That gives me a while to come up with ideas. I think I will disassemble my last Surfy Bear verb, add the color switch and add the trem to the unit. I want to do something different and there's been so many great builds that it won't be easy. IS there anything else coming that we should be aware of as to add to the build thoughts?

Can't wait for the new pedal! Until then I'm in the process of building my Duel Reverb Quilty Bear!

The Kahuna Kings

https://www.facebook.com/pages/The-Kahuna-Kings/459752090818447

https://thekahunakings.bandcamp.com/releases

Yeah, the pedal is ideal.
I've built pedal kits before, so no biggie. In fact, my current trem is one.

Will the kit be around the same price as the fet-verb? I'm ready to be the 1st user.

wfoguy wrote:

Will the kit be around the same price as the fet-verb? I'm ready to be the 1st user.

Sorry I dont know yet.
We will soon present more info about the price.

j_flanders wrote:

After building the Surfy Bear (which sounds great!) I'm now looking forward to building the Surfy Trem.
I placed my order yesterday, but got an e-mail that shipping will take another two weeks.
So, in the mean time I'm looking at the wiring layout/schematic of the Surfy Trem and I'm confused about several aspects:
http://www.surfyindustries.com/download/SurfyIndustries-SurfyTrem_Kit-UserGuide.pdf

1) There is a switch shown on the power supply. How can that be of any use or how would that work?
If you interrupt the power supply there will be no tremolo effect but also no dry guitar signal coming trough either(I think), so why would one include it there?
It doesn't seem to be the switch that disconnects the battery when an adapter is plugged in either.

The schematic is designed for use with a power supply. Battery power can be added but you'll have to find the schematics for that elsewhere on this site. The power switch is to be used before and after the show. During the show you use the foot switch.

2) Why are there two LED's in the schematic? In the demos of the pedal (not the kit) I only see one led which lights up and blinks when the pedal is engaged and which is off when the pedal is off. I don't understand the possible need for a second LED.

The LED on the board is an indication of the speed. The LED in the power line tells you if it's good to go. Thats all. Skip the last if you want, you don't need it.

3) There is an optional footswitch connection in the schematic. Is it optional in the sense that otherwise the only other way to turn off the tremolo effect is to turn the intensity to 0 (like you would on an amp), or is it optional in the sense that, apart from an actual on/off switch, you can wire up a 'remote' switch (like a remote reverb/trem switch for an amp)?
More importantly, does the LED stay lit or keeps blinking whether this switch is on or off?

The foot switch switches the oscillator on and off. The LED will turn off if the oscillator is turned off. I don't really understand what you mean by a remote switch. Isn't that the same switch with a longer piece of wire?

Is there sonically a difference between turning the intensity to 0 and putting this switch in the off position?

No.

I'd like to house this trem in a pedal and wire it up with true bypass. I know the ready made pedal is not true bypass and that there's a 'philosophy' behind it but I can still include the optional switch or turn the intensity to zero to experience non-true-bypass.
Since the (blinking) LED is somehow connected to the oscillator, wiring for true bypass is a little different from usual.
I don't have much experience with this, so could Björn or someone who knows this stuff tell me if the schematic I drew below is the correct way to wire it with true bypass?

That could work. No issues as far as I can tell, except for the fact that I don't know if the switched off LED will affect the working of the oscillator. Good luck!

Last edited: Jun 28, 2017 10:47:57

Gilette wrote:

The LED will turn off if the oscillator is turned off. I don't really understand what you mean by a remote switch. Isn't that the same switch with a longer piece of wire?

Ok, good to know, this means I could also connect the 3PDT to this switch instead of to the rate-LED.
By remote switch I meant something like this:
This would serve the same purpose as the on/off switch on the pcb, but is different from a true bypass switch

Gilette wrote:

That could work. No issues as far as I can tell, except for the fact that I don't know if the switched off LED will affect the working of the oscillator. Good luck!

bjoish wrote:

Regarding the led, I just want to add; its perfectly ok to switch the led as shown on your schematic!

Thank you both for the replies. Once the SurfyTrem arrives I'll let you know how it went.

Last edited: Jun 29, 2017 04:22:29

Thanks for the replies Frank and Björn!
I finally got all the parts in (3PDT, enclosure etc) and built per the drawing above. I changed the LED to a red 3mm LED as I only had a 3mm LED holder. All works fine and it sounds great!

