Going active with Altecs!

[chopsrr]

Originally posted by Old Guy:

<font size="2" face="Verdana, Helvetica, sans-serif">I'm curious as to why Crown does not have three-mode switch, protection guards against shorted output, general overheating, unwanted DC, ON/OFF transient electrical spikes and MAINS induced interference, a heat-sinking device and independant power supplies on their amps.

Oh well That's life.

......................................[/QUOTE]

That D 75 is a really old amp. Crown's newer amps of course have niceties that 30 year old ones don't have.[/QB][/QUOTE]

Guys, I'm getting the D-75A, NOT the D-75. Mine I believe is from Dec 1994.

Also, these amps DO have protection circuits in them. They just don't have delayed relay outputs.

[just me now]

some actually prefer the older silver units.... (I think the D75As have black faces)

why exactly that is i dunno....

but i do have the original D-75s running 802Gs and JBL 075s and they are both great together....

[Old Guy]

Sorry didn't notice the "A". Either are fine amps. My only point is it's not fair to compare older amps as far as features- they just didn't have all the gingerbread in the old days. They focused on sound back then. After good sounding amps became common came all the accessories.

I think even the 75 has a lot of protections.

[LICORNE]

Hello there,

Your not kiddng. I was looking at a High end Company that starts with the letter M.

Power guard only humm.
They have a speaker system with hundreds of tweeters hummm.

I wonder.

....................................

[chopsrr]

Well, I got the D-75A in today. It's in amazingly great, mint shape for a 12 year old amp! There are ZERO marks on it!

The only flaw was that the potentiometers somehow came loose and someone had spun the knobs so that the wires inside had become twisted and came in contact with eachother. So before doing anything else, I pulled the lid off, pulled the potentiometers out, untwisted them, seperated the wires, put them back in, snugged them down nice and tight and closed it back up.

Before I decided to hook it up to my system, I first connected a small pair of RatShack 2-way bookshelf speakers and my old Sony DVD player up to it. With the gains all the way down, I switched it on. No thumps, snaps, nothing. I hit play on the player and started turning up the gains. Everything worked and sounded fine! I let it sit there and play for about an hour or so while I did a few other things around the house including running a pair of interconnects up to the front of the room and running the speaker cables up to the front, as well as going and getting dinner cooking. Multi-tasking baby!! LOL

Anyway, I just want to say that this amp sounds great! Of course, once I get the proper XLR cables and a balanced signal going to it, I'm sure it will get even better. This amp even adds just a little more sparkle to the sound and has also opened up the soundstage a little more. Me likes!

And what would this post be without at least one good picture. Here it is with the Rane crossover sitting up top. The Rane isn't connected yet but will be soon.

[chopsrr]

Well here's the latest. My Klipsch/Altec combo is officially bi-amped!

I have the Solen 51uF caps installed on the (+) terminal of the 902s. BTW, these things are HUGE! They look like small soda cans hanging off the back of the speakers! LOL

I've been tweaking the Rane crossover for the past 5 hours now on all types of music, and I think I have settled on 500Hz as the crossover point. Obviously I still have a lot of tweaking to do with the woofer delay and gains, but for now it sounds pretty darn good... VERY good in fact!

If I had to discribe the sound, I would have to say that it is "ultra clean" at all levels. And there is more detail in the music now as well.

Anyway, as stated before, the small Crown D-75A is powering the Altecs while the old and trusty Technics SU-8099 integrated on the floor is providing 110 watts to the Klipsch woofers. I have yet to see the power meter go past 1 watt to the woofers! And the "signal" LEDs on the Crown barely light up at all. I bet that amp isn't even reaching 0.25 watt!

And now of course are the pictures. Please feel free to comment on the goodies. BTW, the Rane Balance Buddy is sitting on the shelf directly behind the crossover and DVD player.

[chopsrr]

I'd also like to add that the little Crown D-75A makes ZERO noise of any kind on power up and power down. Let me tell you, that is a hgue relief for me!

[MikeInNH]

Originally posted by chopsrr:
I'd also like to add that the little Crown D-75A makes ZERO noise of any kind on power up and power down. Let me tell you, that is a hgue relief for me!

<font size="2" face="Verdana, Helvetica, sans-serif">Crown is noted for that. My main amp for years was a Crown PL-4. Quietest amp I've EVER had. Wish they stayed in the home market. When I upgraded to a home theatre system Crown would have been my first choice.

[bfish]

Looking good, chopsrr!

You should be aware that the protection cap adds 90 degrees of phase delay to the HF. I'm not sure, but think the AC22 and 23 only allow delay adjustment of the LF, so you may have to invert the polarity of the HF, then adjust the LF to match. Adust while playing a test tone or sine wave at your XO frequency, looking for the highest combined level of both drivers at XO.

[chopsrr]

Originally posted by bfish:
Looking good, chopsrr!

You should be aware that the protection cap adds 90 degrees of phase delay to the HF. I'm not sure, but think the AC22 and 23 only allow delay adjustment of the LF, so you may have to invert the polarity of the HF, then adjust the LF to match. Adust while playing a test tone or sine wave at your XO frequency, looking for the highest combined level of both drivers at XO.

<font size="2" face="Verdana, Helvetica, sans-serif">I thought it would be 45 degrees, but I could be wrong.

Don't worry, I have plenty of tweaking to do still, but I'm liking what I'm hearing so far.