Leach Amp 2N3440/2N5415 substitute?

[JojoD818]

Hi,

For those who have already built the Leach amp, can you please post what transistors you used for the Leach amp.

Here is what I already have:
MPSA06/MPSA56
MJE15030/MJE15031

For the output, I have these:
MJL3281/1302 pairs
MJ15024/25 pairs

Can't decide yet which of them I will use for the output.

I am about to start my Leach amp and trying to source out the parts. I have most of the transistors except the 2N3440 and 2N5415 which I can't find here in my country. Do you guys have any substitute for these?

Regards,
Jojo

 

[Netlist]

Hi, JoJo
2N 3440: BSS 48..49, BUX 55, BUY 59..60, 2N5092

2N5415: BFT 19(A,B), BFT 28(A..C), MJ 5415..16

I doubt they will be easy to find.
I didn't check the pin-outs of the substitutes.

/Hugo 🙂

 

[Samuel Jayaraj]

Would you like for me to buy some of the 2N stuff and post them to you? I will check out the price etc., Please e-mail me?

 

[JojoD818]

Samuel,

You have mail.
Thanks.

Netlist,

I'll check if they are available locally.
Thanks

Jojo

 

[JojoD818]

"Hi, JoJo
2N 3440: BSS 48..49, BUX 55, BUY 59..60, 2N5092

2N5415: BFT 19(A,B), BFT 28(A..C), MJ 5415..16

I doubt they will be easy to find.
I didn't check the pin-outs of the substitutes.

/Hugo "


Those transistors are not available here too!

Any other ideas on what transistors I can use as substitute?

 

[Netlist]

Hi, JoJo

Both 2N3440 and 2N5415 are available here.
There must be a way to ship them to you, just like Samuel proposed.

/Hugo

 

[JojoD818]

I guess buying abroad is the only way for me to get those devices.

I just wish that there be substitute transistors for them so that I can adopt the Leach amp to the parts available locally. 🙁

 

[Netlist]

I guess buying abroad is the only way for me to get those devices.

I just wish that there be substitute transistors for them so that I can adopt the Leach amp to the parts available locally. 🙁

I'll give you the basic specs for both transistors:
2N3440: S/Vid, 300/250V, 1A, 1W (S= Switch, Vid= Video)
2N5415: S/Vid, 200V, 1A, 1W(Tc=25ø), >15MHz
(S= Switch, Vid= Video)
Here is some more info on the package type and pinout:
http://www.semicoa.com/pdf/to-39.pdf
Unfortunaltely I can't find decent datasheets on this transistors.
Wait a minute...got something here:
http://eu.st.com/stonline/books/pdf/docs/4080.pdf
and here:
http://eu.st.com/stonline/books/pdf/docs/5233.pdf
Have a look at Zetex.
http://www.zetex.com/3.0/3-3-1.asp?tcatid=6
They might have a good substitute for what you search.
Pound into their sheets or maybe others like ST:
http://eu.st.com/stonline/books/

The keyword is: Dig and you'll find.
Good luck
/Hugo 🙂

 

[TonyTecson]

i am also from manila and i can help you, please call me at 6438957, look for tony...many japaneese types can be used for your leach amp....fyi i have built around 30 units of these circa 1990's......i build my own transformers using 2in,cl e-i cores, i also fab my own pcb...fr4 double sided types, i have used 2sc510a and 2sa510a for the 2n3440, 2n5412 transistors.....

 

[JojoD818]

Netlist,

I like that "dig" thing a lot! Lol.

Thanks very much for the info... I will dig!

Joan2,

I will call them asap tomorrow. Thanks!

JojoD818

 

[naldy]

Joan,

30 units of Leach amps?
are those low TM or superamp?
HAve you tried bridging them?

Jojo,

It seems you are building pretty lots of amps....
I followed your threads and got some questions to ask (if you don't mind 🙂 )
How can you compare the performance of the
class H amp you had for PA system and the P3A (modified rail?)
and the op-amp diff'l input?

Have you tried building the monster amp (500W) on this link:

http://web.tiscali.it/audiofanatic3/Schemi/Tipo/Stato_solido/finali/Schemi_finaliSS.html

Any recommendation for big PA system.

Good luck on your Leach project!

 

[JojoD818]

joan,

I did called that number but the person I spoked to told me that tony is currently out of town.

naldy,

I see you have noticed my amp projects. Indeed, I have built a lot of amps as projects because I just love them (can't explain why).

As for the link you gave, no, I haven't built that amp... yet.

My class H (lots of 2N3055s) really rocks! But not as good sounding as Rod's P3A with moded rail voltage. Actually I am currently listening to it as I type this.

As for the op amp diff. input amp, the sound is very dependent on the characteristic of the op amp. I tried several op amp for the input and guess what, they sound differently 😕

In my opinion, the class H is still the most cheapest but if you are after clean audio, I don't recommend it. Guess what, that is the main reason why I want to build a Leach amp. Then comes a Super Leach amp

Jojo

 

[TonyTecson]

jojo,
i am now back to base, i am trying to dig up my old files, sansui amps uses complementary transistor pairs which can replace the 2n3440/2n5412 although in plastic to220 casing.....

 

[djk]

"Have you tried building the monster amp (500W) on this link:"

There are some problems with that design. The Super Leach is much better.

Very easy to add a ±40V~50V supply and a pair of Schottky diodes to the Super Leach. If done correctly it is virtually inaudible.

 

[JojoD818]

joan,

i'm still finishing up my previous project. i may be starting my leach amp as soon as i pay my bills. 😡 i shall contact you when the time comes. tnx!

djk,

i can't see the link...

jojo

 

[naldy]

jojo,

nice input. just keep us posted on your leach amp.
I will be building the same too when i'm done with my P3A.


djk,

good for me that I opted to build the Leach super amp.

 

[JojoD818]

Is there any reason why I can't use MJE340/MJE350 in place of 2N3440/2N5416? They may have different packge outlines but will it work?

jojo

 

[TonyTecson]

jojo,
replacements for the 2n3440/2n5412 are:

1. 2sc510a/2sa510a or 2sc484/2sa484 (to-5)
2. 2sd600/2sb631/ plastic type
3. tip41c/tip42c and their cousins...plastic types
yes you can also use other types as long as it has a Vce rating of at least 100volts and Ic rating of 1 amp

 

[Christer]

This has been discussed several times before, most recently,
I think, in a thread I started. The problem, as I see it, of
finding equivalents is that it seems impossible to find very
detailed datasheets of these transistors. Hence, it
is difficult to know if there is anything in particular to take into
account when replacing them. It seems from answers I got
that, at least, there is nothing special about them so
it is probably even a good idea to replace them with more
modern types. Still, mode detailed datasheets would be
desirable since at least some amplifiers (it's not only the Leach
using them) may need slight modifications like chaningin the
value of some resistors.

 

[JojoD818]

So I can use MJE340/MJE350 then?

Jojo