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R/E/P => Mastering Dynamics => Topic started by: Alécio Costa - Brazil on April 02, 2011, 01:27:34 AM

Title: Bal/Unbal connections among Ibis EQ, OCL2 and STC8: help troubleshooting
Post by: Alécio Costa - Brazil on April 02, 2011, 01:27:34 AM


I would like to make some questions to the users of the combo IBIS + OCL2 + STC8 + HEDD, like Odeon Mastering, Brad Blackwood and other folks here.

Up to now I have not been able to improve my overal sound quality considerably, inserting the STC8.

In recent jobs, I have even taken the STC8 out of my chain.

However, I guess I have found a problem with the output gain on my OCL2.
I can not use XLR ins/outs simultaneoulsy . One channel drops (!!!)
I have already contacted Pendulum Audio and certainly there is a problem there.
I have substituted tubes, but sound quality improved let us say 5%.

HEDD 192 d/a XLR outs go to IBIS XLR ins and its XLR balanced outs feeds OCL-2 unbalanced 1/4 ins ( Problem may also be here, gain staging with bal unbal connections).

Also, when I use OCL2 1/4 ins and XLR outs, signal arriving at STC8 is a bit weak. So, I have to use some output makeup gain.

Before someone point out, I rarely use more than 2 dB of gain reduction.

However, When using OCL2 inserted on a Yamaha board, for tracking during recording with ordinary insert cables, signal input and output is stronger.

So, seems that on mastering chain, I must use the OCL2 1/4 ins and outs for a while.
Monday is gonna be the day!


a) Do you guys keep OCL2 gain at 12 o´clock position or add some minor make up gain so as to have a stronger signal entering the STC8? I have seen that the OCL2 is not that silent.

When I used the OCL2 alone, adding 4 db at its output and using a fair amount of pentode - tape - triode, my noise floor is not that great. ( –70 to -76 dB, with a “snake dancing” at the Waves PAZ).


b) Which OCL2 connections you guys use : the unbalanced XLR ins or the 1/4 ins? Is there a difference of level, since both are unbalanced?


My connections are like this:

1 - Crane Song Ibis EQ XLR outs feeds OCL2 1/4 inputs.

2 - OCL2 XLR outs going to the STC8 XLR ins with no make up-gain**, signal is too weak. ( I add 2 to 4 dBs of outputgai at the OCL2)

3 – STC8 XLR outs fedd HEDD 192 a/d which goes via AES out to AVID 192 IO digital AES In.



Thanks for your time reading all this!
__________________
Title: Re: Bal/Unbal connections among Ibis EQ, OCL2 and STC8: help troubleshooting
Post by: Alécio Costa - Brazil on April 07, 2011, 01:00:54 PM
anyone?
 :P
Title: Re: Bal/Unbal connections among Ibis EQ, OCL2 and STC8: help troubleshooting
Post by: bblackwood on April 07, 2011, 01:11:34 PM
All XLR I/O here, but all are single ended (chassis ground on each insert @ console).

Not sure my setup will help you, not sure how many folks have both an OCL2 and an STC8.
Title: Re: Bal/Unbal connections among Ibis EQ, OCL2 and STC8: help troubleshooting
Post by: Laarsø on April 07, 2011, 04:53:10 PM

I would like to make some questions to the users of the combo IBIS + OCL2 + STC8 + HEDD, like Odeon Mastering, Brad Blackwood and other folks here.

...HEDD 192 d/a XLR outs go to IBIS XLR ins and its XLR balanced outs feeds OCL-2 unbalanced 1/4 ins ( Problem may also be here, gain staging with bal unbal connections).

Also, when I use OCL2 1/4 ins and XLR outs, signal arriving at STC8 is a bit weak. So, I have to use some output makeup gain.

Before someone point out, I rarely use more than 2 dB of gain reduction.

However, When using OCL2 inserted on a Yamaha board, for tracking during recording with ordinary insert cables, signal input and output is stronger.

So, seems that on mastering chain, I must use the OCL2 1/4 ins and outs for a while.
Monday is gonna be the day!
...
__________________



The part I read in the Pendulum manual reads that the 1/4" unbalanced inputs are not only wired in parallel to the main XLR's but are for -10 dBV (approx. 12 dB lower than +4 dBm, right?) sources, and also that the TRS and XLR jacks should not be in use simultaneously.   Whether that means one handing off to the other, as in your throw, or only for when all jacks are receiving/sending to different sources/destinations at the same time, I _don't_ know...   

