Baja Trembulator schematic, board layout and circuit board  [documentation]

Original effects with schematics, layouts and instructions, freely contributed by members or found in publications. Cannot be used for commercial purposes without the consent of the owners of the copyright.
Post Reply
User avatar
mictester
Old Solderhand
Information
Posts: 2923
Joined: 11 Sep 2008, 20:29
my favorite amplifier: Mesa Boogie, Roost Sessionmaster, AC30
Completed builds: Hundreds! Mostly originals, a few clones and lots of modifications.
Location: Somewhat closer to Amsterdam than before!
Has thanked: 32 times
Been thanked: 844 times
Contact:

Post by mictester »

sinner wrote:
mictester wrote:I'll forward my modified PCB design if anyone wants it.
:applause: Would you like to post it here?
Here's the Veroboard layout. It uses a TL062 for the audio path (low current, low noise, and two op-amps in the package). The second op-amp is used as a unity gain buffer, with a nice low output impedance which will drive long cables OK and isolates the gain control part from the next item it's connected to....
TrembulatorVero.png
This is, quite simply, the very best tremelo I've heard. :applause: There's no noise to speak of, no distortion, and a wide range of control!

Thanks Bajaman for another great design! :thumbsup :thumbsup
"Why is it humming?" "Because it doesn't know the words!"

User avatar
Louishr
Information
Posts: 28
Joined: 30 Mar 2009, 05:27

Post by Louishr »

Hey guys, Here's the fix to my layout, I posted it a while ago somewhere else on the forum and forgot I had posted here as well, This layout works just fine.
Image

User avatar
devastator
Cap Cooler
Information
Posts: 675
Joined: 19 Jul 2008, 16:00
Location: France
Has thanked: 8 times
Been thanked: 22 times

Post by devastator »

Hi folks

I started working on mine, but I would like to add a gain stage and a volume in the end. I'm thinking about building a simple gain stage with AOP but I'm not really an expert about biasing. Like the low impedance coming from the AOP (tremolo) I can just put a 100K resistor to connect the AOP enter to VR, right ?

User avatar
mictester
Old Solderhand
Information
Posts: 2923
Joined: 11 Sep 2008, 20:29
my favorite amplifier: Mesa Boogie, Roost Sessionmaster, AC30
Completed builds: Hundreds! Mostly originals, a few clones and lots of modifications.
Location: Somewhat closer to Amsterdam than before!
Has thanked: 32 times
Been thanked: 844 times
Contact:

Post by mictester »

devastator wrote:Hi folks

I started working on mine, but I would like to add a gain stage and a volume in the end. I'm thinking about building a simple gain stage with AOP but I'm not really an expert about biasing. Like the low impedance coming from the AOP (tremolo) I can just put a 100K resistor to connect the AOP enter to VR, right ?
If you use my modified version, you can use the output op-amp as a gain stage. If you make the feedback resistor a variable, you can vary the gain! If the mod isn't obvious, I'll post an amended diagram in this thread.

The reason for the additional op-amp stage originally was to separate the gain control element (the depth pot and the LDR) from the equipment following it. I found that the "raw" version could be adversely affected by the loading presented by other equipment, so a lowered output impedance seemed a good idea.
"Why is it humming?" "Because it doesn't know the words!"

User avatar
devastator
Cap Cooler
Information
Posts: 675
Joined: 19 Jul 2008, 16:00
Location: France
Has thanked: 8 times
Been thanked: 22 times

Post by devastator »

I didn't see your modified version actually. Yeah that looks like identical.

Here's what I'd like to add on mine. Juste a volume knob to adjust the level and have a boost if need it. I copied the micro amp boost :

Image

But I've some doubt about the frequency corner formed by C1/R1, I think It's ok to have all frequencies (the cut is really low) but I don't know what values putting to baising the "+" input. If the impedance is low I can put a low resistors but I'm not really sure about that (I always use high values (470K/1M) in ovedrive/distortion circuit).

I could change the 4K7 for a 5K trimer and set the volume boost.

In seing your post , creating a buffer to separate the tremolo circuit and the boost could be great too.

Plus I think the gain will be about 47, maybe too lood for a volume pot in tremolo circuit.

User avatar
el pucho
Information
Posts: 9
Joined: 22 Nov 2008, 02:53

Post by el pucho »

Hi,

I'm going to build this pedal using mictester's layout and have a quick query. Would any of these LDR's be suitable. I'm not sure how much your choice of LDR influences the sound, if at all.

http://www.rshelectronics.co.uk/otheropto.htm

Also, what does the 10k trimpot do?

