100W Ultimate Fidelity Amplifier

[apexaudio]

What makes this better than the MM28?

Cascode in VAS

 

[still4given]

Originally Posted by still4given View Post
What makes this better than the MM28?
Cascode in VAS

What does the cascode do to improve the circuit?

 

[apexaudio]

APEX P36

 

[prasi]

waiting for apex p100... Apex is gonna make "out-of-stock" bc550/560 from all suppliers..,

people, stock up on those, before they vanish...

 

[still4given]

Thanks!
If it's possible parts ,parts numbers?

Hi Thimios,

Here is a stab at part values. BC560 is the wrong pinout for this layout. I used 2SA992 but maybe something else is better. There are two resistors that are not in the schematic so I gave them a zero ohm. Maybe Mile can say what they are. Please check against schematic in case I have errors. I guessed on the LED circuit and there is one cap on the bottom right that is not in the schematic. Anyway, I hope this helps.

 

[apexaudio]

Hi Thimios,

Here is a stab at part values. BC560 is the wrong pinout for this layout. I used 2SA992 but maybe something else is better. There are two resistors that are not in the schematic so I gave them a zero ohm. Maybe Mile can say what they are. Please check against schematic in case I have errors. I guessed on the LED circuit and there is one cap on the bottom right that is not in the schematic. Anyway, I hope this helps.

Instead 7k5 and 0R you can use 6k8 and 680R.

 

[thimios]

Thanks Terry and Apex!

 

[still4given]

Thanks!
If it's possible parts ,parts numbers?

Instead 7k5 and 0R you can use 6k8 and 680R.

OK thanks. Do you know the value of the three caps on the lower edge of the layout? One across the +12V input, one across the ground circuit although it is connected. The other one is on the right and it is not indicated what it connects to.

Thanks, Terry

 

[r_jik45]

In the above pic/layout they are marked as 100nF caps.

 

[apexaudio]

MC38

Phono MC Preamp

 

[apexaudio]

MM38

Phono MM Preamp

 

[still4given]

Wow, even more transistors.

 

[apexaudio]

Wow, even more transistors.

All transistor have lower price than one good OP amp.

 

[still4given]

Yeah, but that's 76 transistors for a stereo preamp. I thought 60 was lot.

 

[cgraf]

APEX AX11 question

Hi guys
For nostalgic reasons I would build an AX11. Where I always struggle is how I have to size the heatsinks. Any advise ? I am sure several builts were done and maybe somebody still remembers...

Thanks and best regards
Christoph

 

[shabusf]

Hi Mr. Mile,
BC550C/560C is obsolete now. Could you please suggest alternatives without compromising on the performance.
BC547/557 are available but they are not 'Low Noise' version.

This would even help us in building A40, SR200, P30,etc as well.

Thanks
Sha

Phono MC Preamp

 

[bbcbbs]

试试bc546 bc556 我在很多个放大器上使用过他们,并获得不错的效果,它们有不错的耐压.

 

[Mooly]

please read the forum rules regarding posting in English only.

试试bc546 bc556 我在很多个放大器上使用过他们,并获得不错的效果,它们有不错的耐压.

Try bc546 bc556 I've used them on many amplifiers and get good results and they have good pressure resistance.

 

[bbcbbs]

sorry for that!

 

[shabusf]

Noted. Thank you

Try bc546 bc556 I've used them on many amplifiers and get good results and they have good pressure resistance.