2N2222A phono preamp

[Salas]

Originally Posted by Ivey

OK Salas, this is what I will do.

My grandson and I, will breadboard the unit.

I will use 2N5088 in the front end.

2N3904/6 for all the others. That transistor has a max. db factor of 4.5. Max.!

And I will use a BC139-16.

Metal film polyesters @ 10%. Use polypro's in the final build.

So what do you think of that?

Take Care

Ivey

Sounds like a plan. Riaa caps quality & tolerance is irrelevant in this phase. Your MKTs will do fine. All you need to know is that it will bias correctly and no one stage loop will oscillate. This is a 60dB gain circuit. Will play 0.25mV to 0.5mV MC carts if all goes well. You got such a cartridge?

[Ivey]

I have Pickering V-15 carts, three of them and nine needles for them. Plus one Graddo cartridge, with one extra needle.

I need a MC cartridge, so I will invest in one.

Take Care

Ivey

[Salas]

A Denon DL103 will not set you back for much, and will give a good taste of LowMC world. Although vintage in tone, not super resolution, has quite a following. A classic. Its real compliance is 16cu to check compatibility with your tone arm. Has 40 Ohm source impedance and if you go for it, make R1 (input load resistor) 430R. If you have in mind a bigger investment there are many options and takes some investigation. Regards.

[coolzero]

Originally Posted by Ivey

OK Salas, this is what I will do.

My grandson and I, will breadboard the unit.


Ivey

I wish I had a grand father like you Ivey . Great reading and info you have provided here. Fun to read. Thanks.

[albatros49]

Hi Ivey
How schould this work?! You ar shortening the input with 1uF to ground!
albatros49

[albatros49]

Hi, what about BC413-BC415?!
Ever tried them?
Noise is 1,2db

Greetings
albatros49

[johngalt47]

What happened to this thread?

[sonidos]

Several months ago I saw a post from Ivey's grandson, IIRC. It didn't sound like Ivey was doing well health-wise and so maybe he no longer has the energy to respond.

[morinix]

Damn! Is anyone building this?

[Ivey]

Hello everyone:

I am Joe, the great grandson of Ivey.

my great grandfather is slowly recovering from his illness. We are trying to keep him as inactive as possible to prevent a future heart condition.

I talk to him often, and we always talk electronics, since I am going to college and following his path into electronics.

My great grandfather has tons upon tones of electronic parts, equipment, and a technical library that I hope to inherit. But even now, I have the run of the place, and the time I spent there is endless.

I build his 2N2222A phono amp, to replace the one he built years earlier. But I used the 2N4401 because I came across the complete spec's on the transistor, showing dies, and a host of other information, that shows that it is far better than the 2N2222A, and it has far better gain, and it Nb is a Max 4

Any away, I do not have much time so I posted my PCB layout using a a better gnd area. And I mirrored the image for both channels.

If you have the schematic the layout is straight forward. If not, I could label and id everything later on down the road.

so long

Joe