echoplex (ep-3?) questions

[freak scene]

i just got an old echoples in an "if you can fix it you can have it cheap" deal.  obviously i plan on starting with cleaning the heads and replacing the tape cartrige but i had a few questions about other things.  first i fired it up, and the echo is almost not present, if thats not the tape or heads what else could it be?  what should i look for?  also what is the trimpot inside for (not the record volume one one actually on the board)?  the insides of this thing were amazingly clean!  its a bit worn on the outside, but nothing major.  i really hope i can get this working!  im psyched, i also scored a late 70's deluxe electric mistress last night for 80 bucks, ive been on a gear rampage haha.

[Peter Snow]

Hi FS,

Without looking at the circuit I would guess that the trimpot is for adjusting the record head bias.

Cheers,

Peter

[freak scene]

thats what i assumed, i tried it, no effect on the echo it is still all but non existant.  the next step is to get some new tape on there.  any sights to get it from besides fulltone and tubeplex?  should i just wind my own from old 8 tracks?  if the tape isnt the problem, then is it correct to assume that its the record head (the play head is working fine as far as i can tell, it picks up all the hiss that is normally present in tape echo)?

[Rodgre]

Congratulations on the scores. I have a couple of EP-3s as well, and I love what they do to a guitar tone. Just the electronics themselves sound nice and grungy in a very sweet way.

One thing I found out about when I was trying to clean up one of mine was that a certain issue of EP-3s had an additional compressor circuit tacked on. It was a bad idea and a bad sound, but the compressor itself, was pretty cool and squishy (got to put that in a box one of these days!). Check to see if there is an additional small circuit board floating in there as well.

Don't be terribly surprised if the head is bad though. I have an extra on hand in case any of mine die on me. There must be a way to get a replacement, if you need one.

Cleaning the heads and replacing the tape is the first place I'd look though. Demagnetizing it might not hurt as well.

Roger

[Fret Wire]

http://www.fuzzorama.com/echoplex.htm

[Vsat]

Brass tensioning spring there?
Cheers, Mike

[Peter Snow]

The other adjustment that can affect the level and quality of the tape playback is the "azimuth" of the head.  That is, the angle of the record/playback head in relation to the tape.  Usually there is a spring loaded set screw at the base of the bracket holding the head. Turning this will tilt the head one way or another. I would be very wary of playing with this adjustment until you have eliminated all other possibilities for the bad sound.  In my (very limited) experience of adjusting reel to reel tape recorders, it is difficult to get this adjustment just right.  Maybe for a tape echo it is not so critical... I don't know.  I also don't know if your particular unit has this adjustment available - the head may be fixed in position.

HTH,

Peter

[freak scene]

Cleaning the heads and replacing the tape is the first place I'd look though. Demagnetizing it might not hurt as well.

Roger

hmm how do i go about demagnetizing?  ive cleaned the heads, havent got around to the tape yet.

http://www.fuzzorama.com/echoplex.htm

Thanks!

Brass tensioning spring there?
Cheers, Mike

you mean the one giving tension to the rubber wheel on the left?  if so then yes its there.

The other adjustment that can affect the level and quality of the tape playback is the "azimuth" of the head.  That is, the angle of the record/playback head in relation to the tape.  Usually there is a spring loaded set screw at the base of the bracket holding the head. Turning this will tilt the head one way or another. I would be very wary of playing with this adjustment until you have eliminated all other possibilities for the bad sound.  In my (very limited) experience of adjusting reel to reel tape recorders, it is difficult to get this adjustment just right.  Maybe for a tape echo it is not so critical... I don't know.  I also don't know if your particular unit has this adjustment available - the head may be fixed in position.

HTH,

Peter

im pretty sure mine is fixed, but it seems that the tape is getting contact over the whole face of the head because there are guides on either side of the head.  though im not looking at it right now so i could be wrong.  ill take some pictures tonight and post them.

thanks again for all the advice so far.