Page 11 of 23 FirstFirst ... 9 10 11 12 13 21 ... LastLast
Results 101 to 110 of 228

Thread: New 388 problem

  1. #101
    Join Date
    Aug 2002
    Location
    Denton, TX
    Age
    47
    Posts
    4,600
    Thanks
    128
    Thanked 214 Times in 193 Posts
    Rep Power
    4642456
    Sign in to disable this ad
    Thanks again for the detailed explanations along the way. I really appreciate them.

    Your next request is maybe possible depending on what needs to stay connected and what can come loose. I definitely can't get to it as it is now (with the M BUSS PCB still connected and all the cards connected to the front panel).

    I can unscrew all the nuts on the front panel and pull the cards out, but I don't know how far I'll be able to pull them out with all the connectors still plugged in. (See photo.)

    Can any of these connectors be unplugged while taking those measurements?
    Attached Thumbnails Attached Thumbnails 388-innards-jpg  
    famous beagle

  2. #102
    Join Date
    Aug 2002
    Location
    Denton, TX
    Age
    47
    Posts
    4,600
    Thanks
    128
    Thanked 214 Times in 193 Posts
    Rep Power
    4642456
    Oh, and yes I did order those chips. Should be here today I believe.
    famous beagle

  3. #103
    Join Date
    Apr 2008
    Location
    Pacific Northwest, USA
    Posts
    8,546
    Thanks
    222
    Thanked 218 Times in 198 Posts
    Rep Power
    3753124
    Quote Originally Posted by famous beagle View Post
    Thanks again for the detailed explanations along the way. I really appreciate them.

    Your next request is maybe possible depending on what needs to stay connected and what can come loose. I definitely can't get to it as it is now (with the M BUSS PCB still connected and all the cards connected to the front panel).

    I can unscrew all the nuts on the front panel and pull the cards out, but I don't know how far I'll be able to pull them out with all the connectors still plugged in. (See photo.)

    Can any of these connectors be unplugged while taking those measurements?
    What would be ideal is if you could clip a small flying lead into the 'G' terminal of Q101 or Q102. Do you have any of those small captive clip wires (not alligator clips)? That would be perfect for this...you would remove the M BUSS PCB, and disconnect any connectors to gain access, then clip the lead on the 'G' leg of the transistor, then put everything back together and probe the other end of your flying lead and the terminal on the M BUSS PCB.

    I'm talking about this kind of thing...They come in different sizes and you can get them pretty small, usually in a pack and they don't cost much:

    image-jpeg

  4. #104
    Join Date
    Aug 2002
    Location
    Denton, TX
    Age
    47
    Posts
    4,600
    Thanks
    128
    Thanked 214 Times in 193 Posts
    Rep Power
    4642456
    Quote Originally Posted by sweetbeats View Post
    What would be ideal is if you could clip a small flying lead into the 'G' terminal of Q101 or Q102. Do you have any of those small captive clip wires (not alligator clips)? That would be perfect for this...you would remove the M BUSS PCB, and disconnect any connectors to gain access, then clip the lead on the 'G' leg of the transistor, then put everything back together and probe the other end of your flying lead and the terminal on the M BUSS PCB.

    I'm talking about this kind of thing...They come in different sizes and you can get them pretty small, usually in a pack and they don't cost much:

    image-jpeg
    Ok ... First off, no I don't have any of those captive clip wires, but I could get some. From looking at the picture, I can't tell how they work, but I imagine it would be a bit more obvious if I had them in my hand.

    Secondly, I see that the schematic shows G as the middle terminal on all of those JFETs. Does that mean it's for sure physically the middle terminal? I can't see an identifying mark on the PCB right now (the card is still installed), but I'm just wondering if there will be one since, remember, those four JFETs don't appear on the PCB layout in the manual.

    Thirdly, those JFET leads are tiny and close together! I can see how an alligator clip won't cut it --- especially if it's the middle terminal I'm after. I've searched around for "Flying leads" or "captive clip wire" and haven't found what you showed. Could they be known by another name?

    Or ... is there a reason that I couldn't just make a connection with a piece of hook-up wire by just wrapping it around the terminal (if possible)?
    famous beagle

  5. #105
    Join Date
    Nov 2004
    Location
    Wales
    Age
    42
    Posts
    3,379
    Thanks
    10
    Thanked 105 Times in 96 Posts
    Rep Power
    2215120
    Quote Originally Posted by famous beagle View Post
    From looking at the picture, I can't tell how they work, but I imagine it would be a bit more obvious if I had them in my hand.
    I've not see these befpre, but oscilloscope probes often work the same way. The conductor is usually a hook inside the plastic sheath. You pull the plastic flange back and the hook is exposed. You can then hook it onto the wire or IC pin you want, with the minimum amount of conductive surface exposed, so there's much, much less danger of a short.