Thanks to everyone who put in all the work on this pedal, looking forward to trying it out!

User avatar
devastator
Cap Cooler
Information
Posts: 675
Joined: 19 Jul 2008, 16:00
Location: France
Has thanked: 8 times
Been thanked: 22 times

Post by devastator »

Guys Which trimpot I must buy :

http://www.banzaimusic.com/Trimpots/

:?:

I don't know the good one to put it perfectely in the PCB holes.

Thanks.

User avatar
Geosh
Information
Posts: 24
Joined: 03 Sep 2008, 20:30

Post by Geosh »

mictester wrote:
Here's the Veroboard layout. It uses a TL062 for the audio path (low current, low noise, and two op-amps in the package). The second op-amp is used as a unity gain buffer, with a nice low output impedance which will drive long cables OK and isolates the gain control part from the next item it's connected to....

Do you have the schematic that goes along with this vero? I am trying to get better at understanding the schematics rather than just copying someones layout and I was having issues tracing this layout to the schematic that you previously posted. Maybe it was too late last night and my brain had gone to sleep before I did, but hopefully they are different.

Thanks!!

User avatar
mictester
Old Solderhand
Information
Posts: 2923
Joined: 11 Sep 2008, 20:29
my favorite amplifier: Mesa Boogie, Roost Sessionmaster, AC30
Completed builds: Hundreds! Mostly originals, a few clones and lots of modifications.
Location: Somewhat closer to Amsterdam than before!
Has thanked: 32 times
Been thanked: 844 times
Contact:

Post by mictester »

The schematic is about 12 posts earlier up the thread! I hope your Vero build goes OK.
"Why is it humming?" "Because it doesn't know the words!"

User avatar
Ben N
Cap Cooler
Information
Posts: 506
Joined: 12 Dec 2008, 03:34
my favorite amplifier: Ampeg J12D Jet
Location: Israel
Has thanked: 192 times
Been thanked: 53 times

Post by Ben N »

Louishr wrote:Hey guys, Here's the fix to my layout, I posted it a while ago somewhere else on the forum and forgot I had posted here as well, This layout works just fine.
Image
Why two boards?

User avatar
mictester
Old Solderhand
Information
Posts: 2923
Joined: 11 Sep 2008, 20:29
my favorite amplifier: Mesa Boogie, Roost Sessionmaster, AC30
Completed builds: Hundreds! Mostly originals, a few clones and lots of modifications.
Location: Somewhat closer to Amsterdam than before!
Has thanked: 32 times
Been thanked: 844 times
Contact:

Post by mictester »

el pucho wrote:Hi,

Also, what does the 10k trimpot do?
It sets the maximum LED current. Start with the depth pot at maximum, and the rate set at its slowest and the preset set to MAXIMUM resistance. Put in a tone, and advance the preset until the depth is such that the signal just completely disappears during each cycle. The preset is then correctly set, and the maximum current through the LED is set as low as it can go (guaranteeing long life for the LED, and minimising battery consumption).
"Why is it humming?" "Because it doesn't know the words!"

User avatar
Louishr
Information
Posts: 28
Joined: 30 Mar 2009, 05:27

Post by Louishr »

i used two boards because I combined this with a zvex style sequencer, but the multiple boards let me squeeze it into a small box

User avatar
el pucho
Information
Posts: 9
Joined: 22 Nov 2008, 02:53

Post by el pucho »

Thanks for the info Mictester, getting the parts ordered today so hopefully have this up and running soon.

User avatar
devastator
Cap Cooler
Information
Posts: 675
Joined: 19 Jul 2008, 16:00
Location: France
Has thanked: 8 times
Been thanked: 22 times

Post by devastator »

I've jsut finished mine, it sounds really good.

I'll just add a tiny boost stage at the end to put a volume knob in the third hole in the box.

User avatar
devastator
Cap Cooler
Information
Posts: 675
Joined: 19 Jul 2008, 16:00
Location: France
Has thanked: 8 times
Been thanked: 22 times

Post by devastator »

Completed !

User avatar
el pucho
Information
Posts: 9
Joined: 22 Nov 2008, 02:53

Post by el pucho »

It must be the day to build these, just finished too!

I built using Mictester's layout and maybe spotted a couple of errors.

I think the status LED should be connected to the row below the one stated in the layout, so it connects to the 4k7 resistor, and not the 1k as shown.

Also I think the 10k trim pot is wrong. I ended up connecting lugs 3 & 2 together then used a jumper to connect lug 1 to the 1k resistor. If I'm reading it correctly the way it is in the layout means the signal has nowhere to go after going through the 10k trim pot.

