Can you believe it? Tape Project is ten years old! Thanks to everyone who has supported us in introducing studio quality tape reproduction to the audiophile community!

Author Topic: A810 318 amorphous butterfly heads & time code  (Read 6270 times)

Offline steve00021

  • Jr. Member
  • **
  • Posts: 9
    • View Profile
A810 318 amorphous butterfly heads & time code
« on: November 02, 2011, 02:43:52 AM »
Hi
Just like to know if anyone has ever changed the A810 heads to the 318 type amorphous heads?
I have a set record & repro plus a staggered erase head.
I have made the mods to the head repro amp & the record amp adaptation boards as per Studer instructions.
I am a bit stuck with what to do with the time heads and electronics, can I change the erase head for the required staggered erase head and alter dip switches from 2 track with time code erase to 2 track only.
can the time code electronics read/write PCB & delay PCB just be removed?

any help would be great.

Offline Ki Choi

  • Sr. Member
  • ****
  • Posts: 313
    • View Profile
Re: A810 318 amorphous butterfly heads & time code
« Reply #1 on: November 02, 2011, 10:09:06 AM »
Hi Steve:

For the most (if not all) audiophile application, we just remove the TC head.  I have seen some people install 4 track repro head in its place with a switch - although I am not certain if there are enough worthy 1/4 track pre-recorded tapes to justify the mod.

As for the 318 butterfly heads, I would be interested in seeing the Studer information you are referring to:

"I have made the mods to the head repro amp & the record amp adaptation boards as per Studer instructions."

People who know more about Studer than me stated that having the butterfly heads will increase S/N and output by ~10dB but will give up some in crosstalk spec.  I have used them both but the improvement in longer lasting material used in 318 heads is the key, IMHO.

Ki
Ki Choi

Offline steve00021

  • Jr. Member
  • **
  • Posts: 9
    • View Profile
Re: A810 318 amorphous butterfly heads & time code
« Reply #2 on: November 02, 2011, 10:38:12 AM »
Hi Ki

I have emailed you the Studer document regarding the 318 heads
Maybe then I can just remove the right hand time code head & replace with a dummy head or tape guide(the R/H guide from a A807 looks to fit)
Then there is maybe 2 choices for the L/H time code head
1. replace with a 2 track staggered erase head ?(As I have 318 butterfly heads with .75mm track separation)
2. replace with a full track erase head ?(ok, can not record left & right channel separately)
Then just leave the time code electronic in the machine.

Steve

Offline Ki Choi

  • Sr. Member
  • ****
  • Posts: 313
    • View Profile
Re: A810 318 amorphous butterfly heads & time code
« Reply #3 on: November 02, 2011, 11:38:46 AM »
Hi Steve:

Thanks for the doc.  As mentioned, I had it as well but hadn't looked into it for years...

Unless you are doing your own recording and do have needs to manipulate CH1 and CH2 separately, most of us record or repro both channels at the same time - removing the need for the staggered erase head.  If you are into recording and/or playing two channel material, you could use full track erase head to replace the TC erase head.  I personally like to remove all TC related cards in the rack to reduce any possibility of noise getting into music.

Ki
Ki Choi

Offline steve00021

  • Jr. Member
  • **
  • Posts: 9
    • View Profile
Re: A810 318 amorphous butterfly heads & time code
« Reply #4 on: November 05, 2011, 02:46:27 PM »
Ok, have managed to change the 317 2mm heads for the 318 .75mm heads
have also removed the L/H time code head and replaced with a full track erase head 1.116.079
Can anyone help with the head block wiring, service manual does not seem to have any info on the head block wiring??
The six wires on the timecode head  was wired as::
the top 2 wires (channel 1 erase? green to pin 13 of the 25 dsub connector
orange to pin 12
botton 2 wires (channel 2 erase? orange to pin 24: green to pin 25
left pair of wires (timecode?) orange to pin 21 green to pin 9

The full track erase head 1.116.079 has 2 wires brown & black. I tries these on pins 12 & 13
changes 1 & 2 dip switch's on the periphery controller to 1 on 2 off for full track erase head.
A810 recored ok for about 60 secs or more then I get error EEEC2(failure of record on audio channel 2)

any advise would be great
 

Offline steve00021

  • Jr. Member
  • **
  • Posts: 9
    • View Profile
Re: A810 318 amorphous butterfly heads & time code
« Reply #5 on: November 05, 2011, 03:18:21 PM »
Ok

I tried the wires on pins 24 & 25 now I get error EEEC1, so , looks like maybe I need to
find the correct wiring for the Erase Head.

Offline Ki Choi

  • Sr. Member
  • ****
  • Posts: 313
    • View Profile
Re: A810 318 amorphous butterfly heads & time code
« Reply #6 on: November 07, 2011, 11:27:18 AM »
Steve:

somehow I didn't see your questions before.
I will take a look at the headblock wiring with the TC head in one of my machines and will give you the pin wiring info for the Erase head. 

In the meantime, your current error message of EEEC1 relates to the MPU prohibiting record funcition on CH 1 and may not be related to the Erase head wiring.  It would be the similar error you had for CH2 record prohibit as EEEC2.  I would double check the mods you made to the Record cards and reset the MPU card (either by pushing the reset button on the MPU card or power down/up one extra time).

Ki
Ki Choi

Offline Ki Choi

  • Sr. Member
  • ****
  • Posts: 313
    • View Profile
Re: A810 318 amorphous butterfly heads & time code
« Reply #7 on: November 08, 2011, 12:21:47 PM »
Hi Steve:

I don't have an A810 with full track erase head to confirm the wiring but the non-TC staggered erase head should be wired:

Top (in relationship to the mounting) erase head - Black on Pin 13, Brown on Pin 12 (for TC erase head, Green is on 13 and Orange is on 12)

Bottom erase head - Black on pin 25 , Brown on Pin 24 (TC erase head Green is on 25 and Orange is on 24)

Hope it helps.

Did you check the record section for the EEEC1 and 2 errors?

Ki
Ki Choi

Offline steve00021

  • Jr. Member
  • **
  • Posts: 9
    • View Profile
Re: A810 318 amorphous butterfly heads & time code
« Reply #8 on: November 08, 2011, 01:12:31 PM »
Hi KI

Many Thanks, Attached is a wiring list for the Head block 25 pin dsub Socket on the deck.
I have wired  a staggered erase head as per the list, I took it that Blue on socket = Brown on headblock & Black on socket = Black on headblock.
So Yes, Blk on 13 Brn on 12 Channel 1 & Blk on 25 & Brn on 24.
This now works fine, and yes the EEEC1 & 2 errors have now disappeared, and is recording perfectly.
All I need to do now is re-align the electronics as the output is now noticeably higher than with the 317 2mm heads.
Next is to remove the R/H TC head and both TC pcbs.
Thanks KI for the info. lucky I had staggered Erase Head!!

Will report more later

steve

Offline Ki Choi

  • Sr. Member
  • ****
  • Posts: 313
    • View Profile
Re: A810 318 amorphous butterfly heads & time code
« Reply #9 on: November 08, 2011, 08:04:57 PM »
great news that you got it going.

The calibration section of the Studer A810 manual is very well written (even for German speaking country like Swiss..)
 
Now, give us a report on sonic improvements (?) of the 318 Amorphous heads over the normal 2mm gap heads.

Thanks,
Ki
Ki Choi