All you can really do is go through it bit by bit and look at the values of components you have not yet replaced.. Resistors mostly.. Clean all of the switches, measure voltages at various points to verify things are working correctly.
Have you installed tape in the loop yet?
Need to provide us with a lot more information to get useful feedback back..
Most of the information including expected ac signal and dc voltage levels are there in the schematic, now it is a matter of finding out what works, what doesn't and fixing the issues.
What sort of test equipment do you have?
Have you installed tape in the loop yet?
Need to provide us with a lot more information to get useful feedback back..
Most of the information including expected ac signal and dc voltage levels are there in the schematic, now it is a matter of finding out what works, what doesn't and fixing the issues.
What sort of test equipment do you have?
I successfully restaured a two Dynacords, one S65 and a S62.
That was five years ago and they work like a charm !!
I used all the original values for the capacitors, Sprague Atom, F&T (They have some 32µF*2 500V) and some very great Ero Yellow film for signal path.
You can get rid of all these ugly yellow bugs inside of your S62, they are very noisy and have no Mojo at all...
I also swapped all these ugly brown coax wires with some good shielded cable... that's a hard work but a step further for signal over noise...
Some of the ceramic caps are causing a lot of hiss, they are difficult to find without a scope but if you find them, this really changes everything !!
I now plan to change the motor starter cap (The big yellow one under the 32-32) and swap some of the most important signal caps for some Sozo Mustards. Il will also remove the DYN plugs and replace them with regular switchcraft jacks (maybe only on the S65 wich is more simple and far better than the very complicated S62).
One tip : I also changed the rectifier, voltage was way to high after that but if you check the heaters voltage (6.3v) you'll see that its way to high too... Witch means that you have to use this device under the 240V stetting, not 220.
In france (I'm french also) line is in general closer to 235-240 than 220.
Tip two : Use some Sovtek 12AX7LPS or JJ ECC803S with this device
That was five years ago and they work like a charm !!
An externally hosted image should be here but it was not working when we last tested it.
I used all the original values for the capacitors, Sprague Atom, F&T (They have some 32µF*2 500V) and some very great Ero Yellow film for signal path.
You can get rid of all these ugly yellow bugs inside of your S62, they are very noisy and have no Mojo at all...
I also swapped all these ugly brown coax wires with some good shielded cable... that's a hard work but a step further for signal over noise...
Some of the ceramic caps are causing a lot of hiss, they are difficult to find without a scope but if you find them, this really changes everything !!
I now plan to change the motor starter cap (The big yellow one under the 32-32) and swap some of the most important signal caps for some Sozo Mustards. Il will also remove the DYN plugs and replace them with regular switchcraft jacks (maybe only on the S65 wich is more simple and far better than the very complicated S62).
One tip : I also changed the rectifier, voltage was way to high after that but if you check the heaters voltage (6.3v) you'll see that its way to high too... Witch means that you have to use this device under the 240V stetting, not 220.
In france (I'm french also) line is in general closer to 235-240 than 220.
Tip two : Use some Sovtek 12AX7LPS or JJ ECC803S with this device
Splice tape should face away from the head surfaces. I'm not terribly familiar with these machines, but to troubleshoot them effectively you need a generator, scope and meter. First thing to do is make sure that the record section is working and then verify that the multiple replay heads are ok..
Dnacord s65
Hi everyone!
First of all thanks for a good thread. i found it when looking for the schematics for the echocord.
i was lucky enough to find an old guy out in the country that had a whole barn full of stuff from the 60´s he had worked as an repair man for old amps and speakers and had his own brand back in the day. now the things just collected dust....
so i went home with three dynacord echocord and lots more for s smaller fee...
so here i am with three echocords to restore.... and im certain i need your help.
ive just started the first one that looked ok. and the tubes lid up and everything looked fine but the motor wasnt moving. i later noticed that one of the fuses was blown so that might be why. anyhow im going to the electronic store to buy me some capacitors and i got lots of pics to show you but i dont know how to post them... any suggestions....
take care...
Kindest regards:://Henrik Hoffer
Hi everyone!
