Leach clone, pretty good looking

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JensRasmussen

JensRasmussen

Member
Joined 2002
JensRasmussen said:


You can use BD139/140 for lower voltage models with rails below +- 40V and MJE340/350 for higher rails....

Transistors with similar pinout can also be used with caution

\Jens
Click to expand...

I prefer the MJE340/350 devises because they have a higher voltage rating.

Of cause you need to run the amp at at least +- 50V rails so the BD types are not the best types to use as their rated CE voltage is 80 (If I remember correctly)

Please use thansistors with a rating of 120V or higher.

Sorry for the confusion

\Jens
 
L

LBHajdu

Member
Joined 2002
Is it believed that replacing the MJE transistors with something else will yielded an auditable improvement with out causing any problems? If so, dose anybody have any recommendations (something form digikey or mouser)? I could not even begin to guess what would even work in the circuit. Given the low cost of medium power transistors, testing at least one alternate type seem like a very practical thing to do, especially if they have the same pin out. I have been told by many different people that Zetex makes very good sounding transistors. If anyone has a recommendation that looks reasonable and is available from digikey of mouser I would be willing to try it out. However, at the rate I’m making progress it’s going to take me about 6 months just to get to the point where I can try them out. Leach says, on his web site, that the second stage dose contribute the most to the sound as it is where most of the voltage gain is done.

Leve
 
jacco vermeulen

jacco vermeulen

Member
Joined 2004
forgot the pic

regular : 160 volts
A type : 180 volts
B type : 200 volts
Pins: ECB, like the 340/350
 

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JensRasmussen

JensRasmussen

Member
Joined 2002
The Gerber files are on my website for free download....

I have no plans to offer the smaller boards for sale, I just made them for fun....

I have made a pre flight test on the 10 transistor version, and everything is working. Now I need to start shopping for components… 10 channels is a lot of soldering :) :) :)

\Jens
 
J

jleaman

Banned
Joined 2002
plus.google.com/photos/104656656065604242634/albums/5725366675475046257?banner=pwa&gpsrc
jen's Can you tell me the board sizes of both board's please.

Also
Base Copper Thickness: oz
Plated Copper Thickness: oz
Inner Layer Thickness: oz
Minimum Space: in
Total Number of Holes:
Total Number of Hole Sizes:
 

what is Panelization is that so i can have a number of boards per sheet ?

If you want you can email me personally and we can talk.


Jason
 
JensRasmussen

JensRasmussen

Member
Joined 2002
jleaman said:
jen's Can you tell me the board sizes of both board's please.

Also
Base Copper Thickness: oz
Plated Copper Thickness: oz
Inner Layer Thickness: oz
Minimum Space: in
Total Number of Holes:
Total Number of Hole Sizes:
_

what is Panelization is that so i can have a number of boards per sheet ?

If you want you can email me personally and we can talk.


Jason
Click to expand...

Base Copper Thickness: 2 oz
Plated Copper Thickness: 3 oz
Inner Layer Thickness: No inner layer oz
Minimum Space: 6/1000 in
Total Number of Holes: 443
Total Number of Hole Sizes: 13 (10 different)
Board is 108 x 214 mm = ???? in
PCB must be 2.4 mm in order to support the large caps

\Jens
 
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