SDA SRS with 2 amps?

Bugstyvy

I have 2 Mcintosh MC2300's and would like to use them both, I assume I can wire them one amp top posts, other amp bottom posts? obviously removing the bridge. Am I correct or will there be problems? SDA-SRS blade/blade

chandler9a

As far as I know, that should be fine. My father does that with his 1.2 TLs. Some may suggest however, sell both the Macs and buy a nicer Mac or other amp to run the SDAs, not a bad idea either. Try it out and see how it sounds.

Bugstyvy

I was thinking on getting the mc275 for them, Im just not sure if its enough power though....

chandler9a

I know its expensive but I've always wanted to try the MC402 on the big boys, should be plenty of power.

Schurkey

Are the MC2300 amps common-ground? Can they be strapped negative terminal to negative terminal between the two chassis?

leftwinger57

The better question is how did you ever get 2 2300s .We're talking the ones Jerry used at 300 a side w/those giant meters. The 2105 is a nice amp and was always seen as a professionals set up w/ a c-28 and some AR3a and a Dual 1229. Them was the days. How old are the 2300s? I am so drooling now it's pretty funny at 130 lbs a piece,nice.

Bugstyvy

I bought a stand from a guy in town here and I wasn't sure if the mc2300 would fit, he said it would because his was in there!!
He has tons of mcintosh stuff and he sold me the second one. Yes the Jerry Garcia ones!!
Nice matching pair but I think it may be overkill? I think they are from 73' and 75' but I could be wrong. They are identical and looks ridiculous!! They are common ground but I don't want to tie them together!!

motorstereo

Big Mac's and big polks are a recipe for great sound imo. If it was me I'd be looking for an a1 interconnect to try those 2300's bridged. I don't believe it's overkill as my 1.2's have soaked up all my mc2500 can offer many times without a hint of breakup, distortion or any other problem. Nothing wrong with having more than enough power on tap for the big polks.

Bugstyvy

cant I hook them up stereo? 4 posts per speaker, high L/R mids L/R?

Schurkey

Bugstyvy wrote: »

cant I hook them up stereo? 4 posts per speaker, high L/R mids L/R?

Sure...but if a single stereo amp can handle the current draw, there's no point to using two amps separating the high L/R from the low L/R. Two amplifiers doubles the current capacity, but retains the same voltage capacity.

If the single stereo amp can't handle the current draw, there may be some advantage to installing the second stereo amplifier, but then you're probably better off to use one amp per speaker.

What the hell...you already have the two stereo amplifiers, and you say they're common-ground. Try it and see.

Schurkey

motorstereo wrote: »

If it was me I'd be looking for an a1 interconnect to try those 2300's bridged.

The AI-1 or similar isolation transformer is not an option with Blade/Blade SDA SRS speakers.

pitdogg2

Not to mention most amps do not like a 4ohm signal when bridged..and most of the time you increase the noise in the signal.

motorstereo

So I'm thinking the only way you can run mono's on them is by strapping the negatives together?

leftwinger57

I have a question for you guys that have volume controls on your power amps. This was from an Eric Clapton interview and I know it's not a home stereo but he said when he goes into the studio or onstage for that matter the amps are on full (to the shagrin of the engineer and producer) and he controled the volume and tone through the guitar. With the Macs some do have a power on thump and I was wondering what setting to you use on the amp and then how much control at the pre/amp. Years back when I worked w/ a band the bass player was a Dead Head all the way w/ a 6 string Alembic stereo bass 2 seperate cabinets w/2 15'' JBLs and 2/15'' Guass speakers an Alembic preamp and a Mac 2100 the industrial model. We were all warned before powering up volume pots must be at 0 then set at what he wanted. What do you guys do?

Bugstyvy

pitdogg2 wrote: »

Not to mention most amps do not like a 4ohm signal when bridged..and most of the time you increase the noise in the signal.

There is a 0.5 ohm post so I think it's good to go.

Bugstyvy

motorstereo wrote: »

So I'm thinking the only way you can run mono's on them is by strapping the negatives together?

or you can sell me your MC2500?

motorstereo

Bugstyvy wrote: »

or you can sell me your MC2500?

lol; Sorry the 2500 is staying put............at least till I land a 2600 or a 602.

motorstereo

leftwinger57 wrote: »

I have a question for you guys that have volume controls on your power amps. This was from an Eric Clapton interview and I know it's not a home stereo but he said when he goes into the studio or onstage for that matter the amps are on full (to the shagrin of the engineer and producer) and he controled the volume and tone through the guitar. With the Macs some do have a power on thump and I was wondering what setting to you use on the amp and then how much control at the pre/amp. Years back when I worked w/ a band the bass player was a Dead Head all the way w/ a 6 string Alembic stereo bass 2 seperate cabinets w/2 15'' JBLs and 2/15'' Guass speakers an Alembic preamp and a Mac 2100 the industrial model. We were all warned before powering up volume pots must be at 0 then set at what he wanted. What do you guys do?

