taliska

Re: SSL 9K & 4K (E Series) 500 / 51X NEW BOARDS Mic Pre Thread 2011
« Reply #640 on: August 06, 2020, 02:16:54 PM »
I don't exactly follow the explanation. The polarity relay comes after the output of the 1646. The default position of the relay is unenergized, and the output of the positive pin goes to pin 2 of the edge connector in that state.

I'm not looking at my card at the moment, but if you look at the top of the relay in the comment I just included, the + / - supply is reversed compared with the pdf.

I'm going to try and explain this again, as my original line wasn't very clear (I'm doing this for myself mainly!).

This is a non-latching relay, right?

It's basically an electro-magnet that flips a switch, but that magnet is only going to flip the switch as documented, if you're sending the current through the wire in the direction it expects.

If you accidentally wire up your circuit with the current going the wrong way, it's going to do the opposite thing.

I think that's what happened when the footprint was mirrored, and that's why the work-around was needed?

(again, just guessing here based on the original comments).

« Last Edit: August 06, 2020, 03:10:32 PM by taliska »


Whoops

Re: SSL 9K & 4K (E Series) 500 / 51X NEW BOARDS Mic Pre Thread 2011
« Reply #641 on: August 06, 2020, 04:21:51 PM »
At least that's my understanding of it...it's been A LONG TIME since I last looked at a schematic! LOL.

So that you don't cry for the Schematic any longer, here it is:
 ;) ;) ;D :D ;D :P

https://web.archive.org/web/20110812113023/https://www.dopplerstudios.com/pictures/SSL%209K-42Sch.pdf

Nothing gets lost on the internet, a lot of broken links and websites can be partially be seen with Way Back Machine
« Last Edit: August 06, 2020, 08:09:01 PM by Whoops »

Ricardus

Re: SSL 9K & 4K (E Series) 500 / 51X NEW BOARDS Mic Pre Thread 2011
« Reply #642 on: August 06, 2020, 05:55:35 PM »
Oh, and the issue isn't with the layout of the THAT1246 part of the schematic as I understand it from the comments.

The footprint of the relay is mirrored. This means it will get energised in the opposite direction and effectively swaps the default and energised positions of the relay.

The top of the relay has a pinout printed on it for the relay, but it's actually representing the BOTTOM of the relay. So the relay polarity looks wrong if you don't know that. It says so right in the PDF. That is if it's an OMRON relay like the ones I am using.

Also, the previous post you posted with the pics and what not, had text associated with it that said something was wrong with his Phantom Power implementation, not the polarity/phase switch.
Audio mastering for hire..

taliska

Re: SSL 9K & 4K (E Series) 500 / 51X NEW BOARDS Mic Pre Thread 2011
« Reply #643 on: August 06, 2020, 08:11:59 PM »
The top of the relay has a pinout printed on it for the relay, but it's actually representing the BOTTOM of the relay. So the relay polarity looks wrong if you don't know that. It says so right in the PDF. That is if it's an OMRON relay like the ones I am using.

Ok, good to know, but that's certainly what people were talking about being reversed in the original comments, right?

Also, the previous post you posted with the pics and what not, had text associated with it that said something was wrong with his Phantom Power implementation, not the polarity/phase switch.

Ignore the text of the comment. That wasn't why I quoted it. I quoted it for the pics where it shows the pcb as v.4.2. which clearly predates Bruno's comment about discovery of the issue / fix.

In other words, if v.4.2 predates his fix, then it's impossible for it to include the fix like you seem to think.

...unless of course, he did fix it and just didn't increment the version number...but why would he do that? That would be super confusing, right?

Additionally, I just quickly scanned through the thread, and the last mention of the polarity stuff I can find is in 2015:

There is just one version. So you'll still need to modify it and also do the polarity swap.

I built mine in 2013, so my v.4.2 is likely to be different to yours considering you built them last year.

A.
« Last Edit: August 06, 2020, 08:40:15 PM by taliska »

Ricardus

Re: SSL 9K & 4K (E Series) 500 / 51X NEW BOARDS Mic Pre Thread 2011
« Reply #644 on: August 06, 2020, 11:13:36 PM »
Look, this isn't what I think, as in it's an opinion. I'm telling you that on my boards (all less than a year old) pin 8 from the That 1646 line driver (the + output) goes to pin 2 on the edge card, which is the hot output pin. like pin 2 on an XLR. I am not making this up. I used an ohm meter and tested it 3 different ways.
Audio mastering for hire..