First of all thanks for a good thread. i found it when looking for the schematics for the echocord.
i was lucky enough to find an old guy out in the country that had a whole barn full of stuff from the 60´s he had worked as an repair man for old amps and speakers and had his own brand back in the day. now the things just collected dust....
so i went home with three dynacord echocord and lots more for s smaller fee...
so here i am with three echocords to restore.... and im certain i need your help.
ive just started the first one that looked ok. and the tubes lid up and everything looked fine but the motor wasnt moving. i later noticed that one of the fuses was blown so that might be why. anyhow im going to the electronic store to buy me some capacitors and i got lots of pics to show you but i dont know how to post them... any suggestions....
take care...
Kindest regards:://Henrik Hoffer
Dnacord s65
ok they didnt have it in the electronic store. is it ok to change it to another value? this helps the moter to start like a start motor of some kind right?
ok they didnt have it in the electronic store. is it ok to change it to another value? this helps the moter to start like a start motor of some kind right?
An externally hosted image should be here but it was not working when we last tested it.
Re: Dnacord s65
No! The motor in your echoplex is a synchronous type and the capacitor provides approximately 90 degree phase shift for the motor windings which run in quadrature. This is a moderately critical value and you should replace it with the right cap. You should be able to find the value you need at any number of online vendors and on eBay as well. Using the wrong value will both reduce torque and increase vibration (and probably heating as well) in the motor. It is well worth the wait to get the right cap for this job. Make sure you purchase a motor run capacitor, and the voltage rating must be no less than the original. Modern PPIO types will last practically forever in this application.
Henrik.Hoffer said:
No! The motor in your echoplex is a synchronous type and the capacitor provides approximately 90 degree phase shift for the motor windings which run in quadrature. This is a moderately critical value and you should replace it with the right cap. You should be able to find the value you need at any number of online vendors and on eBay as well. Using the wrong value will both reduce torque and increase vibration (and probably heating as well) in the motor. It is well worth the wait to get the right cap for this job. Make sure you purchase a motor run capacitor, and the voltage rating must be no less than the original. Modern PPIO types will last practically forever in this application.
Hi There,
I am not sure of the year of your unit, and am not an expert on these devices by any means.
The motor capacitor that I pulled out of my 61 Echocord Super was 50uF 125V. I replaced it with a 56uF 450V, which I believe is acceptable as I have read that within 20% of the capacitance value should not affect the circuit.This solved the motor issue for me.
I am not sure of the year of your unit, and am not an expert on these devices by any means.
The motor capacitor that I pulled out of my 61 Echocord Super was 50uF 125V. I replaced it with a 56uF 450V, which I believe is acceptable as I have read that within 20% of the capacitance value should not affect the circuit.This solved the motor issue for me.
Dnacord s65
ok thanks then im going to look up the right capacitator for th motor and order it
this is the top of the echocord before cleaning
This is the inside before changing anything
ive started to change the whole bridge for the trimpots cause the one im working on is broken.
and im going to change the whole button part then i think ive got all that i need to start to put one together that is fully funktional an original.
ok thanks then im going to look up the right capacitator for th motor and order it
this is the top of the echocord before cleaning
This is the inside before changing anything
ive started to change the whole bridge for the trimpots cause the one im working on is broken.
and im going to change the whole button part then i think ive got all that i need to start to put one together that is fully funktional an original.
Dnacord s65
Hi again!
ive got everything working now but there is no echo. the motor is running and there is sound from the guitar but no echo? any ideas i dont think all three heads are dead it must be something else. like the amplification of the echo signal or something anyone got experience with this?
take care...
Kindest regards:://Henrik Hoffer
Hi again!
ive got everything working now but there is no echo. the motor is running and there is sound from the guitar but no echo? any ideas i dont think all three heads are dead it must be something else. like the amplification of the echo signal or something anyone got experience with this?
take care...
Kindest regards:://Henrik Hoffer
Hi,
As far as I can read, the unit is working.
That is:
1. Motor is turning.
2. Tape is new and placed correctly with the splice tape away from the heads.
3. All inputs do work.
4. Tone controlss work to.
5. Echo and reverb controls work.
6. Echo level is low.
Did you check the following:
I assume you cleaned the heads...
