MC7300 joins the lair ...

Update ...

Both plexi pieces removed from the glass successfully. I had to repair a pinhead sized spot of paint damage as a result but that's done. I've got the glass about half cleaned.

The plexi pieces are really scratched up - like to the point that I had to sand them down. I'm waiting for some finer grit paper to finish and that'll be here tomorrow.

The only way I can figure these pieces got so scratched up would be by carelessness when removing the face to replace bulbs. Hey I've come this far ...
 
[QUOTE="damacman, post:

The only way I can figure these pieces got so scratched up would be by carelessness when removing the face to replace bulbs. Hey I've come this far ...[/QUOTE]

Overzealous pet with nails.
 
Well, I gave up on trying to bring the plexi pieces back to life and bit the bullet with McIntosh parts. Only $20 each . . . OMG. Now, I wish I had that time back that I futzed with these damn things.

It would have been cake if the scratches weren't so deep . . .
 
Well, I gave up on trying to bring the plexi pieces back to life and bit the bullet with McIntosh parts. Only $20 each . . . OMG. Now, I wish I had that time back that I futzed with these damn things.

It would have been cake if the scratches weren't so deep . . .
Did you put it to work st least while you wait?
 
Did you put it to work st least while you wait?
Nah. It's going to replace my NAD218THX on the sub in my home theater. Getting that amp out of the rack and this one into the rack will be a pretty major production. So, I'm gonna' delay that until this amp is ready.
 
Well she's all back together and looks just spectacular. I know ... Pictures ... Soon.

I ended up buying replacement plexi pieces from McIntosh ($20 each!) I also ordered new gels to go behind the meters from some guy on eBay. When I pulled the meters, I realized that the stock gels weren't damaged in any way, just filthy. How crap gets in places like this I have no idea. So I just cleaned both sides of each of the gels and the rear of the meters with 409 and wallah. I also cleaned the fronts of both meters and the rear of the glass before putting the new plexi pieces in place. All new CM 7373s and it lights up beautifully.

I sure as hell wouldn't want to be the person at McIntosh responsible for faceplate assembly. Dust is attracted to these clean surfaces like shit flies to your lunch. Fortunately, the 7 dust particles between each plexi piece and the glass is totally invisible once assembled on the amplifier.

I drug it out into the front room and connected it to my Altecs (disconnecting my MC500) and listened to it for the first time since I've owned it. Freakin' thing sounds sweet and looks fantastic!

Soon, I'll get it in the main rack where it's gonna' live. When I do that, I'll get some good pics. One of my MC2600s needs to have the plexi pieces and meters cleaned as well. The other needs a few bulbs. So, I'll likely do all of that while the rack is pulled out.
 
Oh - to the tech that stripped the heads off of half of the phillips screws on this amp, throw your harbor freight screw gun in the trash and buy a Snap-On #1 and #2 phillips screwdrivers.
 
Unfortunately, the MC7300 hasn't worked out as well as I hoped in this application. The subwoofer is a massive 12" dual 4 Ohm driver in a 6 cubic foot vented enclosure tuned to 20Hz. Before connecting the MC7300, I connected my impedance meter to each coil of the woofer and swept it from 20Hz to 80Hz, noting readings below 4 Ohms minimum per coil. Using the amp in stereo and the 4 Ohm taps, the sound is smooth and controlled - just as it was with the NAD.

I've been using it this way for the last two months. While it sounds excellent, the PG lamps flicker far too often. I hadn't taken the time to re-run the room EQ until today, given the change in furnishings. I popped in MI-5, selected Atmos, and played the opening scene. I had to continually reduce the level from what I'm accustomed to with the NAD to keep the PG lamp flashing reasonable. At one point the lamps were on continuously for seconds. Hmmm ...

So, the NAD went back into the system, I re-EQd the room, and the dynamic range returned. Next, I intend to try the 8 Ohm taps and I bet that levels the playing field. However, two other problems remain ...

1 - The left meter sticks. This is heat related and mechanical in nature.
2 - The amp will not come on automatically via my cool guy switched outlet box, which means the misses has to turn the switch OFF then ON to get bass.

The good news is that the amp sounds fabulous on my Altecs. I'll get it sorted.
 