I've found I get the best sound from mine with the amp gains at full and the input at the less sensitive 2.5 setting. I've tried several different combinations but this is what seems to give the best sound to me. Never heard a turn on thump yet...........knock on wood.

Schurkey

motorstereo wrote: »

So I'm thinking the only way you can run mono's on them is by strapping the negatives together?

You could use them as you originally posted--one amp for both channels of HF, one amp for both channels of Mid/Low frequencies.

I just don't think it's going to gain you anything you don't already have with the single stereo amp.

Moving to one stereo amp per speaker will require the negative terminals to be strapped. I am ASSUMING that is possible with your Macs. I haven't verified it.

Bugstyvy

Schurkey wrote: »

You could use them as you originally posted--one amp for both channels of HF, one amp for both channels of Mid/Low frequencies.

I just don't think it's going to gain you anything you don't already have with the single stereo amp.

Moving to one stereo amp per speaker will require the negative terminals to be strapped. I am ASSUMING that is possible with your Macs. I haven't verified it.

I dont see how there would be any difference? the amp output would be the same as bridging but with the benefit of sound quality if I run them stereo. Has anyone done this?

drumiv

I'm not running Macs, but that is exactly how I've got my 2 Parasound 2200II's rigged on my SRS's, also blade-blade('85's); one running high freq., one low. One of the 2200's started acting up, so I pulled it, definite difference 2 vs. 1. Try it.

Schurkey

Bugstyvy wrote: »

I dont see how there would be any difference? the amp output would be the same as bridging but with the benefit of sound quality if I run them stereo.

Amplifier output is NOT the same when used as two individual channels versus bridging the channels.

Two individual amplifier channels doubles the amperage output, but leaves voltage output unchanged. Speaker won't play louder, but might be clearer/more accurate if the speaker load is current-hungry. I am GUESSING that your Macs have no problem with current output, so you gain nothing by doubling the amplifier channels.

Two channels bridged to a single channel increases voltage and current, speaker will play louder if it can accept the additional voltage. The amplifier MAY have problems with driving a low-impedance load because the additional voltage can cause excessive current flow. This depends on the speaker load and the volume level.

For the record, your blade/blade SRS speakers will not accept a bridged amplifier as long as the SDA cable is connected.

Polkie2009

leftwinger57 wrote: »

I have a question for you guys that have volume controls on your power amps. This was from an Eric Clapton interview and I know it's not a home stereo but he said when he goes into the studio or onstage for that matter the amps are on full (to the shagrin of the engineer and producer) and he controled the volume and tone through the guitar. With the Macs some do have a power on thump and I was wondering what setting to you use on the amp and then how much control at the pre/amp. Years back when I worked w/ a band the bass player was a Dead Head all the way w/ a 6 string Alembic stereo bass 2 seperate cabinets w/2 15'' JBLs and 2/15'' Guass speakers an Alembic preamp and a Mac 2100 the industrial model. We were all warned before powering up volume pots must be at 0 then set at what he wanted. What do you guys do?

I used to run a HK Citation 19 power amp along with a Phase Linear 4000 preamp on my 2 channel rig. The Citation 19 had a power button but no gain pot. Basically, when I hit the power button, the amp was ready to run and the volume was controlled by the preamp. And yes, I'd get that thump when powering up.

leftwinger57

So Polkie if for any reason your pre got turned waaaay up your speakers would explode. There must be a way to control or eliminate that power thump.We had the thread of the noise amps made when powering down and like others have said the Adcom sounds like a deflating balloon. All my speakers do this except the 2Bs whether the i/c is connected or not. Btw I love the look of the Phase Linear 4000 w/ the joystick and knobs o'plenty. They are going for some good coin.I just saw a beauty in a case the other day. This is one w/o the walnut case and not as shined up.


http://www.ebay.com/itm/Phase-Linear-4000-Autocorrelation-Preamp-NICE-/201043126355?pt=US_Home_Audio_Amplifiers_Preamps&hash=item2ecf1aa853#ht_919wt_670