    Unfortunately I don't know what they're called either.

  6. #106
    Join Date
    Aug 2002
    Location
    Denton, TX
    Age
    47
    Posts
    4,600
    Thanks
    128
    Thanked 214 Times in 193 Posts
    Rep Power
    4642456
    Quote Originally Posted by jpmorris View Post
    I've not see these befpre, but oscilloscope probes often work the same way. The conductor is usually a hook inside the plastic sheath. You pull the plastic flange back and the hook is exposed. You can then hook it onto the wire or IC pin you want, with the minimum amount of conductive surface exposed, so there's much, much less danger of a short.

    Unfortunately I don't know what they're called either.
    Hmmm ... interesting. Thanks for the info!
    famous beagle

  7. #107
    Join Date
    Apr 2008
    Location
    Pacific Northwest, USA
    Posts
    8,546
    Thanks
    222
    Thanked 218 Times in 198 Posts
    Rep Power
    3753124
    Yes, you squeeze the spring-loaded plunger which exposes a small 'J' hook...you hook the component leg and when you release the plunger, and because of the hook, there's no risk of your clip touching other contacts even in crowded situations.

    You *could* use hookup wire, but I wouldn't...I'd be worried about it coming loose and contacting something else.

    No, the schematic shows a standard diagram for a JFET, but different parts have a different pinout. Often the Tascam gear has the D (drain), S (source), and G (gate) labeled on the board. If it isn't labeled, or you can't get a visual on it you have to get the datasheet for the part. The body of the JFET is flat on one side right? That's how you identify the orientation and where pin 1 is. Sometimes it's on the left, sometimes on the right, and then the function of each pin (D, S, and G) varies from part to part. It's uber essential to mind the pin layout when replacing transistors.

    I'm running from one flight to the next at the moment. Find the original part type in the manual and download the datasheet. It usually shows the pinout on the first page. It's a good idea to do this anyway even if the board is labeled.

  8. #108
    Join Date
    Aug 2002
    Location
    Denton, TX
    Age
    47
    Posts
    4,600
    Thanks
    128
    Thanked 214 Times in 193 Posts
    Rep Power
    4642456
    Quote Originally Posted by sweetbeats View Post
    Yes, you squeeze the spring-loaded plunger which exposes a small 'J' hook...you hook the component leg and when you release the plunger, and because of the hook, there's no risk of your clip touching other contacts even in crowded situations.

    You *could* use hookup wire, but I wouldn't...I'd be worried about it coming loose and contacting something else.

    No, the schematic shows a standard diagram for a JFET, but different parts have a different pinout. Often the Tascam gear has the D (drain), S (source), and G (gate) labeled on the board. If it isn't labeled, or you can't get a visual on it you have to get the datasheet for the part. The body of the JFET is flat on one side right? That's how you identify the orientation and where pin 1 is. Sometimes it's on the left, sometimes on the right, and then the function of each pin (D, S, and G) varies from part to part. It's uber essential to mind the pin layout when replacing transistors.

    I'm running from one flight to the next at the moment. Find the original part type in the manual and download the datasheet. It usually shows the pinout on the first page. It's a good idea to do this anyway even if the board is labeled.
    Ok thanks. Whenever you get a chance, if you could direct me to a source to buy those clip wires you're referencing, I can get some. I'm not finding anything on my own.

    Thanks!
    famous beagle

  9. #109
    Join Date
    Apr 2008
    Location
    Pacific Northwest, USA
    Posts
    8,546
    Thanks
    222
    Thanked 218 Times in 198 Posts
    Rep Power
    3753124
    Mouser...search "test leads".

  10. #110
    Join Date
    Aug 2002
    Location
    Denton, TX
    Age
    47
    Posts
    4,600
    Thanks
    128
    Thanked 214 Times in 193 Posts
    Rep Power
    4642456
    Quote Originally Posted by sweetbeats View Post
    Mouser...search "test leads".
    Ok, will do. Thanks!
    famous beagle

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Problem with Sonar moving slow / Problem deleting old files
    By eternalwinter in forum Cakewalk / Sonar Forum
    Replies: 21
    Last Post: 03-26-2012, 22:47
  2. Replies: 0
    Last Post: 02-08-2012, 17:40
  3. Compression to control dynamics... Tracking problem or Overall problem?
    By Change of POETS in forum Mixing Techniques
    Replies: 15
    Last Post: 02-04-2007, 21:47
  4. problem with inserts (hopefully i'm the problem...)
    By osus in forum Recording Techniques
    Replies: 6
    Last Post: 03-09-2006, 10:44

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •