Creating work while hindered by Pandemic & excessive Heat

[nevetslab]

Here I am Sunday morning, back at the shop at CenterStaging,LLC's main building, where they relocated all of the administration offices, all of the Rental Inventory (apart from the Pro Audio Dept), and the beginning of July, relocated me to set up a temporary shop. So, I've been here since July, and, as the building is air conditioned, its' a WHOLE LOT COOLER than hanging out in the apartment 5 miles away in Glendale, where its' 97 deg F outside, and over 80 deg inside. All the rental apartments you find in the San Fernando Valley, Burbank, Glendale and the surrounding areas have those wall-mounted air conditioning units. Worthless and EXPENSIVE to turn on. Even trying to use them as a fan is a waste of time and energy. All I have at home are two ceiling fans...one over my desk in the front of the Apt, and one over my bed in the bedroom. I salvaged one of those high velocity squirrel cage fans used on stage that we rent and brought that home, after the last Patton High Velocity Cooling Fan failed. Sure wish they continued to make them. I've yet to find one that lasts as long as those Patton Fans did.

So, while waiting for Gallien-Krueger to send the replacement cast aluminum front panels for their Fusion 550 Bass Amp (and other parts needed to restore the four we have here in the shop), and maybe finding the problems in a couple Line 6 Guitar Amp heads that are in the Repair Pile out on the Warehouse Staging Area's zones, I've just run out of work. The Diecast aluminum front panels for the Fusion 550 amps have the rack mount holes placed at the upper/lower corners of the 3U high rack panel, rather than 1-3/8" down from top/bottom of the panels where we normally see them. The rack mount holes are breaking off when mounted in road cases. Only one of the four Fusion 550's we have in our rental inventory hasn't suffered this damage. I can imagine the conversations in their engineering dept from this oversight on the product.

I had an SWR Goliath III 410 Bass Cabinet in here with a gaffers tape label stating 'Blown Spkrs'. Checked it out yesterday, and after removing the front metal grille, finding some of the rubber feet that are used to prevent the grille from bending in, allowing the cone excursion to slam into the back side of the grille, the four cones were in fine shape. Common ailment I've found on SWR, Aguilar, Eden, GK and many other 410 cabinets with light spkr cones, accordion-pleat surrounds, when pushed over time, the cones themselves begin creating a new radial crease just inside the area where the cone joins the surround suspension. These four speakers didn't have that, and, usually when it's gross, I hear it every time I excite the cabinet with LF 1/3 Oct Pink Noise or Sine-Random noise, tuned in the 15Hz-40Hz region. I wasn't hearing that this time, but, after I fetched a GK 1001RB Bass Amp to plug the Fender Jazz Bass into and drive the cabinet (grille still removed), hammering on the low E string, the left pair of woofers were barking loudly, though fine at moderate levels. Yup. Blown, without visual clues.

I haven't been the one who's been ordering the replacement speakers on all of the bass cabinets I've serviced since last November, when I began doing Preventative Maintenance work on the rental inventory. Since Fender bought SWR, and stopped production on all of the SWR amps, I assume the same can be said on their speaker cabinets. I thought I had opened up one of the SWR 410 cabinets, but in checking my database, I had only serviced two of their 410 cabinets, and three of their 810 cabinets, while NOT removing any woofers to get details on the spkr mfgr/model number. I guess I'll have to do that this coming week. Though not much chance in getting expensive replacement parts ordered while there's so little income coming in. I do see equipment going out to clients, but nothing like it had been prior to the Pandemic.

Thus far, all my labor hours have been applied to covering my shop space use...I trade 20 hrs a month labor for shop space, after which I hit billable hours. But, with the Pandemic in full swing, with our entertainment industry still at a standstill, there aren't likely to be any billable hours. Still waiting to hear if I'm liable for April, May & June's shop space while the company has been shut down. I've covered March and July, and nearly thru with covering August hours. CenterStaging had rented out the building (to a steady client) where my normal shop is located, and as such, I'm not allowed in the building without special permission. That hasn't yet become a major problem, having moved essential gear, tools and supplies needed over to the main building where I am now.

