EMS synthi Hi-Fli repair

[bsoncini]

I can give it a go at tracing but having never traced a pedal before to tracing this beast is quite the jump.


Unless anyone else in Europe is up to the task I can ask my friend if it's ok with him to loan it out.  He'd probably say yes if that person was willing to repair it too.

As for scanning the pcbs I'll see what I can do. Any idea to separate the boards with soldered headers?

[PMowdes2]

You really need to see both sides of the pcbs to be able to trace it.  Getting them apart is going to be a seriously difficult job, but if you want to replace the damaged sliders then you are going to have to do it anyway.

The easiest way would be to cut the headers and replace them but easiest isn't always best.  Last thing you want to do is damage it further.

[Scruffie]

The easiest way would be to cut the headers and replace them but easiest isn't always best.  Last thing you want to do is damage it further.

I'd second doing it that way, if you try and de-solder them with the boards connected you'll probably end up flexing the boards more than would be advisable with those old style tracks.

I see it has a few of those old white sockets too, I've found them very sturdy but the contacts often tarnish IME so they're worth cleaning.

[bsoncini]

Scruffie how would you advise cleaning them? And they are sockets as in if I pull on the ic it will come out?

This thing has definately been worked on before there are some standoffs missing. There are definately some bad contacts also. If I touch the board right I get phasing. Seems like all the wave forms work as well as the different phase modes. Can't say I've heard anything that sounds like meow yet though.  The growl switch seems completely worthless. Just makes it sound like water bubbling  maybe I'm missing something

[Scruffie]

I'm sure there are other ways but in the past I've just used a dab of contact cleaner and either a broken IC or something with a sturdy lead to work it in a little and wiped it out with a cotton bud.

That'll be fun to re-flow all those joints

[digi2t]

deleted

[matmosphere]

I can give it a go at tracing but having never traced a pedal before to tracing this beast is quite the jump.


Unless anyone else in Europe is up to the task I can ask my friend if it's ok with him to loan it out.  He'd probably say yes if that person was willing to repair it too.

As for scanning the pcbs I'll see what I can do. Any idea to separate the boards with soldered headers?

This is getting interesting

I would be up for tracing and repair, but I'm in Canada.

[PMowdes2]

Man it would be epic if we could get this traced and get some pcb's fabricated.  Dino and I have just finished a BiPhase clone  and I was sooo excited that we got it working, but a Synthi clone would just be so awesome.  I cant think of anything that comes close to this except perhaps the Ludwig Phase II.

[bsoncini]

As a test yesterday I traced the preamp in the foot pedal. It matches up with the available schematic. Which is readable. Nothing sexy or exciting about the preamp but it's a start.

The fuzz is pretty cool. If you put the rise time to slow the fuzz fades in. Don't think I've seen that in a fuzz before

[bsoncini]

Some more pics.  Other side of the pcb and the preamp.  Never looked for faders before.  Easy to find replacements?

Some of the headers on the bottom right side are green.  I'm not even sue there is a pad there anymore

[Scruffie]

Never looked for faders before.  Easy to find replacements?

Not always but sometimes you can find something close enough, firstly what brand are they? Then you'll want to measure the dimensions and take note of how the pins are grouped.

[bsoncini]

Never looked for faders before.  Easy to find replacements?

Not always but sometimes you can find something close enough, firstly what brand are they? Then you'll want to measure the dimensions and take note of how the pins are grouped.

The faders say AB made in the uk.  Allen Bradley?

The good news is the headers arent actually soldered.  They are these scissor things that clip the boards together and thé board came apart easily

[Scruffie]

Never looked for faders before.  Easy to find replacements?

Not always but sometimes you can find something close enough, firstly what brand are they? Then you'll want to measure the dimensions and take note of how the pins are grouped.

The faders say AB made in the uk.  Allen Bradley?

The good news is the headers arent actually soldered.  They are these scissor things that clip the boards together and thé board came apart easily

Not a UK company but I suppose they might have had a UK base but if they did make sliders, doesn't look like they do any more.

If you use mouser you can just put in the height, length, width and slide-travel dimensions and cross your fingers something matches up.

[PMowdes2]

Never looked for faders before.  Easy to find replacements?

Not always but sometimes you can find something close enough, firstly what brand are they? Then you'll want to measure the dimensions and take note of how the pins are grouped.

The faders say AB made in the uk.  Allen Bradley?

The good news is the headers arent actually soldered.  They are these scissor things that clip the boards together and thé board came apart easily

That's great news, can you get images of both sides of each board??

I think finding replacement sliders is gonna be tricky, is there any indication of what alues they are??

[Marshall Arts]

Never looked for faders before.  Easy to find replacements?

Not always but sometimes you can find something close enough, firstly what brand are they? Then you'll want to measure the dimensions and take note of how the pins are grouped.

The faders say AB made in the uk.  Allen Bradley?

The good news is the headers arent actually soldered.  They are these scissor things that clip the boards together and thé board came apart easily

That's great news, can you get images of both sides of each board??

I think finding replacement sliders is gonna be tricky, is there any indication of what alues they are??

The values for the sliders and the taper is written on the board. I would design an adapter board, if you don't find perfect replacements.