Need a little advice on some AR Mono Block Amplifiers...and Speaker wires

[Bucknekked]

This is quite the story!

I initially dismissed your friend's cable assertion until I read further and got to the magic mystery boxes. I actually wouldn't rule them out, tho the low impedance Wilsons are definitely not good speakers for tube amplification. It just amazes me that someone can spend so much money on this stuff and still not have a reliable system. There are better, more obvious solutions here, but no... "Let's get the fancy MITs with the mystery boxes on them. That'll make everything better!".

Good luck Jim. Don't try to fight it. It hurts less if you just go with it...

@Pogre
Reading through this thread i run up against many of the same conclusions as y'all did. It does amaze me as well that someone can spend this kind of money and end up with a system that's unreliable. I suppose it violates one of my basic policies on audio : Don't upgrade unless you are very sure what you're doing is an actual, audible upgrade. Otherwise, you're gonna spend money, time and frustration to get less than what you had before.

The cable stuff (the magical mystery boxes) has been hashed around so much I hate to even give it a mention. Suffice it to say, as @TLS Guy said, replace that stuff with hangers or zip cord and you'd be better off. I understand the audiophile need for fancy looking cables. It is visible evidence that the audiophile is indeed an audiophile and not just someone who likes music. I don't agree with it, but, I at least understand the tug that fancy shmansy cables have on some folks.

Its also incredibly hard to help someone else with a problem like this. The solution may be obvious, but, to get someone else to agree and recognize it is almost a fools errand. Getting someone to change a behavior is one of the most difficult things one human can ask another to do. I applaud the effort. I hope the OP can have some success.

 

[-Jim-]

Gents,

I appreciate the replies. My friend is typically very intelligent and quite gifted. He had an exceptional career in business, first as a Mechanical Engineer, and later as a partner in an Engineering & Development firm (with 2 others) that had over 550 employees at it's peak. This is the only thing where he's stumbled badly in the 20 years I've known him, and he keeps looking at it with rose colored glasses. As you can probably guess, he's very "comfortable" and could easily afford to scrap this equipment and go in another direction. Personally, when he first told me about one of the earlier AR Amp failures, I tried to convince him to move to a Solid State Amp, and you'd have though I just cussed out the Virgin Mary to the Pope. He thinks Solid State Amps are no where near as good sounding as Tube Type equipment.

He has an early (no HDMI) McIntosh Solid State Home Theater Receiver in his basement Pool Table Room which he thinks (thought?) is terrible. Some years ago he offered to give it to me before I set it up correctly, and got HD from his Satellite Dish into his Panasonic Plasma TV. (Before it was not in 5.1 and 480i) He watches it frequently with his wife, and seems quite satisfied with it now.

I'll go over next week and try to get this sorted. I know we can replace the Speaker Cables easily but we'll have to order Balanced Cables for the Amp /Pre-Amp interconnects. I noticed in the manual I downloaded for the AR REF600 Amp that there are different output terminals for 16, 8, and 4 Ohm Speakers. I'm wondering what the impact is if I shift from the 8 ohm terminals (where I suspect they are connected) to the 4 ohm?

By the way, the manual AR REF600 also recommends "for best results" one uses Audio Research LitzLink 2 interconnects and LitzLine speaker cables . Both of these are just a bit "beefy" standard cables. The interconnects are also available as RCA type. NO fancy boxes in the middle of these cables.

I tried to check what speaker cable is recommended by the OEM for the Wilson Maxx Speakers but those pages are missing from the only manual I could find on line - even though it's 62 pages long!

I'll report back on any progress I make.

 

[Pogre]

He has an early (no HDMI) McIntosh Solid State Home Theater Receiver in his basement Pool Table Room which he thinks (thought?) is terrible.

Tell him you know this guy named "Pogre" who would happily take that horrible sounding gear off his hands...

