Hi All,
I want to build the Class A Bias JFET Cascode boards or PCBs for my new op amps or buy/get them somewhere, while I am waiting for the transistors to get here. I have no experience with making this on my own but want to try. Here is the circuit I am trying to add to my CD Player, please give your opinions, advice and direction as I start a new facet into this hobby (the last facet cost me an op amp.... Ahhh mere flesh wound!).
I will also add the schematic of the area of the op amps in the CD Player for advice on any Caps or other components that I should replace while the PCB is out! Thanks!
Regards//Keith
I want to build the Class A Bias JFET Cascode boards or PCBs for my new op amps or buy/get them somewhere, while I am waiting for the transistors to get here. I have no experience with making this on my own but want to try. Here is the circuit I am trying to add to my CD Player, please give your opinions, advice and direction as I start a new facet into this hobby (the last facet cost me an op amp.... Ahhh mere flesh wound!).
I will also add the schematic of the area of the op amps in the CD Player for advice on any Caps or other components that I should replace while the PCB is out! Thanks!
Regards//Keith
OK, let me ask this in a different way....
I have two NPN transistors that are type TO92. I need to mount them in a Cascode configuration with two pins to attach to my CDP main PCB, into the same holes as the two corresponding pins of the op amps.
I need to mount this onto a small "whatever." That is the question. What is the best way and what is best to use, to make a reliable platform for two small, delicate transistors wired properly to two small pins (also, what would you use for these pins or legs) that attach to the main PCB. Is this something I can make on breadboard or should I buy a PCB kit from the Shack or someplace better or is there a better idea altogether? It would be nice to make it be reliable and professional looking!
I have no experience with making a board or any other options that I am not aware of. If I am missing an option that is just what I need, also please let me know.
My lack of experience is why I am consulting your experience. I would hate to do something and find out a week later about the better way to do this and have to diaassemble the CDP again.
Thanks!
Regards//Keith
I have two NPN transistors that are type TO92. I need to mount them in a Cascode configuration with two pins to attach to my CDP main PCB, into the same holes as the two corresponding pins of the op amps.
I need to mount this onto a small "whatever." That is the question. What is the best way and what is best to use, to make a reliable platform for two small, delicate transistors wired properly to two small pins (also, what would you use for these pins or legs) that attach to the main PCB. Is this something I can make on breadboard or should I buy a PCB kit from the Shack or someplace better or is there a better idea altogether? It would be nice to make it be reliable and professional looking!
I have no experience with making a board or any other options that I am not aware of. If I am missing an option that is just what I need, also please let me know.
My lack of experience is why I am consulting your experience. I would hate to do something and find out a week later about the better way to do this and have to diaassemble the CDP again.
Thanks!
Regards//Keith
You certainly can get adaptors that will let you mount transistors and small chips onto breadboard. They are easy to find from electronics supplies. I got some for transistors last time from Farnell/Newark, sorry I dont know the op amp, Adaptors for chips though can be expensive.
If you are nimble with a soldering iron, you can solder transistors straight into a board. You have to be carefull though, they damage easy if you heat them up too much.
If you are nimble with a soldering iron, you can solder transistors straight into a board. You have to be carefull though, they damage easy if you heat them up too much.
Thanks Blair,
I have been searching, using Google for something to use and keep getting everything but what I am looking for!
Let me search on TO-92 sockets and breadboard and see what I can come up with. I have also been searching for "Pins" and "legs" for electronics and you should see what Google finds!
Just use your imagination and you will have a laugh!
Regards//Keith
I have been searching, using Google for something to use and keep getting everything but what I am looking for!
Let me search on TO-92 sockets and breadboard and see what I can come up with. I have also been searching for "Pins" and "legs" for electronics and you should see what Google finds!
Just use your imagination and you will have a laugh!