One minor thingy is the kinda high tremolo speed/rate at even the (s)lowest setting.
I googled 'tremolo too fast' and got a lot of hits from Fender owners who 'complain' about the same thing. So, just like the SurfyBear this one seems to be pretty authentic as well.
Nevertheless, in some cases I'd really like a slower tremolo.
Currently the slowest rate seems to be 3Hz (I didn't hook it up to a DAW or scope but simply counted the pulses: 100 in 30 seconds, so: 3Hz )

Is there a simple mod to lower the slowest rate? Simple as in: not having to solder anything to the smd components.
Without a schematic I can only guess, but would an extra resistor between the 'speed pot' and the connection to the pcb (which goes to a 10k resistor) accomplish this?
I see the resistance goes from 10k (max speed) to 110k (100k pot + 10k resistor) for the slowest speed.

My other guess is that it'll need to be a quite big resistor to make enough of a difference and that it would probably reduce the max speed to what is currently the lowest speed, so, I'll have to put it on a switch.

For the same reason I guess a larger value pot wouldn't be convenient as it would probably give a range of very slow rates between 0 and 8 and then have the usual speed range in the last tiny part of the turn.

Last edited: Jul 25, 2017 11:26:55

bjoish wrote:

I have not tried this but feel free to experiment

So, I did some experiments.

Lowest speed is 210 bpm (3,5 Hz)
Highest speed is 540 bpm (9 Hz)

The lowest speed I was aiming for is around 180 bpm.
I tried soldering additional resistors in series with the 100k speed pot:

0k extra : 210 bpm
55k extra : 196 bpm
155k extra : 182 bpm

Your guess/suggestion for a 250k pot was spot on. But I'm afraid that too much of the dial will give me slow speeds and only a fraction will be the more usual speeds.
For now I simply soldered an additional linear pot in series with the speed pot. With the speed pot at zero I use the extra pot to dial in lower speeds. (Turned to zero it's as if it's out of the circuit.) It works fine.

I also fed the SurfyTrem a 110 Hz signal and hooked it up to audacity, which gave some very interesting finds:

The screenshot below, shows it's a genuine sine wave tremolo! All too often tremolo pedals list sine and square as modes but in reality they offer triangle and square.

In the screenshot below I have the speed at minimum (210 bpm) and I'm turning the intensity from 0 to 10.
1) It actually gets louder the more you increase the intensity. A great way to compensate for the generally perceived volume loss in tremolos. It also explains why my amp, which I usually set at the edge of breakup, was more distorted as I increased the intensity.
2) The 'real' maximum intensity seems to be around 2 o' clock on the intensity knob. Increasing the intensity any further gives a choppy, on/off, almost square wave sounding tremolo.

The screenshot below is zooming in on speed:0, intensity:10 which clearly shows the on/off cycle
Unless this is choppy sound is intentional, one could argue that the intensity range is a bit too large.

In the next screenshot I have the speed at maximum (540 bpm) and I'm turning the intensity from 0 to 10.
1) The maximum intensity this time is really at 10 on the intensity-knob. So, apparently, the seemingly too wide intensity range is needed to have enough intensity available when the speed is at max.

The screenshot below is zooming in on speed:10, intensity:10

In the next screenshot I have the speed below the stock minimum by using the extra speed pot (it's around 175 bpm) and I'm turning the intensity from 0 to 10.
1)Interestingly enough, while the stock minimum speed gives a choppy on/off sound at maximum intensity settings, at these extra slow speeds the maximum intensity is actually greatly reduced. This is perfectly fine for me as I don't need/want too much of an on/off type of sound at very low speeds.

Conclusion: it's an awesome tremolo and great companion for the SurfyBear! I also really like the fact that you priced the DIY kits so low, this way they're within everyone's reach. Thanks for two great circuits Björn!

Last edited: Jul 26, 2017 19:01:33

orbitbot wrote:

Is there a reasonable resistor to add in series if one would add a "slow" / "fast" range switch?

j_flanders wrote:

stock slowest: 210 bpm
55k in series: 196 bpm
155k in series: 182 bpm

Anything over 100k will also mean that the maximum speed in the 'slow range' will be lower than the stock 210bpm slowest speed in the 'fast range'

To go slower and slower you need exponentially/logarithmically larger resistors. And the lower you want the lowest speed, the narrower the slow range will be.

Last edited: Jul 31, 2017 17:02:48