My brother was going to take these to Goodwill...

[sweetbeats]

Alesis Monitor 2 passive studio monitors.

I love my brother. He has been very, very good to me all our years. He texted me to see if I was interested and if I wasn't "they [were] going to Goodwill".

Hm.

What to do with them.

I know they've had some mixed reviews and he hasn't used them because he was never satisfied with the sound and has a system he likes better, but they should be good for an alternate set, or for a studio feed if I actually had a recording room...I'm a tard.

Anyway, I don't have an amp because my main monitors are a set of Monitor 1 mkII's which are biamped as well as a little 8" self-amplified ESI woofer. I'm using a Behringer CX2310 crossover to handle the splitting and it works for me...anyway, he's "loaning" me this which he also hasn't used in years and years..."loaning" has historically ended up being "keep it"...says it "hums" on one channel. These models have a rep for relatively high self-noise/hum but I guess this particular amp had problems at some point and was repaired but one channel "hums". Maybe I can fix it. Seems to be an amp with some following. Ah! Found the service manual...

Anyway, anybody have any experience with either of these items?

Niiice brother...nice-nice brother...

 

[Herm]

I had that amp when they came out with a pair of huge cerwin vega speakers.
It was all for pa stuff. They where quite the amp at the time but didnt last long and didnt stand up well to the road. The only benifit they had was their weight. They where so much lighter than the peavey cs800 that everyone was using. But most of the peaveys still work

 

[LUNE]

I had the passive monitor 1's a long time ago (prob'ly around when they came out) I used them as the nearfield monitors that they were meant to be and I thought they were workable when you got used to how they sounded (and since that was all I had at the time for monitors I got used to how they sounded). I think those Monitor 2's would be a little harder to find a use for for me perhaps - but you have a large enough room for them? the studio-feed-if-you-actually-had-a-room would prob'ly be a great use for them!

I could be remembering falsely (its been quite a while) but I think I had a general impression when the powered versions of these alesis monitors came out that while it was quite convenient to have the amps inside them and they were supposed to be 'better' somehow for being exactly matched etc. that they were a little more difficult to listen to somehow ('edgy'? 'crystalline'?) than my old Monitor 1 combined with the alesis 100w amp that went with them.
I think those monitor 2's could be a nice far-field monitor if you have' a big enough room (nice enough sounding room acoustic wise) depending what amp you paired them with.

myself I always accept free speakers and then wait for the free amplifier to turn up sometime. (this worked out well for me recently when I finally got a teac 100W amp/receiver (new looking, $5 at the locally owned thrift store - NOT GOODWILL ) to match a pair of Audio Research speakers that were given to me a little over a year ago - I'd never heard the speakers until just a few weeks ago...)
can you have too many working speakers hanging around?
you could just about use those speakers as an acoustic music PA coupled with the right amp. or...they might make the perfect gift sometime for an amateur with a new studio. I don't know how many people i've seen over the years recording and trying to mix on their hi-fi speakers...
...but, I'm a sucker for free stuff

 

[sweetbeats]

Long story short my brother brought the amp and the monitors down last weekend when we got together for a visit so I'm just following up now.

He ALSO brought me his old Alesis Quadraverb. He couldn't remember if it had a problem or not...he thought maybe the PSU wall wart was shot but knowing those are readily available fro about $15 I said "OOOO bring that too!". I used to have a Quadraverb and I don't know why I sold it...it was noisy but in retrospect it just had a unique sound with some of the patches that worked well with some of the things I do so I've missed it. Mine was kind of beat up and my brother's is in really nice shape and the LED display and illumination still work work which is one of the problem areas for these old units.

