[whopnyc]

Has anyone had any noise issues running an analog modded SB3 directly into an amp?  I have tried it with a pair of Quicksilver Mid Monos and a Rogue Stereo 90 and both exhibited noise problems through my Vandersteen 1C's.  The Rogue was louder than the QS and could easily be heard at the sitting position. The QS could  be heard when you walked within about 3 feet of the speakers.  The right channel is a hum while the left channel is more like white noise.  Turning the display off does nothing.  I have tested for ground issues and found nothing.  If I use an integrated, I have no problems unless I turn the volume of the integrated all the way up.  I even took it to a local store and tried the Rogue there with the same results.

I have spoken with Wayne extensively and have even sent it back to him for testing. Nothing is apparently wrong with it.  I have had multiple "experts" give me reasons why this sound may be occurring of which none are the same. Does anyone else have any ideas?

The gain of the Mid Monos is 24 db while the input sensitivity is 1.5 volts. The Rogue has an input sensitivity of 1 volt. I do not know the gain. Some have speculated that the low input sensitivities are issue. I'm at a loss and ready to move in a different direction if I can't figure this out.

Thanks.

[TomS]

I had hum problems with stock and modded SB3's direct to Joule VZN100 tube amplifiers which I assumed were due to the "floating" ground scheme the amps use.  Inserting the Joule LA150 preamp solved the problem. 

I've had no hum/noise problems direct to BEL mono's and Odyssey Extreme SE mono's, though I use the Burson buffer in between now.

[mgalusha]

You don't happen to be using powered subs that connect to the speaker outputs do you? I used to have a pair of Vandy subs and connecting them to the amps when using the SB would result in a hum. I determined the reason was that the subs were on a different circuit branch than my amps.

In my case I was able to correct this by running a piece of wire from the amp chassis to the negative speaker terminal. Note this was on a single ended SS amp and I knew for a fact that the input ground was tied to speaker ground. Unless you're certain of your amplifiers internal configuration I do not suggest doing this. Amps that operate in a bridge mode with floating grounds might be very unhappy about this.

If you are not running speaker level subs then ignore this.

You could try a pair of isolation transformers such as the Jensen ISO-MAX though they are expensive.

Mike

[whopnyc]

You don't happen to be using powered subs that connect to the speaker outputs do you? I used to have a pair of Vandy subs and connecting them to the amps when using the SB would result in a hum. I determined the reason was that the subs were on a different circuit branch than my amps.

In my case I was able to correct this by running a piece of wire from the amp chassis to the negative speaker terminal. Note this was on a single ended SS amp and I knew for a fact that the input ground was tied to speaker ground. Unless you're certain of your amplifiers internal configuration I do not suggest doing this. Amps that operate in a bridge mode with floating grounds might be very unhappy about this.

If you are not running speaker level subs then ignore this.

You could try a pair of isolation transformers such as the Jensen ISO-MAX though they are expensive.

Mike

I'm not running any subs. Thanks for the suggestion though.

[PeteG]

I had a lot of noise after my SB2 was modded.  I had to use the Ethernet hookup to eliminate it, the plus side was it also worked better and faster .

[TomS]

I had a lot of noise after my SB2 was modded.  I had to use the Ethernet hookup to eliminate it, the plus side was it also worked better and faster .

Yeah, I had the same thing on the modded version.  I could hear what sounded like buffering going on as data came in during quiet passages.  It was VERY faint, not a big deal, but I decided to go wired anyway and never looked back.

[whopnyc]

I've tried it wired directly to a PC and direct to a router with no luck eliminating the noise.  Anyone think one of these http://www.ebtechaudio.com/humxdes.html, an Ebtech Hum X, would do anything?

[bluewax]

Ah... edited to reflect that I didn't see that you had tried this fix...

I had a lot of noise after my SB2 was modded.  I had to use the Ethernet hookup to eliminate it, the plus side was it also worked better and faster .

[DSK]

With my Bolder modded SB2 used wirelessly and connected directly to an AKSA power amp, I would get a static-like crackle noise through the speakers every now and then. IIRC it was slightly louder in the right channel. It wasn't very loud and was only just loud enough and often enough for me to feel it was slightly annoying. Sound quality was very good and there was no hum. I don't know for sure that the SB2 was the cause of the noise as I hadn't tried any other sources in this system direct to the amp.

However, when I put back my modded AKSA GK-1 pre-amp between SB2 and AKSA amps, the noise totally disappeared and the sound quality was also much better (more dynamic and alive, quieter and more engaging). Even if there wasn't any noise when running direct to the amps, I wouldn't remove the pre-amp again.

[whopnyc]

With my Bolder modded SB2 used wirelessly and connected directly to an AKSA power amp, I would get a static-like crackle noise through the speakers every now and then. IIRC it was slightly louder in the right channel. It wasn't very loud and was only just loud enough and often enough for me to feel it was slightly annoying. Sound quality was very good and there was no hum. I don't know for sure that the SB2 was the cause of the noise as I hadn't tried any other sources in this system direct to the amp.

However, when I put back my modded AKSA GK-1 pre-amp between SB2 and AKSA amps, the noise totally disappeared and the sound quality was also much better (more dynamic and alive, quieter and more engaging). Even if there wasn't any noise when running direct to the amps, I wouldn't remove the pre-amp again.

I've heard this crackle before also.  It reminds me of the sound I hear through computer speakers or car speakers just before a cell phone rings.  My Blackberry can't be next to my computer speaker as it's constantly communicating.  The crackle is almost constant and very annoying. 

Since I know nothing about electronics, I don't understand how putting a preamp in between stops these noises.  I've noticed the same when using an integrated amp.  Doesn't this seem to mean the preamp isn't letting all the information through? How does the pre know which noise to filter out?

[DSK]

With my Bolder modded SB2 used wirelessly and connected directly to an AKSA power amp, I would get a static-like crackle noise through the speakers every now and then. IIRC it was slightly louder in the right channel. It wasn't very loud and was only just loud enough and often enough for me to feel it was slightly annoying. Sound quality was very good and there was no hum. I don't know for sure that the SB2 was the cause of the noise as I hadn't tried any other sources in this system direct to the amp.

However, when I put back my modded AKSA GK-1 pre-amp between SB2 and AKSA amps, the noise totally disappeared and the sound quality was also much better (more dynamic and alive, quieter and more engaging). Even if there wasn't any noise when running direct to the amps, I wouldn't remove the pre-amp again.

I've heard this crackle before also.  It reminds me of the sound I hear through computer speakers or car speakers just before a cell phone rings.  My Blackberry can't be next to my computer speaker as it's constantly communicating.  The crackle is almost constant and very annoying. 

Since I know nothing about electronics, I don't understand how putting a preamp in between stops these noises.  I've noticed the same when using an integrated amp.  Doesn't this seem to mean the preamp isn't letting all the information through? How does the pre know which noise to filter out?

I know the noise you mean from the mobile phone. This is different, it is much more subtle than that. It is like when you walk across a carpet, building up static in your body, then touch something metal
and there is that tsstssttststst noise as the static is discharged from your body.