wputera said:
richie00boy said:
I don't think you will quite get that much power. Consider the following (with a big power supply).
45v - 1v(bridge) * 1.414 = 62.2 volts DC
62.2 - 5% (regulation @ full power) = 59.1v DC
59.1 - 6v (FET drop) = 53.1 * 0.707 = 37.54 DC RMS
37.54v into 4 ohms = 352 watts (still pretty good)
You should get around 190 watts into 8 ohms (also pretty good).
Cheers
Q
okay Quasi n Richie, thanks again. do u have any suggestion a schematic pre amp for Quasi amp under developtment? I have 4 transistors 2sk 1058 without 2sj 162. How about replacing IRFp450 with this transistor? Or maybe Quasi have any idea about using 2sk1058 as N-channel amplifier?thanks guys 
I'd have to say Greg's SKA has easily the best schematic -
It's simple, symmetrical and delivers great all round performance and amasing sonics!
Look at the tests done by gapag and the reviews both here and elswhere. He could have taken this the exotic audiophile route but chose to make it available as a very reasonably priced kit to share with DIYers everywhere.
The GB300D will do 300W at < 0.025% efficiently using lower supplies and a smaller tranny than most.
And the sound - magnificent.
It's simple, symmetrical and delivers great all round performance and amasing sonics!
Look at the tests done by gapag and the reviews both here and elswhere. He could have taken this the exotic audiophile route but chose to make it available as a very reasonably priced kit to share with DIYers everywhere.
The GB300D will do 300W at < 0.025% efficiently using lower supplies and a smaller tranny than most.
And the sound - magnificent.
how about this schematic ?
i think it is simple too. http://www.wdehaan.demon.nl/various/mjamp/index.html
But how to measure the bias?How many watt for 8 ohm load? What do u expect about this amp? Thank you guys.
i think it is simple too. http://www.wdehaan.demon.nl/various/mjamp/index.html
But how to measure the bias?How many watt for 8 ohm load? What do u expect about this amp? Thank you guys.
HiFiddle: I have never seen Greg's SKA schematic, could you enlighten us about it? Also would you be be so kind as to post the link to the review by gapag you mentioned, thanks.
acoustixman: nice to make your aquintance also. Yes I am interested in emailing you to have a look at your schematic, but it seems I cannot email you due to "being under moderation".
wputera: yes a very simple schematic, looks alot like the Hiraga which you can find out about here:
http://www.tcaas.btinternet.co.uk/hiraga1.htm
Sorry to all if the above looks a bit strange....I haven't worked out how to place multi-line originals as a "quote", and i also havn't figured out how to include the original posters name
... sorry for any offence taken, certainly none was intended... 
The main reason is the fact, that I hate so called "true complementary" topologies, both by the use of BjT or MOSFET output power devices. Unfortunately the most commercial topologies work so.
Yes. please read post #83 aboutAny (logical) reason?
http://www.diyaudio.com/forums/soli...odels-quasi-complementary-power-output-9.html
and post #1 about
http://www.diyaudio.com/forums/soli...ended-integrated-power-amplifier-devices.html
push pull topologies without so called "true complementary" output power stages you will find about this URL collection:
http://www.diyaudio.com/forums/soli...e-ended-related-solid-state-output-stage.html
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Hi Tief, are you saying that you hate class-B amplifiers?
Thanks for the post#83. The Altec 1590 topology is very similar to my PA/ceiling amps. I'm searching for the best possible modification for the amplifiers and the Altec is perfect if the sound quality is as good as being said.
I see that the circuit is single ended with little bias. But to force linearity it uses rough bias/feedback. Resistor divider networks, too many capacitors in the signal path (to block DC). The result is a highly distorted/noisy amp. The spec says below 1% (which is big). You may say that THD doesn't say much but I'm sure it is audible in this amp (like in mine). My amps are capable of 40Hz, the Altecs are specified 45Hz. I don't think the Altec is high-end, but I hope it is!
No, not in general. The disadvantage is harsh sound in high frequency aera above approxximately 5 KHz. But the advantage is a clear and tight bass transmission. For Tweeters pure class a (at best single ended) is the royal way.Hi Tief, are you saying that you hate class-B amplifiers?
I haven't heard and investigate the Altec 1590. This means, that it may be quite, that it's sound is very bad through certainly (me unknown) design errors resp. through unwanted parasitic effects.
Please note: If you have found the best possible circuit topology, you don't have automaticly the best sounded amplifier.
I have just followed some links regarding the Altec amp. It is indeed a low-end amp
I guess the crossover effect in class-B will be minimized if the voltage transformation is kept low, hence current-driven. Using lateral mosfet and a properly designed speaker (using ultra high frequency tweeter such as the dynaudio) I don't think I have ever needed more in the treble region. The speaker affects the treble more than the amp (speaking of hi-end amps) anyway.
Speaking of the best schematic, I wonder why nobody interested to improve the performance of the Mooly's amplifier. Searching for the most suitable transistors, increasing the slew rate (higher rail, regulated front end), removing the feedback cap, improving linearity, improving power etc.
The key to my amplifier implementations is the choice of the transistors!
I guess the crossover effect in class-B will be minimized if the voltage transformation is kept low, hence current-driven. Using lateral mosfet and a properly designed speaker (using ultra high frequency tweeter such as the dynaudio) I don't think I have ever needed more in the treble region. The speaker affects the treble more than the amp (speaking of hi-end amps) anyway.
Speaking of the best schematic, I wonder why nobody interested to improve the performance of the Mooly's amplifier. Searching for the most suitable transistors, increasing the slew rate (higher rail, regulated front end), removing the feedback cap, improving linearity, improving power etc.
The key to my amplifier implementations is the choice of the transistors!
...only before tweaking.I have just followed some links regarding the Altec amp. It is indeed a low-end amp
If you don't like multi-amping systems (i. e. individual circuit topologies for each speaker frequency aera, by three way this means an amp for bass, midrange and high frequency aera - actually the royal way), and you want to have only one big amp for all the aeras at your speakers, I would say, the circlotron (CSPP=Cross Shunt Push Pull) / PPP=Parallel Push Pull) is the best of all topologies.
Check out the URLs by
http://www.diyaudio.com/forums/soli...e-ended-related-solid-state-output-stage.html
and there:
http://www.diyaudio.com/forums/soli...-names-commercial-solid-state-amplifiers.html
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Hi, tief. Thanks, thats interesting links.
There are other reason to get 100W-1000W. Circlomos Isn't classB, and only +/-35V. The difficult things in 100W and up are many things, like thermal, efficiency, component limitations, then how to prevent classB from creating noises when there is any current back from loudspeaker, manage the damper, failure protections, and some more.
Speed and matching devices is not everything (sometimes not needed), single ended classA facing just a current source, and loudspeaker itself is very different between front and back.
There are other reason to get 100W-1000W. Circlomos Isn't classB, and only +/-35V. The difficult things in 100W and up are many things, like thermal, efficiency, component limitations, then how to prevent classB from creating noises when there is any current back from loudspeaker, manage the damper, failure protections, and some more.
Speed and matching devices is not everything (sometimes not needed), single ended classA facing just a current source, and loudspeaker itself is very different between front and back.
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