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Hi everyone. Does anyone hear the Aquaboy too bright? I have managed to lower the treble content by adding a small capacitor in series with the 1Meg resistor but im wondering why is it brightening the signal so much

...i was wandering if maybe the LFO could benefit from the extra 3 volts, using it directly from the 18v rail.

In this case, no, there is no benefit. Remember that this entire section is a low frequency oscillator (it's completely below the audio spectrum of human hearing). It's particular voltage operation has nothing to do with the quality or tone of the audio output. However, there can be a definite effect on the "tone" of the Univibe depending on some parts used in the LFO, namely the LDRs employed (which are generally spec'd at 6.8MOhms or greater dark resistance for maximum depth of effect).

It's good to question these things and you should keep doing that. But in this case I don't believe you'll gain anything by changing the LFO circuit to operate at 18v.

Thanks . I didnt mean by any means to question the desing. I honestly love the harbinger 1.5! I was just curious on why the Easyvibe uses the regulated part the other way around. I have read that some Univibes had almost 24v sometimes on the LFo since it was hooked directly to the output of the transformer (even with the pedal working) and i was thinking  maybe that would make the oscilation somehow "better"? Hehe ... Who knows. I was just curious on why the Harbinger was using the power section like this. I built three of them and didnt even realize this until a couple of days ago. I alwasy though that the LFO was the part runing from "18v" from the charge pump

I have little knowledge of these things but I believe you have to worry about the 18v bulb going POOF on you.  Those things, like most bulbs, are capable of stuff beyond their ratings but given that it's on all the time, and modulated at that, it makes sense to reign it back in a bit.

I see chats all the time about shutting it off when not needed but I think running it a bit cool makes more sense.  The wear and tear is at power up and pushing the limits.

You are right about that.. Maybe i could use a higher voltage bulb?

This is just a mod I prefer for the Univibe. Some bulbs can actually run at 18v, but regulating the LFO guarantees it is always consistent through operation. Possibly it might lengthen the operational life of the bulb, too, but that's just me speculating.

Regulated voltage is less critical in the audio path of the Univibe which is why I chose that little bit of extra headroom you get from 18v vs 15v. Does it make a huge difference? Probably not. But, it certainly doesn't hurt either!

Thanks for replying! I actually love the Harbinger 1.5 and have built 3 of them already but i was wandering if maybe the LFO could benefit from the extra 3 volts, using it directly from the 18v rail. Im just not 100% sure if running both lines LFO and signal path from the same 18v would be transfered into weird noises in the singal path.. So maybe i could try using the 15v regulator for the singal path. What do you think? The Univibe has some little filtering for the singal path but that is, i think to, get the ripple off from the transformers output.. Maybe i could run both LFO and Singal from the lt1054[s output?

Hi everyone. Does anyone know why the harbinger 1.5 uses 18volts for the signal path and 15 regulated for the lfo and not the way around? I wonder why the easyvibe uses the other way around. 18v for the lfo and 15v for the signal path. The harbinger sound super good but im wondering how different would the lfo behave at 18 instead of 15. Also, would the lfo behave worse if fed directly from the unregulated 18v from the charge pump?

The thing is that the clock noise is even audible when i remove the jacks from the enclosure and put them far away... Any idea of a capacitor resistor swap that could lower theclock noise? I used the true bypass wiring and used shielded wires everywhere. Its my second build and the first one doesnt have this clock noise. I checked every single component and everything is fine. Should i reflow every solder joint?

Is it normal to have clock noise?

Please help. I have distortion in pins 1 2 3 and 7 of the compander. Any ideas?

[one]

Input jack and output jack wiring is also very important.
If both jacks are grounded to the enclosure, I would use a fiber washer or some other method to remove one of the jacks, input or output, from grounding to the enclosure.  Ground the jack you isolated to the PCB ground.  This can help reduce oscillations through a ground loop created through the enclosure itself.  It's amazing how many noise issues this solves.  Many times grounding both jacks to the enclosure is fine, but it can cause an issue in some circumstances.  By grounding the enclosure at only one point (to create an EMI shield) you eliminate a possible unwanted ground return current.