 

[Mikado463]

Gents,

I appreciate the replies. My friend is typically very intelligent and quite gifted. He had an exceptional career in business, first as a Mechanical Engineer, and later as a partner in an Engineering & Development firm (with 2 others) that had over 550 employees at it's peak. This is the only thing where he's stumbled badly in the 20 years I've known him, and he keeps looking at it with rose colored glasses. As you can probably guess, he's very "comfortable" and could easily afford to scrap this equipment and go in another direction. Personally, when he first told me about one of the earlier AR Amp failures, I tried to convince him to move to a Solid State Amp, and you'd have though I just cussed out the Virgin Mary to the Pope. He thinks Solid State Amps are no where near as good sounding as Tube Type equipment.

He has an early (no HDMI) McIntosh Solid State Home Theater Receiver in his basement Pool Table Room which he thinks (thought?) is terrible. Some years ago he offered to give it to me before I set it up correctly, and got HD from his Satellite Dish into his Panasonic Plasma TV. (Before it was not in 5.1 and 480i) He watches it frequently with his wife, and seems quite satisfied with it now.

I'll go over next week and try to get this sorted. I know we can replace the Speaker Cables easily but we'll have to order Balanced Cables for the Amp /Pre-Amp interconnects. I noticed in the manual I downloaded for the AR REF600 Amp that there are different output terminals for 16, 8, and 4 Ohm Speakers. I'm wondering what the impact is if I shift from the 8 ohm terminals (where I suspect they are connected) to the 4 ohm?

By the way, the manual AR REF600 also recommends "for best results" one uses Audio Research LitzLink 2 interconnects and LitzLine speaker cables . Both of these are just a bit "beefy" standard cables. The interconnects are also available as RCA type. NO fancy boxes in the middle of these cables.

I tried to check what speaker cable is recommended by the OEM for the Wilson Maxx Speakers but those pages are missing from the only manual I could find on line - even though it's 62 pages long!

I'll report back on any progress I make.

get some XLR IC's from Blue Jeans cable and while you're at it speaker cable as well. use the 4 ohm taps and give it a go !!

 

[highfigh]

Someone needs to test the equipment, rather than make feeble attempts to solve the problem without looking at the whole system at the same time. I would start by measuring the impedance of the speakers with and without the cables. If a difference is seen which could cause the problems in the amplifier, change the speaker cables and test it again. If it still looks like crap, try using different speakers.

I don't remember seeing any mention of the components that were replaced in the amplifier- I would like to see that list. If it's the same parts every time, it would verify my recommendation in the first paragraph because using the other amplifier risks damaging that and repeating the exercise in futility.

Seeing a recommendation for cable by a speaker designer raises a giant red flag, for me. Two steps needed for any audio system WRT speaker cable:

1) Buy some cable of adequate length and gauge
2) Connect it to the amplifiers and speakers.

 

[Mikado463]

Someone needs to test the equipment, rather than make feeble attempts to solve the problem without looking at the whole system at the same time. I would start by measuring the impedance of the speakers with and without the cables. If a difference is seen which could cause the problems in the amplifier, change the speaker cables and test it again. If it still looks like crap, try using different speakers.

I don't remember seeing any mention of the components that were replaced in the amplifier- I would like to see that list. If it's the same parts every time, it would verify my recommendation in the first paragraph because using the other amplifier risks damaging that and repeating the exercise in futility.

Seeing a recommendation for cable by a speaker designer raises a giant red flag, for me. Two steps needed for any audio system WRT speaker cable:

1) Buy some cable of adequate length and gauge
2) Connect it to the amplifiers and speakers.

keep in mind that while most speakers talked about on this forum are of a reactive nature, stats on the other hand provide a capacitive challenge and as such that should be taken into account with speaker wire, especially if long lengths are involved.

if memory serves me right I think Spectral amps all but insist the use of MIT cabling, forgot the reason, have to look it up ..........

 

[Pogre]

not true for all Wilson's, I've heard Sasha II's being driven by a pair of Rogue Audio Apollo's that where simply amazing. Granted they're a nominal 4 ohm speaker but with relative good sensitivity.



yeah........ just like some car brands !

