Repairing a tape echo with tubes (Dynacord Echocord Super 62a)

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kevinkr

kevinkr

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Re: Dead Heads

woodenturn said:
My problem is that my heads are toast. Any ideas on where I could get replacements and what the cost would be?

I can get them refurbished I think for 30 bucks each, not sure if there are alternatives.
Click to expand...


The Magnetic Head Company can probably provide replacements, but I would expect them to cost more than what it costs to relap the existing heads - provided that they can be relapped. (Depends on whether or not the gap has started to open up.) Check replacement cost first though..

http://www.magneticheadcompany.com/

I have done business with them and can very highly recommend their products, and customer service.
 
R

Radioman62

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Joined 2005
binatech.se/hem
Measuring data from the heads

Hi all echo diggers :)

I don't know if some of you in this thread allready have mailed me. I get mail now and then about my own homepage which tells about my restoration of a S62 unit.
I see I maybe also have to change the selen rectifier. I have heard about the smell and the mess when they broke but I have still not experienced any problem in all years with old equipment. Hmm. I have several of them in different units. Radios and guitaramps f.e. :eek:

Anyway, I have some data on the heads which I measured with a LCR meter some years ago. The heads are very high impedance and hard to find. I havent tried to find any myself but some years ago it was nearly impossible without special order to a manufacturer in China, which my Echocord-friend in Canada, Greg eventually tried. Please look at this page where you also can download the hole servicemanual (in German), not only the schematic. The manual is for the S62 but I also have alink to the S65 schematic which seems to be the same scan as a post above here. :)
 
T

tooney

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Joined 2008
igrowrecords.com
echocord mini restore

hi !
i just bought an echocord mini and it was sounding great ..i have cleaned it, degmagnatized & cleaning heads & new tape .. what a great unit !! :D
but last day, circuit fuse blows .. and blows again ... motor still runs but no sound !! :eek:

i would like to ask bigmuff or anyone living in europe :
I live in FRANCE and i don't which fuse to use ..

220 or 240V ? bigmuff said 240 for france ..
but with a fuse ... 400mA/T or 125mA/T for circuit fuse ?
and for, main fuse please?

thanks for help

musically,
tooney

ps: i have ( and can share) the HD schematic and user's manual (echocord super76.;similar )
 
kevinkr

kevinkr

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Find out why the fuse is blowing FIRST. Do not install another until you have done so unless you want to compound the damage already potentially done.

I would go ahead and replace the selenium rectifiers and supply capacitors before proceeding too far.

Use a ballast lamp in series with the AC power to limit fault current if you want to trouble shoot. (If you can't trouble shoot find a qualified technician to repair your unit.)
 
unclejed613

unclejed613

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ballast lamps are most often used to "soak up" the difference between line voltage and a filament string on AC-DC "hot chassis" equipment. since the filament string is a series string across the AC line, sometimes the filaments don't add up to (for instance) 120V, maybe they add up to 90V, so a 30V ballast lamp is added to the string to make up the difference. a dropping resistor for 30V/500mA would have to be a 20W ceramic which with mounting hardware would probably cost twice as much as a ballast lamp and tube socket, plus the resistor would cause a bit of a warm-up delay compared to the lamp which starts out at a low resistance which increases the same as a tube filament.
 
kevinkr

kevinkr

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unclejed613 said:
ballast lamps are most often used to "soak up" the difference between line voltage and a filament string on AC-DC "hot chassis" equipment. since the filament string is a series string across the AC line, sometimes the filaments don't add up to (for instance) 120V, maybe they add up to 90V, so a 30V ballast lamp is added to the string to make up the difference. a dropping resistor for 30V/500mA would have to be a 20W ceramic which with mounting hardware would probably cost twice as much as a ballast lamp and tube socket, plus the resistor would cause a bit of a warm-up delay compared to the lamp which starts out at a low resistance which increases the same as a tube filament.
Click to expand...


I now regret using the term "ballast lamp" as it was in reference to a series connected external lamp for protecting the power transformer during troubleshooting. That was the usage he was asking about from my earlier post. (Post #45)
 
T

tooney

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igrowrecords.com
ok thanks for help !
so , i just have to plug a light in series before main supply ?
i switch on the light when i use my echo ;) !!! that's it ?

i m a beginner in electronic and i learn a bit of theory .. just to sold my broken parts ..change cap ,etc .. thanks for this tip ;)

for the rectifier , do you the ref. of this part in the echocordMINI ?
i have seen in a previous post > 800 PVI ?? /1A ?

regards
 
kevinkr

kevinkr

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Basically use the lamp in series to limit the current to a safe value, a 230V 100W lamp should be fine for this purpose - only for trouble shooting, once you are sure you have repaired the problem you don't use it any more.

Yes a silicon bridge rectifier having a PIV rating of greater than (plus que) 800V ought to be fine.. Current rating of 1A or 2A is more than required - higher voltage and current ratings are fine as long as you have the space.

Replace all of the condensateur chimique as well. Mostly like one of these is the culprit, in any event replace them.. :D (sans penser)

cliquez ici: http://wiki.jelectronique.com/condensateur

Good basic French language explanation of capacitors on the above link. Note that there are radial and axial types. Only shown are radials, you have many axials and these are also available..
 
T

tooney

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Joined 2008
igrowrecords.com
thank you for all those tips !
now, im sure that i gonna restore it !!
i have used it in my album and i m fallin in love of vintage gears ;)
i gonna learn and learn !! DIY :d
i will let you know when it will be replaced ..

ps : if anyone need a pinch roller for dynacord echocord , i found a guy in germany , send him your old roller for brand new rubber ;)
20 € .; really a good pro !

hellmut jung

contact me for his contact ..
for tape loops .>> tapeecho.com highgrade for sure ;)

thank you for your help

musically,
tooney
 
kevinkr

kevinkr

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I apologize for loosing track of the thread, but I have had some serious computer problems and missed all of the notifications for this thread.

While a replacement rectifier will work, hopefully you can find a suitable silicon bridge to replace it at some point. Should have better long term reliability.
 
T

tooney

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Joined 2008
igrowrecords.com
no problem kevin ;)
i have already change the rectifier for B30 C350 .. very bigger than original one , i had soldered some wires on board...
this 1st unit work well now but a little noise when i put the EQ to the high tone .. i have degmagnetized heads .. but still ..
this works well apart from that ..


my major problem is my second unit .. i don't find where the problem comes from .. unit switch on , motor runs ok but no sound !!:eek:
circuit's fuse blows out again !!.. does it comes from transfo ??

thanks
 

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