I might be totally wrong as I'm not very knowledgable when it comes to building these things.

A couple of other things: I think I'm getting a bosst in volume with this pedal on, is there any way I can add a volume control?
I also quite fancied a hard/soft switch, but I'm not really sure how to do this.

It's sounding like a huge upgrade to my EA Tremolo so far, thanks to Baja, and anyone else who contributed to this.

User avatar
phibes
Transistor Tuner
Information
Posts: 1107
Joined: 10 Dec 2008, 01:17
my favorite amplifier: HIWATT motherfucker!
Location: United States
Has thanked: 75 times
Been thanked: 189 times
Contact:

Post by phibes »

For the hard/soft switch just hook a switch up to jumper out the trimpot. It'll get very choppy.

I did a few other things to this and I love it. For a faster speed without going to overboard I changed the resistor in series before the rate pot to 1K and then changed the pot to a 25K lin. I also changed a few things for the depth that Baja wrote in another thread. I changed the 1uf bipolar after the 1.8k resistor to a 4.7uf and then changed the pot to a 10k lin. Try em out.
GuitarlCarl - "TGP = The Gear Polishers"

Image Ken

User avatar
mictester
Old Solderhand
Information
Posts: 2923
Joined: 11 Sep 2008, 20:29
my favorite amplifier: Mesa Boogie, Roost Sessionmaster, AC30
Completed builds: Hundreds! Mostly originals, a few clones and lots of modifications.
Location: Somewhat closer to Amsterdam than before!
Has thanked: 32 times
Been thanked: 844 times
Contact:

Post by mictester »

el pucho wrote:It must be the day to build these, just finished too!

I built using Mictester's layout and maybe spotted a couple of errors.

I think the status LED should be connected to the row below the one stated in the layout, so it connects to the 4k7 resistor, and not the 1k as shown.

Also I think the 10k trim pot is wrong. I ended up connecting lugs 3 & 2 together then used a jumper to connect lug 1 to the 1k resistor. If I'm reading it correctly the way it is in the layout means the signal has nowhere to go after going through the 10k trim pot.
You're completely right! The layout below is the corrected one!
TrembulatorVero.png
The LED is fed via the 4k7 resistor, and the preset connects to Pin 6 below through the 1k.

I must have been tired when I put that layout up. Sorry!
"Why is it humming?" "Because it doesn't know the words!"

User avatar
el pucho
Information
Posts: 9
Joined: 22 Nov 2008, 02:53

Post by el pucho »

No problem mictester, more thank you for putting up the alyout I'd be completely lost trying to plan a layout from a schematic.

I don't seem to be getting anywhere with the hard/soft thing. Is it the 18k resistor I need to jumper out, or the 10k trimpot (I used mictester's layout)?

Thanks for the tips Phibes, I'm going to mess around with those speed combinations and see what suits me best, a little faster would be nice.

About the volume control, could I just add a pot between the output of the circuit and the output jack? Or is there a resitor somewhere that controls the output volume?

The other thing I noticed is mt Depth pot seems to work backwards, turned up to 10 gives no effect and at 0 gives full effect. Is this normal?

I want to try and finish this tonight and get it boxed up, problem is I can't stop playing through it and get back to working on it.

Cheers again guys.

User avatar
phibes
Transistor Tuner
Information
Posts: 1107
Joined: 10 Dec 2008, 01:17
my favorite amplifier: HIWATT motherfucker!
Location: United States
Has thanked: 75 times
Been thanked: 189 times
Contact:

Post by phibes »

el pucho wrote:No problem mictester, more thank you for putting up the alyout I'd be completely lost trying to plan a layout from a schematic.

I don't seem to be getting anywhere with the hard/soft thing. Is it the 18k resistor I need to jumper out, or the 10k trimpot (I used mictester's layout)?

Thanks for the tips Phibes, I'm going to mess around with those speed combinations and see what suits me best, a little faster would be nice.

About the volume control, could I just add a pot between the output of the circuit and the output jack? Or is there a resitor somewhere that controls the output volume?

The other thing I noticed is mt Depth pot seems to work backwards, turned up to 10 gives no effect and at 0 gives full effect. Is this normal?

I want to try and finish this tonight and get it boxed up, problem is I can't stop playing through it and get back to working on it.

Cheers again guys.
The 10k trimpot is what needs to be jumped. Mr. Fuller does his that way.

Sounds like you wired your depth knob backwards.
GuitarlCarl - "TGP = The Gear Polishers"

Image Ken

Post Reply