I also assume your heads are in decent state; the front with the gap is not to much eroded.
A flat rectangular surface is an indication of excesive wear allthough 1 mm is not to bad.
A. The DC settings of the Oscillator tube Ro6, ECC82.
If the signal you injected (guitar for example) is erased after passing the Erase head, your osc. is working.
B. The DC settings of the Read Head preamp tube Ro3, ECC83.
C. If these are all ok, try to inject a signal at pin 2 and later at pin 7 of Ro3. Be carefull with the high voltages inside. They can kill you!
If in doubt, feel free to ask how to do it.
Do you hear something and can you adjust volume and tone.
C. If that's ok, try to adjust the hight of the heads but do this slowly and one head at the time.
Start with the Read heads and adjust for max noise (no signal applied to the unit) or max signal (with a test tone applied)
Do this then for the second Read head.
D. Did this change any thing?
Continue with the adjustment of the hight of the Write heads.
Again one head at the time and adjust for max signal.
This would do the trick.
If all this is not working, the heads must be gone.
Cheers and good luck,
tarzan
As far as I can read, the unit is working.
That is:
1. Motor is turning.
2. Tape is new and placed correctly with the splice tape away from the heads.
3. All inputs do work.
4. Tone controlss work to.
5. Echo and reverb controls work.
6. Echo level is low.
Did you check the following:
I assume you cleaned the heads...
I also assume your heads are in decent state; the front with the gap is not to much eroded.
A flat rectangular surface is an indication of excesive wear allthough 1 mm is not to bad.
A. The DC settings of the Oscillator tube Ro6, ECC82.
If the signal you injected (guitar for example) is erased after passing the Erase head, your osc. is working.
B. The DC settings of the Read Head preamp tube Ro3, ECC83.
C. If these are all ok, try to inject a signal at pin 2 and later at pin 7 of Ro3. Be carefull with the high voltages inside. They can kill you!
If in doubt, feel free to ask how to do it.
Do you hear something and can you adjust volume and tone.
C. If that's ok, try to adjust the hight of the heads but do this slowly and one head at the time.
Start with the Read heads and adjust for max noise (no signal applied to the unit) or max signal (with a test tone applied)
Do this then for the second Read head.
D. Did this change any thing?
Continue with the adjustment of the hight of the Write heads.
Again one head at the time and adjust for max signal.
This would do the trick.
If all this is not working, the heads must be gone.
Cheers and good luck,
tarzan
Amp rating for replacement rectifier
Hello all,
First, the current state of my unit (a 61 echocord super) is that I have replaced all the capacitors which were bad. Initially the magic eye was not responding to signal but after the last round of capacitor changes it came to life. New tape installed.
As of today, I also have the issue of very low echo volume, and additionally when the tape is running (echo engaged) there is a repeated cycle noise which also shows up in the magic eye.
I have not yet changed the rectifier, and was wondering if I can replace it with an 800 v 2amp one? Such as the one at the top of the page here http://www.lauermann.at/120.htm
Any suggestions? Is it possible it may be the source of the low echo?
Thanks in advance
C.
kevinkr said:
Hello all,
First, the current state of my unit (a 61 echocord super) is that I have replaced all the capacitors which were bad. Initially the magic eye was not responding to signal but after the last round of capacitor changes it came to life. New tape installed.
As of today, I also have the issue of very low echo volume, and additionally when the tape is running (echo engaged) there is a repeated cycle noise which also shows up in the magic eye.
I have not yet changed the rectifier, and was wondering if I can replace it with an 800 v 2amp one? Such as the one at the top of the page here http://www.lauermann.at/120.htm
Any suggestions? Is it possible it may be the source of the low echo?
Thanks in advance
C.
Definitely replace that selenium rectifier, even if good it is a ticking time bomb.. More than likely it is not good and the supply voltages are way too low for proper operation. Not necessarily the cause of your difficulty, but one thing that is easily eliminated.
Your rectifier choice should be fine. Trim voltages by changing the mentioned resistor only if they are off by more than about 5%.
Your rectifier choice should be fine. Trim voltages by changing the mentioned resistor only if they are off by more than about 5%.
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