So anyway, here's the loot:

First, the monitors...the tweeter dome on the right speaker is dimpled. Replacements are available at about $30 though I don't know if it is even necessary at this point. They cabinets are in good shape...actually they are in good shape all around and I know for fact they are low mileage, but after some offline dialog with GCalo I'm going to stick with my current monitor setup (Alesis M1 Active mkII's, ESI SW8000 sub, Behringer CX2310 crossover). I was thinking the Carver amp might be a better performer and the idea of ONE two channel amp and simple passive speakers as opposed to FIVE amplifiers total in my current setup (one amp for each driver in the satelites and the sub), as well as more crossovers and then the whole wrinkle regarding sub placement and the anomalies THAT can cause...I was just drawn to the good old classic passive stereo pair and separate amp. Well, the crossovers are vanilla in the Monitor 2's, and some decisions were made regarding crossover points to boost power handling (namely the HF crossover point is at 6kHz which is apparently relatively high and would contribute to the muddy mids and imaging)...and after opening up my current monitors it is clear that the cabinet, driver, amp and crossover design is good...they are a significantly better option than the ones from my brother. So I'm not sure what I'll do with these. The other thing too is that the ones from my brother are physically quite a bit bigger than my current monitors and the room is not that big so that supports sticking with what I've got. Free gear...hard to walk away from it.

And then the amp...I guess they weren't known for their midrange performance, but they do have a following. Looks like something toasted in the amp, like toasted-taosted. It is working now though at first the output was REALLY low...I thought it was a level matching issue (since the amp lacks input sensitivity controls...I thought the output level on my media player was just not hot enough) but then partway through one song it suggested otherwise, like suddenly started BLASTING. Okay. It works. Just finicky I suppose from sitting for years. Here's the guts with a closeup of the area where there used to be a burned up something in the PSU section...not sure how extensive the repair was...I'd be shotgunning components in close schematical proximity to the cooked one and I'm not sure that was done...you know...analyzing what happened and determining what *might* have been effected and then replacing all those parts...

So not sure what will become of this amp, but at present there's no need for it here.

And that leaves the Quadraverb. I had high hopes. Powered it up and everything lit up and I thought "Huh! Maybe there's nothing wrong!" Then I realize literally everything lit up including the LED metering...pegged on clipping. See?

Arg! Hooked it up to a headphone amp to listen to what was coming out of it and its a nice hardcore 60Hz hum. Checked the output of the power transformer and it is a clean and proper 9VAC. Reseated all the socketed IC's...no difference...unplugged all the connections to the main board (like to the input and output level pots, the LED meter, the LED display and button panel), same thing ***MMMMMMMMMMMMMMMM!!***

Nothing cooked looking on the main PCB...I removed the heatsink plate (shiny aluminum rectangle on the center right of the main PCB):

Hm...should've done step one...check the power supply rails.

The Quadraverb runs on +/-12VDC rails as well as a +5VDC rail. Look at the -12VDC regulator (the middle one). Notice that the +12VDC and +5VDC regulators have aluminum standoffs to couple them to the heatsink plate...notice that the -12VDC regulator does not. The PCB around the -12VDC regulator shows more signs of heating than the other two...duh. Why'd they DO that??

Well its no surprise that the -12VDC regulator is toast...it is putting out about +6VDC AND is producing a really unique looking AC waveform too, heheh. So, I'm going to order some parts to recap the entire thing (25 caps total), replace all the regulators as well as the rectifier diodes for good measure and mod the heat management. I honestly don't know if that will solve the problem and actually I may pull a -12VDC regulator from something here and try that first to see if it works and THEN spruce it up.

 

[stevieb]

I've seen my share of working Quadraverbs and similar for $50 or less, seems pointless to repair something if parts alone might cost more than that...

I am not a Carvin fan (I just think an employee of a company should not blast someone just because that person points out a dumb move the company made,) but I would think the amp is worth repairing, esp. if you do it yourself.

You can often pull out a dimpled speaker dust cover with a vacuum. Works like a charm, just bring the vacuum nozzle to the dust cover slowly, until it pops back out. Usually happens before the nozzle touches the speaker.

And IS YOUR BROTHER NUTS??? Sure, Alesis M2's may color the sound, but good GOD, use 'em in the bedroom as, well, SPEAKERS, if nothing else presents it's self.