Regards//Keith
KP11520 said:
Hi Keith,
just want to clarify what you are attempting. I'm assuming you are removing two existing 5534 types and replacing with each with one OPA627 + two transistors? I would build this on stripboard/Veroboard and physically attach it using a couple of plastic pillars to the main board. The self-adhesive ones might be ok but you may be able to reuse one of the existing pcb mounting holes or find some other way. You an then wire to the holes of the removed 5534 using fine multistand or single core wire.
If you want to mount it using the connections from the opamp pins only then look at wire-wrap sockets or wirewrap pins. Very few people do wirewrap any more but the pins are long and sturdy. Alternatively companies like Samtec do a dazzling variety of extended DIL and SIL headers which could be used.
Hope I have correctly understood what you are attempting.
James
James,
You understand perfectly and have given me some search terms to use as well! I think my biggest problem is the terminology I am using for my searches. After seveal days (2 hours each), I have come up with Squat (nothing useful).
You mentioned several very helpful things: stripboard/Veraboard, plastic pillars, fine multistrand or solidcore wire (that takes some doubt of degrading the mod, using wire, away), wire-wrap sockets and wire-wrap pins, Samtec and Extended DIL and SIL headers.
I think another problem is, for a newbie, I want the same results that the experienced and professionals would expect.
Thank you for stopping by and shedding some much needed light!
Regards//Keith
You understand perfectly and have given me some search terms to use as well! I think my biggest problem is the terminology I am using for my searches. After seveal days (2 hours each), I have come up with Squat (nothing useful).
You mentioned several very helpful things: stripboard/Veraboard, plastic pillars, fine multistrand or solidcore wire (that takes some doubt of degrading the mod, using wire, away), wire-wrap sockets and wire-wrap pins, Samtec and Extended DIL and SIL headers.
I think another problem is, for a newbie, I want the same results that the experienced and professionals would expect.
Thank you for stopping by and shedding some much needed light!
Regards//Keith
Hi
I have been up for 2 days, woking on a pcb design for my gf's fast approaching birthday. So I am not thinking very straight.
I have been browsing Farnell for parts for the amp I am designing, and must have looked at my account 3 or 4 times before realising that I could find those transistor sockets from my previous purchase.
Here they are
Sorry for being such an unhelpfull dilbert.... My brain is fried!!!!
Blair
EDIT
DIP to SMT converters
Dont know if this is exactly what you are looking for, but it may help your search.
Surface mounting stuff onto printed boards is pretty easy if you use some liquid flux. A pen dispensor is my favourite. They last for a long time if you are doing the odd IC once in a while. I have seen Ziff socket versions as well, but they cost a lot. I'd invest in the flux and learn how to do it properly. You get better results for lless money. I learned all I needed from web tutorials. There are quite a few video tutorials if you search hard.
I have been up for 2 days, woking on a pcb design for my gf's fast approaching birthday. So I am not thinking very straight.
I have been browsing Farnell for parts for the amp I am designing, and must have looked at my account 3 or 4 times before realising that I could find those transistor sockets from my previous purchase.
Here they are
Sorry for being such an unhelpfull dilbert.... My brain is fried!!!!
Blair
EDIT
DIP to SMT converters
Dont know if this is exactly what you are looking for, but it may help your search.
Surface mounting stuff onto printed boards is pretty easy if you use some liquid flux. A pen dispensor is my favourite. They last for a long time if you are doing the odd IC once in a while. I have seen Ziff socket versions as well, but they cost a lot. I'd invest in the flux and learn how to do it properly. You get better results for lless money. I learned all I needed from web tutorials. There are quite a few video tutorials if you search hard.
Hello Blair,
Thanks again! I understand the fried brain thing completely because of my lack of knowledge and experience and way too many fruitless searches.
I spent days looking for video tutorials and only found one place at Tangentsoft.com. You aren't kidding about looking real hard!
I do hope, however, that as you fry your brain, you are at least using a healthy oil that won't add too much Cholesterol. Better yet, have a Pint to two, the alcohol helps keep the Cholesterol down, numbs the pain of your brain frying, and ultimately helps you fall asleep in your chair with your face down in the PCB.
