Delegate (Warden) Upgrades

[Chuck D. Bones]

Similarities:
They are both optical compressors.
Both fit in a 125B box.
Both use the same LED & LDR.
Both use the OPA2134 audiophile-grade dual opamp.
Differences:
FG uses two LED/LDR pairs, W uses one pair. They both achieve the same objective, but by slightly different means. Ideally, the FG LDRs should be matched. In reality it probably doesn't matter very much.
W has more available gain and sustain.
W has a RATIO knob which sets the how much the comp can reduce gain. FG has a BALANCE knob which kinda does the same thing.
Both have TREBLE controls (W calls it TONE), but they are tuned differently and the FG is capable of more treble boost. Whether you need that much boost is for you to decide.
W has variable ATTACK and RELEASE. I find it useful to be able to slow down the ATTACK so the beginning of each note retains some dynamics. The FG is wired for fast attack and fast release. The FG's BALANCE control mixes in some uncompressed signal, so you can vary the dynamics that way.
W has a charge pump for more headroom.
FG has a higher parts count, 75 vs. 54.
W has more knobs, 6 vs. 3.
FG has buffered bypass, W has true bypass.

 

[kubavit]

Thank You a lot !

 

[kubavit]

Hello again. I have a question especially to You @Chuck D. Bones.
I created the PCB based on your version. After soldering and connecting I have a problem.
There is sound from the pedal, but the white LED does not blink at all. On the DC power-on, the white LED turns on, and then slowly turns of. during playing LED does not respond. Also I cannot hear any compression sound. Could You help with this case ? Schematic in teh attachement. I have used SS12A instrad od 1n5817 diodes and B1M pot instead of C1M.

P.S. when turnin off the power supply when the pedal is on there is noticable 'squeeze' sound in the AMP. I can share the PCB etc.

BR,
Jakub

 

[Chuck D. Bones]

That schematic matches what I built. A couple of questions:

Are you testing the board where light from the room can get to the LDR?

The numbers 5-10k next to the LDR, what do those represent?

 

[kubavit]

Yes, there is a lot of the light from the room (there is no enclosure yet)
the LDR is: http://electropark.pl/fotorezystory/5471-fotorezystor-5-10k-5mm-gl5516.html (5-10k is the resistance period)

 

[Chuck D. Bones]

The room light is overwhelming the LDR. You have to test it with the LDR in complete darkness. If it's not in the enclosure, then put a cardboard box over the board and dim the room lights for testing.

You really need a C1M SUSTAIN pot if you want to use the top end of the range. Otherwise, the top end of rotation, between 4:00 and 5:00, will be too touchy.

BTW, I swapped my internal LED out for something with a lot less output: a 3mm green diffuse LED.

 

[kubavit]

Thank You. I will simulate the full darkness and let You know about the results.

1. With green intetrnal LED it will compress more smoothly ?
2. C1M is really hard to get. I will have to order it in China I think.

 

[Chuck D. Bones]

It's not about LED color, it's about how much light falls on the LDR. Go back and read the last paragraph in my first post in this thread.

There are a number of sources for C1M pots, including Tayda & Small Bear.

 

[kubavit]

Thanks a lot. It worked in the complete dark environment. So in my understanding the more light falls onto LDR the more compressed signal is ?

 

[Chuck D. Bones]

In a manner of speaking. The more light on the LDR, the lower the resistance. The lower the LDR resistance, the lower the gain. For smooth compression, you have to set the ATTACK above zero and the SUSTAIN below max.

 

[daeg]

Anyone else getting a volume spike when the Delegate engages? Seems like during bypass, the envelope is at 0, so the gain is at max, then when you hit the footswitch, your signal gets full gain applied before the envelope can catch up.

I'm not much of a compressor guy so IDK if this is normal with Feedback style Compressors, but I find it unpleasant.

 

[Chuck D. Bones]

It's normal with high SUSTAIN settings, but can be easily fixed. What are your control settings?

 

[daeg]

It's normal with high SUSTAIN settings, but can be easily fixed. What are your control settings?

Here's where I've had it for the last few months. (Using a 1-10 scale)
Attack: 3, Ratio: 6, Release: 0
Level: 4, Tone: 6, Sustain: 7

The duration of the volume spike is proportional to the Attack time, as you'd expect. The circuit also makes an unpleasant click when 'Attack' is set to minimum and 'Ratio' is high.
It totally makes sense why it happens, I'm just surprised I've never heard guitarists complain about it before, especially given how picky gearheads are.

 

[Chuck D. Bones]

Indeed. The fix is simple. If your stomp switch is hardwired (no breakout board), remove the wire between pins 1 and 6. Connect a wire between pins 1 and 2. Now the guitar signal is always fed to the board. The compressor will track the signal level, even in bypass. We can get away with this because the Delegate's input impedance is high.

If you have a breakout board, you remove the wire between the Delegate board IN pad and the breakout board. Connect a wire between the breakout board's far left pad (the one that goes to the input connector) and the Delegate board IN pad.

 

[cooder]

Indeed. The fix is simple. If your stomp switch is hardwired (no breakout board), remove the wire between pins 1 and 6. Connect a wire between pins 1 and 2. Now the guitar signal is always fed to the board. The compressor will track the signal level, even in bypass. We can get away with this because the Delegate's input impedance is high.

If you have a breakout board, you remove the wire between the Delegate board IN pad and the breakout board. Connect a wire between the breakout board's far left pad (the one that goes to the input connector) and the Delegate board IN pad.

So to understand you correctly there, is it that the input of pcb should always be connected to input jack/incoming signal to achieve this? Correct?
The switch would just switch between bypass straight through and out of pcb?

 

[Chuck D. Bones]

Exactly.

 

[daeg]

Now the guitar signal is always fed to the board. The compressor will track the signal level, even in bypass. We can get away with this because the Delegate's input impedance is high.

Hah, I was just about to say I wish it wasn't True Bypass; it would make so much more sense to just feed it the input signal when disengaged and only switch the output.

In my case I used the Relay Bypass Module, but eventually I'll want to build another compressor and do this.

 

[benny_profane]

Just to clarify for those at home just tuning in, these are not PCB defects. These are design "issues" that are also present in the original pedal, the PCB is true to the original circuit.

Now with that out of the way, maybe we should work up a Chuck's Boneyard Edition Delegate PCB so folks who want to try these mods don't have to start cutting things.

Is the boneyard edition a serious idea or was that a joke? I’d be interested in picking that board up.

 

[Robert]

Is the boneyard edition a serious idea or was that a joke? I’d be interested in picking that board up.

Yep, not a joke.

 

[Flying]

Hi, it looks like this PCB layout was done in May, but it's not materialsed is that due to the current situation or was there a problem with the design?

And it would be great to hear feedback from anyone who's compared the two. I'm deciding whether to jump in or wait!