Page 3 of 3 FirstFirst 1 2 3
Results 21 to 30 of 30

Thread: Help Assessing Fostex R8 Heads! (Need your two cents)

  1. #21
    Join Date
    Sep 2017
    Posts
    14
    Thanks
    1
    Thanked 2 Times in 2 Posts
    Rep Power
    0
    Sign in to disable this ad
    Quote Originally Posted by Steenamaroo View Post
    I don't know a huge amount about these machines, but I know methodology always pays.
    I'd follow JP's whole post, line by line.
    Ok SO - It's seeming like track 4 doesn't play back anything (whether the 4th track on the head recorded it or otherwise).
    So we're left with the possibility of either a bad channel card or a fault in the connection to the head? What does it mean if the head is open circut? Could this be possible even if every other channel records perfectly?

  2. #22
    Join Date
    Nov 2004
    Location
    Wales
    Age
    41
    Posts
    3,145
    Thanks
    1
    Thanked 64 Times in 59 Posts
    Rep Power
    2161683
    Quote Originally Posted by sammcdougallIV View Post
    Ok SO - It's seeming like track 4 doesn't play back anything (whether the 4th track on the head recorded it or otherwise).
    So we're left with the possibility of either a bad channel card or a fault in the connection to the head? What does it mean if the head is open circut? Could this be possible even if every other channel records perfectly?
    Let's just double-check. Am I right in thinking that you recorded on all 8 tracks, flipped the tape over, and when you played it back, track 5 was playing back (in reverse) something that had just been recorded by track 4?

    If so, that means that the head and the connection to it is fine.
    Remember that the R8 is a 2-head deck. One of those two heads is an eraser, which means that the audio head is doing double-duty for both recording and playing back. Hence if that track on the head can either record OR play back, it means the head is perfectly fine (in which case that the problem most likely lies in the channel card somewhere).

    To answer your question about the head going open-circuit, that's the worst-case scenario. An 8-track record head like this consists of 8 coils, one for each track. If something utterly catastrophic happens, it is possible for the coil to melt on one or more tracks, which destroys the head element for that track. Ultimately an electrical circuit is a closed loop which electricity flows through. If a component fails such that electricity can no longer flow across it, it is said to be open-circuit because it's no longer a closed loop.
    Last edited by jpmorris; 6 Days Ago at 14:47.

  3. #23
    Join Date
    Sep 2017
    Posts
    14
    Thanks
    1
    Thanked 2 Times in 2 Posts
    Rep Power
    0
    Quote Originally Posted by jpmorris View Post
    Let's just double-check. Am I right in thinking that you recorded on all 8 tracks, flipped the tape over, and when you played it back, track 5 was playing back (in reverse) something that had just been recorded by track 4?

    If so, that means that the head and the connection to it is fine.
    Remember that the R8 is a 2-head deck. One of those two heads is an eraser, which means that the audio head is doing double-duty for both recording and playing back. Hence if that track on the head can either record OR play back, it means the head is perfectly fine (in which case that the problem most likely lies in the channel card somewhere).

    To answer your question about the head going open-circuit, that's the worst-case scenario. An 8-track record head like this consists of 8 coils, one for each track. If something utterly catastrophic happens, it is possible for the coil to melt on one or more tracks, which destroys the head element for that track. Ultimately an electrical circuit is a closed loop which electricity flows through. If a component fails such that electricity can no longer flow across it, it is said to be open-circuit because it's no longer a closed loop.
    No - it's actually the worse scenario - track 4 neither records nor plays back anything. No audio will be recorded or reproduced on track 4 no matter what's on the tape.
    I'm hoping the problem is to do with the channel card. How best can I access them on the R8? like - how is the best way to remove one without damaging them? doesn't seem like you can pull them from the front.

  4. #24
    Join Date
    Aug 2005
    Location
    U.K.
    Age
    32
    Posts
    17,973
    Thanks
    894
    Thanked 750 Times in 668 Posts
    Rep Power
    1000000
    Quote Originally Posted by jpmorris View Post
    Let's just double-check.
    Quote Originally Posted by sammcdougallIV View Post
    No - it's actually the worse scenario - track 4 neither records nor plays back anything.
    Sorry, let me double double-check.
    When you attempted to record to tracks 4+5 then flipped the tape, what did channel 5 do?
    Quote Originally Posted by Grawlf View Post
    That's a tad too much terminology. What do you mean by 'mix'?
    Quote Originally Posted by Steenamaroo View Post
    No VST can emulate that smell.