I never said it was true for all Wilsons, but for the speakers being discussed it is.

If one is going to insist on using tube amplification, then the next logical step would be to identify speakers that will play well with it. I'm sure there are plenty of other stupid expensive esoteric speakers out there that would work better. From what you're telling me he could have even chosen a different Wilson.

 

[Mikado463]

I never said it was true for all Wilsons, but for the speakers being discussed it is.

If one is going to insist on using tube amplification, then the next logical step would be to identify speakers that will play well with it. I'm sure there are plenty of other stupid expensive esoteric speakers out there that would work better. From what you're telling me he could have even chosen a different Wilson.

Wilson has gone through quite a few changes since the ones in discussion here were introduced. Present day offerings are far more 'amp friendly'.

As for the MIT cables, they are more than just 'speaker cables' , rather a network device within a speaker cable. far more complication than should be IMO

 

[Swerd]

I appreciate the replies. My friend is typically very intelligent and quite gifted. He had an exceptional career in business, first as a Mechanical Engineer, and later as a partner in an Engineering & Development firm (with 2 others) that had over 550 employees at it's peak. This is the only thing where he's stumbled badly in the 20 years I've known him, and he keeps looking at it with rose colored glasses. As you can probably guess, he's very "comfortable" and could easily afford to scrap this equipment and go in another direction. Personally, when he first told me about one of the earlier AR Amp failures, I tried to convince him to move to a Solid State Amp, and you'd have though I just cussed out the Virgin Mary to the Pope. He thinks Solid State Amps are no where near as good sounding as Tube Type equipment.

I'll go over next week and try to get this sorted. I know we can replace the Speaker Cables easily but we'll have to order Balanced Cables for the Amp /Pre-Amp interconnects. I noticed in the manual I downloaded for the AR REF600 Amp that there are different output terminals for 16, 8, and 4 Ohm Speakers. I'm wondering what the impact is if I shift from the 8 ohm terminals (where I suspect they are connected) to the 4 ohm?

I'll report back on any progress I make.

Your friend who owns those speakers and frequently repaired tube amp must be a very good friend. But it seems he won't listen to anyone. Perhaps the next time his amp blows up (and it will), you should privately communicate with the repair shop. Send them this impedance curve and ask them if they believe a loudspeaker with such impedance properties could be the reason for the frequent amp failures. I agree with TLS Guy that the very low impedance magnitude, and the extremes in impedance phase angles are probably the main reason for the repeated amp failures.

I looked up the review in Stereophile to get it's link, and to see what text may accompany the impedance figures. I learned that there are three versions of the Wilson MAXX speaker, all of which were reviewed and measured. Each version has different looking impedance curves.

Do you know which version MAXX your friend has? Whichever version he has, I urge you to read the Measurements sections of the reviews and see just how amplifier unfriendly these speakers are. If your friend has the original MAXX version, I would say dangerous instead of unfriendly.

Wilson MAXX, reviewed May 11, 1999

Text accompanying Figure 1 for the 1999 review of the MAXX:

A health warning accompanies the higher-than-usual sensitivity: namely, the measurably difficult, amplifier-taxing load impedance. With some precision I got a minimum value of 2.2 ohms in the near-peak spectral power band of the lower midrange (fig.1). In contrast to the rather amplifier-friendly SLAMM and WITT, this more or less rules out tubed amplifiers.

In theory, even a 4 ohm load should not fall below 3.2 ohms, and although the MAXX's rear-panel label does admit to a "4 ohm" load impedance, one could legitimately call this speaker a 3 ohm load. In this light the sensitivity doesn't look so good; the true output for a real, as opposed to a "8 ohm" watt, is in fact closer to 87-88dB.

The load variation will certainly stretch the weaker amplifiers, while good, low-resistance speaker cable will also form a necessary part of the investment. Given the price of the speaker, most sensible, appropriate solid-state amplifier choices, from Mark Levinson to Krell, will have sufficient current capability—though I sometimes feel that even these hearty beasts can sound still lighter on their feet when stressed less heavily than this.