Ricardus

Re: SSL 9K & 4K (E Series) 500 / 51X NEW BOARDS Mic Pre Thread 2011
« Reply #645 on: August 06, 2020, 11:16:57 PM »

Additionally, I just quickly scanned through the thread, and the last mention of the polarity stuff I can find is in 2015:


 I would suggest that is an important factoid. No one has mentioned it in 5 years, so maybe it got fixed?
Audio mastering for hire..

taliska

Re: SSL 9K & 4K (E Series) 500 / 51X NEW BOARDS Mic Pre Thread 2011
« Reply #646 on: August 07, 2020, 05:05:41 AM »
I would suggest that is an important factoid. No one has mentioned it in 5 years, so maybe it got fixed?

Yeah, maybe....but there doesn't seem to be any explicit statements in the thread that a fixed version was ever released, while there are a couple of comments stating that there was only ever one version.

I'm confident for my boards that this was the right thing to do (mainly because of their age and the thread comments), and at some point I'll run a signal through and check whether it inverts (assuming my oscilloscope still works!).

I'm going to check-out from this thread now, but I think I'm going to suggest the following to any that come after me:

- If the pcb you have requires the corner of the meter board to be cut, then that means it was never fixed, and so it's unlikely that the polarity issue was fixed also.

A.

Ricardus

Re: SSL 9K & 4K (E Series) 500 / 51X NEW BOARDS Mic Pre Thread 2011
« Reply #647 on: September 05, 2020, 03:35:03 PM »
I am building another pair of these, and I gotta say, these are a fun build, but I am at the one part that I find boring and monotonous...

Soldering all 27 of those identical ceramic bypass caps. Oy. It's always the one part I do not look forward to.
Audio mastering for hire..

kml23956

Re: SSL 9K & 4K (E Series) 500 / 51X NEW BOARDS Mic Pre Thread 2011
« Reply #648 on: September 28, 2020, 11:49:26 AM »
Does anyone have the 4k info? I have two boards that need building.
Music is for kids:

Whoops

Re: SSL 9K & 4K (E Series) 500 / 51X NEW BOARDS Mic Pre Thread 2011
« Reply #649 on: September 28, 2020, 12:54:14 PM »
Does anyone have the 4k info? I have two boards that need building.

Use Waybackmachine.
All the links and docs in the first post of this thread are available in waybackmachine


kml23956

Re: SSL 9K & 4K (E Series) 500 / 51X NEW BOARDS Mic Pre Thread 2011
« Reply #650 on: September 30, 2020, 11:50:00 PM »
Wayback worked for the BOM but not the 4K schematic. Does anyone have the schematic?
Music is for kids:

Whoops

Re: SSL 9K & 4K (E Series) 500 / 51X NEW BOARDS Mic Pre Thread 2011
« Reply #651 on: October 01, 2020, 08:03:11 AM »
Wayback worked for the BOM but not the 4K schematic. Does anyone have the schematic?

Wayback machine works for ALL the files in the first post.
The link to the schematic was also posted by me here in this exact page of this thread, some posts back

kml23956

Re: SSL 9K & 4K (E Series) 500 / 51X NEW BOARDS Mic Pre Thread 2011
« Reply #652 on: October 07, 2020, 12:12:32 PM »
Where is the 4k because this link is only the 9k? There are no transformers in this schematic:

https://web.archive.org/web/20110812113023/https://www.dopplerstudios.com/pictures/SSL%209K-42Sch.pdf
Music is for kids:


 

Related Topics

  Subject / Started by Replies Last post
143 Replies
43309 Views
Last post October 09, 2020, 05:21:52 AM
by Isax1984
6 Replies
2364 Views
Last post August 03, 2010, 09:15:25 AM
by jsteiger
372 Replies
81114 Views
Last post August 24, 2020, 11:06:24 AM
by jsteiger
98 Replies
26986 Views
Last post May 22, 2011, 09:16:50 AM
by [silent:arts]