It does have a downside..... a disappointing birthday for the Girlfriend. So please use cautiously!
Good luck to you!
I can do more effective searching now!
Regards//Keith
Thanks again! I understand the fried brain thing completely because of my lack of knowledge and experience and way too many fruitless searches.
I spent days looking for video tutorials and only found one place at Tangentsoft.com. You aren't kidding about looking real hard!
I do hope, however, that as you fry your brain, you are at least using a healthy oil that won't add too much Cholesterol. Better yet, have a Pint to two, the alcohol helps keep the Cholesterol down, numbs the pain of your brain frying, and ultimately helps you fall asleep in your chair with your face down in the PCB.
It does have a downside..... a disappointing birthday for the Girlfriend. So please use cautiously!
Good luck to you!
I can do more effective searching now!
Regards//Keith
I suggest that you acquire the huge, free, paper versions of the catalogs from mouser.com (1854 pages) and alliedelec.com (2192 pages) (Digikey.com is good, too, but their paper catalog is not quite as helpful.) It's much easier and MUCH, much faster to just look at the pictures while browsing sections of the catalogs, than to try to search "blind" on the web. After that, it's easy to go to their site, search for a part number, and download the datasheet or go to the manufacturer's webpage. (Actually, mouser.com makes that part the easiest. But alliedelec.com's catalog now has mostly color photos. Both are _extremely_ valuable for more-easily "finding out what's available".)
Note that Mill-Max makes lots of different types of single "PC pins" and "PC Receptacles", and headers and sockets, too. Mouser.com carries many/most of theirs. It might be worth it to download the Mouser catalog pages that have the pictures of all of the Mill-Max pins and headers, etc. It's only a few pages. You might also want to look at things like the Aries Electronics Inc "DIP Fork Headers", such as mouser.com # 535-08-600-10 .
You might find some better ideas, or at least maybe some clues, here: http://www.electro-tech-online.com/general-electronics-chat/29827-easy-daughter-board-question.html .
If you do decide that you need to be able to etch a PCB, for almost no cost, with almost no equipment or supplies, in less than an hour, with high-quality results, I have it all right here:
http://www.fullnet.com/~tomg/gooteepc.htm
Good luck. Please let us know if you come up with something that works well.
- Tom Gootee
http://www.fullnet.com/~tomg/index.html
Note that Mill-Max makes lots of different types of single "PC pins" and "PC Receptacles", and headers and sockets, too. Mouser.com carries many/most of theirs. It might be worth it to download the Mouser catalog pages that have the pictures of all of the Mill-Max pins and headers, etc. It's only a few pages. You might also want to look at things like the Aries Electronics Inc "DIP Fork Headers", such as mouser.com # 535-08-600-10 .
You might find some better ideas, or at least maybe some clues, here: http://www.electro-tech-online.com/general-electronics-chat/29827-easy-daughter-board-question.html .
If you do decide that you need to be able to etch a PCB, for almost no cost, with almost no equipment or supplies, in less than an hour, with high-quality results, I have it all right here:
http://www.fullnet.com/~tomg/gooteepc.htm
Good luck. Please let us know if you come up with something that works well.
- Tom Gootee
http://www.fullnet.com/~tomg/index.html
Hi Tom,
Every time you have responded to one of my posts and to many other members posts, you have always been more than extremely helpful! I want to thank you for that!
