Zvex - Box of Metal  [traced]

General documentation, gut shot, schematic links, ongoing circuit tracing, deep thoughts ... all about boutique stompboxes.
User avatar
Wlat
Information
Posts: 13
Joined: 25 Jan 2011, 16:49
my favorite amplifier: ENGL E656
Location: Hoorn, the Netherlands
Has thanked: 8 times
Been thanked: 3 times
Contact:

Post by Wlat »

Page 8) should be page 8 ) of course...

User avatar
rcustoms
Resistor Ronker
Information
Posts: 426
Joined: 01 Oct 2009, 14:12
Location: COLOMBIA
Has thanked: 363 times
Been thanked: 520 times
Contact:

Post by rcustoms »

[quote="Wlat"]Hi!
It's been a while since I started working on the noise gate. Somehow life got in the way...
Anyway, I'm at it again and started to use Eagle now for a pcb. I took Madbean's excellent layout as a basis (hope that's allright?) but I'm still having a bit of trouble getting the noise gate parts neatly without to much "spaghetti".
Here's my layout so far [unverified]:
04 PCB.png
Does anyone have a tip for getting a better layout?

Thanks,
Wlat[/quote

send me teh eagle files and i help you to optimaze
http://www.rcustomspedals.blogspot.com
guitars,pedals and amps.
@zuleta.rafael(Instagram)

User avatar
served
Information
Posts: 6
Joined: 01 Feb 2010, 11:04
Been thanked: 3 times

Post by served »

Wlat wrote:
served wrote:Hi,

Do you have a schematic with the original Gate control around?

I already built the BOM but now I feel like there is too much noise in this pedal. Is there a way to add a Gate function to the pedal?
How complicated is it? Does any one have a glue how Zvex made it?
View my posts of feb 2011 and feb 2012 (both page 8). Alas, not verified yet. I'm having trouble finding time to complete this project...

Greetings,
Wlat
Hi Wlat.

Thank you for this!

Actually I think I was ignoring your post because I first thought that you are creating something new and that Zvex didn't do it that complicated. I was more thinking that it will look like Fuzz Factory Gate. But its a good thing you have going on there.
I think I will put it on a sepparate PCB. And will use your schematic.

User avatar
internalevidence
Information
Posts: 2
Joined: 24 Dec 2012, 00:51
my favorite amplifier: Roland JC120
Location: Argentina

Post by internalevidence »

Hi all,

Kind of reviving an old thread, I chose this pedal as my first build and I'm quite happy with the results, no issues so far. :D
However, I'm not that happy with the eq section, I find it quite heavy and undefined on low frequencies. Have you tried doing any mods to the tone stack?, any recomendations would be greately appreciated.

Best Regards,
Emanuel.

User avatar
moose23
Information
Posts: 47
Joined: 22 Aug 2009, 16:36
Has thanked: 1 time
Been thanked: 5 times

Post by moose23 »

internalevidence wrote:Hi all,

Kind of reviving an old thread, I chose this pedal as my first build and I'm quite happy with the results, no issues so far. :D
However, I'm not that happy with the eq section, I find it quite heavy and undefined on low frequencies. Have you tried doing any mods to the tone stack?, any recomendations would be greately appreciated.

Best Regards,
Emanuel.
Few ideas on here:

http://tagboardeffects.blogspot.ie/2012 ... metal.html

User avatar
Chewbacca
Information
Posts: 22
Joined: 13 May 2012, 07:51
my favorite amplifier: Madamp A15Mk2 TSX Modded
Location: Eisenach, Germany
Been thanked: 8 times
Contact:

Post by Chewbacca »

Wlat wrote:
View my posts of feb 2011 and feb 2012 (both page 8). Alas, not verified yet. I'm having trouble finding time to complete this project...

Greetings,
Wlat
Hi Wlat,
I have built the BOM on my on Vero Layout and the BOM part works great.
I have also built the Gate according to your schematic, but I can't get the J175 to switch the Effect on.
I have measured the LDR Part of the VTL5C9 and the resistance is changing as it should so the LED part seems to work fine, but the voltage changes on the Gate of the J175 do not make it switch the signal through. It is blocking the signal all the time.
Where did you find the idea to put the LDR between VCC and the gate of the J175?
Did you make any progress on the gate in the meantime?

User avatar
Chewbacca
Information
Posts: 22
Joined: 13 May 2012, 07:51
my favorite amplifier: Madamp A15Mk2 TSX Modded
Location: Eisenach, Germany
Been thanked: 8 times
Contact:

Post by Chewbacca »

The Gate works!
I have finally made the gate work. I built the gate based on Wlats schematic, but I wired the J175 switching FET that it connects the output signal to ground when it is closed (no voltage on Gate) and cuts this connection - i.e. allows the signal top go to the output - when it opens. The gate voltage comes from the resistor side of the VTL5C9.
I might need to do some experimenting and fine-tuning, but it seems to work this way.
Attachments
FetSwitch.png
FetSwitch.png (7.51 KiB) Viewed 3140 times

User avatar
Chewbacca
Information
Posts: 22
Joined: 13 May 2012, 07:51
my favorite amplifier: Madamp A15Mk2 TSX Modded
Location: Eisenach, Germany
Been thanked: 8 times
Contact:

Post by Chewbacca »

..... and the Gate footswitch can be wired to cut the connection between the J175 and the Volume Pot.

