Jaycar/Silicon chip Studio 350 opinions?

[Optical]

Is there a general opinion of this amplifier? It doesnt look too bad in terms of simplicity and performance. How would you compare it to say the p3a?


All the studio350 details are online here:

part 1

part 2

[Optical]

ok, well i have just finished building two of these suckers..
I managed to build them both into a 3U rack case too

so far i have only tested it out with 4R subwoofers and the only sub that could handle even half teh power was a phenix gold 1000W 15". anyway, that doesnt say much..

I have a question, how could i put an attenuator pot on the input as a volume control? After reading so much debate on the gainclones im no longer sure i can use a pot without upsetting the frequency response as the intended use is for full range studio monitors

I'll post some pics and full range impressions when i can

here is the schematic

http://us1.webpublications.com.au/st...00503_15mg.jpg

[Stocker]

but how does it sound?

[Optical]

well, fantastic for subs.. but in a few days i will have them hooked up to some studio monitors and then some large full range cabs .. time will tell!

[Mandrake5]

I have just finished to build one, with only half of the power transistors. And i made some tortures to this great amplifier. I plug it to my electrostatic loudspeaker prototype, about 0.5 ohms of impedance... I have plenty of power and audio spectre is excellent maybe a little too brite. But this can be corrected with a simple equaliser circuit.

What amazed me is the high PSRR when there is no signal input there is absolutly no hiss or hum hearable even the ear stuck to the speaker.
And i have just 5400uF on each side of the dual supply polarities.

There is still some errors in the construction details, like the output self
6.8uH. In the text they says use a 3 meters long 1mm diameter copper wire... In reality it's 1 meter long. You have to use 0.5 inch diameter inside core make about 6 turns each layer (that make about 0.25 inch of thickness) and you repeat for about 3 layers, +- 21 turns. It's difficult to layers rigid wire like that it tends to spread between previous layers, so i put a tape on top of each layer. Voila!

Here is a photo of my prototype:[IMG]Close up[/IMG]
[IMG]My prototype at work[/IMG]

[Mandrake5]

I think that the electromagnetic canceling topology
greatly improve the quality of this amplifier. I've compare
this design to some others and found that performance
is very high for a not so complex circuit. I encourage even
beginners to build this Studio350. Just make shure to follow
first testing instructions very well, because quiescent current
can destroy your complete high power transistors in split second...


A photo of my loudspeaker protype.


[IMG]My prototype[/IMG]

[Scott_drake]

I have a 300VA 50-0-50v toroidal transformer lying round. Will this supply be enough to power this amp. And does anyone know the actual PCB dimensions.

Thanks Scott

[jmateus]

I've built two versions of this excellent amplifier, one for subwoofer purposes the other as a regular amplifier.
I'm very happy with the sound quality and simplicity of construction and above all with the setup after the construction.
No noise, no hum, a very quiet amplifier.

I think that after the SC480 this amplifier satisfies my needs
either as a subwoofer amp or a full range one.

[awpagan]

It is very easy to convert this amp to
regulated power supply on the input stage and unregulated on the output

allan

[TOHEED]

Hi there i'm newbie

You, Mandrake5 or some one, Can please post the complete
testing instruction of Studio 350

like "bise" adjustment and also the adjustment of "VR1" as stated
by SC.

I have no access to them