HiMy little 'how to measure for balance' piece was a bit general but should help others try to get to grips with the vast mess that is 'balancing'. It is a shame that some manufacturers still make gear with interfacing to the 'outside world' that is so fussy. There are several 'self balancing' chips out there that are only a couple of Dollars apiece that would allow either balanced or unbalanced use without all this 'messing about' (DRV134, SSM2142, THAT 1646 (?) all being 'equivalents'). It is of course also possible to use a handful more components to achieve similar effect. Using transformers as Matt B says is a good but expensive way around the 'problem' and I suppose adds a touch of colour to the equation.
Hope things are getting clearer now. Matt S
On 03/12/2011 03:11, Jared Miller wrote:
I see, this makes more sense now. Maybe it would be worth getting a basic balanced distribution amp that you could patch into when you need it. This would buffer the 192 outs from affecting your inputs to the console. However, I'm not sure if this would be any better than your current fix.Jared On 12/2/11 2:08 PM, Matt Boynton wrote:I guess I wasn't totally clear at first. I lose level when I plug into an unbalanced input *and* the half normal at the patchbay is connecting to the balanced line input at the same time. One solution is dead patching the line in. I do experience cross talk when using the 192 outs to send to an unbalanced effect. In that situation I pass the signal through a set of UTC's I have specifically for this problem.Matt Boynton Vacation Island Recording 90 Walton Street Brooklyn, NY 11206 Tel: 347 225 3201 www.vacationislandrecording.com <http://www.vacationislandrecording.com>On Fri, Dec 2, 2011 at 2:38 PM, Jared <[email protected] <mailto:[email protected]>> wrote:Maybe I'm just confused, but it seems that maybe there is some miscommunication here. I know that Matt S knows a lot more about this stuff than I do so maybe I'm missing something. If that is the case please correct me. If we are talking about the output of this Series 1 all outputs being unbalanced into the balanced inputs of a DD HD192 there should be no level difference. The way I understand it is the problem with the DD HD192s is plugging its output into an unbalanced input; which is not the case in Matt B's console unless he is using insert returns. So there should not be any issues losing 6dB in his scenario. He has balanced line inputs. I've used my console that is very similar to Matt B's with a DD HD192 for about six months and I have never had a problem with levels or noise. But like I said maybe I'm missing something. Jared -----Original Message----- From: Matt Boynton Sent: Dec 2, 2011 12:43 PM To: "[email protected] <mailto:[email protected]>" Subject: Re: NEOTEK: Series 1 Noise Problem Interesting. Thanks Matt. Matt Boynton Vacation Island Recording 90 Walton Street Brooklyn, NY 11206 tel: 347 225 3201 <tel:347%20225%203201> www.vacationislandrecording.com <http://www.vacationislandrecording.com> On Dec 2, 2011, at 12:58 PM, Matt Syson <[email protected] <mailto:[email protected]>> wrote:Hi If the 192 instructions tell you to lift the negative it suggests that the outputs are not 'transformer like' but a simple amplifier out on the hot and another amplifier out with phase polarity reversed for the negative. With this scenario 'grounding' it will drive signal current into the ground causing possible crosstalk, distortion and maybe even damage to the converter outputs. A 'simple' test for this type of output is to measure a continuous tone signal at a convenient level, say 2 Volts on a multimeter, connected to measure BALANCED (between pins 2 and 3 of an XLR or hot to cold). Now, while monitoring the output level, short one side to ground. With a transformer or 'electronically compensating' output the signal level will not change, or only by a tiny fraction. Shorting EITHER hot OR cold should produce no significant level drop. I suspect that with the 192 outputs you would see a fall of 6dB (Half the original level). In this case you must connect the signal into a balanced input or if you have no choice with an unbalanced input, cut the 'negative' and accept the inevitable signal level loss. With the negative cut you will not damage anything. Matt S On 02/12/2011 17:12, Matt Boynton wrote:That's what my issue was. Sometimes lifting the shield isn't the answer though. For example, a digi192 suggests on the rear panel to lift the negative wire instead of the shield. Which is different than any other converter I've encountered. I have the studio wired with the shields lifted on the converters so whenever I plug into an unbalanced input on the neotek the signal is 6 db or so lower. To remedy this I'm getting a new converter. Matt Boynton Vacation Island Recording 90 Walton Street Brooklyn, NY 11206 tel: 347 225 3201 <tel:347%20225%203201> www.vacationislandrecording.com <http://www.vacationislandrecording.com> On