User avatar
Chewbacca
Information
Posts: 22
Joined: 13 May 2012, 07:51
my favorite amplifier: Madamp A15Mk2 TSX Modded
Location: Eisenach, Germany
Been thanked: 8 times
Contact:

Post by Chewbacca »

OK - here's the whole thing as I have build it.
It works – but please leave comments and recommend improvements.

I have used daughter boards because I have built the gate after the BOM - for the next version I'll come up with a one-board layout.
I could not get a TLE2426 so I used an Opamp as a rail splitter. All it does is produce 1/2Vcc – I guess a simple voltage divider would have also done the trick.

I changed the gate pot to B250K - you could even use a 100K or a C250K. With a 500K – only the range between 2 and 5 o clock is really usable otherwise the gate will cut off everything but hard strumming. I also omitted the 15K (R27) in Wlat's schematic. This way the gate pot is connected directly to ½ VCC and at 5 o clock the gate will let a note ring almost to its natural death. The rest of the pot range is only useful if you have any noisy pedals before the BOM.

The gate picks its trigger signal directly from the input which makes it a very fast opening, but also a very fast closing gate - very effective. I used a 3PDT switch for the Gate switch so I can cut the connection between D of Q7 and the Vol pot, use one pole for switching the gate LED and use the third pole for cutting off the input for the gate circuit. This way, when the gate is off, the signal runs only through the BOM.

Despite the three boards, the boards are pretty compact so everything fits in a size B enclosure. Pay attention to the cuts under some of the resistors and ICs.
R8 and R9 share a hole (black ring).
I could not find a proper symbol for the VTL in the program so I used an IC symbol – Pins 1 and 2 on the left are the LED Pins and the pins on the right are the Resistor pins.

R38 is now 1M - I have experimented a little and this value seems to keep the gate open the longest.
You can experiment with C19 – it affects the way the gate closes. The lower the values the more stutter you get.
You can replace the R34 trimmer with a 1K - it does not make much difference anyway. Actually I am not sure why there is a trim pot in the schematic.

The orange, red and black track markings on the boards are for orientation purposes only. Black is ground, red is Vcc and orange is Vr (1/2Vcc).
I usually draw these on my board with a felt pen - makes building easier.

I left out the LED and switch wiring - you should be able to figure this out by yourself.
bom+gate.png
Another question:
Does anyone else experience problems with the Mid control. It seems not to do much at all and it seems to cut the mids when turned fully clockwise.
This is almost a standard Marshall tonestack - only R22 and C8 are different.
I put Pin 3 of the Mid pot against ground and Pin 1 goes to Pin 1 on the Bass pot - this is correct, isn't it?

User avatar
Intripped
Cap Cooler
Information
Posts: 670
Joined: 25 Aug 2009, 01:03
Location: Italy
Has thanked: 989 times
Been thanked: 305 times

Post by Intripped »

Try and swap pin 1 and 3 of the pot, it should cut the mids when turned counterclockwise IMO

User avatar
Chewbacca
Information
Posts: 22
Joined: 13 May 2012, 07:51
my favorite amplifier: Madamp A15Mk2 TSX Modded
Location: Eisenach, Germany
Been thanked: 8 times
Contact:

Post by Chewbacca »

Thank you , but that was not what I meant. The Mid increase when I turn clockwise, but they decrease again when the pot is fully turned to the 5 O clock position.

User avatar
Vaernima
Information
Posts: 1
Joined: 02 Jul 2013, 13:33

Post by Vaernima »

So, hey all! This is my first post.
I'm into this pedal at the moment. Keen to know exactly whats going on with it.

Has anyone got a completed whole schematic of this (including the gate, not necessarily including the switches and LED's etc....just a good looking schem)...??
That would be big fat Oprah tits if you did.

Thanks guys!!

User avatar
bigzed
Information
Posts: 1
Joined: 13 Dec 2015, 14:25

Post by bigzed »

Hi,

My first post too....Just built this and it is amazing! Just one thing though the bass seems to do zilch! Any clues how to improve the bass?

User avatar
POTL
Resistor Ronker
Information
Posts: 335
Joined: 26 Sep 2016, 03:11
Has thanked: 58 times
Been thanked: 67 times

Post by POTL »

Hello
Tell me the zener diode is necessary or can I replace it with 1n4148?
I want to energize the circuit from 18 volts to increase the headroom like on JFET effects

User avatar
Alsassius
Information
Posts: 6
Joined: 30 Dec 2017, 04:30
Has thanked: 2 times

Post by Alsassius »

rasta_maleek wrote:Up for GAS :applause:
Hola! suena genial! Que layout usaste de los que se postearon aca?
Saludos!!!

Post Reply