Hamlet Delay by Jon Patton

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MAO
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Hamlet Delay by Jon Patton

MAO
This post was updated on .
09/04/2017 Update: New layout added, dated 09/04/2017. Verified and noise free.

08/26/16 Update: I was unable to get rid of the noise mentioned below while using the charge pump. I removed the charge pump, rebiased the 2n5457 and the pedal is quiet. I'm concerned the layout itself may be the issue. Maybe the ICs are to close to each other? FWIW, The pedal still sounds really good running at 9Vs.    



Info here

Version 1.2 Build Doc

I converted the 25k tone trimmer an external pot, and reversed the connections so CW = brighter/noisier CCW = darker/less noise. 50k linear may be better for more highend rolloff (and more noise rolloff)

If using an LT1054, lift pin 1. And the zener can be increased to 12v.    

(note the ICL7660SCPA is mounted upside down)







1978 Gibson Les Paul Standard, Cherry Sunburst, Nickel Tone Zone & Air Norton Pickups, Sweet 16 wiring
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Re: Hamlet Delay by Jon Patton

Mark SL
How do we add a bypass led?

It is confirmed other than that.

Thanks
MAO
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Re: Hamlet Delay by Jon Patton

MAO
This post was updated on .
2 options:

1. Tails - non true bypass (verified)
Use DPDT stomp switch, FS1 to lug 1, FS2 to lug 2, LED(-) to lug 4, PCB Stomp Ground to lug 5 and input jack ground (lugs 3 and 6 not used)
Input jack tip to PCB in, Output jack tip to PCB out. LED+ to PCB LED+

2. No tails - true bypass (verified)
Use 3PDT stomp switch wired as usual.
Jumper FS1 and FS2
Add additional 4M7 resistor across input jack tip and ring.  
1978 Gibson Les Paul Standard, Cherry Sunburst, Nickel Tone Zone & Air Norton Pickups, Sweet 16 wiring
MAO
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Re: Hamlet Delay by Jon Patton

MAO
After boxing this one up, I was getting strange noises in the tails bypass mode.

Seemed like the PT2399 was not happy when breaking FS1 and FS2 connection and leaving FS1 hanging.

I could get rid of the noise by grounding FS1 while in bypass mode, but there was a pop echoing when the switch was opened or closed.

At some point I'll try the 1776 opto-tron switch to see if that allows the grounding of FS1 without the pop.

For now, I went with true bypass as described above. I also went with the 50K linear Tone pot. Helps get rid of some noise with the longer delay times.


1978 Gibson Les Paul Standard, Cherry Sunburst, Nickel Tone Zone & Air Norton Pickups, Sweet 16 wiring
MAO
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Re: Hamlet Delay by Jon Patton

MAO
I was unable to get the Tails bypass quiet, in fact, I later realized there was still some residual noise with the effect on. Even when battery powered. Thought I had it resolved a couple of times, but when using headphones I found there was still a faint noise in the background.

While audio probing with headphones, I discovered when I removed the charge pump the noise would disappear. (I tried swapping charge pumps, no change)

At this point, I'm not 100% sure if it was the layout causing the issue, maybe the charge pump is too close to the PT2399? Or if I had a bad component/solder joint somewhere I couldn't pin down.  

I suspect it may be the layout though as I ended up unplugging the charge pump, replaced the pump's 1n5817s with jumpers, re-biased the 2n5457 to 4.5v and the pedal is quiet. The tails bypass is quiet as well.

It actually still sounds great with just the 9v supply.

If someone else builds this layout and also has charge pump noise, let me know and I'll re-do the layout and better separate the ICs 
 
       
1978 Gibson Les Paul Standard, Cherry Sunburst, Nickel Tone Zone & Air Norton Pickups, Sweet 16 wiring
MAO
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Re: Hamlet Delay by Jon Patton

MAO
This new layout is noise free. Verified by me.

Changes to the original circuit:
I added some additional power supply filtering.
Tone control originally 25k trimmer, 50k allows dialing out a bit more noise. CCW = less treble/less noise
Delay pot originally 100k with a 150k resistor across lugs 1 & 3 giving a bit more available delay...along with some noise.
Volume control originally a 10k trimmer.

