Quiet Solid State Amplifier Recommendations

[boputnam]

Interesting...

1) Are all the components into the same AC outlet (same AC ground path)? Guessing they are.

2) The XR4001 is the only balanced component, correct? If so, all other components are finding an additional AC ground through the XR4001.

My grab is you are going to need an isolation transformer before the XR4001, between the DB-1A and the XR4001. Try that Radio Shack thingy first, before spending a lot of money - it should show if the diagnosis is on-track.

[trekman]

There is no other way besides a transformer? I would rather not get involved with those in the signal path. Nothing can be done using xlr to 1/4 and wiring it a certain way?

[boputnam]

Not that I'm aware of.
I - at one time... - tried all the possible wiring configurations myself. Futile, and I solder good!

The isolation transformer worked excellent for me on my unbalanced preamp. You will notice almost no signal loss, nor decrease in S/N ratio.

One day I realized I had something like three of them dangling off the preamp, between almost every component! That's when I finally admitted to myself that the preamp really was the issue, for me, since everything else downstream (and some components upstream...) were balanced.

Out went that preamp and in came the Adcom GFP-750, and Dixie Bell!! problem solved.

Now I have quite a cache of unused isolation transformers!

[trekman]

Will the balanced preamp need balanced sources such as Tuner, cassette, etc.? Thanks.

[JuniorJBL]

Unplug EVERYTHING from that circuit. Make sure you are not on a GFI circuit as well. Then plug only your stereo equipment in. It is also best to make sure that your circuit that you are using does not have any lights on it. You want to have only one point of ground to eliminate ground loops. If you have some bad outlets you can also get ground loops.

If you plug all your equipment in and you still have noise then you have a problem with your equipment (if you have determined your circuit is good). Then you need to do Bo's troubleshooting tip's (BTT).


I have a mix of balanced and single-ended equipment and there is no noise in my system. alot of times I have found the circuit that people use has their fridge on it and that just creates havoc with audio equipment. A light will always feedback to the neutral from the hot side as well. I hope this helps

[boputnam]

Will the balanced preamp need balanced sources such as Tuner, cassette, etc.? Thanks.

[Mike Caldwell]

Hello
When you refer to "noise" with the Ashly hooked up is it in the form
of hum or hiss, static, white nosie ect. The type of noise can point to
different problems.

Mike Caldwell

[Ken Pachkowsky]

Now I have quite a cache of unused isolation transformers!

%^%$, I thought maybe I could sell you some...

Ken

[trekman]

Hello
When you refer to "noise" with the Ashly hooked up is it in the form
of hum or hiss, static, white nosie ect. The type of noise can point to
different problems.

Mike Caldwell

Hi Mike.
A little hiss, which seems normal for compression drivers.
The woofers have a grainy hum, perhaps centered at 240hz or lower, but not bassey sounding. Thanks, Malcolm

[trekman]

..... Unless your adaptor had the RCA connector insulated from the rest of the XLR connector body it will connect the signal ground to the chassie ground on the XLR equipment that you plug it in to. Most pro audio equipment has the chassie ground isolated from the audio signal ground and or has a switch or a jumper to remove to help in ground hum isolation........
Mike Caldwell

Progress so far is leaning towards Bo's isolation transformer. The Klark doesn't seem to be the problem. Unbalanced preamp seems to be the source. With a balanced amp and the preamp disconnected noise is very low. With unbalanced amp noise is higher, ac adaptor inplace reduces it.

I thought perhaps using the +- on TRS plug (and no ground), too standard 1/4 on other end might do something, but much worse, and made the fault lights come on on the Phase A60 when ac adaptor used.

So last attempt before radioshack transformers...

My RCA to XLR does connect rca sleeve to the xlr sleeve. But I can pull the guts out and resolder. That leaves the 3 pin holder with or with out sleeve on one end, and rca female on other. How do I wire for the Klark? Thanks, Malcolm

[johnaec]

Trekman - you may find this link informative: http://www.rane.com/note110.html

John

[boputnam]

Progress so far is leaning towards Bo's isolation transformer.

At least we know that will work.

ac adaptor inplace reduces it.

:shock:

My RCA to XLR does connect rca sleeve to the xlr sleeve. But I can pull the guts out and resolder. That leaves the 3 pin holder with or with out sleeve on one end, and rca female on other. How do I wire for the Klark?

If I understand ("3 pin holder"...? = XLR male), you should disconnect Pin1 (shield) at the Klark end of the interconnect. But, I expect this might howl, too.

Thanks for the updates. Now, get that "ac adaptor" into the trash...

[trekman]

Thanks everyone for the good advice. In the end I probably should have done more online research and could have spare you guys the effort.... I wasn't expecting the balanced verse consumer interface to be such a problem. Lifting pin one on the rca/xlr adaptor did nothing by the way. The balancing transformer seems to help a little more. Thanks again, Malcolm

[Charlie4350]

Trekman, I used to run a thin wire from the chassis of my crossover to chassis of the preamp before my system was fully balanced. It reduced hum/noise significantly. I had the crossove sitting on the preamp and if they weren't making contact just right, major hum. Finally I figured out to run a wire and no more problems. At the time it was Hafler 110 preamp (unbalanced) 5234, and my brandy new QSC EX amps (balanced).

[boputnam]

....I wasn't expecting the balanced verse consumer interface to be such a problem.

You are only the most recent to admit to falling into this snake pit. It is very difficult to overcome.

In the end, a balanced preamp may be your most satifsying solution - and in my case, revealed an enormous (read: stunning) improvement in audio quality. I was quite ignorant of what I was missing.