Thank you very much i didnt know that. But i also tried with both jacks floating outside of the enclosure and i still have the oscilattion

Well, I've never owned an original DM-2 so I can't say for sure. It's possible the stock flip-flop circuit/fet switching prevented this from happening but AFAIK no one has ever cloned the DM-2 with that bypass circuitry.

BTW - this issue with the oscillation being present in bypass won't be unique to the Aquaboy. It can happen in any analog or PT2399 delay if the oscillation isn't controlled in some way like I mentioned in my previous post. It's just the nature of the beast.

Thabk you very much foe taking the time to reply. The pedal sounds awsome and i built it with the mod board. I think im going to try to lessen the feedback amount rising the resistor to the left of the ne570 to 36k but im afraid i will lose the self oscilation option which is very nice to play with

What i hear is crazy oscilation if i max the feedback pot qhen the pedal is bypassed.

When the delay is in self-oscialltion mode the amplitude of the feedback continues to multiply with each repeat and becomes much greater than the natural volume decay out of the BBD. This creates runaway volume gain which is going to bleed into bypass no matter how you wire it. IOW, self-oscillation is more of an effect you can achieve when you play with the feedback control but it's not a setting you want to keep in bypass.

There are a few ways you could get around this, though:
- Use a 4PDT that disconnects the feedback path on bypass. This is a bad idea since you will quickly find any mechanical pop from the switch is going to create a very unpleasant sound when you turn the effect on.
- Use some kind of FET based switching that disconnects the Feedback pat instead. This is a much better solution most likely but complicates the circuit a lot if you are doing the entire bypass as some kind of flip-flop.
- Use diodes to clamp the oscillation. Put two 1N4001 diodes back to back between pins 3 and 1 of the Feedback pot to clip the repeats once they get above the threshold of their forward voltage (and keeps the repeat amplitude from running away). This can sound cool but it will clip the delay some.
- Use a momentary switch for generating self-oscillation instead. Here you connect an normally open SPST between pins 3 and 2 of the Feedback pot. When you press it the repeats instantly go into self-oscillation.

Thank you very much for replying! Do you know if this also happened on the original DM2? As i was building this for a friend who wanted an exact copy of the DM2

Just to clarify, you're hearing the clock whine, not the crazy oscillations when feedback is maxed? 
Are you using a 3PDT? Which wiring? Grounding the input or output when bypassed?

Thabk you for replying i solved the whine provlem. What i hear is crazy oscilation if i max the feedback pot qhen the pedal is bypassed. Its bleeding through the input or output wire somehow. Wiring is the one that the pdf provides which grounds the input when bypassed. I noticed that if a ground the input wire from the jack with an aligatot clip, the oscilations stop so my guess is that they are bleeding into the input wire. I tried puting far away the input and output jack but that didnt solve it. The oscilations are faintly at the back but is not acceptable. Im wondering if is there anything wrong with the design or if its something with me because i read a lot of complaints similar

Please help. My aquaboy bleeds signal when bypassed and feedback y maxed. Ivetried every suggestion in the forum and it decreased a lot but the oscilation is still there blreeing. Any component swap sugesttions to reduce the noise to 0?

Please help

 

Was the delay at max. delay time (fully cw)? Or is the whine audible at every setting.

Try adjusting the cancel trimmer for min. whine. Another possibility is to adjust the clock trimmer, so that when this pot is maxed the longest time is still at a higher frequency.

Thank you for replying. I managed to get rid of the whine but im still getting delay signal bleeding in bypass. If i max the feedback pot and mix y hear oscilation when the pedal is bypassed. Any suggestion to get rid of this proboem? Lowering the clock trimmer and the bias trimmer got rid of this but i ended up with very short and distorted delays when pedal is on. Is this the whine bleeding into feedback? I dont understand. If i move the IN jack close to the elecrrolitic capacitor just under the MIX pot pads the oscilation and whine are noisier. Im curious if that capacitor is producing noise. Its a Nichicon 50volt capacitor. It just be very good quality