Siegfried Meier

SSL Clone Headroom
« on: July 02, 2004, 01:19:25 PM »
I've recently finished one of the Gyraf Audio versions and have noticed a limited amount of headroom when using it with a Neve output or a Digi 888 output.  They're all +4 units.  The Clone distorts pretty bad until I turn it down to the point where it's level is really low.  Anyone else experience this and know of a fix (or perhaps if I have a problem with mine?).  Thanks.

Best regards,
Siegfried Meier


JayDee

SSL Clone Headroom
« Reply #1 on: July 02, 2004, 02:30:00 PM »
yeah, I also mentioned that on the input. I put it after the sontec and it there was not much headroom till distortion. I think of some input pots/resistors...

matthias

SSL Clone Headroom
« Reply #2 on: July 02, 2004, 03:21:41 PM »
I never had any problems with headroom...
balanced and unbalanced...

gyraf

SSL Clone Headroom
« Reply #3 on: July 03, 2004, 06:22:22 AM »
Hi Siegfried,

Welcome to "The Lab"..!

What are the input and output levels you can reach before distortion?

measured in mV AC, preferably, as the input/output metering on DAW's are relative and depends entirely on setup.

If your voltmeter is not an expensive type, it's best to measure levels at a relatively low frequency, e.g. 300Hz.

Jakob E.
..note to self: don't let Harman run your company..

Siegfried Meier

SSL Clone Headroom
« Reply #4 on: July 06, 2004, 10:09:52 AM »
OK.  Here's what I've found.  When connected to a console through a Bantam patchbay, the unit is very clean and has an extreme amount of headroom.  However, when connected directly to a Digidesign 888, the sound is distorted and doesn't have enough level into ProTools.  This appears to be a balancing issue with the SSL Clone, as I've been told it is not a truly balanced output.  I was advised to wire the output differently.  Any comments on this?  Thanks.

Best regards,
Siegfried Meier

Svart

SSL Clone Headroom
« Reply #5 on: July 06, 2004, 10:14:58 AM »
yeah, correctly.   :green:   sorry, couldn't resist!
Welcome to the GroupDIY leper colony! when something falls off, we just replace it with a tube!
occupation: General Electron Mayhem

Alesis X2 information repository:
http://www.theopiumdenproductions.

gyraf

SSL Clone Headroom
« Reply #6 on: July 06, 2004, 10:25:29 AM »
It seems like your Digi888 is not balanced connected then? In this case, connect input- to ground, and leave output- hanging, like on any electronically balanced stuff (not counting the "quasi-floating" designs).

Jakob E.
..note to self: don't let Harman run your company..

Siegfried Meier

SSL Clone Headroom
« Reply #7 on: July 06, 2004, 12:30:23 PM »
Well, the Digidesign 888's are indeed balanced units, and I've never had a problem interfacing them directly with any other gear, including Focusrite ISA110's, Smart C1's, Distressors etc.  There's just something finicky with the Clone.  I also did a test where I came from the console patchbay out into the Clone, and directly into an 888.  Same distortion.  However, if I use the patchbay to interface the ins and outs, it's great.  Perhaps if I just make special cables for direct 888 connection, then I could leave the unit wired the way it is.  The way I see it, it's not the input that's the problem, it's strictly the output.  Thanks.

Best regards,
Siegfried Meier

ChrisA

SSL Clone Headroom
« Reply #8 on: July 06, 2004, 12:39:27 PM »
I've connected the clone to an 888, 001, a 192, an apogee rosetta 800, an api, a neve, and a quad eight console. I have not had a problem like you described with any of them.

gyraf

SSL Clone Headroom
« Reply #9 on: July 06, 2004, 12:44:37 PM »
The only thing that could possibly make the clone output stage clip below some +22dBm, is when one of the output phases is shorted to ground - mostly from looking into an unbalanced input.

Try checking AC voltages (referenced to ground) on both the + and the - phase outputs when loaded with the 888. This would show if any unhappy shorting occurs.

Jakob E.
..note to self: don't let Harman run your company..


Siegfried Meier

SSL Clone Headroom
« Reply #10 on: July 06, 2004, 03:07:56 PM »
OK.  So here's the fix.  We know the 888 is definitely a balanced unit.  I wasn't getting the problem through the patchbay because the bay has got other gear attached to it that is transformer isolated and balanced.  A direct connection to the 888 caused the problem.  So, leave pin two alone, but wire the ground wire that is feeding pin one to pin three and lift pin three entirely.  This corrected the problem.  Thanks.

Best regards,
Siegfried Meier

SSL Clone Headroom
« Reply #11 on: July 06, 2004, 03:32:52 PM »
I think you just made your output unballanced. If this fixed your clipping problem, then the the 888 is not ballanced input or is not working correctly. Since you verified the clone through other gear, it can not be your problem. The interface between the clone and the 888 is not ballanced so if you want to really fix the problem, look at the input of the 888 and clone as Jakob suggested, otherwise you will have two pieces of gear that don't work well as opposed to one.

Siegfried Meier

SSL Clone Headroom
« Reply #12 on: July 06, 2004, 04:11:57 PM »
Well, considering I've testing it with 4 different 888 24's and 1 888 16, it's probably not the 888's.  I realize that the connection is unbalanced, but if it works, it works.  This problem also sometimes occurs with other electronically balanced units, and as far as I know, is the only fix.

Best regards,
Siegfried Meier

SSL Clone Headroom
« Reply #13 on: July 06, 2004, 07:25:57 PM »
All I'm saying is, if you investigate a little further, you can find the real culprit here, not just a quick fix. I am not the one using the gear so I, of course, don't need to be satisfied with it. As long as you are, that's what counts.

Greg

SSL Clone Headroom
« Reply #14 on: July 06, 2004, 08:51:03 PM »
This is interesting. See if you can really find what's going on here. I've used the GSSL with various outboard gear going to a 1" and an ADAT. I haven't had any headroom issues. Investigate further b/c I think it'd be better to keep the unit balanced if you can.
Greg Stein
New Orleans, LA

Siegfried Meier

SSL Clone Headroom
« Reply #15 on: July 07, 2004, 11:32:16 PM »
So I made a couple of cables wired up the way I described above.  They don't work, although when I tested this using alligator clips, I was able to make the Clone work properly.  Tell me, are you guys directly connecting the Clone output into an 888, with a direct XLR cable??  I can't for the life of me figure out what the hell is going on here.  What is shorting out in this setup, that doesn't occur when I use a console patchbay??  Thanks.

Best regards,
Siegfried Meier

gyraf

SSL Clone Headroom
« Reply #16 on: July 08, 2004, 04:13:09 AM »
Are you absolutely sure you got the +/0/- connections to the XLR's pins 1,2,3 right? Note that on the the pcb they're not coming out in any logical way.

Jakob E.
..note to self: don't let Harman run your company..


 

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