Post your Solid State pics here.

[fotios]

This is my new attempt to decrease the rise time - or to increase the intrinsic+extrinsic slew rate as like many people - with myself sticked in the single LTP pair in input - i know that the symetrical LTPs in input can provide a lower rise time by 30% at least thus a greater slew rate - by replacing the input stage transistors with Toshibas instead OnSemi according to the advice and the gift (40 pairs of complementary Toshibas!!!) of my good friend from WALES "aandy", the advice of my good friend "sandyK" from Australia to replace all ceramic caps with silvered mica, and finally to the advice of the very polite J. Curl for the foil caps.
Well, from 2ìs the rise time had droped at 1,47ìs! I promise to post some curves - as usually and not only numbers - in the next days.
In general this project it is:
A class A/B amp. but with an increased iddle current at 50mA per output device.
A supply level of +/-60Vdc giving a power of 190W/8Ù (20-20000Hz).
A mix of Toshibas and OnSemis bipolars at whole; not FETs!
A THD+noise so small, that i can't measure it with my poor means for measurements.
The same for IMD.
A killing bass reproduction as in my previous model.
An improvement in mid-high reproduction by 100%. The Toshibas and the caps make the difference!
Current mirrors and CCS in all of the input stage.
Tripple darlington configuration in output with EF topology.
Non inductive parts - as soon as possible - in whole circuit, such as metal film resistors yet in 3W, metal oxide and metal plate resistors (a gift from FUTABA to me- many thanks LIVY!!).
Many thanks also to the carefull design of PCB. You may look at the symmetry of tracks, the thickness and nainly the ROUNDED corners. From my experience, a nice circuit can be destroyed from a bad layout drawing!
My better greetings in my friend Lineup who don't reply in my e-mail, and that if this project had implemented with symetrical input stage - that means with double LTP pairs - then the bandwidth may can touch the 250KHz (-3dB). Instead with its simple LTP it touches the 180KHz (-3dB). I promise documents in next days.
The architecture of this project it is almost the same with my project "Dirty Harry". This is the benefit of using current mirrors and constant current sources. The same framework for different power or quality amplifiers by substituting only few resistors and multiplying the output transistors, and changing the power supply level.
All the PCB hardwork is maden at MY HOME.
Below are the first photos

[dudaindc]

Nice boards (as usual) Fotios.
I look forward to more construction details.
Thanks for sharing the results of your experiments.

[fotios]

Originally posted by dudaindc

Nice boards (as usual) Fotios.
I look forward to more construction details.
Thanks for sharing the results of your experiments.

Thanks for your kind words.

Your reply it gives me courage to continue against the difficulties that i confront in my daily life.

Thanks again

Fotios

[hienrich]

very tasty work there Fotios............

are you using the 2SC2240/2AS970 pairs.......on your symetrical diff part of these amps?



cheers

[gmphadte]

Did u have any specific reason not to have filter caps on the board.

Gajanan Phadte

[smithy666]

Here is my latest project, a subwoofer amp for a Scanspeak 23W sub, using an Aussie Amplifiers NS150 module. Crossover is the Borbely All-FET, xover at 100Hz. The other amps are Stochinos.
First pic is the finished module

[smithy666]

Second pic is the amplifier without sides/front panel on.

[smithy666]

Here is the output at the onset of clipping, 1kHz sinewave, out 103V P-P, just over 165W RMS into 8R

[fotios]

Originally posted by hienrich
very tasty work there Fotios............

are you using the 2SC2240/2AS970 pairs.......on your symetrical diff part of these amps?



cheers

Thanks hienrich.
Yes, you guess right. A total description of devices used is:

1) 2SC2240 - 2SA970
2) MJE15030 - MJE15031
3) MJL3281 - MJL1302
4) MJL21193 - MJL21194
5) MPSA06 - MPSA56

All resistors are metal film, except the emitter resistors which are metal plate and the zobel resistor which is a special fire proof metal oxide film resistor. There is not any inductive part at whole.

All caps in pF range are Cornell-Doubilier silvered mica.
All caps in nF range are WIMA polypropylene MKP type.
The only 3 electrolytics are Panasonic ECA type for audio use.
The big input dc blocking cap it is SCR silvered foil MKP.

Fotios

[fotios]

Originally posted by smithy666
Here is my latest project, a subwoofer amp for a Scanspeak 23W sub, using an Aussie Amplifiers NS150 module. Crossover is the Borbely All-FET, xover at 100Hz. The other amps are Stochinos.
First pic is the finished module

Hi smithy

Nice circuit. And above all, the parts you are using are of first quality as i can see.
My compliments sir!

Fotios