As a layman it is pain for me to build a input stage with transistors. to match same hfe/characteristic of Transistor, Current Mirror with lot of equations, etc etc... makes me crazy!! then I found a vintage diagram from the internet that inspire to build that amp.
so, which one will be good for the input stage, Transistor or OP-AMP? did I do some thing wrong in the schematic? Please comment.
Thanks
opu
so, which one will be good for the input stage, Transistor or OP-AMP? did I do some thing wrong in the schematic? Please comment.
Thanks
opu
Attachments
You don't need 300w (assuming stereo) for home audio. What you need is good high SPL speaker drivers. For subwoofer duty, 150w is still quite high for home entertainment.
@NanoFarad This amp will use on of my friends who has Wilson Tower Speaker, Mordaunt-Short book shelf, CAT Speaker and Canton Speaker.
That RCA 300w diagram is a moldy oldy from the era before Motorola invented SOA to qualify transistors. About 1980 on Moto power transistors trounced RCA in the dirt. Starting with MJ802. You don't need 8 pairs outputs anymore for 300W. Any power amp that high powered would be class H with dual voltage rails, if not class D digital (which cannot be diy). The second schematic with 5532 could work, but 2sa1943 2sc5200 are a bit wimpy when one can buy On Semi MJ15024/25.
Really for large home power amp one should buy the honeybadger kit from diyaudio store. See the link up in the banners.
My solution is PA speakers with 98 db 1w1m sensitivity and Harmonic Distortion 25 db down from 5 w output. I can drive myself out of the room with 50 w/ch. Peavey SP2(2004), most affordable copy of the Altec/JBL series VOT to 4367 to M2 (which I cannot audition and never could buy in my flyover city).
Really for large home power amp one should buy the honeybadger kit from diyaudio store. See the link up in the banners.
My solution is PA speakers with 98 db 1w1m sensitivity and Harmonic Distortion 25 db down from 5 w output. I can drive myself out of the room with 50 w/ch. Peavey SP2(2004), most affordable copy of the Altec/JBL series VOT to 4367 to M2 (which I cannot audition and never could buy in my flyover city).
Last edited:
Although this a DIY website, if you are wanting a power-amp of 300W + per channel I would first check Ebay etc.
Here is an example of absurdly low cost for 700W per channel with TRUE HiFi specifications. ( miles ahead of old RCA circuits )
https://www.ebay.com.au/itm/296515230266?_trkparms=amclksrc=ITM&aid=777008&algo=PERSONAL.TOPIC&ao=1&asc=20240131095853&meid=8f14607db20548eeacfc14beaf040f08&pid=101949&rk=1&rkt=1&itm=296515230266&pmt=0&noa=1&pg=4375194&algv=RecentlyViewedItemsV2&brand=Mackie&_trksid=p4375194.c101949.m162918&_trkparms=parentrq:80f877d51900a57d2d2397e9ffff4416|pageci:fd5728d2-3a7f-11ef-a992-5e1f2535cf5d|iid:1|vlpname:vlp_homepage
( heavy weight / high cost postage though )
Here is an example of absurdly low cost for 700W per channel with TRUE HiFi specifications. ( miles ahead of old RCA circuits )
https://www.ebay.com.au/itm/296515230266?_trkparms=amclksrc=ITM&aid=777008&algo=PERSONAL.TOPIC&ao=1&asc=20240131095853&meid=8f14607db20548eeacfc14beaf040f08&pid=101949&rk=1&rkt=1&itm=296515230266&pmt=0&noa=1&pg=4375194&algv=RecentlyViewedItemsV2&brand=Mackie&_trksid=p4375194.c101949.m162918&_trkparms=parentrq:80f877d51900a57d2d2397e9ffff4416|pageci:fd5728d2-3a7f-11ef-a992-5e1f2535cf5d|iid:1|vlpname:vlp_homepage
( heavy weight / high cost postage though )