PYE Compressor/Limiter Thread *boards shipping* BOM up!

[Grummy77]

I just bought the case and pcb from dan...nothing else yet. So the hairball meters do not fit, and the meter adjust hole has to be drilled?

Both a friend of mine & myself bought cases from Dan. The Hairball meters seem to fit perfectly on his case but on my case the holes are a bit wide. So however i put in the meters there is some extra space. We also find that the adjustment on the front of the meters gets in the way & they don't sit flush. I ended up drilling holes to make space for the adjustment screw to get them to sit flat. We also noticed that the colour on the faceplate is different between the two of our cases, & that the screws on my faceplate don't line up perfectly. So when I put mine together the faceplate bows a little. lso my friend noticed some bubbles under the paint of the bottom of his case. He figures there must have been rust painted over. Pretty disappointing considering how much we paid for the cases. Yours might be ok though. Just seems like it's a bit of a gamble ordering from that place.

 

[Grummy77]

So after a few years of sitting on the parts & stuffing the board a little at a time. My friend (also in this thread) & I are coming close to completion. We're very exited to finish. We are just unclear on a few things & hoping some of the more experienced builders on here will be able to shed some light for us.

1 - Where do we solder in the side chain transformer?

2 - Is it possible to have a seperate sidechain in with this transformer?

3 - What are you guys using for the dual/Stereo link switch?

 

[Rob Flinn]

1. you solder it where the header called t4 is
2. I don't understand your question
3. A standard miniture toggle switch dpdt

 

[Grummy77]

1. you solder it where the header called t4 is
2. I don't understand your question
3. A standard miniture toggle switch dpdt

Thanks for the quick response I kind of figured 1 & 3 out looking through everything on here. I don't know how I missed that.

2- I'm asking if there's a way to implement an external side chain input on here easily. Has anyone on here done that? Is it even possible? Would it be as simple as having a switch connecting another input to the sidechain transformer & switching between the existing path & the external in? Or am I totally out to lunch?

 

[eddie_ruff_]

Received the boards and case from Dan today. I did a quick test fit and the front faceplate bows. This may be something I can remedy, but for now I'll start compiling the various carts for all the components. Should I make my own build thread or clutter this one up even more?

 

[Rob Flinn]

Thanks for the quick response I kind of figured 1 & 3 out looking through everything on here. I don't know how I missed that.

2- I'm asking if there's a way to implement an external side chain input on here easily. Has anyone on here done that? Is it even possible? Would it be as simple as having a switch connecting another input to the sidechain transformer & switching between the existing path & the external in? Or am I totally out to lunch?

Personally it's not something I would implement, so I don't really have an interest in spending any time on it. 
Why don't you try it and report back.

 

[shot]

Received the boards and case from Dan today. I did a quick test fit and the front faceplate bows. This may be something I can remedy, but for now I'll start compiling the various carts for all the components. Should I make my own build thread or clutter this one up even more?

Go throught this thread and read it. Entirely!
Stuff that is now boring to read will at some point if you go troubleshooting ring in the back of your mind and you'll know to return and re-read again parts that are relevant. At that point you'll be much more familiar with the schematic and parts and it won't be boring to read.

Stick to the BOM posted by SR1200
Use the PYE3 14SCHB.pdf schematic as a reference
Triple check everything
And you'll probably be without problems!



Luka

 

[frederickalonso]

I have the pcb's but need to order the parts when i have time.

 

[eddie_ruff_]

I should be able to get the wiring finished this weekend! But I'm sure I'll have some troubleshooting to do...
Also, I'll be sending 24VDC to the boards...should I be sending 24VAC instead since there appears to be on board rectification? I guess I'll lose a some voltage to the diodes but I should be able to meet the 18-22 VDC range.

 

[eddie_ruff_]

additional pic

 

[eddie_ruff_]

So far so good. The choppers were calibrated to 250kHz spot on. I do have one question though, for the 18-22VDC measurement....is this measured between B+/B- or is it measured between B+/ chassis ground? I have 18.38 between B+/B- and 23.28 between B+/chassis ground. I should be good then right?

 

[desol]

Measurement is between  B-neg(+) and B-pos(-). I set mine to 22v.

 

[Ilya]

B+ and chassis GND should be tied together at a single point. So they should measure the same.

 

[eddie_ruff_]

Ok made a couple changes. My B+ is tied to chassis ground on pin 1 input xlr. I get -22 at B-(positive probe) to B+ (Negative DMM probe).
I guess I am confused about the whole analog ground thing. isn't there technically DC on B+ after retification?

 

[Ilya]

Has anybody measured the actual ratios of this comp? I'm having very funky readings with mine...

 

[bruno2000]

Has anybody measured the actual ratios of this comp? I'm having very funky readings with mine...

Yes.  I'll see if I can find my AP graphs and post.
Best,
Bruno2000

 

[Ilya]

Yes.  I'll see if I can find my AP graphs and post.
Best,
Bruno2000

I saw your graphs in this thread somewhere. And they look quite good.

My graphs look like approx. 3.5:1 at all ratio settings. And ratios are very level dependent.

Could you please elaborate on which preset trimmers values you used? Also, did you put in 82p cap or 1n cap after the osc? I've scoped the base of the chopper with both values and couldn't get the graphs that look like in the original unit. And I get a ton of static GR if I don't tweak the R42 drastically lower (<1K).

Another question if you don't mind. Were you able to get unity gain through the compressor without additional output stage?

 

[bruno2000]

I saw your graphs in this thread somewhere. And they look quite good.

My graphs look like approx. 3.5:1 at all ratio settings. And ratios are very level dependent.

Could you please elaborate on which preset trimmers values you used? Also, did you put in 82p cap or 1n cap after the osc? I've scoped the base of the chopper with both values and couldn't get the graphs that look like in the original unit. And I get a ton of static GR if I don't tweak the R42 drastically lower (<1K).

Another question if you don't mind. Were you able to get unity gain through the compressor without additional output stage?

I don't remember about the osc cap.  Used whatever the original BOM said.  No weirdness on the trimmers IIRC.
I could never get unity gain, thus the added Neve output section.  Still working on the 4060 output section that added the needed gain.
https://groupdiy.com/index.php?topic=65187.0
Best,
Bruno2000

Edit:  Added pdf of comp curves (?)

 

[Ilya]

Actually, I would argue that the circuit has all the gain as it is.  It's possible to verify this by removing the chopper transistor completely (removing the 555 chip won't work since the chopper is still biased half open and shunts the signal to GND).
This means that we have static gr going on which is wrong. From the original scopes it shows just short downward spikes that shouldn't drop the level noticeably.

I suppose that the interaction of the circuit and the blocking osc is not as simple. And 555 osc behaves differently.

It would really help if somebody could scope the base of the chopper without input signal and post the graph here.

 

[bruno2000]

Actually, I would argue that the circuit has all the gain as it is.  It's possible to verify this by removing the chopper transistor completely (removing the 555 chip won't work since the chopper is still biased half open and shunts the signal to GND).
This means that we have static gr going on which is wrong. From the original scopes it shows just short downward spikes that shouldn't drop the level noticeably.

I suppose that the interaction of the circuit and the blocking osc is not as simple. And 555 osc behaves differently.

It would really help if somebody could scope the base of the chopper without input signal and post the graph here.

I respectfully disagree.  I tried everything I could to get unity gain from the comp.  The best I could do was a 6dB loss with some pretty wild value changes.  Add to that that the output section in the 4060 schematic adds about 28dB of gain.
Best,
Bruno2000