 

[briank]

Bummer about the Quadraverb being frizzle fried, but if a cheap fix takes care of it then what the heck, probably an interesting piece to have around. We have some big old Teac speakers for the studio feed and some old Electro-Voice Sentrys for control room couch speakers...I'd put the M2s on the same sort of duty. You weren't kidding when you said that amp was toasted, looks like it's been through a pretty catastrophic failure!

 

[GCalo]

--- What to do with them.---

Bring them immediately to GoodWill!!!

 

[evm1024]

You should toss the carver and alesis into the trash. My trash to be exact.....

--Ethan

 

[sweetbeats]

I've seen my share of working Quadraverbs and similar for $50 or less, seems pointless to repair something if parts alone might cost more than that...

I am not a Carvin fan (I just think an employee of a company should not blast someone just because that person points out a dumb move the company made,) but I would think the amp is worth repairing, esp. if you do it yourself.

You can often pull out a dimpled speaker dust cover with a vacuum. Works like a charm, just bring the vacuum nozzle to the dust cover slowly, until it pops back out. Usually happens before the nozzle touches the speaker.

And IS YOUR BROTHER NUTS??? Sure, Alesis M2's may color the sound, but good GOD, use 'em in the bedroom as, well, SPEAKERS, if nothing else presents it's self.

The parts for the Quadraverb will be a whole lot less than $50...the key components if it is just the supply and regulator sections would be a few bucks, and I've got IN4004 rectifiers sitting around so I'm going to swap those and I've got a spare -12VDC regulator so in a sense, to get it going would be free. Replacing ALL the regulators with new and recapping it will be $10~15. Seems like a better deal to me than a completely stock one in relatively unknown physical condition for $50.

Not "Carvin"..."Carver".

Its not a voicecoil dust cover that's dimpled. Tweeter dome.

And as far as my brother being "nuts"? You should see some of the other stuff he has for studio monitoring and home theatre. Let's just say there's a legitemate reason the Monitor 2's have been in a closet for a number of years.

Ethan, that's such a nice offer but...I just couldn't burden you with that.

 

[Beck]

I always thought the Alesis Monitor Two's were pretty decent in a good room. Is the dimple torn through or is the dome still intact? If still intact you can use the blow dryer/vacuum cleaner trick to bring it back out. Heat it with a blow dryer and use a vacuum hose with a small or no attachment to smooth it back out.

I owned the original Qverb some years back when it was new, and it wasn’t so bad, but honestly I thought the verbs in the Midiverb III were a bit smoother. It had some other cool effects though… fun to play with. I’ve owned a Q2 for years now and love that thing… whole ‘nother animal.

Cool score… have fun!

 

[A Reel Person]

Cory,...

Please stop taking things apart and take your medication!

 

[sweetbeats]

I always thought the Alesis Monitor Two's were pretty decent in a good room. Is the dimple torn through or is the dome still intact? If still intact you can use the blow dryer/vacuum cleaner trick to bring it back out. Heat it with a blow dryer and use a vacuum hose with a small or no attachment to smooth it back out.

Well, Tim, its funny...there are about 5 or 6 small dimples in the dome around nd the periphery...like the silk material expanded and buckled. They're small and the dome material is soft and I don't think they will stay if pulled out. I'm going to try to use some tape to gently pull on one of them but I betcha once the tape is released the material will dimple right back to where it was.

And I'm sure I would be fine with the sound but I think a deal-breaker is that the room is only about 10 x 11 with a 7ft ceiling...

Please stop taking things apart and take your medication!

HAHAHA!!!! But the pills are IN the gear...I SWEAR!!

 

[sweetbeats]

So I've been messing with the Quadraverb...I found a finned heatsink in salvage that I can mod and will work to mount the regulators and still fit under the hood...That should help with cooling. And I replaced the rectifier diodes in hopes that that might be the issue but no the problem still persists. Not too surprised. I'm pretty sure the -12V regulator is hosed. I'm going to replace all of them. Costs a couple bucks. I tagged onto Mouser order GCalo put in so pretty soon we'll see if we can get this Quadraverb to sit and speak.

