STUDER A820 1/4" morphed into 1/2"

yjwu

Well-Known Member
Jun 28, 2011
78
12
913
Taipei, Taiwan, Republic of China
I just added 1/2" tape playing (recording will be waited until calibration is done) capability to my STUDER A820, which was resurrected on June 16, 2014, after 16 days working in dark.
Magnetic head assembly was pieced together from:
1) A STUDER time code demo assembly; maybe a historical collectable?
2) An A807 1/2" four track magnetic head assembly, with reproduced head 1.318.740, recording head 1.318.645 (modified to 1.318.745) and erase head 1.016.817?magnetic heads for 1990 released STUDER A820 MR?); also the scrape flutter filter roller, one of the 1/2" tape guide.
3) A Preamplifier was from a A810 mono head block, modified to 1.820.717.81.

More works need to be done:

1) Head identifier setting was still the same as 1/4" two track setting.
2) Erase head not connected yet.
3) Recording function check and calibration. Erase resonance frequency?
4) Only track 1 and 3 were used now. I will try track 1/2, 3/4 in parallel or in series to court more magnetic particles on tape to work together.
5) Cover aluminum plate still need more work; I had done most all the work by hand now, but still have no clue on how to mill the recess for pinch roller and guide roller left and right.

I also tried mounting 1/4" four-track ReVox heads, playback was O.K. Lower level due to narrower track width. With no tape on machine one channel had much more noise when the headphone volume was turned all the way up; maybe the head pre-amp was the culprit.

The 1/2" tape was a 14" reel with artist "The speaking cannaries", recorded at 30ips. Wow, I did not want to polish my 1/2" heads with that tape!
 

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