Powerful 2-channel amps compatible with blade-blade SDA's?

Larry Chanin

Hi All,

Please forgive another amplifier posting, but I was wondering whether you could help me with a specific question about capable 2-channel amplifiers suitable for my blade-blade SDA-1C speakers. As you probably know these speakers are not compatible with the A-1 interconnect, and require common ground amplifiers or amplifiers in which the ground terminals of both channels can be tied together without damaging the amplifier. (At this time I'm not interested in modifying the crossovers to be compatible with an A-1 interconnect.)

I'd be interested in hearing about the some of the more powerful 2-channel amplifiers that are known to be compatible with blade-blade SDA's. (If you know of a powerful 3-channel amp that is compatible, please list it as well.)

In addition to listing the amplifier's power specifications into 8 and 4 ohms loads, I'd also like to know whether the amp has a fan or not, and whether it's rackmountable. Obviously, I'd appreciate any other information or comments you have regarding the amplifier that you deem relavent.

Thanks in advance.

Larry

ND13

Bad info, sorry

Emlyn

Rotel RB1090. Not set up for rack mounting. 380/700+ watts. Runs cool, no fan.
Parasound Halo A21. Rack mounting kit included. 250/350+ watts. Runs hot, no fan.

SCompRacer

A Carver TFM-35 did OK with my SRS 2's. 250 @ 8, 350 @ 4 IIRC. TFM-45 did a little better, 375 @ 8, 500 @ 4. I can second Emlyn's RB-1090 suggestion.

Dennis Gardner

Larry,

As most know here, I like the Odyssey Statos line. 150 WPC into 8, 260 wpc into 4. They have the HT3 for a 3 channel model also. 3 different levels of cap upgrades too that make those transients pop. All models use the same case construction that has 19 inch wide front panels that could be rack mounted by contacting Klaus at Odyssey to let him know what your needs are.

I've run my Stratos extremely hard without any heat buildup at all. They are sturdy enough to stand on and are sealed to keep out dust and moisture.

dorokusai

ND13 wrote:

I'm using a Parasound HCA 1200 II. It's rated at 315 wpc at 4 ohms. It's more than enough for my room, which is 26x18. It's one of the smaller PSounds, too.

It's not one of the smaller Parasound's.

LC - Almost any Parasound amplifier will work, from about 1995+....anything earlier should be double checked as it is most likely NOT a John Curl design.

ND13

>>>>

dorokusai

At the time the HCA-1200 MKII was out, there were two models below it, hardly the small one. It's the model that was upgraded into the HCA-1500, again, not the smallest. The HCA-2200 MKII and 1200 MKII are the absolute starting points in any Parasound.

ND13

Never said the SMALLEST just smaller . When I was looking for an amp on AGon, it WAS one of the SMALLER HCAs that were available at the time. And I'm going by the power ratings that the SELLER'S were claimimg.

I've deleted the post so no bad info will be passed on, sorry LC.

ND13

dorokusai wrote:

At the time the HCA-1200 MKII was out, there were two models below it,

What were they so I'll know. The 1200 is the smallest in the HCA series I've come across. Thanks.

dorokusai

HCA1000/A(100X2/135X2) & HCA800(90X2) MKII. The late 90's had alot of model change and redesign. The HCA600(60X2) may have existed also, but it didn't last very long.

Larry Chanin

dorokusai wrote:

LC - Almost any Parasound amplifier will work, from about 1995+....anything earlier should be double checked as it is most likely NOT a John Curl design.

Hi Mark,

I'm very partial to Parasound. All my current amplifiers are John Curl designed Parasound amps, and I like them very much. As Emlyn mentions, they do run hot, but I have a lot of ventilating space in my rack so it hasn't been a problem so far.

I'm currently driving my mains with an HCA-2200 II, which on paper is very close to the power ratings of the Halo 21 and the soon to be released "NewClassic" 2250 amp. Perhaps it's too close to bother with such a minimal upgrade.

However, the old HCA-3500 might be a worthwhile upgrade. It's rated for 350 watts and 500 watts for 8 and 4 ohms respectively. It also has twice the peak current capacity of the Halo at a hard to believe 120 amps.

Larry

dorokusai

The HCA3500 is a beast. I don't think there's much, if anything that it couldn't handle. An amplifier should laugh at everything you hook up to it, period....overkill is always good and 120 amps is definetly in that area. The prices on the HCA are pretty fair and they're easily picked up on Audiogon.

I agree on the specs on the HALO, but remember that it's built a little better from the boards up....so the sound is a little smoother. If aesthetics are an issue, some say the HALO is "nicer" but I call it "pretty". That's sarcastic of course.

