Old Japanese Envelope Modifier questions...

[gigimarga]

Hello,

Searching for another Slow Gear-like stompbox I found this schematic: http://experimentalistsanonymous.com/diy/Schematics/OOP%20Japanese%20Electronics%20Book/rockin-VCF-1.gif.
I want to try to build it, but I don't understand the alternative values for some resistors (between paranthesis and/or like * sign).
Anyone has more informations about it? What type are the transistors and diodes? What means the circled T? What value has the Zenner diode named 02Z 2.2A?
What are the alternative values for? Maybe for a noise-gate?

Thanks!

[frequencycentral]

What means the circled T?

Tantalum caps.

[blueduck577]

just a few guesses -

the diodes in the lower left are specified to be 1N60s, a germanium diode.  They were probably chosen just because of their low forward voltage, so you could probably sub in any germaniums here.  You probably would be able to get away with schottky diodes also.

the diodes in the bottom middle portion appear to be there just to isolate the attack and decay pots, to allow the cap below to charge/discharge at different rates.  1N4148 would be a fine sub.

the bipolar transistors are doing pretty run-of-the-mill stuff here so the actual transistor type isn't too critical.  2N5088, 2N3904...etc

the JFET also is just a follower.  J201, etc will probably be fine.

the mosfets seem tricky, but there appear to be pin numbers next to a lot of the terminals, so I'd guess it's a mosfet array of some sort.  seeing how there are both n- and p- channel mosfets, as well as that lone inverter, I'd guess that it's a CD4007.  look up the datasheet and check the pinout to see if it matches



just my 2 cents, don't take my word for any of this, but I'm pretty sure that my advice is ok.

[Mark Hammer]

Just to make it clear.  The schematic may say "Rockin VCF" but it is mis-titled.  This IS an envelope modification circuit, and does not do anything like an autowah.

[gigimarga]

What means the circled T?

Tantalum caps.

Thank you frequencycentral!

[gigimarga]

Thank you very much blueduck577!

You was right 100% about the MOSFETs! I didn't post the link to the layout (http://experimentalistsanonymous.com/diy/Schematics/OOP%20Japanese%20Electronics%20Book/rockin-VCF-pcb-1.gif) because I thougt that's unuseful....sorry

The last problem is the strange Zenner diodes

[gigimarga]

Just to make it clear.  The schematic may say "Rockin VCF" but it is mis-titled.  This IS an envelope modification circuit, and does not do anything like an autowah.

Thank you Mark!
My question is if this thing sounds something like a Slow Gear or not?

[gigimarga]

More by mistake I found the last answers (about the Zenners) here: http://www.diystompboxes.com/smfforum/index.php?topic=19422.msg117937!

[Gila_Crisis]

if you are interested in something like this you can take a look at the slow gear (you'll find the project on GGG and topopiccione) or at this one:
http://gaussmarkov.net/wordpress/circuits/gator-clone/

[gigimarga]

if you are interested in something like this you can take a look at the slow gear (you'll find the project on GGG and topopiccione) or at this one:
http://gaussmarkov.net/wordpress/circuits/gator-clone/

Thanks Gila_Crisis, but I've built both of them and I am not very happy with the result: both of them are hard to tweak and very limited...anyway, Gator seems to be much better than Slow Gear