference is low (3.97 vs 4.19E) I vote for Exicon selected ones ...
Matched MosFets, no issues on P channel behavior, right price ... I think you can't get better Laterals in the market!
Just my opinion, though 🙂"
So, maybe I should order from Exicon.
Thank you again,
Na' sai kala kai sy!
Vagelis
Vageli file, den ksero ti na sou po gia tous Eksikons - einai ligo parakseno... 
He says: "selected ones" - maybe they can be ordered as matched pairs ? I don't really know - I had experience with two pairs of Exicons only and they were not matched...
He says: "selected ones" - maybe they can be ordered as matched pairs ? I don't really know - I had experience with two pairs of Exicons only and they were not matched...
I checked datasheets for ECX10N20 and ECX10P20 and they show quite a difference in curves - I would not call them a matched pair (unless someone does a selection/matching job before sending them to customers).
Edit: OK, I've searched some more and found a page about their "selected" parts. it's here:
http://www.profusionplc.com/parts/ecx10n20-s
So, it's not really about matching P to N parts - it's matching N parts to N parts and P parts to P parts which makes paralleling easier, but it's not really tight - about 10% matches are offered. I can live without that because k1058/j162 come naturally in that match span. Matching P to N would be good ...
Edit: OK, I've searched some more and found a page about their "selected" parts. it's here:
http://www.profusionplc.com/parts/ecx10n20-s
So, it's not really about matching P to N parts - it's matching N parts to N parts and P parts to P parts which makes paralleling easier, but it's not really tight - about 10% matches are offered. I can live without that because k1058/j162 come naturally in that match span. Matching P to N would be good ...
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So, it seems that your Greek is pretty good - how come this?
Well, I will better stick to the original 2SK1058/2SJ162 pair. A quick search in ebay gave plenty of results of available pairs, as, for example:
1pair Transistor HITACHI TO-3P 2SJ162/2SK1058 J162/K1058 100% Genuine and New | eBay
100% New And Genuine 2SJ162 2SK1058 Transistor K1058 J162 TO-3P | eBay
Could I trust such vendors?
I have two questions regarding those MOSFETs:
1. Is it necessary and/or possible to match P and N channel MOSFETs? And, if yes, how close this matching should be?
2. Could this 2SK1058/2SJ162 pair be used also to build an F7?
Regards,
Vagelis
I lived 4 years long in Athens kai ematha ligaki tin Elliniki glossa... 😀
1. No need to match P to N - they are close enough by nature.
2. Yes - All modern lateral Mosfets are spin-offs of original Hitachi parts (2sk135/2SJ50) and they hardly differ one from another.
So, Exicons, Profusion or Renesas doesn'r really matter, but don't buy them on ebay, there's a 99% chance that you'll buy fake parts. Buy from big renowned sellers (Reichelt, Mouser, Digikey, Farnell and similar).
1. No need to match P to N - they are close enough by nature.
2. Yes - All modern lateral Mosfets are spin-offs of original Hitachi parts (2sk135/2SJ50) and they hardly differ one from another.
So, Exicons, Profusion or Renesas doesn'r really matter, but don't buy them on ebay, there's a 99% chance that you'll buy fake parts. Buy from big renowned sellers (Reichelt, Mouser, Digikey, Farnell and similar).
Den emathes aplos ligo tin Elliniki glossa, tin emathes poly kala!
Thank you for your help so far. I am going to get a few pairs from the still ongoing forum group buy.
Best regards,
Vagelis
Some speakers are sensitive to humidity.. who knows what is the cause of 'gentle touch'..
Yes, humidity is a factor - nothing sounds dry here 😊
Those 14A laterals are two 7A pieces in one case/package
Those 14A laterals are two 7A pieces in one case/package
