Need help with solid state tape echo.
bencahill
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#1
7th August 2010
Old 7th August 2010
  #1
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Need help with solid state tape echo.

Hi guys and gals,

I just picked up a cheap Echolette Echo 400 tape echo unit. This unit has also been issued as the Dynachord EC504 with a different front panel layout. I assume the guts are the same.
Need  help with solid state tape echo.-echolette_echo400_frontpanel.jpg
The preamp section is working fine but there is a lot of noise on the echo output section. The level of the repeat is very low, almost inaudible.
When the "Return" knob (equivalent to "mix") is brought up from 0, there is a lot of noise.
The "Duration" (feedback(?)) pot does nothing. I have pulled out the pot and checked it and it works fine. There is only one repeat per head so there is obviously a problem here somewhere, besides the noise.

The motor seems to be working perfectly and the machine is in good condition generally. I have tried it both with 2 and 3 pin cables in a system with proper grounding, I've looked over and cleaned as much of the guts as possible. I have used the original tape loop - I'm waiting for new ones to arrive from ebay - but although this could be the reason for the low repeat volume, it wouldn't cause noise, right? I have checked all the wiring and traces too, at least those I can access without completely dismantling the unit. And everything seems fine. . .

So, some questions:
Firstly, does the play head look ok?

Need  help with solid state tape echo.-echolette_echo400_playhead.jpg

The 4 record heads are in much better condition than this so I am not worried about them.

Some of the ceramic caps look a bit "lumpy", I didn't think it was possible for ceramic caps to do this due to age - so have they always been like this?

I understand that recapping the echo section (if not the whole unit) will help with the noise, what should I start with? The Poly film caps?
There are a few of what I assume are electrolytic caps, but they are different form the ones I have worked with before, see the picture below.

Need  help with solid state tape echo.-echolette_echo400_caps.jpg

Do I read the orange one as 47 microfarads at 40 volts?

I would really like to get this up and running.
Thanks for your time.
#2
8th August 2010
Old 8th August 2010
  #2
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fireberd's Avatar
 

The head looks crappy. Have you cleaned it and demagnetized it? Bad tape can cause level and noise problems. Wait until you get the new tape and see how it works.
bencahill
Thread Starter
#3
8th August 2010
Old 8th August 2010
  #3
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Thread Starter
I have cleaned it but not demagnetised it.
No demagnetiser. I will get one soon as I also have an old tandberg 1/4" deck that needs some love.

The noise is there regardless of the tape loop being there or not. That's why I think the problem is electric.
Is there a way to check the integrity of the play head?
I will report back after trying the new tapes.
Thanks.

Last edited by bencahill; 8th August 2010 at 04:05 PM.. Reason: Looked into demagnetising.
#4
8th August 2010
Old 8th August 2010
  #4
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fireberd's Avatar
 

If it's not the tape, the noise can be anywhere and anything from a cap (or caps) to a bad op amp somewhere.

Recapping something old will help with sound and noise - how much depends on the unit. I've installed some "LeMay mods" in some Peavey steel guitar amps (Session 400, Nashville 400, etc) and recapping the preamp/EQ board, especially in an older Session 400 amp that has discrete components really helps.
#5
6th October 2013
Old 6th October 2013
  #5
Gear interested
 

Recently I got the same machine. The seller told me it worked perfectly about two years ago and it was in the closet since then. It powers up, the tape is running ok, the signal passes through but I can't ignite the efect. When I start the tape there is more hiss/hum which gets louder if I turn up the volume on the machine and if I turn the "return" knob. Only bass and treble knobs on the "channel" section seems to work, other not (except the return knob). If I pull out the guitar cable the pop sounds under effect but not the signal from guitar - it looks the heads are working...

If someone could help me with fixing this gem it would be great!

hey bencahill ... did you fix your machine yet? what was the problem?
#6
7th October 2013
Old 7th October 2013
  #6
Lives for gear
 
drtechno's Avatar
 

yea that tape head is thrashed.
I don't know if someone could relap that head either.
you could ask Mr. French at JRF Magnetics if he could relap that head.
#7
6th December 2013
Old 6th December 2013
  #7
Gear interested
 

Does anybody has a schematics for this Echolette Echo 400?
(maybe is the same as Dynacord EC 504)

I would need it badly!

Does anybody know anything else about this machine except the info which could be found on the net? Does anybody have it?
#8
7th December 2013
Old 7th December 2013
  #8
Gear interested
 

I will get one soon as I also have an old tandberg 1/4" deck that needs some love.
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