Aligning and calibrating my Sony APR5000 machines

[topoxforddoc]

My APR5002, which was serviced and aligned by Lodgesound (Stewart) a few months ago was a bit out of kilter. Also the mint APR5003, which I bought a few months ago, needed alignment and calibration too.

Thanks to some advice from Stewart, a test tape and some test tones on my Macbook, I spent a fruitful day setting up my 2 Sony APR R2R machines for repro, sync and record. I bought a pair of PPM meters and an Alice Matchpak to match the unbalanced RCAs with the XLRs on the R2R machines. A bit of patience and a few phone calls later, both machines are done. I rewarded myself with some more wine (each glass is a portion of fruit) and a new tape - a Boxing Day 1972 Lou Reed recording at Ultrasonic Studios - a greta way to end the evening.

[Audio Al]

:)

Wish I was clever like you :)

[topoxforddoc]

:)

Wish I was clever like you :)

Al,

It wasn't that difficult, to be honest. Once you've done it once, you wonder why it took so long to learn :)

[topoxforddoc]

More fiddling tonight. With 2 APRs, each having 9 pre-sets, this could take a while to finish :)

[337alant]

Good work Charlie :eyebrows:
think it would be worth investing in a Signal generator IMO as you can accurately set the output level (db or true rms) from the generator so your preset Cal levels are spot on.
I have found on a few of my decks that the VU meters were out and needed adjustment when you set the decks input / output levels with an accurate signal and meter at the output.
Accurate record and playback azimuth and correct Bias for the tape type can also make a difference to reference levels.

You can adjust presets for different tape types with one reference tape. mine are all 250nWb/m so when adjusting the playback levels for a 320nWb/m tape I adjust the meter levels to -3db

Alan

[topoxforddoc]

Alan,

Thanks. Stewart (Lodgesound) kindly sent me a wav. file with test tones at -18 dBfs (corresponding to BBC PPM 4 levels). On Stewart's advice, I have bought a pair of PPM meters and an Alice Matchpak to allow me to use RCA to XLR in a calibrated fashion. The test tones are fed out of my Macbook Air using the 3.5 mm headphone jack using a 3.5 mm stereo jack to twin RCA. The RCAs are fed into the Matchpak. I have checked the test tone file output on the PPM meter and made a minor adjustment to the Matchpak to ensure that I get PPM 4 (0VU standard or -4 dB on VU meters). This acts as my test tone generator with consistent PPM 4 level tones at 1 k, 10 k & 15 k.

Once I am happy they I am getting constant PPM 4 output from the Macbook Air, the PPM meter is then swapped over to the output leads from the R2R, so that I can check the record levels against PPM4. I have then be able to adjust the repro, sync and record levels along with bias for each tape type (I use LPR35, SM911 and SM900) at all 3 speeds 7.5, 15 & 30 IPS. I have finished the 15 IPS alignment and am part way through the 7.5 IPS so far.

I have learnt masses from Stewart, who has been brilliant at helping me along this great new adventure.

Charlie

[topoxforddoc]

Alan,

Thanks. Stewart (Lodgesound) kindly sent me a wav. file with test tones at -18 dBfs (corresponding to BBC PPM 4 levels). On Stewart's advice, I have bought a pair of PPM meters and an Alice Matchpak to allow me to use RCA to XLR in a calibrated fashion. The test tones are fed out of my Macbook Air using the 3.5 mm headphone jack using a 3.5 mm stereo jack to twin RCA. The RCAs are fed into the Matchpak. I have checked the test tone file output on the PPM meter and made a minor adjustment to the Matchpak to ensure that I get PPM 4 (0VU standard or -4 dB on VU meters). This acts as my test tone generator with consistent PPM 4 level tones at 1 k, 10 k & 15 k.

Once I am happy they I am getting constant PPM 4 output from the Macbook Air, the PPM meter is then swapped over to the output leads from the R2R, so that I can check the record levels against PPM4. I have then be able to adjust the repro, sync and record levels along with bias for each tape type (I use LPR35, SM911 and SM900) at all 3 speeds 7.5, 15 & 30 IPS. I have finished the 15 IPS alignment and am part way through the 7.5 IPS so far.

I have learnt masses from Stewart, who has been brilliant at helping me along this great new adventure.

Charlie

[337alant]

Charlie Yes I agree Stewart is a very knowledgeable and helpful engineer and a very nice guy to boot
I also bought a test tape from him last year for Nab Eq 7.5 and 15 IPS speeds
Looks like you got it sussed
Im also using the LPR35, SM911 and SM900 tapes and they are very nice

Alan

[topoxforddoc]

Alan, it took a while to understand it and get the right bits together at a sensible price (the Alice MSU10 PPM unit was £95 and the Alice Matchpak £49 on Eb*y). The 2 Alice units were as bargain, as the MSU-10 is now over £1200 new and the Matchpak2 would be over £200.

Stewart persuaded me to buy a Dolby 363 unit with Dolby A and Dolby SR. Got to figure that out next,as I understand that SR (Spectral Recording) is the dogs boll*cks.

[topoxforddoc]

I must say that this R2R fettling is all consuming - routine stuff today - cleaning tape path and demagnetising. It's like tweaking a vinyl reply system, but better :)

[Ali Tait]

Must get the Tandberg done at some point. Sounds great as it is, but there's always the thought that there could be more to be had..

[topoxforddoc]

Good luck, Ali. By the way, how's my old 401 doing?

Charlie