Try to make it work again Studer B62

Johnny Vinyl

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:D great
I think i am gonna sneak the portable B 62 into the Amsterdam concertgebouw , and do some recording :cool:

Now that would be cool to do....if you get away with it!:D
 

andromedaaudio

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The b62 is almost ready the A 80 next week , gonna pick them up in a week or so a lot of parts had to be ordered thats one reason it took so long
For the tapetechs on this forum , the B 62 stops before the end of the tape when rewinding , you then have to push the rewind button again and its starts rewinding again , with this problem it takes about 3 or 4 times to push the button to fully rewind the tape , any ideas what it might be , the tech is still looking into it , but i thought i post it here as well .
He said it was adjusted far off and plays absolutely wonderfull now
The B 62 apparently also has special heads , not standard ones
 
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andromedaaudio

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ready , i picked them up today , the A 80 is running perfectly , i ll try the b 62 later this week
It actually says A 80 RC , it looks im cheated :D serial no: 04494
I ve set the output to 0 db on the Vu meters playing the testtone as advised iirc , sounds a lot better

Update : it has been totally recapped ,so the electronics have to be under power for a while to settle ,but its getting to sound promising ;) , tape handling is also great


_DSC0043 by andromeda61, on Flickr


_DSC0041 by andromeda61, on Flickr



_DSC0044 by andromeda61, on Flickr



_DSC0045 by andromeda61, on Flickr
 
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mep

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That Studer looks super-clean!. Is it the lighting or does the right channel VU meter have a bulb burned out in it? The left channel meter appears to be way brighter.
 

andromedaaudio

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Yeah i found that as well , the guy who did the revision also does equipment cleaning as a part of his business .
Youre right, on the first pic you see the light of the right channel is still working later not, the meter itself is still okay though.
The revision was quite a bit more work then he had expected (and priced in) , the A 80 was quite a mess .
The soundquality makes up for a lot , and i expect it will improve some more.
Its low noise as well
 

andromedaaudio

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Last edited:

Ki Choi

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Mark has sharp eyes, the VU meters have burnt out lamps on both channels. In addition, I am not sure if it is just the photos but one of your transport photos show both Play and Stop PB lamps on at the same time. If the machine is at Stop mode, it should not have both on. Also one of the other photos show Rew and Stop PB lamps on at the same time as well. The Stop lamp should blink only when you hit the Zero return button and while the transport is trying to get back to Zero count and before it comes to Stop. If the lamps on at the wrong time, you should check pull up resistors in the PB assemblies. I have seen few that got hot and have changed their values or if the PB switches are solid-state version in your machine, they may be faulty and need to be replaced.

The head seems to have plent of life left but the reflection show on repro head as having possible worn flat part to be more than 1/4"... If so, you will have difficult time sweeping 20 - 20Khz. Maybe it is just the photo or have it relapped.

Based on seeing new caps in your transport power supply regulator board, rest of the transport cards have new caps. I can't see your audio power supply regulator board to see if the two big filter caps and two smaller 47uF caps were also replaced. I assume so.

As for the audio boards, you will find that if the tech didn't make modification to C34 470pF capacitor (Polystyrene type) on Record Amp card, your VU meters will go beyond full scale when biasing for modern tapes such as ATR or RMGI 911/900 etc. I would suggest C34 to be changed to 150pF or lower to increase dynamic range of your record bias.

For both Record Amp and Repro Amp boards, your photos show older generation A101 discrete "opamp" devices (black rectangular part in Record Amp and blue potted part in Repro Amp). Since you are in Europe, it should be easy for you to obtain modern replacement A101s from a seller in Germany (eBay).

Lastly, there are caps on both Record and Repro Amp boards that must be replaced (and yours had been done so). However the electroytic caps on signal paths are debatable. Some people (who know more about Studer than myself...) consider the Tantalium looking caps (but they are not Tantalium type) are Studer special ingredient that gives the Studer "its own sound" and would be dead against replacing them. If you have spare boards, you can try them both ways and make up your own mind.

As I had stated elsewhere, it is far better to have a well taken care of Mk I (or just A80RC) than worn down and neglected A80RC MkII. You have a very nice A80RC from what I can see.
 

andromedaaudio

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Thanks for the info , the stop button is constantly on , so that is not working properly , but functionally not a problem , i post some more pics , with a card with 2 more caps replaced , the stabilzer card middle pic .
It seems like the revision could have been done better then but anyway the unit is working fine besides that.
i am a little worried about the heads which show some wear the repro indeed more then the other , how bad is this for the sound 1/4 wear ???
If i measure the flatness i measure about 5 mm on the repro and 4 on the record


_DSC0054 by andromeda61, on Flickr


_DSC0056 by andromeda61, on Flickr



_DSC0055 by andromeda61, on Flickr
 

Ki Choi

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To save bandwidth, I won't quote your post with photos.