Dec 2, 2011, at 9:43 AM, Tom G <[email protected] <mailto:[email protected]>> wrote:Hello Matt, Interesting. I do have some noise in my left master channel/monitor however it is only the monitoring section. When I mix down to tape or digital the signal is fine. I'll check into this too...I am guessing its more of a power amp and may not be related to my preamp issue. Thanks! Tom --- On *Wed, 11/30/11, Matt Boynton /<[email protected] <mailto:[email protected]>>/* wrote: From: Matt Boynton <[email protected] <mailto:[email protected]>> Subject: Re: NEOTEK: Series 1 Noise Problem To: [email protected] <mailto:[email protected]> Date: Wednesday, November 30, 2011, 3:51 PM I had a problem where my speakers had a fairly high frequency buzz in them regardless of the position of the control room volume pot. I isolated it to the convertors. I ended up lifting the shield wire on the ins and outs of the convertors and the buzz was gone. Maybe its something similar. Matt Boynton Vacation Island Recording 90 Walton Street Brooklyn, NY 11206 Tel: 347 225 3201 <tel:347%20225%203201> www.vacationislandrecording.com <http://www.vacationislandrecording.com> On Wed, Nov 30, 2011 at 3:39 PM, Ike Zimbel <[email protected] <http://mc/[email protected]>> wrote: > > Hi Tom, > Do the channels have to be side by side, or any two at random? Does this > mean that you are using two and only two pre-amps when this happens, or do > you mean when it's a pair, like overheads, while using other channels for > other inputs (IOW, can you only use ONE mic-pre on the Neotek at the > moment?)? If that's the case, does the problem steadily get worse if you use > more channels? > I very much doubt this is a grounding issue (in the 60hz hum sense, anyway), > but it MIGHT be an interface issue between the direct outs of the Neotek and > the input of the converters. > Best, > Ike > > > On 11-11-30 3:27 PM, Tom G wrote: >> >> Hello All, >> >> I have been battling an issue with my Neotek Series 1 console on and off >> now for about six months. When I use any two preamps (of the console) at the >> same time, I get a noise on one channel. According to my frequency analyzer, >> it is approx. 4k and is high enough in gain to make the track unusable. When >> I use outboard pre's there is no problem whatsoever. >> >> I thought it may be a ground loop or something similar, but floating the >> grounds did not help. I'm using SSL converters and it doesn't seem to matter >> what inputs of the SSL I'm using nor what channels on the Neotek I >> use...still the same noise. But only when using two channels together. >> >> Any thoughts? I have not tried completely floating all grounds except for >> the console. Once I get my tape machine back home and hooked up, I am >> curious if I get the same result. Although as stated, floating the two >> channels in question was no help. >> >> Thanks! >> Tom >> >> > > -- > Ike Zimbel, > Zimbel Audio Productions Ltd. > Toronto > 416-720-0887 <tel:416-720-0887> > > "Studio House Calls". Repairs and upgrades to analog audio equipment > including: AMEK, dbx, Neve, Neotek, MCI, Soundcraft and more. Authorized > Warranty service for Allen& Heath, Clear-Com, Drawmer, Soundcraft, SPL and > Yamaha. Ask about our RF frequency co-ordination services! > www.zimbelaudio.com <http://www.zimbelaudio.com> > > ------ > > View the list online at: http://www.mail-archive.com/[email protected] > > You can unsubscribe at anytime by sending an email to > mailto:[email protected] <http://mc/[email protected]> with "unsubscribe neotek" in the message > body. If you have any difficulties, or questions --please send an email to > mailto:[email protected] <http://mc/[email protected]>. > > The Neotek list is lovingly hosted by Catapult Web. Remember that any > message or reply sent to the list will be automatically forwarded to all > subscribers. > > Vive Le Neotek! > > Thanks. > ------ View the list online at: http://www.mail-archive.com/[email protected] You can unsubscribe at anytime by sending an email to mailto:[email protected] <http://mc/[email protected]> with "unsubscribe neotek" in the message body. If you have any difficulties, or questions --please send an email to mailto:[email protected] <http://mc/[email protected]>. The Neotek list is lovingly hosted by Catapult Web. Remember that any message or reply sent to the list will be automatically forwarded to all subscribers. Vive Le Neotek! Thanks.------ View the list online at: http://www.mail-archive.com/[email protected] You can unsubscribe at anytime by sending an email to mailto:[email protected] <mailto:[email protected]> with "unsubscribe neotek" in the message body. If you have any difficulties, or questions --please send an email to mailto:[email protected] <mailto:[email protected]>. The Neotek list is lovingly hosted by Catapult Web. Remember that any message or reply sent to the list will be automatically forwarded to all subscribers. Vive Le Neotek! Thanks.