1978 Gibson Les Paul Standard, Cherry Sunburst, Nickel Tone Zone & Air Norton Pickups, Sweet 16 wiring
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Re: Hamlet Delay by Jon Patton

Stymie13
Hey, what are the two wires on the bottom left between the 100n cap and the transistor? Thanks for the layout!
MAO
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Re: Hamlet Delay by Jon Patton

MAO
Oops, looks like I didn't label those.

They are "extra" ground hookups, I use them for the input jack ground and the stomp switch ground.

Keeps the offboard wiring tidy
1978 Gibson Les Paul Standard, Cherry Sunburst, Nickel Tone Zone & Air Norton Pickups, Sweet 16 wiring
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Re: Hamlet Delay by Jon Patton

Stymie13
Got it, thanks again.
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Re: Hamlet Delay by Jon Patton

Stymie13
Finished this layout. Very cool delay, love the tone control. Unfortunately, I'm getting some motor boating/oscillation when the delay is bypassed. The frequency changes with the delay control and seems to be silenced if I turn the output volume down below unity. I should have some time to tinker with it tomorrow, any thoughts would be appreciated.
MAO
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Re: Hamlet Delay by Jon Patton

MAO
Sorry to hear that.

I had a similar issue with the 1st layout I had tried.

I ended up having to remove the charge pump to get rid of the noise.

Try removing it and see if the noise goes away. You may need to re-bias the 2n5457 for 4.5v

If you have the same results, I'll build another one and get back to you.


1978 Gibson Les Paul Standard, Cherry Sunburst, Nickel Tone Zone & Air Norton Pickups, Sweet 16 wiring
MAO
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Re: Hamlet Delay by Jon Patton

MAO
Another thing to try (without removing the charge pump) is to wrap a wire tightly around the 220nf, completely covering it from top to bottom (hopefully it's a box cap or greenie), and ground one end of that wire, essentially you are then shielding the exterior of the 220nf cap, just be sure you don't short anything else out.

I would just use your regular hookup wire, wrap the cap with it as best you can and ground one end with an alligator clip to the enclosure. It's just temporary, so it wont really matter how long you have to run that wire to ground it somewhere convenient. Again, just be careful you don't short anything else out.  

If the noise goes away, that cap is acting like an antenna when the stomp switch is open (which leaves the input of that cap floating)  

Looking at the layout again, I'm now worried it may be to close to the charge pump...

Jon had the 220nf and PT2399 a little bit farther away from the charge pump in his perf layout.

Now I'm going to have to build another...most likely the week of the 23rd.

 

1978 Gibson Les Paul Standard, Cherry Sunburst, Nickel Tone Zone & Air Norton Pickups, Sweet 16 wiring
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Re: Hamlet Delay by Jon Patton

Stymie13
Thanks MAO. I tried insulating the 220n cap just as suggested, no effect on the noise. I played with Q2 bias which also had no discernible effect. Pulling the charge pump definitely eliminates it. The few minutes I played it with/without the CP, I couldn't really tell the difference between 9V and 18V. I understand the headroom in theory but even with a hot signal (humbucker>G2 Muff>Hamlet) I couldn't tell much difference. The PT2399 noise is unbearable in a recording/studio environment but for live, loud, heavy rock it doesn't bother me. If you know it's there its noticeable when all other instruments drop out leaving just the delayed guitar signals but so is snare vibration, 60 Hz hum, etc.
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Re: Hamlet Delay by Jon Patton

Stymie13
I wonder if the 7660S is the culprit? I don't have an LT1054 to try but am curious if it makes a difference in this application.
MAO
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Re: Hamlet Delay by Jon Patton

MAO
Sorry to say, I tried that with the 1st layout without success.

And I agree, the delay still sounded great at 9v.

I really thought the noise issue was solved with layout #2.
I sent an email to the guy I made it for, waiting to hear back.

What puzzles me is why the noise when interupting the delay path? What is it about opening that connection causes the charge pump noise to become apparent? Not sure.

I remember if you ground that connection when open, no noise, but you do get a repeating click when you engage the delay.

I wonder if it would be better to open the signal path after the delay chip, rather than before it?


1978 Gibson Les Paul Standard, Cherry Sunburst, Nickel Tone Zone & Air Norton Pickups, Sweet 16 wiring