thanks for suggestions sir... 🙂
can we add class h stepper?
and how max volt supply if we add class h stepper?
thanks regar
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It's possible to add class H steper and use +/-60V, +/-120V...
Can you post some pictures and what about sound ?
Regards
NAD used this at their models 2400 and 2600. For 6db more undistorted output power too much effort - so I think.
By a lot of commercial amp devices this resistors are the main reason for burned PCBs, even by such brands like Krell and Mark Levinson.
By closed chassis cover the max temperatur at the resistor should be not more than 25 degrees (better 20 degrees) about ambient.
This means resistores like follow:
http://cfnewsads.thomasnet.com/images/large/015/15067.jpg (for heatsink mount) or
http://img.directindustry.de/images_di/photo-m2/max-250-k-x003a9-5-250-w-001-1-mal-13783-3434033.jpg
http://hifibau.de/product_info.php/info/p15_Leistungs-Widerstand-50-Watt.html
Another solution is the use of 8 or 10 smaller devices in serial mode.
By the use of a TO126 outlined Transistor there is the possibility of chassis mounting (base connected to GND). Nevertheless those approach is simple, too.
Circuits from Stan Curtis used this approach e. g. Monrio MC25, Moth 30W and Mission Cyrus ONE - go to
A Paul Kemble web page - Mission Cyrus 1 integrated amplifier.
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It's simple to add transistor instead resistor but this transistor need heatsink...
would upright mounted cement be better cooled ?
but maybe 5 series mounted 2k/3watt mounted upright in a circle ?
but maybe 5 series mounted 2k/3watt mounted upright in a circle ?
That's would be too large.
I think better is use a medium trans like MJE350 + small heatsink.
reminds me, I have 'some distance' I need covered, so I could just as well use a 40mm 10watt, horisontally 😉
but this is good info to have before final layout, thanks!
2 resistors 4k7/2W series in vertical position will be ok for 1,5W disipation.
I use transistor in SR50 but there is no need for heatsink.
http://www.diyaudio.com/forums/solid-state/173462-studio-reference-amplifier-3.html
I use transistor in SR50 but there is no need for heatsink.
http://www.diyaudio.com/forums/solid-state/173462-studio-reference-amplifier-3.html
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Why do you don't cascode LTP input?!
MPSA92 have low gain, low Ft. Cascoded them with small signal devices like BC560C to get more better result.
And add an active CCS.
MPSA92 have low gain, low Ft. Cascoded them with small signal devices like BC560C to get more better result.
And add an active CCS.
"Keep it simple" seems to be your excuse for sub-standard design. This is very sad.🙁
Moreover, there is no way your choosen output transistors will safely operate from 110V rails without SOA violation with real loads. No way at all. 
I can design high-standard amplifier and I already did, but nobody don't want to build that amplifier, and this amplifier already was made by several people.
I was considering cascode LTP with zeners but I want to keep it simple, and 2SA970 can be use for LTP or some better transistors. SR50 use cascode ... and this amp is not popular at all. I don't want to build this amplifier it's only for people who want to diy it for fun.
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Moreover, there is no way your choosen output transistors will safely operate from 110V rails without SOA violation with real loads. No way at all.
Simple VI limiter keep current at 0,6A per output in shorted amp out or 3A per output with 50V output voltage.
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Apex,
I suggest you consider the audience you have attracted.
The vast majority looking at your designs are only there because you publish high power designs. These same Power hungry Members in general do not understand what makes a good amplifier and what makes a bad amplifier. All they want is silly power ratings.
I suggest you consider the audience you have attracted.
The vast majority looking at your designs are only there because you publish high power designs. These same Power hungry Members in general do not understand what makes a good amplifier and what makes a bad amplifier. All they want is silly power ratings.
the BC560 can also used by nearly direct replace. To reduce the voltage (Vce Voltage) only two additional resistors must be introduce in the collector lines. As an additional wanted effect occurs a lower thermal value above ambient (less power loss) even by enhance the idle current through the input differencial amp (3-5mA is a better value for good sound than only 1,3mA - the currently value).
This I have often realized by several high voltage audio power amps like NAD to avoid burned PCB areas arround the input stage with TO92 small signal transistors.
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http://www.diyaudio.com/forums/soli...ur-solid-state-pics-here-179.html#post2547057
APEX NX16 proba u ku?i/testing in the house AVI - YouTube
http://www.diyaudio.com/forums/soli...ur-solid-state-pics-here-179.html#post2547057
http://www.diyaudio.com/forums/soli...ur-solid-state-pics-here-223.html#post2877556
APEX F100 by 44250 (with smps power supply) - YouTube
http://www.diyaudio.com/forums/soli...imate-fidelity-amplifier-116.html#post2885214
APEX AX12 u 44250 izvedbi/done by 44250 strano - YouTube
http://www.diyaudio.com/forums/solid-state/164093-100w-ultimate-fidelity-amplifier.html#post2135804
Apex AX-11 - YouTube
Apex AX11 on Http://forum.diyaudioproject.eu - YouTube
http://www.diyaudio.com/forums/solid-state/173462-studio-reference-amplifier.html#post2300775
Apex SR200 on http://forum.Diyaudioproject.eu - YouTube
http://www.diyaudio.com/forums/solid-state/236256-retro-amp-50w-single-supply.html#post3497279
all that on one (HiFi) side and BA1200,B500 and H900 on the other (PA) side,now you could reconsider your conclusion! all other versions of HiFi amplifiers were product of someone else´s wishes for more power. APEX knows very well what is high power amplifier and what is HiFi amplifier,he proved it so many times so i don´t see what is the problem here? all i can see from you is obstrtucting mr. APEX ,unnecessarily and unjustifiable discouraging other members to build his designes. i can say that because i personaly have quite a few his amplifiers,and also personaly know so much people that just love to listen his amplifiers of all kinds.
if you are bothered by type of people that APEX attracts here,please help yourself by sharing some of your designes that are more HiFi than those with APEX logo and i am sure that people will appreacheate and follow you and your work.
what APEX said ever to ostripper,or Nelson Pass,or anyone else for sharing their designes? on the other side - what ever said ostripper,Nelson Pass or anyone of reckognised designers to mr.APEX? NOTHING because they are not bothered each with other,they are looking their bussiness and their designes,trying to improve themselves and their designes,minding their own bussiness,keeping their nose where it should be.
try to share some designes instead suggestions like previous one...
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I know that but I can't change what they want, there is many bad designs on the net, and there is many comercial brand amplifier similar to BA1200. This amplifier is simple and work, it is good enough for diy.