I have a review of the HCA3500 I can fax/mail to you....Stereophile found it even more powerful than the specs. For example....peak power ratings @ 1kHz, 1 channel driven....441@8/854@6/1538@4/2230@1....that's hardcore. It apparently wasn't "happy" running that kind of load, as distortion increased dramatically after 1200watts...but it still did it.

Another comment I enjoyed, "...clearly superior to the Rotel RB-1090 and seemed to essentially match the Bryston 7BST($5K/Pr.), the previous bass champion in my system." - Robert Deutsch

amulford

Larry,

Sunfire makes a couple of amps you might want to look into. The 300-2 is rated at 300 WPC @ 8 Ohms, 600 WPC @ 4 Ohms.

They also have the Signature 600-2. Ratings on that are 600 WPC @ 8 Ohms, 1200 WPC @ 4 OHMS.

Both have two output options : a current source designed to emulate a more tube like sound and a voltage source which is more SS oriented. Neither have any fans, due to a patented design. Both are not "rack mountable" per se, but are designed for rack placement.

Further information can be found at the website, Sunfire.com

ohskigod

SCompRacer wrote:

TFM-45 did a little better, 375 @ 8, 500 @ 4.

this is the same as a Carver TFM-42 (different power meters) and a Carver m4.0t. I used mine to power SDA 1B's with fantastic results. runs cool too

Larry Chanin

dorokusai wrote:

The HCA3500 is a beast. I don't think there's much, if anything that it couldn't handle. An amplifier should laugh at everything you hook up to it, period....overkill is always good and 120 amps is definetly in that area. The prices on the HCA are pretty fair and they're easily picked up on Audiogon.

I agree on the specs on the HALO, but remember that it's built a little better from the boards up....so the sound is a little smoother. If aesthetics are an issue, some say the HALO is "nicer" but I call it "pretty". That's sarcastic of course.

I have a review of the HCA3500 I can fax/mail to you....Stereophile found it even more powerful than the specs. For example....peak power ratings @ 1kHz, 1 channel driven....441@8/854@6/1538@4/2230@1....that's hardcore. It apparently wasn't "happy" running that kind of load, as distortion increased dramatically after 1200watts...but it still did it.

Another comment I enjoyed, "...clearly superior to the Rotel RB-1090 and seemed to essentially match the Bryston 7BST($5K/Pr.), the previous bass champion in my system." - Robert Deutsch

Hi Mark,

Thanks, I'll be sending you an email.

Those Stereophile measurements are quite impressive. Can we make any reasonable approximations as to what these measurements would equate to for both channels being driven? For example, at 6 ohms would it be reasonable to conclude that it should be able to handle about 427 watts?

I agree with you regarding the aesthetics. Frankly, I like the understated look of the old and new Classic Parasounds, more than the silver Halos.

What got me thinking about more power was the War of the World's Blew my LSiC thread.

Over at Siegfried Linkwitz's web site I found a discussion of how to calculate Amplifier power needed to sustain a Reference Level if you know the type of speaker, the volume of your room, the Reverberation Time of your room, the efficiency of your speakers and the reference level desired.

I've attached a screen shot of an Excel spreadsheet that calculates various amplifier power ratings needed to reach various sound pressure levels. It looks like if the HCA-3500 were powering SDA-1Cs in my moderate sized, relatively dead room, I could expect to sustain an SPL level of about 105 dB from each speaker, or about 108 dB total, before reaching the speaker or amplifier ratings. (Refer to the column second from the right.)

In the article Mr. Linkwitz recommends 20 dB of headroom over the reference level. That's an increase in power requirements of 100 times. The column at the extreme right shows that for levels over 100 dB maintaining that amount of headroom is not feasible, but it could be done for a 85 dB signal.

Regards,

Larry

I-SIG

dorokusai wrote:

I have a review of the HCA3500 I can fax/mail to you....Stereophile found it even more powerful than the specs. For example....peak power ratings @ 1kHz, 1 channel driven....441@8/854@6/1538@4/2230@1....that's hardcore. It apparently wasn't "happy" running that kind of load, as distortion increased dramatically after 1200watts...but it still did it.

Another comment I enjoyed, "...clearly superior to the Rotel RB-1090 and seemed to essentially match the Bryston 7BST($5K/Pr.), the previous bass champion in my system." - Robert Deutsch

Holy ****. If they are in fact common ground despite the dual-mono design (the 2200 is) then I think I really will try to find some funds to upgrade asl well.

Larry, you can go first!

Wes