Another pic
An externally hosted image should be here but it was not working when we last tested it.
JensRasmussen said:
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
OK. I had a feeling this would be the answer. However from SPICE sims im not convinced by the MJE parts. I'm currently looking at Japanese video driver transistors for this but models for them are few and far between.
I have had no problem using the MJE types...
Sure they are not the fastest in the world, but they work fine, and are easy to find almost all over the world.
If you find anything good, please post the info - thanks
\Jens
Sure they are not the fastest in the world, but they work fine, and are easy to find almost all over the world.
If you find anything good, please post the info - thanks
\Jens
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
Leve
Member
Joined 2002
My favorite medium power transistors: 2SC2238 and 2SA968.
25 watts, 180 volts, 1.5 amp max, 70< Hfe < 240, 100 mHz.
25 watts, 180 volts, 1.5 amp max, 70< Hfe < 240, 100 mHz.
Another pic
Front view, semi assembled
\Jens
Front view, semi assembled
An externally hosted image should be here but it was not working when we last tested it.
\Jens
jleaman said:
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....
\Jens
The 10 transistor version will be avalible when all has been tested.
Pricing is 250 dkkr / pcs. for the current batch.
This is roughly US$45
\Jens
Pricing is 250 dkkr / pcs. for the current batch.
This is roughly US$45
\Jens
From the back
\Jens
An externally hosted image should be here but it was not working when we last tested it.
\Jens
Member
Joined 2002
What about the other version.. the one with out all the transister's... I want to boards of that version..
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
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
Member
Joined 2002
I'll solder some for free : O ) if i download your gerber files i can send them to a pc manufacture and they can print the boards for me right ?
Yes you can... be sure to tell them that you want atleast 2 oz of CU.
Maybe you could ask arround for others that might want some boards.
\Jens
Maybe you could ask arround for others that might want some boards.
\Jens
Member
Joined 2002
Member
Joined 2002
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
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
jleaman said:
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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