My fit is totally shucked

Shizelbs

Oh man, I have the worst headache right now, and here is why...

First, my system consists of Pioneer DV 434 --> Dodd ELP --> Sunfire Symphonic Reference stereo amp --> Polk SDA SRS 2.

Power cables are Signal Cable magic power cords and all ICs are Signal Analog IIs.

Second, the Sunfire was recently taken to the Sunfire shop in Snohomish, WA, and given a clean bill of health.

My problems. 1) Loud **** hum. It is independent of the volume from the pre. It comes on once the pre is switched from mute to operate. Its annoying, but music seems to cover it up well, however I am concerned that the hum is mucking up the overall quality.
2) My new problem is this; the music is heavily favored to the right speaker. I always felt that prior to today, the sound, music, whatever was clearly, but only slightly biased to the right side. This was with everything I played. All discs. Now, the balance is clearly to the right. The left speaker is getting some sort of signal, but it is clearly, obviously getting a weak signal.

My hypothesis is that the problem lies with the Dodd ELP pre. Well, at least the balance problem. Lets forget the hum for now. I have switched between tubes, and that does not resolve the problem. Next I switch the ICs connecting to the back of my amp, so that the left channel is going into the right amp channel and visa versa. Make sense? This results in the left speaker being the predominant speaker, and the right being the little ****. Next I perform the same switch, but this time on the pre. Result: Right speaker good, left is the ****.

I have checked all connections to be tight. I have tried different power strips. I have switched out speaker cables, and double checked their connections.

I have not had any good results with this setup yet, but want to do everything I can before I throw in the towel, ditch tubes, and go back to 5.1 HT. My 2 channel is really pissing me off right now.

RuSsMaN

Do you have another set of tubes, or did you just swap the position of the tubes already there?

Shizelbs

My tube switch was with a totally, previously okay, set of Mullards. It was not just a switch of position with the same pair.

RuSsMaN

Call Gary, period. I'll help how I can from my end.

Shizelbs

Will do.

HBombToo

Originally posted by Shizelbs
Will do.

have you made any headway?

HBomb

Shizelbs

Okay, just got the pre back from Gary Dodd. He performed all of the upgrades to the pre and brough it up to date.

The hum is still audible when the volume is completely down. It is, however, much quieter. As in, tolerable. I think its a hum coming from the transformer in the amp. So, between the high gain of the pre, the general beefiness of the amp and the efficiency of my SDAs, I think the hum I am getting now is a pretty good trade off. I may purchase a much cheaper, lower power amp to swap out (and fuel the habit). I will get some good listening time in before much longer.

danger boy

sounds like something is causing the hum.. that much you know. and the amp is just doing what it's suppose to do. amplify. unfortunately, it's amplifing the hum.

I'd remove the Dodd from the mix... and use another pre/receiver, just so you can isolate the problem. That might give you the best idea where the hum is coming from. I hate hum.

Shizelbs

Well, since I got the pre back from being serviced, its much, much quieter. I think its coming from the amp, so that will be my next thing to switch out and isolate.

Shizelbs

Tonights the night I finally get to listen to my 7 month old rig in all its glory.

michael_w

Do you have a cable box or cable cable running anywhere near the 2 ch system? Disconnect it and see if anything changes...

Shizelbs

michael_w wrote:

Do you have a cable box or cable cable running anywhere near the 2 ch system? Disconnect it and see if anything changes...

I did try all that stuff. When I turn on a nearby light, the sound changes in the system. Let me tell you, the wiring at my apartment blows, thats for sure. But, yes, I did try disconnecting, pretty much the whole apartment, including EVERYTHING in that particular room.

Gary Dodd concurs with my theory that between the beefy amp, the high gain of the pre and the efficiency of the speakers, the remaining hum is just what I am going to have to live with.

shack

Shizelbs wrote:

Gary Dodd concurs with my theory that between the beefy amp, the high gain of the pre and the efficiency of the speakers, the remaining hum is just what I am going to have to live with.

yep...me too...

F1nut

You might want to check into getting one of these, http://www.psaudio.com/products/upchbmoreinfo.asp

shack

In my case I'm not sure that would help. I has to be between the amp and pre because I isolated everthing else.

michael_w

Would it help any to try and get the pre and amp as far away from each other as possible or is it an internal thing not interference roaming around?

Shizelbs

I did try all the quality power strips in the house. That changed nothing. I will be getting one once we move into the new house anyways though.