Regarding the rectifier diodes...man...THAT was a bit of an adventure. Those things have been getting pretty hot...hot enough to discolor the PCB and what a mess trying to get the old ones off...its a glass fiber PCB and usually the traces and lands hold better to those boards but, as I've learned, not if they've been stressed and overheated. Sheeeeeesh...the factory diodes were IN4001's which only have a 50V rating. Now, sure, I understand the logic there as the power transformer is rated at 9VAC so the rectifiers are only going to see around 18V total and 50V is about a 150% error threshhold, but if the transformer goes, which the old ones are prone to do, who knows what might get thrown at the rectifier, and if THEY can't handle it then they're going to be more likely to pass it on downstream, and if there aren't any ceramic disc caps in there for the high voltage spikes (and I don't see any) and the main filter caps aren't very big (which they're not) then the regulator is going to get hit...I don't know for sure but I know my brither had to get a replacement wall transformer at one point so maybe things were weak and pluss there is NO thermal management on the -12V regulator...anyway, I put in IN4004 diodes (400V rating)...overkill but they're cheap and I had them on-hand, but it was just plain mess because the PCB is double-sided (which is always a pain to get stuff off of anyway) but the traces and lands were lifting like crazy and the board scorching...I usually do really well with keeping the contact to minimum but this was just a mess because those diodes were getting hot. I scraped back the varnish on the traces to allow more contact area with the tails on the new diodes, put one of them underneath the PCB because that allowed for a better contact with its input and output traces, and, where possible, spaced the diodes off the board so more air can get around them...the factory components were installed right snug to the board. Had to get a little creative because the shaft for the power switch comes plunging right through the rectifier section (so two diodes had to be leaned over), but I'm pretty sure this will, at the very least, not be any worse than what was in there, and hopefully will offer better longevity.

Pics of the new rectifiers above and below the PCB. I know...ugly...not my proudest moment, but it was clear to me when I started taking things apart that the original install was an accident waiting to happen, or maybe it already had:

 

[GCalo]

read an article to extend the leads to mount heavy duty rectifier diodes about 1/4" above the board for better cooling and less possible board damage.

This is a good case in point.

 

[sweetbeats]

Yeah, I've started doing it just as a general rule of thumb where possible...can't remember if it was evm1024 that suggested it or who did when I rebuilt the PSU for the 388, but that board has a nice brown spot under the rectifiers so I left some breathing room for those. And 9VAC isn't a lot or anything but I have to figure the IN4001's would certainly be taxed more and run hotter than anything higher rated.

 

[GCalo]

Think of it as a free heat sink!

 

[sweetbeats]

So I pulled those regulators off and it just irritates me...the -12V regulator essentially had NO heat management. With all three removed you can see the discoloration on the PCB under where that one was mounted...just seems slip-shod and on top of that there were some possible ground loops with the way they mounted the old heatsink (which only contacted the +5 and +12V regulators.

I'll get that all fixed.

Found a neat little heatsink in spare parts that I was able to trim up that'll work great here and should help things. I trimmed it on my compound miter saw...a little scary but came out nice overall.

Here it is ready for the first cut to reduce the height it would be in the Quadraverb case:

Here it is after that first cut:

And then to trim up two rows of tines (allowing room for existing components on the PCB):

Finally, this is what it will sort of look like sitting on the PCB:

 

[TyphoidHippo]

This is awesome.

....I can't think of anything else to add, sorry. I'm eager to see more

 

[sweetbeats]

Throwing the towel in on this one...put the new regulators in and the problem persists. The rectifier diodes remain cool as do the +/-12V regulators, but the 5V regulator gets hot pretty quick. That feeds logic world and I ain't goin' there. So unless anybody has any ideas the Quadraverb is going in a box somewhere as a parts unit for someday in the event I get another one.

Oh well. Win some, lose some.

 

[c7sus]

That Carver is a POS. Send it to me before it starts giving you problems.

The Quadraverb is an excellent doorstop.

Stevieb---- dumber than a box of hammers. Don't ever change!!!