There's always room for improvment when you are taling about 30+ year old machines. Some of the improvements are more for increasing reliability and longevity than for better sound, IMO. As an example, your audio stabilizer board shown in the photo above had all the electrolytic caps replaced. Although I can't see their values, judging from the age of the board from other components used, they are probably 3300uF. Later A80RCs have bigger 4700uF caps. Also the bridge rectifiers on your board are round 1A type. I use much bigger 3A square type - not for better sound but for higher reliability, etc.

With the repro head wear I see in your photos, I would suspect you would have signifcan loss of HF frequencies above 10K. You will know immediately when you run the MRL cal tape. I think 5mm wear is right at the boarder line of having to replace the head instead of being able to relapp...unfortunatley.
 

mep

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Mark has sharp eyes, the VU meters have burnt out lamps on both channels. In addition, I am not sure if it is just the photos but one of your transport photos show both Play and Stop PB lamps on at the same time. If the machine is at Stop mode, it should not have both on. Also one of the other photos show Rew and Stop PB lamps on at the same time as well. The Stop lamp should blink only when you hit the Zero return button and while the transport is trying to get back to Zero count and before it comes to Stop. If the lamps on at the wrong time, you should check pull up resistors in the PB assemblies. I have seen few that got hot and have changed their values or if the PB switches are solid-state version in your machine, they may be faulty and need to be replaced.

The head seems to have plent of life left but the reflection show on repro head as having possible worn flat part to be more than 1/4"... If so, you will have difficult time sweeping 20 - 20Khz. Maybe it is just the photo or have it relapped.

Based on seeing new caps in your transport power supply regulator board, rest of the transport cards have new caps. I can't see your audio power supply regulator board to see if the two big filter caps and two smaller 47uF caps were also replaced. I assume so.

As for the audio boards, you will find that if the tech didn't make modification to C34 470pF capacitor (Polystyrene type) on Record Amp card, your VU meters will go beyond full scale when biasing for modern tapes such as ATR or RMGI 911/900 etc. I would suggest C34 to be changed to 150pF or lower to increase dynamic range of your record bias.

For both Record Amp and Repro Amp boards, your photos show older generation A101 discrete "opamp" devices (black rectangular part in Record Amp and blue potted part in Repro Amp). Since you are in Europe, it should be easy for you to obtain modern replacement A101s from a seller in Germany (eBay).

Lastly, there are caps on both Record and Repro Amp boards that must be replaced (and yours had been done so). However the electroytic caps on signal paths are debatable. Some people (who know more about Studer than myself...) consider the Tantalium looking caps (but they are not Tantalium type) are Studer special ingredient that gives the Studer "its own sound" and would be dead against replacing them. If you have spare boards, you can try them both ways and make up your own mind.

As I had stated elsewhere, it is far better to have a well taken care of Mk I (or just A80RC) than worn down and neglected A80RC MkII. You have a very nice A80RC from what I can see.

Talk about sharp eyes! Ki is the man.
 

andromedaaudio

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Talked to the tech and asked about the heads according to him they measured within specs at 10 khz , but he also said that at studios they change them at 3,5 mm .
Later on i will have them changed plus have the lightening repaired and maybe have the other mods/improvements carried out

B 62 at 7,5 ips very nice machine also , sounds fantastic.
whats left is the speaker project to finish:D
Look forward also to do some recordings and hear the results

_DSC0059 by andromeda61, on Flickr
 
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andromedaaudio

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Playing some old beethoven basf taperecordings , sound very good very dynamic and transparent , piano and voices is where tape immediately excels.
I have a question though how do i fit the "" butterfly plate ? "" secure on the A 80 , one part is missing ???


_DSC0060 by andromeda61, on Flickr


_DSC0061 by andromeda61, on Flickr
 
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andromedaaudio

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Got it working: the butterfly head /base had gotten a bit exentric so it scraped the surface , aligned it a bit and put some connecting tape underneath for lift
playing some Old dutch broadcasting society tapes , these are great sounding tapes .

_DSC0064 by andromeda61, on Flickr


_DSC0065 by andromeda61, on Flickr
 
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andromedaaudio

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After a couple of months comparing tapes / swapping audiocards a80 versus b62 cards .
I ve come to the conclusion i like the B62 more .
The B 62 feels solid /compact and sounds more energetic , it sounds like the A 80 is more laid back versus the B62 more energetic intense.
When this never ending speaker project is finished im gonna upload the B 62 playing some of its self recorded pianomastertapes.
The a 80 vu meterbridge is flimsy, the b62 version is much more solid
 
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RogerD

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andromedaaudio

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Thanks , just trying to lower the noise floor a little bit more , i might go for King cello in the future ,maybe also record if he does that , and compare
 

microstrip

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Just found this thread - I can not see how I missed it - I love the A80!

Your repro head looks really in poor shape. Flat heads can also affect the performance due to scrape flutter. The heads of my PR99 had a flatness around 2.5mm and could decently play 10KHz, but the machine suffered from measurable scrape flutter. After I send them to be relaped to John French of JRF, on the advice of an expert of the Tapeproject forum, the problem completely disappeared. For more information please see http://www.tapeproject.com/smf/index.php?topic=1051.5;wap2
 

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