104z 'Multihead'

[willi]

Hi

Wouldn't it be great if Moog offered a 'multihead' output option on the MF-104z? This would function similarly to some tape delay units that have multiple heads. Combinations of multiple record and playback heads that can be selectively enabled or disabled can lead to some great effects. These outputs are sometimes mixed together before final audio output, but another option would be to have discrete outputs so individual processing effects are possible.

IIRC, the 104z has 1024 discrete steps of BBD... so perhaps it would be possible to tap the output lines of the BBD chips somehow? Does anyone know how feasible this is?

[DeFrag]

Check out the Strymon El Capistan Delay.
It seems to be the most accurate tape emulator available.
It sounds awesome with more control than thought possible!
...on my short list

http://www.strymon.net/products/elcapistan/

[Just Me]

I love my Strymon El Capistan! I put up a short demo of it with the Voyager playing with the different modes on Soundcloud.
http://soundcloud.com/medusal-obligation/strymontest1

[willi]

Looks like a nice pedal. Too bad it only has one expression pedal input.. Not a bad price considering it's sound, but since I already own a 104z the only need I really have for another delay is for a simple slapback (leaving the 104z free to do more crazy things). Thanks for the link!

How about tapping the BBDs in the 104z? Anyone know which chip it uses?

[blue_mono]

Looks like a nice pedal. Too bad it only has one expression pedal input.. Not a bad price considering it's sound, but since I already own a 104z the only need I really have for another delay is for a simple slapback (leaving the 104z free to do more crazy things). Thanks for the link!

How about tapping the BBDs in the 104z? Anyone know which chip it uses?

Hi all I have also been curious to what BBD chips the 104z has, and by searching the forum I found it uses MN3008's. How many of them there are, I haven't figured out yet. There is a gut shot in a thread here on the MF forum, and it shows two MN3008 chips on the main board. There has got to be more considering the delay time offered. Can anybody confirm how many BBD chips the 104z actually has? If it has more than two BBD's, the potential for multi tap mods are better and would be quite awesome... Please, could any Moog techs or other "lernead" speak up?


blue-mono

[EricK]

Heres a link to the large picture of the 104 circuit. Maybe this will help.

http://www.flickr.com/photos/48878097@N ... otostream/

[latigid on]

My 104SD has seven MN3008s. Two on the main board and another five on a daughter board. (You'll only see this if you remove the circuit; it's on the other side.)

If anybody has ideas for mods of course I'm interested

My thought was to split the signal for a stereo delay, not sure how easy things like this would be to implement.

[willi]

Stereo output would be a great addition!

There is some interesting information about BBDs in this thread: http://www.diystompboxes.com/smfforum/i ... ic=73155.0

I noticed on the MN3008 pinout there are 2 outputs, but the linked thread seems to indicate these are 'complimentary'... At any rate the final output of the last MN3008 probably goes to a buffer or other output circuitry, and this may complicate such a modification...

[willi]

On my 104z daughtercard, there are 3 MN3008 chips. There are spots for fourth and fifth chips, and a jumper...

[Jaguarfooger]

On my 104z daughtercard, there are 3 MN3008 chips. There are spots for fourth and fifth chips, and a jumper...

Woah! So--with the blank spots for fourth and fifth BBD chips in the 104z, can a stock 104z be upgraded to a 104SD by just dropping two more delay chips onto that daughtercard? Would anything else need to happen to the circut for such an upgrade to work?

Has anyone any first hand experience with this---or discussed such an upgrade with a Moog rep?

[woodington]

I may well be wrong, but I'm sure it was said that the removal of some chips was due to the need to improve signal to noise levels.
More chips = more noise ?
I don't know.
I'm sure the need to keep the product line going for longer by putting fewer chips in might also have contributed to the thought behind the decision.
So it might not be an upgrade (so to speak) if you tried to fit more chips is what I was thinking.

[latigid on]

More chips = more noise, but also more delay time. It's then possible to run the clock faster for an equivalent delay time which increases frequency bandwidth and allows more signal to pass.

[woodington]

So I was wrong then ?

[EricK]

Those chips aren't impossible to find, are they? Seems like when this thread popped up I looked for some.