Finally powered up the 4350's today for the first time

[neanderthal]

Are the White's balanced, or not?

Yes the manual say's the inputs are electronically balanced. I attached the manual if you want to take the time to dig thru it. On page 7 mine are hooked up like in figure 1. It makes no difference if the shield wire is hooked up or not. I do have the 4390 input transformer.The outputs are connected as in figure 3 on page 8 again with no effect on shield wire connected or not. I do not have an output transformer

I was going to eliminate (bypass) the equalizers and go straight to the 10B from the preamp to possibly narrow it down a little farther.

[neanderthal]

Krunchy has a technical ground dedicated to his audio gear. Hence the spikes in the yard etc. If he did what he was told he will have lifted the domestic ground ie no connection to the outlet.

He will have a series of e mail from me that hhe can forward to you on this subject.

Take your system down to its most basic form ie disconnect all outboard gear like AV stuff etc. Your power amps should run quiet with no input connection ,switch off and hook in your x/o but with no input connections. what happens now ? Hum - if yes you have a multi ground within THAT setup and you probably need to lift the ground on one of the power amps ( it will ground also through the signal leads )

Keep on going that way until the culprit shows up. Happy hunting

I'll also try this this weekend when I have enough time to dedicate to this without interuptions...Thanks macaroonie

[Krunchy]

Pete, I'll try to hook things up saturday, probably late afternoon/early eve, will post results.

[neanderthal]

Pete, I'll try to hook things up saturday, probably late afternoon/early eve, will post results.

Hey Krunchy you don't have to on my account whenever you get to it is fine with me

[Krunchy]

Not a problem, I've been itching for an excuse to fire them up anyway.

[Krunchy]

Hi Pete!,
had a chance to hook the system up & play a couple of songs, everything sounded fine & dead quiet (when nothing was playing).
With Macaroonie's help I implemented this system as a precaution plus it just made sense under the circumstances at that point in time (ie: the construction ). I did not have any GL issues prior to the implementation of the technical grounding as I mentioned previously, & with the minor monetary investment it was a no brainer... even for me

Personally I dont think it would hurt to apply this grounding system for your situation seeing as how you already have a dedicated circuit in place, which frankly is the hardest part of the equation. Adding the dedicated grounding rods etc. would be pretty simple. That being said there might be more to your particular situation & circumstances then the actual grounding per se as has been alluded to in other posts. Like I said all this technical stuff in not my forte but I would think it is something other than the grounding since you did not have these problems before:dont-know .

Did you have a chance to do further investigating into the possible culprit.
Keep us updated & let us know how you make out & good luck.

fred

[neanderthal]

Hi Pete!,
had a chance to hook the system up & play a couple of songs, everything sounded fine & dead quiet (when nothing was playing).
With Macaroonie's help I implemented this system as a precaution plus it just made sense under the circumstances at that point in time (ie: the construction ). I did not have any GL issues prior to the implementation of the technical grounding as I mentioned previously, & with the minor monetary investment it was a no brainer... even for me

Personally I dont think it would hurt to apply this grounding system for your situation seeing as how you already have a dedicated circuit in place, which frankly is the hardest part of the equation. Adding the dedicated grounding rods etc. would be pretty simple. That being said there might be more to your particular situation & circumstances then the actual grounding per se as has been alluded to in other posts. Like I said all this technical stuff in not my forte but I would think it is something other than the grounding since you did not have these problems before:dont-know .

Did you have a chance to do further investigating into the possible culprit.
Keep us updated & let us know how you make out & good luck.

fred

Hi Krunchy I didn't get a chance today to try to isolate where the ground loop is coming from, I was over at Fort Leavenworth all day but I'll be all over it tomorrow. The results on your system is great news and I hope I can have the same before too long.

I do have a balanced power conditioner located and spoke for. All Iam waiting on is for the guy to get an extremely heavy duty package job done and it'll be on the way.I told this guy that I'd rather wait a week or two til he has it boxed up good enough to take a possible 3ft drop (typical UPS,FEDEX) than to hurry and have a jerky pack job,damage and fight to get them to pay off on ins claim.

I'll start with macaroonie's suggestion ,with the amps and if quiet then plug the crossover in and keep working backwards til the problem appears. Something tells me it is going to be the bryston 10b. I'll post the results tomorrow without fail on what I found out.---Pete

[Ken Pachkowsky]

This made my system dead quiet.... and for a 4-way system with 6 amplifiers that is a major accomplishment.

All balanced outputs should have pin 1 active at the source and removed at the amplifier. Just for clarity...

I had pin 1 connected at the Deqx Balanced Output (XLR) but snipped or disconnected at the Boulder Amplifier Input (XLR).

Many here will confirm it took me months to eliminate the problem. Only when I was told this technique (called telescoping inputs) was I successful in completely solving the problem...no cheater plugs or anything and my system was black between tracks. It was a tech on Gearslutz that taught me this.

Ken

[neanderthal]

This made my system dead quiet.... and for a 4-way system with 6 amplifiers that is a major accomplishment.

All balanced outputs should have pin 1 active at the source and removed at the amplifier. Just for clarity...

I had pin 1 connected at the Deqx Balanced Output (XLR) but snipped or disconnected at the Boulder Amplifier Input (XLR).