I have been on the right path with the other suggestions posted here. I decided that stripboard isn't terrible but will investigate what you posted. I found something recommended on another post called "Stripboard Magic" and downloaded it. I just needed to put the two JFETs and two pins on the board in the right configuration. I used the schematic tool and it configured the stripboard. But it didn't do it right and wouldn't let me do what I wanted. So i downloaded the spec sheet from Fairchild and looked at the schematics from Tangentsoft and the hyperlinks he has about Biasing JFET Cascodes and figured out how to get the most efficient design. One of the things that threw me off was when the tool rotated the JFET 180 degrees on the schematic, it also put the "Source" on the top (unmarked of course) and not the bottom where it belongs. This way when it configured the board, the "Source" and Drains" were a mess. Glad I felt something wasn't right and checked and learned some fine DETAILS. All the other schematics I saw, regardless of being rotated 180 degrees had the Drain on the top, Gate in the middle and Source on the bottom. I am assuming that is standard for schmetics. These are N-Channel JFETs in a TO92 case. So, it needs a peice of stripnoard 4 to 5 wide and 3 high for the whole thing. I finished that configuration last night and decided to work on which pins or legs to mount with the op amps today and hence, here is your post picking up right where I need!
I call that divine intervention and maybe you know something about that!
You are right about the web-sites... almost useless for any instructional value and now that I know the hard copy catalogs are significantly better, I will order some! I have been frustrated many times on Digi-Key's site and did better finding their parts on Google over the web than on their own search engine in their domain! YIKES!
The road has unfolded before me and my destiny awaits! I know this is "Mickey Mouse" stuff to the experienced guys but I am getting a lot of satisfaction (and remember Christina Aquilera came from the Mickey Mouse Club, so this is better than you think)!
Thanks Again and I will report back when I have a completed product!
Regards//Keith
Every time you have responded to one of my posts and to many other members posts, you have always been more than extremely helpful! I want to thank you for that!
I have been on the right path with the other suggestions posted here. I decided that stripboard isn't terrible but will investigate what you posted. I found something recommended on another post called "Stripboard Magic" and downloaded it. I just needed to put the two JFETs and two pins on the board in the right configuration. I used the schematic tool and it configured the stripboard. But it didn't do it right and wouldn't let me do what I wanted. So i downloaded the spec sheet from Fairchild and looked at the schematics from Tangentsoft and the hyperlinks he has about Biasing JFET Cascodes and figured out how to get the most efficient design. One of the things that threw me off was when the tool rotated the JFET 180 degrees on the schematic, it also put the "Source" on the top (unmarked of course) and not the bottom where it belongs. This way when it configured the board, the "Source" and Drains" were a mess. Glad I felt something wasn't right and checked and learned some fine DETAILS. All the other schematics I saw, regardless of being rotated 180 degrees had the Drain on the top, Gate in the middle and Source on the bottom. I am assuming that is standard for schmetics. These are N-Channel JFETs in a TO92 case. So, it needs a peice of stripnoard 4 to 5 wide and 3 high for the whole thing. I finished that configuration last night and decided to work on which pins or legs to mount with the op amps today and hence, here is your post picking up right where I need!
I call that divine intervention and maybe you know something about that!
You are right about the web-sites... almost useless for any instructional value and now that I know the hard copy catalogs are significantly better, I will order some! I have been frustrated many times on Digi-Key's site and did better finding their parts on Google over the web than on their own search engine in their domain! YIKES!
The road has unfolded before me and my destiny awaits! I know this is "Mickey Mouse" stuff to the experienced guys but I am getting a lot of satisfaction (and remember Christina Aquilera came from the Mickey Mouse Club, so this is better than you think)!
Thanks Again and I will report back when I have a completed product!
Regards//Keith
OK, so stripboard has won. Easy enough, it is only two transistors. with two leads to the main PCB to the op amp, (pin 4, -Vs and pin 6, output, I mistakenly put pin 7 at the top of this post).
Here is what it will look like in the attachment:
I just hope somebody can check what I want to do so I can confidently move forward with no dramas.
I have started another thread in Digital asking for help checking what I want to do: http://www.diyaudio.com/forums/showthread.php?postid=1267940#post1267940
Thanks!
Regards//Keith
Here is what it will look like in the attachment:
I just hope somebody can check what I want to do so I can confidently move forward with no dramas.
I have started another thread in Digital asking for help checking what I want to do: http://www.diyaudio.com/forums/showthread.php?postid=1267940#post1267940
Thanks!
Regards//Keith
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