So, I guess I'll resume Preventative Maintenance work, and rack up more hours to cover shop space. Having survived thus far on the UPA benefits, which just ran out of the Federal funds the end of last month, now it gets interesting from a survival standpoint. While we're now in the dog days of summer, hottest we've seen this year so far, I'm thankful I can come in to just get out of the heat and hang out at the shop. There's always something to do here, even though there's no income. My Yamaha P2100 power amp that I had restored last November to use in the Loudspeaker Test Station I set up, now the Ch A has crapped out (it was Ch B that didn't work when I inherited it a few years ago). So, I'll pull it apart this week. If I can get into my shop down the street, I have to bring over my HP 6227B Dual Tracking Power Supply, which had one channel fail recently, so there's another project.

So, onward until they close up around 5PM today. Then, I gotta go endure the heat, which of late, is still in the mid-80's at 11PM out here in Burbank/Glendale.

[Leo_Gnardo]

the last Patton High Velocity Cooling Fan failed. Sure wish they continued to make them. I've yet to find one that lasts as long as those Patton Fans did.

What? No more Patton fans? Man, they're the bomb! Sorry to see 'em gone. I got turned on to Patton in 1992 when my personal pet pop star was complaining about needing some ventilation on stage. Standard old window box fans were not cutting it. Next time I had a day off, IIRC was in Cincinnati. So I took a hike around the corner from the hotel to the nearest hardware store, where they happened to have a Patton on demonstration. It was blowing stuff off the shelves! "This is it!" sez I, snagged one and brought it back to the hotel, then on stage the following day. Lots of wind, and well-focused, it did the trick. Also built tough as nails. Luckliy I managed to sideline a Patton for home use. It's a good 25 years old and still works like day one. Rarely do I need such wind power, but it's good to have it when necessary. Sic transit gloria, or something like that. Phooey.

One weird thing about fans - any of the bladed ones not squirrel cage - if you have them in close proximity to an amp or monitor the reflection of sound off the blades can play hob with what the listener is hearing. I found out while testing amps in my pro facility aka living room. Fan on - adds a rumbly distortion to the audio. Fan off - sounds clean like it's s'posed to. Happens to musicians on stage too. "You can have a breeze, or you can sound good Mr Rockstar, what's your choice?"

The Diecast aluminum front panels for the Fusion 550 amps have the rack mount holes placed at the upper/lower corners of the 3U high rack panel, rather than 1-3/8" down from top/bottom of the panels where we normally see them. The rack mount holes are breaking off when mounted in road cases.

So... are you going to drill rack mount holes in the more appropriate spots? I sure hope so!

Stay kool!

[glebert]

One weird thing about fans - any of the bladed ones not squirrel cage - if you have them in close proximity to an amp or monitor the reflection of sound off the blades can play hob with what the listener is hearing. I found out while testing amps in my pro facility aka living room.

I've had this screw me up trying to tune an acoustic guitar by ear sitting under a ceiling fan. It modulated the air pressure and would cause a warble, couldn't figure out why I couldn't get the tuning right.

[nevetslab]

Interesting acoustics phenomenon. My band didn't have any ceiling fans where we rehearsed at my place in Gardena....only a portable air conditioner that forces cooling air out a narrow mouth of adjustable slats, so I don't recall us having that problem. I could see how that would drive ya nuts. Next to my desk at my shop, I have a dual 120mm fan box containing 120mm 105 CFM fans blowing at me (normally used to cool off power tubes, now that I decommisioned my darkroom.....they used to be mounted to my labyrinth-constructed ventilating dark room black-out windows panel to exhaust the chemical fumes from the converted bathroom to the outside, while not allowing light inside. I'll have to borrow an acoustic guitar from the Guitar dept to hear this. Or, borrow one of the large fans that I've seen elsewhere in the warehouse.

[Helmholtz]

Probably some Doppler effect of the reflected sound involved.

[Leo_Gnardo]

Probably some Doppler effect of the reflected sound involved.

My thoughts exactly. Sort of an evil ghost Leslie. Sure had me going on some amps I had repaired and was giving the listen test. Sound straightened out instantly when I switched off the fan.

[drewl]

Yeah, I didn't read your latest novel, but can you replace your AC?

And I've been busier than ever during the pandemic.

It seems like everyone and their mother is getting every piece of junk they can find repaired.

[nhbassguitar]

You’ll lose a lot less bass drivers if your management will allow you to mod every bass amp and add a 3rd-order HPF (f3 = 50 Hz) somewhere in its internal signal path. Trust me, it works.