John Atkinson, who did all of Stereophile's measurements, was always very gentle with his words if he criticized a speaker. Those words (above) are the worst sounding of his I've ever read.

Wilson MAXX2, reviewed August 14, 2005

The MAXX2's impedance still looks unusually ragged, and dips very low between 200 and 300 Hz, but it's extremely wide phase angle variations at 6kHz and higher are much improved over the first MAXX version. Atkinson's accompanying text:

My estimate of the Wilson's voltage sensitivity was significantly higher than average, at 89.7dB(B)/2.83V/m, but not as high as the specified 92dB figure. The speaker's impedance (fig.1) reveals it to be a demanding load for the partnering amplifier, with a value ranging from 4 to 6 ohms for most of the audioband and dropping to a minimum of 2.25 ohms at 240Hz. The combination of 3.8 ohms and a 33.4º capacitive phase angle at 162Hz, a frequency where music has considerable energy, will also demand an amplifier that can source a good amount of current, as MF found in his auditioning.

Wilson MAXX3, reviewed September 14, 2009

The MAXX3's impedance doesn't look much different or better than the MAXX2. Atkinson's accompanying text:

At an estimated 89.6dB(B)/2.83V/m, the MAXX 3 has the same sensitivity as the MAXX Series 2, and is within experimental error of the specified 90dB. The impedance (fig.1) is broadly similar to that of the MAXX 2; however, with a minimum value of 3.4 rather than 2.25 ohms, and a less extreme electrical phase angle, the MAXX 3 will be significantly easier to drive.

 

[-Jim-]

Gents, thanks for the recent comments and suggestions. My friend is a very good friend, so I will continue to try to support him. I'm pretty certain these are the first generation Maxx Speakers; which have the saddest measurements. I will confirm next week.

The suggestions for "someone" (which of course seems to mean me) to test the equipment is interesting, but of course I lack the necessary test gear, and procedures to do so. I have little doubt the equipment has aged, and perhaps the cross overs in the Wilson's is not what they once were, and the AR equipment probably has drifted well off spec. But the focus here is to not have another Amplifier failure, and not really about the sound quality the equipment now produces.

I mucked about with Tubes decades ago just for grins to learn how they functioned (my Dad was an Electrical Engineer, and had lots of cool gear => scopes, frequency generators, meters, etc., , which he showed me and my brothers how to operate); and even though I have Electrical Technician level training (in addition to being a Licensed Electrician), I have not worked in that field in 25+ years. I limit my hands on board level gear repair to simple things, like building and repairing computers for close friends and family. (I recently built a new Boat Computer for my friend's 42 foot Cabo, which I have been on many week-long fishing trips over the years in the Pacific Northwest.)

I am strangely fascinated by what's inside the MIT cable boxes and what the circuitry looks like. The photos I've been able to see have all the components "potted" to hide what exactly is going on, and even obscure what's there. Somewhere someone must have posted what's really going on inside these Boxes. If you find it, please share the Link.

 

[Trell]

Good start here at AH.
Cable haters? Not hardly. We love cables. I have cables.
What we don't like are the peddlers of snake oil claims, got it?

Cables of various types is an eternal subject that never gets old, as @NINaudio kindly reminds us of

 

[Pogre]

Cables of various types is an eternal subject that never gets old, as @NINaudio kindly reminds us of

Wow. The person @mtrycrafts quoted is the (banned) idiot who gave me my first bunch of "dumb" reactions...

 

[NINaudio]

Cables of various types is an eternal subject that never gets old, as @NINaudio kindly reminds us of

Wait, what!? What'd I do? How'd I get dragged into this thread too?

 

[NINaudio]

Wow. The person @mtrycrafts quoted is the (banned) idiot who gave me my first bunch of "dumb" reactions...

You have subsequent bunches? ALL of mine are from one member.