For what it's worth, I have been using the OCL-2 unbalanced, in and out, via the XLR connectors.   I'd recommend you do it that way (tying pin3 to pin 1 on the male XLR - or floating pin 3 - whichever looks quietest on your FFT display).    The Female XLR will automagically be fed an unbalanced signal, because that's the way the OCL-2 is.  One-sided board.  Not the loneliest number you'll ever do, imho.


 


Cheersø,
     Laarsø
Title: Re: Bal/Unbal connections among Ibis EQ, OCL2 and STC8: help troubleshooting
Post by: Alécio Costa - Brazil on April 08, 2011, 11:37:32 AM
Thanks, Folks.
In fact, there might be a problem with my OCL2 as I already mentioned.
I can not use XLRs In/Out. One channel drops.

In insert mode, ( 1/4 ins and outs) signal is OK.

When using 1/4 ins  and XLR outs, both channels function, but with this "-10dbv" dropped signal.

Brad, single ended you mean unbalanced, right? sorry for the repetitive question.
Title: Re: Bal/Unbal connections among Ibis EQ, OCL2 and STC8: help troubleshooting
Post by: bblackwood on April 08, 2011, 11:53:47 AM
Thanks, Folks.
In fact, there might be a problem with my OCL2 as I already mentioned.
I can not use XLRs In/Out. One channel drops.

In insert mode, ( 1/4 ins and outs) signal is OK.
Yah, def something wrong there.

Quote
Brad, single ended you mean unbalanced, right? sorry for the repetitive question.
Yah, unbalanced, sorry for the confusion.
Title: Re: Bal/Unbal connections among Ibis EQ, OCL2 and STC8: help troubleshooting
Post by: PBM on April 08, 2011, 01:28:12 PM
Thanks, Folks.
In fact, there might be a problem with my OCL2 as I already mentioned.
I can not use XLRs In/Out. One channel drops.

In insert mode, ( 1/4 ins and outs) signal is OK.

When using 1/4 ins  and XLR outs, both channels function, but with this "-10dbv" dropped signal.

Brad, single ended you mean unbalanced, right? sorry for the repetitive question.

Have you called or e-mailed Greg directly about this? In my experience he's one of the friendliest and most helpful men on the planet and could probably sort you out in a trice.

Cheers,

Eric
Title: Re: Bal/Unbal connections among Ibis EQ, OCL2 and STC8: help troubleshooting
Post by: Alécio Costa - Brazil on April 08, 2011, 02:20:41 PM
I need to contact him again.
In 2009, he pointed on some soldering problem on the board, but it was rare or almost impossible to happen.
I will ask him again.
Thanks for your concerns, folks.
Let us set fire to this forum! ( in a positive sense)


:)
Title: Re: Bal/Unbal connections among Ibis EQ, OCL2 and STC8: help troubleshooting
Post by: Laarsø on April 08, 2011, 05:24:13 PM
Thanks, Folks.
In fact, there might be a problem with my OCL2 as I already mentioned.
I can not use XLRs In/Out. One channel drops.

When you write, "one channel drops," do you mean when there is only a cable in the XLR jacks and _not_ in any of the TRS jacks?

In insert mode, ( 1/4 ins and outs) signal is OK.

When using 1/4 ins  and XLR outs, both channels function, but with this "-10dbv" dropped signal.


The manual explains that those 1/4 ins are _for_ -10 dBV sources.  It also explains that the XLR and TRS jacks are not to be used _simultaneously_, as in your description, I believe.  The _INSERT_ TRS ins are for the side chain. 

SE (single-ended) is the same as "unbalanced."   


Please first try using the OCL-2 in unbalanced mode using _only_ the XLR connectors.   Don't use any 1/4" connectors, first, and then see if there is any oddness.   

Good luck,

Cheersø,
    Laarsø
Title: Re: Bal/Unbal connections among Ibis EQ, OCL2 and STC8: help troubleshooting
Post by: Alécio Costa - Brazil on April 09, 2011, 01:16:43 AM
I´m doing new tests, which we intend to conclude on monday.

