Official 33609 builder's tread. See 1st page for updates.

[dmp]

I bought a bunch that I don't need. I'm not sure how many I have, but I'll check tonight...

 

[Biasrocks]

I bought a bunch that I don't need. I'm not sure how many I have, but I'll check tonight...

Thanks, that'd be great!

Mark

 

[fredlaprod]

Hi everybody,
Just to say that a new 33609 is born.....
It works at the first powering....
I start calibration, but I only got a multimeter and the plasma displays of my ssl 4056G. I think this not enough accurate to do it well.
Do you know if there is any way to calculate dBs with a single multimeter?
I make some research over the web, but there are too many ways to to it.
So can you give me a trick?
Thanks again to Igor and Tat

Fred

Ps: I will post pictures soon....

 

[ultra-alex]

.....
Do you know if there is any way to calculate dBs with a single multimeter?
I make some research over the web, but there are too many ways to to it.
So can you give me a trick?
....

http://www.sengpielaudio.com/calculator-db-volt.htm

cheers, alex

 

[fredlaprod]

Hi everybody, here are two pictures of my new gear....
Btw, can somedy help me: I don't hear the relays when using the bypass switch....
I only hear them when the bypass switch is on and when I power up the 33609.... I also can hear them when I power down the rack, but no noise when I use the bypass switch with the main power on.....

Thanks

Fred

 

[fredlaprod]

And another one....

Fred

 

[nielsk]

Where did'ja get those knobs? I like the way that looks...

 

[fredlaprod]

Plastic knobs..... Les cyclades électronique, Bd Diderot, Paris.....
They give a kind of Focusrite Red Serie's look.....
Btw, it works perfectly now......

 

[Biasrocks]

Curious if there was any consensus on the value of R10' (6K8 or 24K) in the compressor release section,
as detailed here.

http://www.groupdiy.com/index.php?topic=26218.msg322694#msg322694

Or perhaps someones has had a chance to verify against a production version?

I'm also looking for a technical manual or a schematic/parts list for the original version of the limiter,
10/11/12 I believe. I have the "C" tech handbook along with the J/D version from the Neve site, but
I'm missing the original 33609 documents. Anyone have one to share?

Mark

 

[Biasrocks]

I'm a little confused on how to figure out the values for the gain switch for
different transformer configurations.

I'm using a LO1166 configured 50:600 +10db on the output, which sounds great
but I can't get the limiter threshold high enough to get +4 on the output with
the gain switch setup for +8db instead of +10db.

Could you tell me how to calculate the values for the gain switch for +10db.

Any help would be appreciated.

Edit: I see in an earlier post, that you suggest changing RV4 to 50K in order to calibrate
the limiter section properly. Is it necessary to adjust the gain values if this is done or
am I okay since I'm getting an extra 2db on the output as opposed to 4db less?

Hmmm, I see RV4 is already at 50K in the revision, so I guess I'll up it to 100K to get
enough adjustment for the limiter threshold.

Mark

BTW, for people who using ungaped version of 1166
(2567 IIRC), +4 instead of +8 db:

There's resistors arround gain switch.
OLD-->NEW
1m0-->2k4
2k4-->820
820-->390
390-->240
240-->160
160-->91
91r-->75
75r-->51
51r-->43
43r-->36
130-->91

 

[Biasrocks]

Hmmm, well it seems I've caused some sort of problem securing one of the transformers
on to the board.

After I tightened down the zip ties on the 10468 transformer I've ceased getting a signal
from the secondary side of the transformer.  ??? Getting signal fine up to the primary side
measured right on the transformer.

If I power off the board and inject signal into the transformer while still attached to the
board I get a strong signal back from the secondary when measured at the test point.
As soon as I power up the board, the signal disappears. Perhaps I've shorted something
out or broke a trace by over tightening the zip ties?

I've beeped the traces around the transformer and all seems okay.

Any ideas where to look?

Mark

 

[kazper]

Did you use anything to isolate the transformer case to the OEP and other options vias?

If your cool there I would remove zip ties and look for damage to the pcb. Use a multimeter and trace the pcb connections from point to point to find open traces.

Kaz

 

[Biasrocks]

Yes, I used the boards that were included.

Actually I had the unit operational with the zip ties in place, just when I tightened them down, all hell broke loose.

I'll have a closer at the traces tomorrow.

Edit: I have a 4.2v offset on the primary of the interstage transformer, that doesn't seem right especially since there's two big
honkin' 470uf caps right ahead of the transformer. Pulled the cap and no shorts, no voltage on the primary, put the cap back in and
the offset came back.  ???

Anyone else got 4-5Vdc on the primary of the interstage?

Mark

 

[Biasrocks]

Well, I'm stumped. Changed out the 470uf's and I've still got 4.1vdc into the primary.

If I remove the leads from the secondary to the board I still get no signal so it can't be anything
down stream of the transformer. I can only assume that it's the DC on the primary that's
shutting down the transformer, since it passes signal just fine when I power down and
inject signal directly into the transformer.

Can anyone do me a favor and confirm wether this DC offset is supposed to be there
and their on their build. You would have to measure at the interstage primary.

Mark

 

[dmp]

Mine is taken apart at the moment, so I can't measure it. But looking at the schematic, there is ~4v on the positive side of the caps and no ground reference for the primary side of the transformer, so maybe it could build up a DC voltage from leakage across the caps.
Polarity of the caps is right? The negative side of the cap should be facing the transformer.
It sounds like you have a mean gremlin lurking in there someplace.

 

[Biasrocks]

Mine is taken apart at the moment, so I can't measure it. But looking at the schematic, there is ~4v on the positive side of the caps and no ground reference for the primary side of the transformer, so maybe it could build up a DC voltage from leakage across the caps.
Polarity of the caps is right? The negative side of the cap should be facing the transformer.
It sounds like you have a mean gremlin lurking in there someplace.

Thanks, it's driving me nuts currently.  :'(

The caps are definitely oriented correctly.

Gave it the chopstick test and nothing.

If you get a chance after you reassemble I'd really appreciate it if you could measure for a DC voltage on the primary side
of the interstage.

Mark

 

[Biasrocks]

Okay, well I've got one channel functional again.

I'm not 100% sure what the cure was but I ended up pulling both transformers off the
board, replacing the two BC241's right after the JFET which seemed to have gotten rid
of the 4V offset to the interstage, I'm now down to around .11v of offset which seems
much more reasonable. Lastly it seems that there were cold solder joints around the
primary transformer, probably as a result of over tightening the zip ties. Next time I'll
be more careful to get them secure but not too secure.

It's 2:00am here, so I'm off to bed and hopefully I can get the second channel up and
running tomorrow and all we'll be well in 33609 land, aside from the gain issue which
I've yet to find an answer for, but I live to fight another day!  

Thanks for the moral support and the suggestions guys. 8)

Mark

 

[Rob Flinn]

I found the best way to fasten the transformers is to use cable ties, but not too tightly, & then use some hot melt glue to stop the transformer slopping around.  I tend to use hot melt glue with all larger caps too.  I like that type of glue because it is pretty secure, but in the event of needing to change a component, its is also quite easy to remove.

 

[dmp]

Way to go! I like to see those late night posts with a good result.
I'll be putting mine back together as soon as the Elma's arrive and can help with measurements then.
I don't see how there would be voltage on the primary with the BC214s to blame. It only points to the obvious for me - that there was a short somehow across one of the capacitors.

 

[tomcat]

OA202 instead of 1n4153 is a good substitute here?

Or does anybody know a source for 1n4153? Didnt get them with the pcbs