 

[Pogre]

You have subsequent bunches? ALL of mine are from one member.

Mine are almost all from 2 members. One bunch is recent, a dickhead who assumed I rated his post dumb so he went through the whole thread and marked all of mine dumb! Then he realized it wasn't me, apologized and never fixed it!

I have ONE that boredsystem gave me, and I have to admit, it was a pretty dumb post so I couldn't even get upset about it, lol. Iirc it was something about rolling boogers and flicking them... slightly off topic too...

 

[Pogre]

But hey, I wear my dumb ratings like a badge of honor. If that's what they had to resort to then in my mind I won! Dumb ratings from dumb people don't bother me.

 

[highfigh]

keep in mind that while most speakers talked about on this forum are of a reactive nature, stats on the other hand provide a capacitive challenge and as such that should be taken into account with speaker wire, especially if long lengths are involved.

if memory serves me right I think Spectral amps all but insist the use of MIT cabling, forgot the reason, have to look it up ..........

Check the MIT site and you may find that they recommend Spectral amplifiers. Not much happens without reciprocity.

 

[-Jim-]

Hi Gents,

You won't believe this but my friend just came back to me, and asked me to help him replace the MIT Cables, as he desperately wants to avoid another AR amplifier failure. He never hooked the system up after he got the repaired AR Amp back, as he pondered what to do next. He said that 90+% of the time the failures occur when he is playing vinyl, so to start (as a bit of a compromise I thought) I suggested we replace those MIT cables in that pathway first (he initially wanted me to just do them all). All of his interconnects are MIT and have boxes on them - some have 2 boxes on each end!

When I arrived at his house he had already disconnected the Speaker Cables and replaced them with a very decent pair he already had in hand. So we are looking for some Interconnects. The first is a pair of 30 foot balanced interconnect cables from the pre- amp to each power amplifier. Next is a 3 foot (yes 36 inch) pair with RCA jacks for the phono cartridge to phono RIAA pre-amp. The MIT RCA Cables installed had a very interesting clamping collar on the RCA connectors. (I've never seen them before, but they were impressive.) He also wants an 80 inch pair of Balanced Cables from Mark Levinson CD Digital Processor to the Pre-Amp.

Swerd, these are the first generation of Wilson Maxx speakers. Sorry if I didn't confirm this earlier. Today I again advised my friend that if the cables are not the problem, it's probably the impedance mismatch between the AR Amps and the Speakers. (I sent him a link to the Stereophile's Review and a copy of the impedance graph ages ago.) He said he doesn't think that's the case, as he had no issues with the AR Amps for at least the first 5+ years of ownership. But I am not guaranteeing the cable change out is the total remedy! But at least it will eliminate the MIT "Boxes" from the equation.

Personally, I am just fine with Monoprice Cables for my gear, but I was hoping for a bit better esthetic as the long cables are visible running to the Monoblock AR Amps. I checked out Blue Jean Cables, but their Balanced Cables use only Belden 1800F Balanced Audio Cable which is pretty plain with no "woven cover" like the MIT balanced cables.

The Belden 1800F is single shielded and I've just read some technical papers where the twisted pair and the outer shield are more than sufficient for magnetic, or radio frequency (RF) interference, as long as both ends of the shield connect to the chassis of each device involved via the XLR Connector. (Modern balanced cables should always be manufactured this way. I know some folks do "lift" the shield of one end when bothered by humming. Hopefully we'll see none of that here. ) As I mentioned earlier, my friend's security technician (he's got about 30 wireless cameras all over his property) suggested the RF from those devices, or RF noise from the VHS radios on the Boats / Ships going by => as my friends house is right on the water near Deep Cove, BC => may be causing the problem. So now I can debunk that theory.

I just noticed the Blue Jean / Belden 1800F Balanced Audio Cable has a 24 AWG twisted pair, and the Monoprice Premier Series XLR Male to XLR Female has a 16AWG twisted pair. Comments please.

