Studer A80-R Problem

poulb

New Member
Feb 17, 2012
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Hi. I have a studer A80 that cannt record. ( both channals) Its a 1/4" sterio mashine. (ozilator board has 2 relays). Erase and playback is ok. Signal through record amps is ok. record button lights up. heads are clean. power suply to audio boards is ok. I have the service manual. Does some one know this mashine? Thanks in advance. Bjorn.
 

amirm

Banned
Apr 2, 2010
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Seattle, WA
Ki Choi is our resident tape hardware expert. PM him if he doesn't answer and hopefully he can chime in. Welcome to the forum btw :).
 

tony ky ma

Industry Expert
Aug 21, 2010
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Whitby Ontario Canada
Hi Bjorn
Before to pull the record card out check the record ccur ( front of the record card) plug in a current meter DC and AC for checking if any bias current and audio current in there, if not that means the ralay for recording maybe not working and if there is fine then check the cable to recording head
tony ma
 

Ki Choi

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May 13, 2010
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Hi Bjorn
Before to pull the record card out check the record ccur ( front of the record card) plug in a current meter DC and AC for checking if any bias current and audio current in there, if not that means the ralay for recording maybe not working and if there is fine then check the cable to recording head
tony ma

I agree with Tony's suggestion.

Is this A80-R new to you and does it have a VU meterbridge?
When you input 1Khz test tone into the input connectors, can you monitor the test tone from the VU meterbridge by pushing the Input button?
 

poulb

New Member
Feb 17, 2012
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Hi Tony. No curr. record relay on ozilatorbord is working .24v reed-relays on record amps getting energized but no record. Mabey faulty reed-relays but both? must find a way to check. thanks Bjorn
 

Ki Choi

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May 13, 2010
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Hi Bjorn:

You can solder in a temporary wire to the signal side of the reed relay contact (if you don't have the extension board) to confirm if the reed relay is bad... not easy but doable.

Ki
 

poulb

New Member
Feb 17, 2012
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Hi Ki Choi. It doesnt have vu meter only a litle speaker with a swiths for playback ore input . it also has a channal selector (channal1 / 2 ore both) The erase head on this mashine is full track only 2 wires. I have plugged a cd player to input and it goes trough rec amps to monitor ok. the mashine also has a mono/sterio swiths , doesnt seem to have enny affect on the recording problem. Thanks Bjorn
 

poulb

New Member
Feb 17, 2012
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Hi again thanks for info. I took the whole audio basis board of and laid it on its back plugged boards in an messured power supply to reed relay 24v ok so they are getting energized when i press record. must find a way to check wether ore not they are switshing. Bjorn
 
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Ki Choi

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May 13, 2010
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You might want to double check the jumpers on the audio basis board if this machine is new to you and don't know if it was working properly prior to you trying it. I have seen wrong jumpers for Stereo/Mono card on A80RC that came from a studio.

Also A80 sends record and repro signal up to the VU meterbridge and get it back after level adjustment from the pots if it is in Uncal mode. I would suggest you start tracing the signal from input to the relay output contact. The other common fault on Record Amp cards I had experienced is with the A101 module...

However, above problems due to parts failure such as the A101 or reed relay going bad usually happen to one of the two cards and rarely to both at the same time. Thus, think about the possible cause as shared common function for both CH1 and CH2 such as the signal routing up to the VU meterbridge, etc.

Ki
 

poulb

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Feb 17, 2012
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Ki do you mean iliminate/bypass the reed contact? will have to fig out wish pins to solder the wire to thanks Bjorn
 

Ki Choi

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May 13, 2010
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Ki do you mean iliminate/bypass the reed contact? will have to fig out wish pins to solder the wire to thanks Bjorn
Send me your email address where I can send you the datasheet for the SPDT relay. You can also access it here:

http://www.serelays.com/library/section8/105A_172DIP.pdf

It is the WD172DIP-150 relay.

You can bypass/jumper the contacts per drawing to see if the signal will go through but it will be temporary measure.

Ki
 

poulb

New Member
Feb 17, 2012
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Hi again Relay from the link you sent me look different from the ones on my mashine. they are red color. it says erni dilrid-b 1A1W24V 72L48 on them . but mabey its the same diagram? Thanks Bjorn
 

Ki Choi

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May 13, 2010
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Yes, although it looks different, they are electrically the same relay with 24V coil and SPDT relay contact that matches Studer circuit board pin layout exactly.

Ki
 

Ki Choi

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May 13, 2010
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Hi Bjorn:

It's a basic and silly question but have you engaged the SAFETY switch on the meterbridge (if you had one) or equivalent switch (on your custom VU meter under the machine you mentioned) to enable record function on both channels in the first place?

Ki
 
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poulb

New Member
Feb 17, 2012
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Hi Ki thanks for suggestion. There are no meters on this mashine. It has one litle speaker with a swiths input ore reproduce. All wires to this litle amp/speaker are solderd to the back of the audio basis bord. It is origional eqipment for this mashine. It swithsis between record ore reproduse amps. It also has a channal select button channal 1 ore 2 ore both. I have tryed all possible positions. It didnt help to solder wire to reed relay ( pins 1 and 7) so looking for somthing that effects both channals. Mabey mono/sterio card ore ozilator card. Bjorn
 

Ki Choi

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May 13, 2010
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You can jumper contact 10 and 11 on the Record Amp card to bypass stereo/mono circuit. If it's not the cause fro your problem, only solution for you is to inject 1khz test tone in the input terminal and trace it to the Record amp card contact 12 and 13 and follow it all the way down to record head...
 

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