Apeaker Amp.

[adi316]

speaker amp.

Hi,

i am trying to build the amp in the attached diagram and it does not seem to be working. i have all the components in eh diagram but i could not find the transistors in digikey or newark so i got alternatives that is retrospect could be the problem....

i have a 1N914-TPCT-ND as my 1N191 diode
BU406FS-ND as my 2N628
2N5210-ND as my 2N525
and MPF102 as my 2N167

i hope you can help me make this work i need it for my research summer job....

 

[Nigel Goodwin]

That amplifier looks decades old, and really poorly designed even back then.

An MPF102 is an FET isn't it?, you can't replace a transistor with an FET.

 

[adi316]

i kinda new to this and i tried to work with what i have in the lab. is there any other cheap alternative to the transistors? i ave to make this specific amp to work cause i need to reproduce an old experiment

 

[Pommie]

A google search produced **broken link removed**. On the page is an equivalents link.

Mike.

 

[john1]

Dunno.
Don't think it is.
If it is, it didn't work for me.
It seemed to me to be a page offering to sell people PDFs of details.

Which isn't quite the same thing.

 

[Pommie]

Dunno.
Don't think it is.
If it is, it didn't work for me.
It seemed to me to be a page offering to sell people PDFs of details.

Which isn't quite the same thing.

Try looking again. The "buy now" button is for the actual transistors not the PDFs . The equivalents link is slightly down the page.

Mike.

 

[adi316]

sorry to sound a little stupid but it doesn't look so helpful, i see a lot of links to a lot of different transistors but none of them seem to be available to buy or doesn't seem to fit my circuit

 

[Pommie]

The first transistor (2N628) has a few equivalents listed, the first one (2N6284) is available at Newark for $3.00.

Mike.
Edit, relooking at the page, I'm now not sure if the 6284 is equivalent to the 628.

 

[adi316]

will it do the same job as the 2n628 thought?

 

[Pommie]

I think I may have misread the page and it's actually showing equivalents for the 2N6284. Sorry.

Mike.

 

[shokjok]

It should work if you remove the 6V battery, and tie the ground from the joined 12V batteries to the ground connection of the former 6V battery positive. Not having built this circuit, what is the required RMS output?