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Problems using my ARC Balanced Line Driver w/ Maidstone

 
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O'Shag
Intermediate Contributor 50+


Joined: 28 Feb 2008
Posts: 69
Location: City of The Angels

PostPosted: Tue Apr 08, 2008 12:13 am    Post subject: Problems using my ARC Balanced Line Driver w/ Maidstone Reply with quote

This question regards my system configuration. Because my MFA preamp does not have balanced drive output ( it has single-ended rca connectors only), and my amps have just balanced 'inputs' w/XLR connectors (my Mark Levinson amps also have CAMAC connectors that I've never tried), an Audio Research BL1 active balanced line driver/converter has been used to convert the non-balanced signal to a true balanced signal. I assume (but am not sure) that this is more 'correct' given that using an rca/xlr adapter on each cable does not convert the signal to true balanced with appropriate voltage gain.

I've not really noticed noise before when using the Monitor Audio Gold Reference 60s with the BL1 in circuit, but when using the Maidstone I hear distortion when I put my ear reasonably close to the drivers. There is a faint but persistent buzzing sound evident during the quiet between pieces of music.

When I substitute regular adapters for the balanced line driver, the signal is more transparent and clear without noise. I understand that the signal is much shorter ie you don't need two cables when using adapters, but why would I hear the distortion and buzzing when using the Maidstone, which is not so noticable when using the the Monitor Audios? I can't think how grounding issues could affect the Maidstone but I'm not sure. My only concern with removing the balanced line converter (active) from circuit is that the signal itself will not be truly balanced going into the amps. Could this have a negative effect on the amps over the long haul? The Maidstone sounds exceptionally clear and defined without the balanced line driver, and I'm tempted to remove it altogether. Any feedback or experience as such is very much appreciated.
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O'Shag
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Joined: 28 Feb 2008
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Location: City of The Angels

PostPosted: Wed Apr 09, 2008 4:05 am    Post subject: Reply with quote

Hi Sound59,

Thanks much for the sound advice Very Happy I now feel more comfortable about removing the balanced line driver from the system. I suspect that the transformer in the BL1 may have been noisy. There is a marked difference in performance with the unit removed, and they buzzing noise has disappeared. Given your professional studio experience, perhaps you've experienced transformers getting noisy over time? I ask, because I have two Tice Powerblocks/Titan power conditioning and energy storage systems. If you are not familiar with these units, they have a large transformer, and even when new, a small amount of buzzing was unavoidable (according to the manufacturer). These units are from the 90s so are getting on. They do an admirable job subjectively speaking, but have become noisy, where the buzz is somewhat intrusive during quiet passages. I did replace the insulated rubber mounts that support the transformer (which is heavy) as the older ones had long given up the ghost, but it doesn't seem to have lessened the buzzing. Do you know of any way to reduce buzzing in an older transformer, or is this inevitable with older transformers? It could also possibly be some wiring. I noticed that the insulation has worn off some of the wire inside with bare copper showing.

Do you have a home system setup besides the studio?

Many thanks again for your very helpful advice Sound59.
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O'Shag
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Location: City of The Angels

PostPosted: Thu Apr 10, 2008 11:25 pm    Post subject: Reply with quote

Hi again Sound59. Its great that you've worked as a sound engineer at the BBC. Not too many can say they've done that. Your use of the BBC monitors at home is understandable. All of the LS3/5a type speakers I've heard have been unfailingly faithful and musical to listen too. Never heard the Quad amps.

I've been in a couple of bands myself, and it was great fun. Was recruited by the last group of ne'r-do-wells more than 12 years ago, when a few of the members happened to be perusing through Guitar Center and heard me tinkling away (badly) on the keyboard. For a while, I was the token English guy in the band, which I believe they felt help 'pull the birds'. Also, I'm not what you would call very talented, but was as good as any of those guys. I guess we were reasonably entertaining to listen to at small gigs. I also have played rhythm guitar with a rock band, and a blues band (enjoyed that). Nowadays, I don't get the time unfortunately, but I do miss it. I make up for it by going to live gigs in some venues here in Los Angeles when I get the chance.

Your point about the use of very long runs of good but not 'audiophile quality' cable when recording at the studios does make a lot of sense. I am inclined to believe that most of the 'super' cabling in the consumer audio industry is, to a large extent, hyped up by marketing and Speaker Guru confirmed this. But there are a few exceptions I feel. Transparent cables, sound full-bodied and 'there' primarily because they have the weight for lower-mid and low frequencies. I did discover that the Maidstone uses Van Damme Total Definition Ultra Pure OFC from the terminals to the crossover and from there to the upper terminals on the bass module. As standard, the jumpers included are also by Van Damme. Food for thought really, because I find myself wondering how much a difference using Transparents will make when they have to go through the Van Damme cable in the speakers.

Van Damme, an English company, is not 'audiophoole' at all and instead caters almost exclusively to the professional industry. Have you had experience with Van Damme?

Thanks again for taking the time to advise.
Cheers mate
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Laemmle
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Joined: 11 Apr 2008
Posts: 22

PostPosted: Fri Apr 11, 2008 9:37 pm    Post subject: Balanced KUBE 107's Reply with quote

I run a full balanced system.