  5. #25
    Join Date
    Nov 2004
    Location
    Wales
    Age
    41
    Posts
    3,145
    Thanks
    1
    Thanked 64 Times in 59 Posts
    Rep Power
    2161683
    Quote Originally Posted by Steenamaroo View Post
    Sorry, let me double double-check.
    When you attempted to record to tracks 4+5 then flipped the tape, what did channel 5 do?
    Indeed - we do need to be sure of this, otherwise it's just a guessing game.

  6. #26
    Join Date
    Sep 2017
    Posts
    14
    Thanks
    1
    Thanked 2 Times in 2 Posts
    Rep Power
    0
    Quote Originally Posted by jpmorris View Post
    Indeed - we do need to be sure of this, otherwise it's just a guessing game.
    When I did this, track 4 was silent and the meter did not show any signal. (Though there was definitely something on the tape.

  7. #27
    Join Date
    Nov 2004
    Location
    Wales
    Age
    41
    Posts
    3,145
    Thanks
    1
    Thanked 64 Times in 59 Posts
    Rep Power
    2161683
    Quote Originally Posted by sammcdougallIV View Post
    When I did this, track 4 was silent and the meter did not show any signal. (Though there was definitely something on the tape.
    But what did track 5 do?

  8. #28
    Join Date
    Sep 2017
    Posts
    14
    Thanks
    1
    Thanked 2 Times in 2 Posts
    Rep Power
    0
    Quote Originally Posted by jpmorris View Post
    But what did track 5 do?
    Nothing. When the tape is flipped and track 5 is playing what track 4 ought to have recorded, it doesn't play anything. So when I record on track 4 + 5 and the tape is not reversed, track 5 will play back the recorded signal and track 4 will not.
    when the tape is flipped, neither 4 nor 5 will play back the signal.

  9. The Following User Says Thank You to sammcdougallIV For This Useful Post:


  10. #29
    Join Date
    Nov 2004
    Location
    Wales
    Age
    41
    Posts
    3,145
    Thanks
    1
    Thanked 64 Times in 59 Posts
    Rep Power
    2161683
    Quote Originally Posted by sammcdougallIV View Post
    Nothing. When the tape is flipped and track 5 is playing what track 4 ought to have recorded, it doesn't play anything. So when I record on track 4 + 5 and the tape is not reversed, track 5 will play back the recorded signal and track 4 will not.
    when the tape is flipped, neither 4 nor 5 will play back the signal.
    Okay, thanks for confirming that. What I would do next if it were me, is get a multimeter and do some continuity tests. I'm a little nervous about the idea of putting a meter directly over the head given that it's the most vital and expensive part of the entire machine, but it might be worth checking continuity on the cable connecting the head to the PCB.

    Did you ever try swapping audio cards? I'm not sure whether the head is connected via a bus or point-to-point wiring to the audio card on these machines, I'd have to find a schematic. If it's point-to-point, swapping the channel card won't help because the head would still be attached to the same channel card...

  11. #30
    Join Date
    Sep 2017
    Posts
    14
    Thanks
    1
    Thanked 2 Times in 2 Posts
    Rep Power
    0
    One thing I did figure out for sure: the channel card for track 4 WAS bad - but that didn't seem to be the root cause of the issue.
    When I swapped channel 3's good card with channel 4's, 4 didn't work at all and 3 recorded with a weak, distorted sound. Changed them back and took out 4's card completely. Back to 7 tracks

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. Fostex 80 heads adjustment/relap/ etc.
    By Blue Jinn in forum Analog Recording & Mixing - Tape & Gear
    Replies: 9
    Last Post: 01-29-2014, 17:07
  2. Interchange heads for fostex 80, R8, and E8..
    By ReelFostex! in forum Analog Recording & Mixing - Tape & Gear
    Replies: 0
    Last Post: 01-16-2010, 18:04
  3. Fostex Model 80 heads or re-lapping
    By ReelFostex! in forum Analog Recording & Mixing - Tape & Gear
    Replies: 2
    Last Post: 12-27-2009, 16:05
  4. Makes No Cents?! Explain Cents Please
    By gethypedmusic in forum Newbies
    Replies: 10
    Last Post: 09-30-2009, 19:46
  5. I Need Your 2 Cents Please
    By Wise1one1 in forum Gear Reviews & Questions
    Replies: 8
    Last Post: 03-08-2005, 14:04

Posting Permissions

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