All things Green Pre

[Phrazemaster]

Another knob pic, closer...notice how rough they are...

 

[Phrazemaster]

and finally through the miracle of modern elbow grease, and subsequently finer and finer grades of sandpaper, the (mostly) finish knobs. Sorry the photo is a tad blurry.

I will infill the dots with colors to match my design.

 

[PAGEN]

Hi

Is it normal to have a signal trough the preamp without power on an ic's mounted or not mounted?
Even the volyme pot is responding. I'm trying to get some life in to my newley build Green.
I have sound, but not very nice sound.

Thanx.

 

[Ptownkid]

Phraze...your front panel looks great! Really cool to see the metamorphosis from your original design to the end!

 

[peterc]

Yes.

There are a few paths that carry the signal, like the feedback resistors on the opamps, so there is a good chance of something bleeding through.

Peter

Hi

Is it normal to have a signal trough the preamp without power on an ic's mounted or not mounted?
Even the volyme pot is responding. I'm trying to get some life in to my newley build Green.
I have sound, but not very nice sound.

Thanx.

 

[PAGEN]

All up and go now. Found a faulty Ne5532. The number one. It got real hot. Replace it and now it's ok. Did the cmrr adjustment by ear and i works fine. Now I will do the other adjustment to get it finetuned. And after this it's time for one more green to be build. This is like a drug.

Thanks to all who make this possible. And for help.

Mats

 

[Phrazemaster]

Thanks Ptown; the panels arrive today; I'm excited!

 

[Phrazemaster]

I have a question about the psu. I have added some led's with relays for driving them; in fact I had a board made for them (pic posted here).

So those in the know:

The leds (12 of them) and relays (8 of them) for 4 channels of green collectively will draw about 220ma off a positive rail of the psu.

Am I taxing the psu too much like this? Would I be better off making another psu board running in parallel just for these? I'm a little concerned that I will be lopsiding the psu by asking for too much from just the positive rail. Yes, I am a newbie, but boy have I spent a helluva lot of hours trying to understand all of this.

Thanks in advance,

Mike

 

[Phrazemaster]

OK I'm getting to wiring the torroid and the front panel switch and fuse.

I am posting a simplified wiring diagram here, gleaned from much reading/thought. Does this look right?

I realize the primaries need to be in parallel since I'm in the US with 110vac, and I've omitted that detail from this drawing; assume there will really be 4 wires to the torroid for the primaries; two for each leg in parallel.

Thanks any thoughts. I don't want to burn the house down.

By the way, my IEC connector already has a built-in switch and line filter, which I am also not showing here; I'm just going to use the extra rear-panel switch as an extra margin of safety and also for checking fuses.

Thanks!

Mike

 

[Phrazemaster]

PS I found this article extremely helpful in deciding on this scheme:

http://sound.westhost.com/psu-wiring.htm

Thanks again any thoughts.

Mike

 

[Phrazemaster]

Also a question about the PSU. I have version 6 (not 6a). When I bought the kit I was sent v.4 overlay, which I assumed would be fine since that is exactly what Peter sent me when I bought the board.

I am posting a pic of the v4 overlay Peter sent me when I bought the psu board. Notice the empty slots for what looks like capacitors (green rectangles).

Should I add capacitors here? I notice in the v6a of this board there are caps. Should I follow the v6a as much as possible? Yet my board does not exactly match v6a.

I'm cornfused. A little help?

Thx,

Mike

 

[peterc]

You can leave out those caps, they were for extra stages of boost

 

[Phrazemaster]

Thank-you Peter.

 

[Phrazemaster]

OK, perhaps dumb questions, but I just can't seem to get this clear in my mind even after reading a lot of posts. I am attaching a pic with my silly concept of where grounding goes on the PSU.

My understanding:

1) The PSU has 2 sides labelled G for ground: one for where the PSU connects to the green channels (left in the pic), and one for where the torroid 0V connects (right in the pic). Is that right?

2) I am also to take a wire from the PSU G (where the torroid 0V connects) and connect this to the star ground, then to IEC mains ground...correct?

3) Do I even need to attach the torroid 0V center tap to the PSU, or just take the torroid 0v center tap directly to the star ground?

4) The other 2 torroid hookups to the psu connect to the other two positions marked in blue (in right of pic), and it doesn't matter which torroid wire goes to which because it's AC - correct?

I'm really sorry if this stupidly obvious; it's really hard for me. I cannot begin to say how many hours I've spent trying to understand this all...and yet it's probably so simple. Thanks in advance for your support.

Mike

 

[peterc]

1. Yes
2. Kinda. Yes on the PSU G to Star Gnd. The IEC mains Earth cable must connect directly to the star gnd.
3. Reference & stability
4. Correct.

Peter

 

[Phrazemaster]

Thank-you Peter.

Would there be any problem just attaching the torroid 0V directly to star ground, and bypass PSU G point? Then also attach PSU G to star ground?

Thank-you.

Mike

 

[Phrazemaster]

Thought I'd post some pix of the front panels, which I designed and front panel express executed...All I can say is, WOW! They are amazing craftsmen, and if you can afford to have your panels made, they offer a stunning service.

 

[Phrazemaster]

'nother pic

 

[Phrazemaster]

and another...

 

[Phrazemaster]

more