Driving my 107's are a ARC SP-15 and a McIntosh MC252....in between these two is a KEF Pro KUBE ...fully balanced....fantastic! Had George Kaye change all the op-amps and replace with high end examples....this is the way to go.....
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O'Shag
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PostPosted: Sat Apr 12, 2008 8:21 pm    Post subject: Reply with quote

I love the ARC SP15, and may get one at some point. It was the matching preamp designed for my Classic 150, and I'm sure there is a strong synergy there, plus it allows for balanced in and out. A requirement I have is that there be two main outs to accomodate biamping, and thats the only drawback of the SP15 as there is only one balanced out. Some would prefer the SP10 or SP11 - not me.

KEF pro KUBE? Never heard of a balanced kube before. Was it modified to be balanced or balanced as stock? I'd like to find one, and upgrade my KUBE. I have a soft spot for the 107. Thats why I never sold mine. But I'd like to get into a pro kube as you describe. Please advise.
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O'Shag
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PostPosted: Sat Apr 12, 2008 8:57 pm    Post subject: Reply with quote

Actually Laemmle I just read your introductory post, and my question regarding the KUBE is answered. So George Kaye can do this? Does it improve the overall performance of the 107 and in what respects?
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Laemmle
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PostPosted: Sat Apr 12, 2008 9:55 pm    Post subject: Reply with quote

O''blocked word',

The 150's are great amps....albeit MONSTERS! I had both e 120's and V140's before moving to my McIntosh Mc252.

Some info for you from ARC SP-15 owners manual.

"There are two (2) sets of output connectors which are connected internally in parallel. One set should be connected to your electronic crossover or power amplifier. The additional set is provided for connection to an additional amplifier for remote or background use, or for bi-wire amp systems (where separate power amplifiers are used for bass and treble, but no electronic crossover is used).

Direct Output Connector:

"Provides the most direct signal path by feeding the signal directly from the SP15's output stage, thus bypassing phase inverting circuitry and phase inverting switch. Provides the highest possible signal output quality, but with less total system control flexibility".

Balanced Output Connectors:

"For those who want to operate their preamplifier and power amp in "balanced" mode.

The balanced KUBE was called a professional KUBE by KEF....it is fully balanced in and out. Andrew Jones told me one was working at Abbey Road Studios for EMI. If you want I can dig out the invoice and get the KEF original part number.

Whe the KUBE died, George Kaye replaced all the OEM op-amps with top of the line examples.

What can I say......I am still in love with the reproduction I get from this system.....I would have to be Richard Branson or have his money to make me look for something "greater".





O''blocked word' wrote:
I love the ARC SP15, and may get one at some point. It was the matching preamp designed for my Classic 150, and I'm sure there is a strong synergy there, plus it allows for balanced in and out. A requirement I have is that there be two main outs to accommodate bi-amping, and thats the only drawback of the SP15 as there is only one balanced out. Some would prefer the SP10 or SP11 - not me.

KEF pro KUBE? Never heard of a balanced kube before. Was it modified to be balanced or balanced as stock? I'd like to find one, and upgrade my KUBE. I have a soft spot for the 107. Thats why I never sold mine. But I'd like to get into a pro kube as you describe. Please advise.
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Parts
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Joined: 13 Jan 2006
Posts: 176
Location: Edinburgh

PostPosted: Sun Apr 13, 2008 3:52 am    Post subject: Reply with quote

Laemmle,

Information, documents, user manuals, and decent pictures of the Kef Pro Kube with XLR are rare over here. I myself have still never seen one in the flesh, nor found any literature.

I have been after one for a some time too.

I do remember it being mentioned when I bought my Kef back in the early 90's, and I am sure someone mentioned it having more adjustment? And being slightly larger?

Steve
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Laemmle
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Joined: 11 Apr 2008
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PostPosted: Sun Apr 13, 2008 4:41 am    Post subject: Reply with quote

The pro KUBE has three toggle switches, one for contour, one for LF extension, and one to run the system sans equalization.

Size:
8" deep
17" wide
2" high.

Front comes off to gain access to the toggle switches.


quote="Parts"]Laemmle,

Information, documents, user manuals, and decent pictures of the Kef Pro Kube with XLR are rare over here. I myself have still never seen one in the flesh, nor found any literature.

I have been after one for a some time too.

I do remember it being mentioned when I bought my Kef back in the early 90's, and I am sure someone mentioned it having more adjustment? And being slightly larger?

Steve[/quote]
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Parts
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Joined: 13 Jan 2006
Posts: 176
Location: Edinburgh

PostPosted: Sun Apr 13, 2008 11:21 am    Post subject: Reply with quote

Laemmle wrote:
The pro KUBE has three toggle switches, one for contour, one for LF extension, and one to run the system sans equalization.

Size:
8" deep
17" wide
2" high.

Front comes off to gain access to the toggle switches.


I would love some glossy big pictures of this, I have never seen one!

I post pics using Photo Bucket, here's one of my Kef R107.
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proffski
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Joined: 22 Aug 2003
Posts: 1297
Location: Tewkesbury UK

PostPosted: Sun Apr 13, 2008 11:31 am    Post subject: Reply with quote

GORGEOUS!!!
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Laemmle
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PostPosted: Sun Apr 13, 2008 4:34 pm    Post subject: Reply with quote

Steve,

Send me your e-mail(pm) and I will attach photos for you...I think this will be easier for me.

L
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