How are the fans failing? If it’s bearings, try this (before the bearings actually fail). Lay the fan on the floor so its rotor is vertical. Run a bead of 5W-30 or 10W-30 motor oil (conventional, not synthetic) around the edge where the rotor shaft enters the motor case. Spin the motor slowly for a few seconds to encourage the oil to migrate downwards. Come back a half hour later and see if the oil bead is gone. If it is, add another bead, spin the motor again, wait for the bead to disappear, etc. Do that maybe a half dozen times. Then turn the unit upside down relative to the way you had it. If you can see the rotor shaft from the rear of the fan, do the same thing: soak the area where the shaft enters the case, and repeat as above. Do that every couple hundred hours or so of runtime and your bearings will last indefinitely. Of course I’m assuming there’s no provision for oiling on those motors. Sometimes it’s easy to miss little cutouts in the motor housing intended as oiling points.

I’ve never had A/C anywhere I live. Don’t have it in either of my 2 trucks, either. I live single, so there’s no one around to yell at me for it. I’ve never had good luck with A/C health-wise. Seems like respiratory issues always show up.

[glebert]

You’ll lose a lot less bass drivers if your management will allow you to mod every bass amp and add a 3rd-order HPF (f3 = 50 Hz) somewhere in its internal signal path. Trust me, it works.
\

I would be interested in someone doing a blind listening test, from the bass player's perspective, of whether this changes the sound/feel noticeably. Since (I believe) Nevetslab is maintaining backline rental gear it is pretty important that the amp/cabinet sound/feel exactly like the artist expects it to. You can say "well, an SVT rolls off everything below 60 Hz" and the response might be "but I didn't ask for an SVT".

I would also wonder if this would help protect the amp output stage, in addition to the speakers. Seems like it would reduce the current demand on the output devices considerably.

[nhbassguitar]

Actually an SVT+810 starts rolling off around 90, but the concern around missing low end is valid, especially with a 5-string, even more so with a downtuned 5-string.

However, the main concern with live sound equipment is SURVIVABILITY. Especially when a business’s profit margin depends on the equipment coming back in reusable condition. Will the player notice the difference with the HPF. Of course he will, and no blind test needed. So, he’ll goose up the bass control and be happy. The average active bass control will have a Q low enough that the fundamentals of his lowest string will be only minimally restored (due to the HPF) when the control is run up, but the chest-hitters—which don’t damage drivers due to overexcursion—will come alive and make him smile.

And... his sound will be a lot tighter and have far more “immediacy.”

Bass players (and synth players) typically aren’t hearing their instruments’ fundamentals; they’re hearing the harmonics of those fundamentals. But most bass players are ignorant of that fact. So from a player-experience perspective, the combination of a 50 Hz HPF and a boosted bass control should generate few if any objections. They’re not running filter numbers in their heads; they’re only liking or not liking what they hear.

OT: I’ve done the same HPF trick with some of my bass amp builds, using inter-stage RC time constants. I can get three first-order time constants before I even hit a phase splitter, and there’s my HPF. Easy peasy.

[nevetslab]

Later in the day, after googling SWR Golliath III 410 Bass Cabinet speakers, I found the Eminence Legend CA10-8 (290-4802) 10" 8 ohm woofer called out as the woofer used in those cabinets. I've yet to open one back up to confirm, but, as we have six of the 4-ohm versions and three of the 8 ohm versions, I now somewhat doubt if these $120 woofers are going to be the ones installed. There are enough cabinets to go thru, and no doubt will have to cobble together working cabinets from those that are afflicted with the years of abuse. I already see a pair of SWR 410 cabinets in the growing pile of gear for sale, though not the Golliath III variety.

I fully agree with the inclusion of a 3 or 4 pole HPF in the signal path of our rental bass amps inventory. The Sealed bass cabinets, such as the Ampeg SVT 810's, Orange 810's, being two that come to mind....tend to less likely suffer from damage being driven below 40Hz, while the majority of the ported cabinets in our inventory, those have been the ones that suffer from woofer failure. This would be a worthwhile project to engage in. Though there's a lot of gear in our inventory that's on loan from the equipment manufacturers, no doubt for the exposure of their gear with our high end clientele. Retrofitting a rugged packaged bipolar-powered HPF module into the signal path ahead of the power amp, probably after the power amp input Effects jack. I'll have to put a list together to see just how many bass amps we have in our inventory. I suspect any of the gear owned by the mfgrs would strongly object to such a modification, even though it's something they should be doing. Any ported bass cabinet.....once you're below the box tuning, those speakers will happily attempt to follow what you give it until they self-destruct.........nothing there to prevent that. Some of the amps do have a single-pole.