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Oh - to the tech that stripped the heads off of half of the phillips screws on this amp, throw your harbor freight screw gun in the trash and buy a Snap-On #1 and #2 phillips screwdrivers.

yeah, this reminds me of the guy i bought my thorens table off, was using a coat hanger to hold up the dust cover....scraping right along the inside edge.

you'll be pleased to know i hurled him off the balcony. i dislike people who abuse nice gear.

sucks about that 7300 - i am somewhat shocked it can't run the sub...you might also try running the 2 voice coils in series if the amp has a mono mode.

what's a cool guy switched outlet box? i have an one-for-all x10 IR receiver (URC 3000) that my harmony remote talks to. I don't have it connected to a power amp, but it works the fans and lights real good. it's kinda old, but perhaps you can find one...I am sure they have heavy-duty appliance modules too.
 
The MC7300 can run the sub in mono with the coils in parallel (strapped) or with the coils in series (bridged). There really should be no audible difference in doing either vs the amp driving one voice coil per channel in stereo considering I'm feeding both channels the .1 signal from the pre/pro. I've tried all of those variations in the past, just not this time.

At the end of the day, an MC7300 is probably a 800-900 watt amplifier. So, one would expect it to at least equal the NAD. When I do reinstall it, I'll use the 8 Ohm taps and find out.

The cool guy box is a custom outlet box I built that accepts a 12V trigger from the pre/pro to turn the amp ON and OFF automatically via the pre/pro power up/down sequence. It's wired with 12AWG so it'll handle up to 20A, Neither amp has a trigger input so this simplifies things for the family.
 
And that my friend is why I continue to use the Crown Macro-Tech 5002VZ on my subs, when I had my MC352, I tried using that on my subs, then I even swapped it around and had the MC452 on the subs........only took a few seconds to realize the Macro-Tech was unbeatable!!
 
And that my friend is why I continue to use the Crown Macro-Tech 5002VZ on my subs, when I had my MC352, I tried using that on my subs, then I even swapped it around and had the MC452 on the subs........only took a few seconds to realize the Macro-Tech was unbeatable!!
And 5kW on tap even! I'd use my MT2400 in a second if the fans didn't run continuously!
 
With a local client having some sort of issue with his MC7300, now Tony's, and a previous post with a autoformer issue makes me wonder if something is happening with MC7300s in general.

The MC7300s uses the same outputs (MJ15023/24s) which if I remember correctly are also used in the Macrotechs. The Crowns are a bridged design, well executed for the pro market but hardly of "audiophile" DNA.

Would be interesting to test a Mac with the PG LDRs pulled or with the autoformers bypassed.
 
And 5kW on tap even! I'd use my MT2400 in a second if the fans didn't run continuously!

Yeah that's the problem with a lot of pro amps, fortunately, the 5002VZ has its 115VAC fans with 60VAC on them at idle so they run very slow, hardly even notice them, there's more noise from the triacs and transformer....I hardly even notice it, if the system is on and the room is quiet (IE no music which is just ridiculous) its noticeable though.....
 
With a local client having some sort of issue with his MC7300, now Tony's, and a previous post with a autoformer issue makes me wonder if something is happening with MC7300s in general.

The MC7300s uses the same outputs (MJ15023/24s) which if I remember correctly are also used in the Macrotechs. The Crowns are a bridged design, well executed for the pro market but hardly of "audiophile" DNA.

Would be interesting to test a Mac with the PG LDRs pulled or with the autoformers bypassed.

Yes, matched MJ15024/15025 (Crown stamp their own part numbers on, just like Mc do, and in red marker pen put a gain rating on them), the Crown is a Grounded bridge design which is unique to Crown, have a look at the specs Chris, they can hold their own in Audiophile world....They show excellent SNR and Distortion figures...as well as a great sound, which seems to pair brilliantly with McIntosh amps.....
 
I held a tray of transistors in my hands too many years ago, while I was teasing the lovely ladies testing each one and putting them into 6 matched categories. Only one, probably a more secular worldly woman, got my teasing. Watching them pull these silver objects out of trays and putting them in the testing equipment looked just like the matrons in Vegas feeding slot machines.

I did not say that the Crowns were bad sounding amps, just that their inherent DNA was geared to the pro audio world were priorities and compromises are considerablely different than home audiophile designs.

I have always considered Crown leaning out of the pro market towards home audio just like Mac has always leaned toward the pro expectations with their home designs.
 
With a local client having some sort of issue with his MC7300, now Tony's, and a previous post with a autoformer issue makes me wonder if something is happening with MC7300s in general.

The MC7300s uses the same outputs (MJ15023/24s) which if I remember correctly are also used in the Macrotechs. The Crowns are a bridged design, well executed for the pro market but hardly of "audiophile" DNA.

Would be interesting to test a Mac with the PG LDRs pulled or with the autoformers bypassed.
Other than the meter, I don't think mine has anything at all wrong with it. I believe I just chose the wrong taps. Need more grunt.
 
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