My MF-104z dead. AGAIN!

The Moog Forum Moogerfooger Forum
1

Hopefully I know what is going wrong.
I assume that VCA chip is fried, that was the problem 3 years ago. When I power it it has some feedback going on (green light) and there is
huge noise when I plug it into amp. And there is something going into VCA (also green light).
Thank gods my technician replaced this chip 3 years ago, but he didn’t solder it on PCB. He soldered a socket for that chip and gave me another replacement chip. He said there is something wrong with power, so he assumed that it will work for a while, but he said it will happen again.

So let check this.
I hope I’m right.

And I just got Slim Phatty. What a shame…

And I must say that if I had to pick one device and say that this is my sound, it would be moog delay!!!
:neutral_face:

2

Well… It is like new again!!!
:laughing: :laughing: :laughing: :laughing: :laughing: :laughing:
:sunglasses:

3

The z in 104z stands for ZOMBIE! :wink:

4

I know exactly what you mean! It’s a desert Island pedal for sure, as long as it is working properly.

Once I got it, It became the permanent end of the audio chain. Now if we only had 3 or 4 more.

5

I’d put it on an aux bus on a mixer so you can get multiple sources on it at different levels. Not the same as having multiple delay times, but still useful. The voltage controlled delay is capable of some extremely crazy sounds, especially when using s&h to skip the delay time around. If I only had an oscillator and a 104z I would be happy.

6

Hi All,

I’m glad to be back, missed you all. Sadly it’s a brief visit to bring you good cheer.

Your MF-104’s, 104z’s and 104-sd’s are not fried!

There is a structural design flaw in the chassis of the pedal which causes a ground loop and potential voltage spikes.

This has been addressed in another thread where the posters mentioned finding the jumper pins touching the inside of the chassis. This is very bad news.

Clip them or put caps on them and you are good to go.

My MF-104Sd was fried for a good six months, or so I thought. I took it to Dale Diamond, my friend who is an electrical engineer and boutique pedal designer (http://www.soundsubstance.com), for another look. He opened it up and studied it with an oscilloscope and what did he see: voltage drainage, spikes, oscillations and ground loops generating from the pins and chassis. He fixed the problem. :mrgreen:

I don’t think any other fix would be permanent. You need to get to the root of the problem, then take further preventative measures. Go to a pro like I did. I’m not saying the Moog service cats aren’t pros, but Bob ain’t with us anymore and he would’ve seen the problem ASAP I have no doubt.

My delay has never sounded better!

Good luck, and keep on echoing endlessly.

7

Ok, I will check If there is the same problem with mine.
But this is strange. I just changed the chip and is like new.

Thanx for the info!

I love my MF-104z.

I would love to have another!

But they are bit hard to get these days.

8

Which chip is it?

9

Before big briar or the new Moog, did Bob ever design a delay?

10

I don’t believe so, but if someone wants to prove me wrong, be my guest. :confused:

11

Where are the pins located that need to be clipped? big or hard job for the novas?

:mrgreen:

12

You should probably concsult moog tech support before you start clipping stuff. Id try capping them first at least or inserting something between them and the chassis. The jumper in question is located on the daughter board. You have to remove the cheek piece to see it, but I don’t remember which piece.

13

Cool, cheers mate :mrgreen: