1975 Eventide Instant Flanger

[Ampzone]

Just picked this unit up and it is not working. I have never used or worked on one. On power up LED flickered for a second on initial power up then it was lights out out and there was mild smell of smoke (shut off right then), I noted the regulators were getting very very hot. There are a few tantalums downwind from the regulators so I am going to look there first.

Anyone with exp on these?

schematic
http://img.photobucket.com/albums/v3...ide_contrl.jpg

[Leo_Gnardo]

Just picked this unit up and it is not working. I have never used or worked on one. On power up LED flickered for a second on initial power up then it was lights out out and there was mild smell of smoke (shut off right then), I noted the regulators were getting very very hot. There are a few tantalums downwind from the regulators so I am going to look there first.

Anyone with exp on these?

No experience on the Instant Flanger in particular, but I'd suspect those old tantalums as well as every other filter cap in the thing. I've had to replace plenty of old Ta's in mix consoles from that era. Be a mean dentist and "yank 'em all." You can replace with affordable electrolytic caps without harm. Let's hope "lights out" was the fuse popping before any further harm was done.

I'd like to try an old Eventide Omnipressor, if I ever found one I could afford. Like free. Dream on.

[Ampzone]

No experience on the Instant Flanger in particular, but I'd suspect those old tantalums as well as every other filter cap in the thing. I've had to replace plenty of old Ta's in mix consoles from that era. Be a mean dentist and "yank 'em all." You can replace with affordable electrolytic caps without harm. Let's hope "lights out" was the fuse popping before any further harm was done.

I'd like to try an old Eventide Omnipressor, if I ever found one I could afford. Like free. Dream on.

Hey Leo, thanks for chiming in. Well I found 3 bad tants and replaced them, one was smoked. I had a bag of good high grade Panasonic 3.3uf caps 50v that were perfect and the Flanger uses all 3.3uf 25v tants save one or two. I have replaced about 6 so far as some had drifted as well. There maybe 15 more still there that read good on the cap meter.. I did find a totally burnt 10ohm resistor which I replaced as well. After all of this it powers up and I can switch the circuit in and out with the "line" switch. "doppler" makes it louder but no flanging to be had.
OSC light does pulse so now I am puzzled. At least we no more smoke and it it alive. PS caps are good as well.

So now why will it not flange?

[Ampzone]

mode zero - phase shifter phaser flanger chorus delay vintage effects photos mp3 demos some pictures...note the removable card has two 10ohm and two 470ohm resistors in the middle. The top 10ohm was cooked. should i just shotgun all tants with the 3.3uf panny caps?