[nevetslab]

On the long-since-died Patton High Velocity Air Circulator fans.....the failure was always the sleeve bearings. I had tried 3-1 oil, WD-40 over the years, and a few times, got a few more days of run time before they began screeching and came to a dying halt. I'd pull the fan blade assy off, pull the motor from the cage and open them up, hoping to be able to restore order, but, lost the battle every time. After the last psuedo-replacement fan I tried...think it was a Craftsman brand, I haven't spent any more money in that realm. The Mustard-colored Snoot-mouth squirrel cage fan is still running full bore at home and hasn't failed yet. Very directional. With the hot summer nights out here in the valley area, it helps a lot. With wall-to-wall carpeting, and no proper air flow thru the apartment, it's always loads hotter inside than it is outside, once the temperature finally drops below 80 deg F.

[nhbassguitar]

Ouch. Yeah, the small number of additional days you got out of those bearings doesn’t surprise me. That’s because neither of those products was intended for that purpose. Not even close. 3-in-1 probably turned to wax in your fans as soon as it saw the first signs of heat. And WD40 just broke down after an hour from heat and bearing pressures, and left behind nothing except metal shavings. 5W-30 or 10W-30 has always worked for me. In fact I’ve got fans made in the 1970s that are still running quiet as a mouse. They get motor oil dripped down their shafts onto the bearing surfaces, from both ends, twice a year.

For those contemplating synthetics, the reason I don’t recommend those is because that stuff tends to migrate, which is fine in a sealed environment with a pump and a recovery system, but not in a fan application where it can tend to “leave the premises.” You pretty quickly end up with dry bearings (again). Not only that, but also the guts and the motor casing wind up with a nasty oil film which makes a great dust magnet. The crap that film attracts and holds in place over many months can eventually plug vent holes and cause the motor to overheat. Besides, that amount of film strength, heat resistance, and lubricity is major overkill in a (relatively) low-speed fan-bearing application.

Anyway, I hope this helps someone who’s got a fan he doesn’t want to give up.

[Leo_Gnardo]

On 10" speakers for bass... I never understood why they have become such a standard item. If you want BASS stop muckin' around - get an 18" on the job! Ah for the good old days - 1974 I saw Hot Tuna at Lenox Mass, Jack had about 16 cabs stacked up on stage, all JBL 18's powered by 4 SVT heads. Didn't need any PA, the sound from his rig just walloped you in the chest. As it should. Even a single 18 is awesome for most purposes. Remember, it's a BASS not a treble. Rant over.

[nevetslab]

Ouch. Yeah, the small number of additional days you got out of those bearings doesn’t surprise me. That’s because neither of those products was intended for that purpose. Not even close. 3-in-1 probably turned to wax in your fans as soon as it saw the first signs of heat. And WD40 just broke down after an hour from heat and bearing pressures, and left behind nothing except metal shavings. 5W-30 or 10W-30 has always worked for me. In fact I’ve got fans made in the 1970s that are still running quiet as a mouse. They get motor oil dripped down their shafts onto the bearing surfaces, from both ends, twice a year.

For those contemplating synthetics, the reason I don’t recommend those is because that stuff tends to migrate, which is fine in a sealed environment with a pump and a recovery system, but not in a fan application where it can tend to “leave the premises.” You pretty quickly end up with dry bearings (again). Not only that, but also the guts and the motor casing wind up with a nasty oil film which makes a great dust magnet. The crap that film attracts and holds in place over many months can eventually plug vent holes and cause the motor to overheat. Besides, that amount of film strength, heat resistance, and lubricity is major overkill in a (relatively) low-speed fan-bearing application.

Anyway, I hope this helps someone who’s got a fan he doesn’t want to give up.

Well, in this instance, not having researched the subject or talking it over with someone who HAS had success extending the working life of these fans, I blew it....repeatedly. So much for my experience as a bicycle repairman in my youth. Those Patton fan motors never had oiler ports. Should I go down this road again with whatever brand is out there that speaks of quality build factor, I'll be all the wiser now. Thanks!