I did also try separating the pre amp the amp, physically from each other, as much as my ICs would allow. That also changed nothing.

Tried different power cords, ICs, music, sources, chairs, clothes, everything.

danger boy

sorry to hear you're running into such bad hum problem. you've put together a good 2 ch rig.. and then it hums. there must be some solution. something isn't right. what, i don't know. but a hum like that just doens't seem that common.

I sometimes get hiss coming from my system.. but a hum would mean something is interfering with something some place in the system. very odd.

your amp checked out ok, the Dodd has been ugraded, good high quailty IC's. how about your speaker wires?

How loud is the hum anyways?

Shizelbs

Its hardly noticeable now. You can only hear it, if you choose to listen for it, when nothing is playing.

W WALDECKER

sorry to hear about the hum issue,but maybe it does not originate from your pre amplifier. you may have some type of ground loop problem.i would like to help but i never ran into this problem before. maybe doro or russman could point you in the right direction.

Shizelbs

Its a hum coming from the amp. Its not a ground loop. You can hear the hum from the amp itself, even when its the only thing powered. You have to stick your ear up to it, but its there. Then, when the system as a whole is on, its manifested through the speakers.

F1nut

Transfomer hum, get the UPC-200 Humbuster or a new amp.

beardog03

my system does it also...
moreso with the Rotels...not as audible with the Parasound HCA-3500

I tried everything I could think of also....

may be the amp as you say....

Now my volume is making a scratchy sound when I turn the nobb with no music playing.
Maybe I will send the dodd in and have it upgraded as you did and see if that helps..

Shizelbs

F1nut wrote:

Transfomer hum, get the UPC-200 Humbuster or a new amp.

I'll probably do both. The humbuster before the other. Thanks for the rec'.

dorokusai

It's rare that you NEED a component to remove "hum" from your system.

It sounds like you have a transformer issue, and it's not rare. They by nature hum, every single one of them, it just depends on how they are wound and what board level component is receiving/amplifying the interference.

I'm happy to see a PSAudio product drop into the normal ppl bracket, as the rest of their gear is ridiculously overpriced. The UPC series is certainly worthwhile, if you subscribe to the idea. I 100% agree that simple protection is better than nothing.

Spike and/or surge protection should be first and foremost in the mind, the rest is smoke, application specific and garbage.

michael_w

Lemme know if you wanna get rid of your sunfire

W WALDECKER

if the hum is coming from the sunfire amplifier and is not just a faint noise emenating from the unit itself but is going thru your loudspeakers but sunfire says it checks out ok. i dont buy it! if a amp of that quality and cost is putting noise through your speakers besides music somethings wrong on thier end and they need to fix it!

danger boy

W WALDECKER wrote:

if the hum is coming from the sunfire amplifier and is not just a faint noise emenating from the unit itself but is going thru your loudspeakers but sunfire says it checks out ok. i dont buy it! if a amp of that quality and cost is putting noise through your speakers besides music somethings wrong on thier end and they need to fix it!

i agree. do you have another amp to swap it out with?

Shizelbs

Not at the moment, no.

BobMcG

With the rest of the system off, transformer hum can run the range of being barely audible with your ear right on top of it to audible from a distance. Some amps have their own grounding switches incorporated into them that allows you to choose between two settings. You may not have an excessive hum problem in either setting but if you have fairly audible hum in one setting you can flick the switch and eliminate the hum. I'm guessing the Sunfire doesn't allow for this.
That aside, you don't seem to have an overwhelming hum problem anyways until the "system" is on. Maybe your amp and preamp just don't work and play well together. (Lack of synergy there?) Can you swap out the preamp just for a quick test to see if the amp hum is still getting magnified? What were you using before the ELP?

IMO, If Gary cleared the ELP for take off you can bet it's ok. On the other hand if Sunfire cleared the amp, it may just happen to fall within their accepted specs perhaps even barely so gets an ok from them. (A transformer is a VERY expensive item to just swap out.) Either way none of this means the two will get along.

BTW: The SOUND changes when you throw a light switch???? :eek: That's not a good sign!

ND13

I got my Dodd ELP yesterday and hooked it up and I get a slight hum thru the speakers also. But it's only when you take the pre out of standy mode and it is slight and does not affect the sound quality once the music starts. Actually< I can only hear it when close to the speakers, not when in my normal listening position(SDA sweetspot) . So I'd have to say it's just a minute consequence of tube gear. I don't plan on getting rid of the Dodd anytime in my near future, the sweet sound is worth a little hum, don't you agree???