help with echoplex please

[rockinrendell]

i just picked up an echoplex ep3. ive opened it up and cleaned inside,tape path,pots,etc. the problem im having is i can hear previous played material. does anyone know how do deal with this? is this sign of bad record/erase head? i guess i need to take it apart again and check all the solder joints and make sure its attached. suggestions?

[52 Bill]

i just picked up an echoplex ep3... the problem im having is i can hear previous played material.

Weren't we just discussing this recently.

Does the rest of the unit work? Do you hear straight signal? Does the unit record and playback a new signal? Is this a solid state EP-3 with 3 heads?

[rockinrendell]

yes the unit works. i get echos, runaway osolation, the sound on sound seems to work(maybe to well). when not using the sound on sound and using the echos, i still hear the previous played music. its still echoing ok but the stuff i played before is bleeding through but not quite as strong as the sound on sound. if this makes sense. if i put a small magnet next to the tape before the record head(like the univox ec80a) no more previous music. so something isnt right obviously. dont know if its the switch,record/erase head or in the circut itself. im no engineer. i know enough to investigate or get myself in trouble depending on if im lucky or not. so far im not having luck with hunting down the problem. i thought maybe the trim pots inside may have something to do with it. no luck there. is there any info here or anywhere that can help or is there anyone here that can walk me through this. im sorry if i missed any previous dicussions.

[rockinrendell]

and yes its a solid state ep3 with three heads.

[52 Bill]

and yes its a solid state ep3 with three heads.

Regis has a great site with a whole lot of EP-3 (and other models) info. Check out the thread on Echoplex tape for his link.

[rockinrendell]

his website didnt help with this problem. i did some reading here in past posts and it could be bad oscilator tranny or bad record/erase head according to a couple posts i read. i tried to calibrate it the best i could with my ear. it works great except for the background playing that wont totally erase or at all.

[52 Bill]

...it could be bad oscilator tranny or bad record/erase head

If the unit is recording, then the oscillator is running and ok, so that rules out the transistor.

It could be the erase head or the head alignment. Do you have a ohmmeter? If you do, read the resistance of the erase head. How does it compare to the schematic?

[rockinrendell]

the multi meter i have is old and the batterys are shot and you can buy them just anywhere these days.

[rockinrendell]

if it is head alignment, which head would most likely be the one thats off? i just talked to a buddy and from what he said it could be head alignment or bad erase head or the circut driving the erase head isnt strong enough or something like that. how can i check the head alignment and set it if i need to?

[uboat229]

most echoplexes dont erase and were never intended to erase.... they just record over the old sound

frankie uboat

[Enzo]

Um, then what is the erase head there for? You have to erase the old signal from the tape to lay down a new one in its place.

[uboat229]

hi Enzo.... i have a market electronics ep2.... first batch and it has 2 heads... a playback head and a record head....you dont have to erase the old signal... it disappears when you record over it..... i never took apart or had an ep3..... and probably wont since i knew mike battles and how gibson screwed him.... i also dont have a sos echoplex... so maybe you have one of these and then i just dont know....

frankie uboat

[Enzo]

I don;t have either, I have serviced them for many years. If you look at your record head, I think you will find on the face of it it has two pole sections, one is the erase, and the record is right next to it. I linked a schematic in another thread, but here:

http://bmamps.com/Schematics/Effects..._1549-2749.pdf

That is for early serial numbers, I don;t know which one you have. But note the record and erase heads are M2A and M2B, meaning they are both in the same part. The old signal disappears because that erase function precedes the record by a millimeter or two on the head as tape streams by.

I just sold off my selection of record and playback heads for both tube and solid state versions of the Echoplex a couple months ago (closing out my shop, I'm old). I have one playback head left.

[uboat229]

im new to this forum and still learning..... i went to post the one comment that is right after yours with the first schematic... it disappeared on me and i posted another which i dont see now.... in that one i said i stand corrected and noticed that the erase and record head were the same and on the slider. i also said im not too old to learn or to dumb to admit when i made a mistake.....so thanks for the help and schematics... and education......mike was my echoplex tech... id just take it to his house when i wanted something done on it..... no sn# sticker left but he said it was from first batch of ep2's. no side pocket and no hinges.... just the 2 funky side latches..ever meet him?

thanks

frank

[Enzo]

Nope, never did.

I did see that post, so it didn't disappear. I think we are having the same conversation in two places, so that may be confusing.

If you look at the source of the schematic links I posted, he has a bunch of Echoplex schematics. Several EP2, an EP1, some EP3s and an EP4. Interesting to look at the evolution of the design. And in fact he has TONS of schematics for all manner of things we work on here. That site belongs to nickb who posts here regularly. So thanks to him, I just passed them along.