I remember a late night review @gene did where he mentioned some "good looking cables" but I think they were speaker cables and not interconnects. Perhaps he can advise. (Not likely...I guess.)

Do you guys know of any "pretty" balanced cables (OMG!) that will do the job? Or should I look to sourcing some woven covering and shrink tubing and do it myself over one of the cables mentioned above? Sorry to bother you again but I really like to get this sorted once and for all.

 

[lovinthehd]

Hi Gents,

You won't believe this but my friend just came back to me, and asked me to help him replace the MIT Cables, as he desperately wants to avoid another AR amplifier failure. He never hooked the system up after he got the repaired AR Amp back, as he pondered what to do next. He said that 90+% of the time the failures occur when he is playing vinyl, so to start (as a bit of a compromise I thought) I suggested we replace those MIT cables in that pathway first (he initially wanted me to just do them all). All of his interconnects are MIT and have boxes on them - some have 2 boxes on each end!

When I arrived at his house he had already disconnected the Speaker Cables and replaced them with a very decent pair he already had in hand. So we are looking for some Interconnects. The first is a pair of 30 foot balanced interconnect cables from the pre- amp to each power amplifier. Next is a 3 foot (yes 36 inch) pair with RCA jacks for the phono cartridge to phono RIAA pre-amp. The MIT RCA Cables installed had a very interesting clamping collar on the RCA connectors. (I've never seen them before, but they were impressive.) He also wants an 80 inch pair of Balanced Cables from Mark Levinson CD Digital Processor to the Pre-Amp.

Swerd, these are the first generation of Wilson Maxx speakers. Sorry if I didn't confirm this earlier. Today I again advised my friend that if the cables are not the problem, it's probably the impedance mismatch between the AR Amps and the Speakers. (I sent him a link to the Stereophile's Review and a copy of the impedance graph ages ago.) He said he doesn't think that's the case, as he had no issues with the AR Amps for at least the first 5+ years of ownership. But I am not guaranteeing the cable change out is the total remedy! But at least it will eliminate the MIT "Boxes" from the equation.

Personally, I am just fine with Monoprice Cables for my gear, but I was hoping for a bit better esthetic as the long cables are visible running to the Monoblock AR Amps. I checked out Blue Jean Cables, but their Balanced Cables use only Belden 1800F Balanced Audio Cable which is pretty plain with no "woven cover" like the MIT balanced cables.

The Belden 1800F is single shielded and I've just read some technical papers where the twisted pair and the outer shield are more than sufficient for magnetic, or radio frequency (RF) interference, as long as both ends of the shield connect to the chassis of each device involved via the XLR Connector. (Modern balanced cables should always be manufactured this way. I know some folks do "lift" the shield of one end when bothered by humming. Hopefully we'll see none of that here. ) As I mentioned earlier, my friend's security technician (he's got about 30 wireless cameras all over his property) suggested the RF from those devices, or RF noise from the VHS radios on the Boats / Ships going by => as my friends house is right on the water near Deep Cove, BC => may be causing the problem. So now I can debunk that theory.

I just noticed the Blue Jean / Belden 1800F Balanced Audio Cable has a 24 AWG twisted pair, and the Monoprice Premier Series XLR Male to XLR Female has a 16AWG twisted pair. Comments please.

I remember a late night review @gene did where he mentioned some "good looking cables" but I think they were speaker cables and not interconnects. Perhaps he can advise. (Not likely...I guess.)

Do you guys know of any "pretty" balanced cables (OMG!) that will do the job? Or should I look to sourcing some woven covering and shrink tubing and do it myself over one of the cables mentioned above? Sorry to bother you again but I really like to get this sorted once and for all.

I could make you some good looking cables for a fair price compared to MIT....say $500 each for some "pretty" cables

 

[-Jim-]

I could make you some good looking cables for a fair price compared to MIT....say $500 each for some "pretty" cables

Thanks for the offer lovinthehd, but I'm looking for something already manufactured.

I really have no idea where to even go looking. Any hints will be appreciated.