Many here will confirm it took me months to eliminate the problem. Only when I was told this technique (called telescoping inputs) was I successful in completely solving the problem...no cheater plugs or anything and my system was black between tracks. It was a tech on Gearslutz that taught me this.

Ken

Thanks Ken for the input when I jump into this tomorrow I'll also give this a shot and see if it resolves the noise issue--Pete

[neanderthal]

The first attempt today I unhooked everything except cables from the amps to the 4350's. FWIW the shield on all interconnects are unhooked on all inputs and connected on all outputs The Lows from Crown K2 to 2235's dead quiet both sides.

The high's from Pass Labs X150 to highs on 4350's quiet on left side and small amount of ground loop (Hum) on right side. When I said small amount of ground loop(hum) I have to be right up on the speaker (head real close) to hear it,still not right other side is dead quiet.

I went ahead and connected the bryston 10b and ground loop(hum) on right side was a little more pronounced and also noticable on left side now.I can now hear the ground loop(hum) standing 3ft away.I did try to connect the shield on both the inputs and the outputs at the same time,soldered it to the other tab in the XLR connector that looks like it will ground each connector to the chassis on both the 10B and the X150. No shield combination I tried effected it in any way.

I think til I get this delt with there isn't any sense connecting the White 4400's in the mix. I just don't understand why with just the cables connected to the 4350's to the amps and nothing else connected it had ground loop only on the right side from the X150 to the highs on the 4350's. I'm going to stop with this today and try to get another game plan.For now Iam out of ideas what to try next.

[macaroonie]

OK swap the power amps for now Pass to LF etc and try again. Yes I know its a PITA then connect the 10B annd then swap the bass o/p cables left -right see what happens. if the hummmmmmmmm moves then you have a cable issue if not you have a 10B issue

[Ken Pachkowsky]

Ok

Make sure everything is plugged in on the same circuit....its critical.

Be aware....as nice as the 4400's are they are prone to GL problems.....I have never had a silent pair yet.....at least 5 pairs.

Ken

[boputnam]

FWIW the shield on all interconnects are unhooked on all inputs and connected on all outputs

That is the way - with Pin1 disconnected at the inputs, not only does it break the chance of a GL, the interconnects also cannot deliver RF to the device.

The high's from Pass Labs X150 to highs on 4350's quiet on left side and small amount of ground loop (Hum) on right side.

Can you swap the PassLabs outputs, just for fun, and see if the GL follows the crossed outputs (shows up on L).

This I find MOST interesting:

The Lows from Crown K2 to 2235's dead quiet both sides.

GL are centered at 60Hz - you should hear this in the 2235's if it is indeed a "real" GL. I am beginning to suspect there is a Pass Labs problem.

I went ahead and connected the bryston 10b and ground loop(hum) on right side was a little more pronounced and also noticable on left side now.

IMO, this is merely an increase in the gain stage - it doesn't seem that the Bryston added anything except some gain.

No shield combination I tried effected it in any way.

Your Pin1 drops are fine. Do not try and reconnect Pin1.

I just don't understand why with just the cables connected to the 4350's to the amps and nothing else connected it had ground loop only on the right side from the X150 to the highs on the 4350's.

As I said, try swapping channels on the PassLabs and see if it follows the swap.

OK swap the power amps for now Pass to LF etc and try again.

Yes, I'd also do this, but after we determine if there is something amis with one side of the PassLabs X150.

[neanderthal]

That is the way - with Pin1 disconnected at the inputs, not only does it break the chance of a GL, the interconnects also cannot deliver RF to the device.

Can you swap the PassLabs outputs, just for fun, and see if the GL follows the crossed outputs (shows up on L).

This I find MOST interesting:
GL are centered at 60Hz - you should hear this in the 2235's if it is indeed a "real" GL. I am beginning to suspect there is a Pass Labs problem.

IMO, this is merely an increase in the gain stage - it doesn't seem that the Bryston added anything except some gain.

Your Pin1 drops are fine. Do not try and reconnect Pin1.

As I said, try swapping channels on the PassLabs and see if it follows the swap.

Yes, I'd also do this, but after we determine if there is something amis with one side of the PassLabs X150.

Thanks Bo...I'll jump on this tomorrow (tues.) night when I get home at more of a decent hour. Iam beat and am going to bed, Iam so tired I ache---Pete

[neanderthal]

I finally got a chance today to spend time on the ground loop after a relentless week. I got such a good deal on a balanced power conditioner I bought it and it is in the rack. I was curious as to what effect it was going to have, and I can't lose anything for the brother inlaw price I paid for it.

Before when I only had the amps and cables plugged in I had a small amount of hum out of one side of the Pass Labs X150 all of that is gone and it is dead quiet.

With the amps, bryston10B plugged in it is dead quiet. So I threw the White 4400's into the mix. One of the 4400's is dead quiet and the other one if you touch the middle of the RCA connector it induces a 5 second hum and then is quiet. Only one of the 4400's does this. Possible input transformer issue on one 4400?? It had this issue before I installed the Balanced power conditioner.

I swapped input cables to the 4400's and it did not help it. I swapped cables running to the 10b from the 4400's and the hum changed channels. I think I might have an issue with one of the 4400's.It doesn't matter what kind of grounding scheme I try it doesn't cure or effect it in any way.Other than that this system is as quiet as if the rack was unplugged from the wall.