I guess we addressed the problem.

The Unbal/Bal stuff on the manual and that Laarso also stressed here was properly followed since day 01.

 I will post what I have found. It is funny/weird... :)
Just confirm on monday .
Title: Re: Bal/Unbal connections among Ibis EQ, OCL2 and STC8: help troubleshooting
Post by: Laarsø on April 09, 2011, 09:52:17 AM
The Unbal/Bal stuff on the manual and that Laarso also stressed here was properly followed since day 01.

That's very good, however some time after day 01, you apparently disobeyed the manual and tried using the XLR's simultaneously with the 1/4" TRS jacks...  :-[  The manual is quite clear about that being counterindicated.   I should be interested in learning the cause of the Gaultieri output channel problem you are having, whatever the cause...

Good luck  ;),
     Laarsø

Title: Re: Bal/Unbal connections among Ibis EQ, OCL2 and STC8: help troubleshooting
Post by: Alécio Costa - Brazil on April 09, 2011, 10:36:05 AM
No, bud.
Maybe I mistyped. Never used both connections at the same time.
Please, shoot me now!
:)
Title: Re: Bal/Unbal connections among Ibis EQ, OCL2 and STC8: help troubleshooting
Post by: Laarsø on April 09, 2011, 06:59:40 PM
No, bud.
Maybe I mistyped. Never used both connections at the same time.
Please, shoot me now!
:)

Mistyped is fine.  I thought you were saying 1/4 in used with XLR out and things are not right....  This would be true, indeed.   I'll put my blunderbuss down now. We love the OCL-2 and hope it is able to do good things for you once this is solved. 

Boa tarde,
     Laars_øglethørpe
Title: Re: Bal/Unbal connections among Ibis EQ, OCL2 and STC8: help troubleshooting
Post by: bblackwood on April 11, 2011, 12:24:58 PM
Update, Alecio?

(edit: sorry Alecio)
Title: Monday afternoon tests
Post by: Alécio Costa - Brazil on April 11, 2011, 07:10:34 PM
Alecia? LOL
Hey, I just changed some connections here...

Hi, folks
Today we changed connections here. I tested BAL XLR, Unbal XLR ( as the manual recommends) and the old 1/4 unbal plugs.

I was surprised and also got  ashamed to discover that my OCL2 always went nuts whenever and because we changed cables without doing a total power cycle.

I took a specific song and mastered it with: ( Pin 1 +3 ground, Pin 2 positive)**
a) PT HD Daw > Hedd > Ibis > OCL2 > Hedd >PT HD  Daw ( Ocl2 Unbal XLR Ins)**

b)PT HD Daw > Hedd >  Ibis > OCL2 > Hedd >PT HD  Daw ( Ocl2 Unbal XLR Ins with a bal cable)
(OK, not recommended)
 
c) PT HD Daw > Hedd >  Ibis > OCL2 > STC8  Hedd >PT HD  Daw ( Ocl2 Unbal 1/4 Ins with)


Conclusions and details

1) XLR Unbal and the XLR bal provided me a slightly better noise floor. Curiously, with everything at bypass, my peak noise floor readout at pt HD in went to -80 (XLR bal) and -74 (XLR unbal)

2) XLR connections provided a tighter bass;

3) I added the STC8 with output gain at +5.6 L / +6.0 R at the last test, substituting the +-5.0 db of digital gain I was doing at the daw input.  I had difficulty to match both sides. Threshold and output gain were always problematic to tune.
So I ended up doing a stereo link preset with something like:

Peak Threshold : off
Threshold: 1.5
Attack: 6
Release: 4
Shape: 6
Preset: Var A Mod

With this setting I was able to achieve a reasonable tone, but I still need to dig more with the presets.

STC8 did provided a better low end, with a minor improvement to the overall sound, if compared to the masters done only with OCL2. a 15% better tone.... I still have not found the sweet spot where most say that the STC8 is a giant leap, when inserted on the chain.

Doubts:
1) Although not recommended, why did the bal cable provided me a better S/N ratio if the OCL2 input is not balanced? We used the same cable, jut redid the soldering.
OCL2 output gain at Zero ( 12 o´clock).

Thanks for your considerations!