HK-730 meets IMF ALS 40II

[dyche01]

For work and family reasons, I will be spending the next few months on the East Coast, and so I have been putting together a home-away-from-home stereo system. I shipped my HK 730 tuner and arranged to pick up a pair of IMF ALS 40II speakers locally. I have never listened to the IMFs but I heard great things, so I thought I would give them a try. When I looked more closely at the specs on these speakers, however, I realized that I had misread them. The sensitivity is given as 98 dB, but that is measured with 40 W continuous power. I generally think in terms of 1W at 1m, so 98 dB sounded fantastic. Sadly, converting from the 40W spec to the 1W spec puts these speakers closer to 80 dB.

I am wondering whether this receiver/speaker combination will turn out to be a match made in hell. The HK (rated at 40 WPC) does not have the most stable power amplifier in the world. Will it have the oomph to drive the IMF's? Will it die in the attempt?

Anyone ever tried this combination?

 

[dyche01]

I guess folks here are just shaking their heads in disbelief at the stupidity of the question.

 

[dyche01]

Thanks for all the great responses!

Based on your comments (and a quick look around my basement) I have decided to box up and ship out my old Fisher 1058 receiver. The Fisher throws 90 Watts per channel and I won't be as sad if it blows. I can also use the tuner and pre-amp of the HK, which are somewhat better than the Fisher. The real question ultimately is whether I want to ditch the HK/Fisher for a better high-powered amp or ditch the IMFs for more efficient speakers.

 

[mark warren]

I guess you will just have to give them a try..................... good luck!

 

[dyche01]

Okay, having bought too much speaker, I decided to double down and get more amp as well. Thus, I now own my first piece of McIntosh gear, a very handsome MC754. The output is conservatively 100 wpc; its built like a tank; and it only weighs 21 lbs. I plan to pack it up and ship it out just before I leave.

I gave it a listen last night and compared it to my beloved Marantz 1180DC. The comparison wasn't quite fair because they were driving different (but similar) speakers, but I was both pleased and dismayed to hear how much better the Marantz sounded. Pleased because I have put so much work into the Marantz and dismayed because I spent more money on the Mac. I will try a fairer comparison tonight.

 

[dyche01]

Packed up the 754 and shipped it off today.

One thing I learned from AK is the importance of double-boxing.

 

[dyche01]

I made it to Baltimore. The McIntosh also arrived safely and I picked up the IMF speakers. Last night I set up the system and started listening to it. Due to some muddiness in the sound quality, the HK-730 turned out to be a non starter, even as a pre-amplifier. This is an all-original unit that probably needs new capacitors in power supply and tone board. My little NuForce DAC has a volume control so I have been using it a a pre-amp for my digital sources.

I was bowled over by how many of you weighed with great suggestions and predictions of how this would turn out. I know that some of you even have money riding on the outcome, so I will come straight to the point. The MC 754 sounds really good with the IMF's! In particular, these speakers produce an amazingly rich and detailed bass. The upper midrange could be better but the problem might be with the hardened and cracked foam surrounds. Thanks for kibbitzing!

 

[hunter00]

I unfortunately didn't see this post of yours earlier or I would have chimed in.
I owned the IMF als40ii for many yrs and just finally reluctantly sold them last spring to a very happy buddy.They are quite efficient as I drove them with tube amps only the last 10 yrs before that they were teamed up with my HK 930 {45 wpc} and my HK 630 so they were used lots with solid state as well,never a problem.
Where they realy shined tho was with tube amp,seeing duty with dynaco st70,mkiv mono's/Fisher/hhscott/electrohome/eico push pull tube amps.Not many people have ever encountered these speakers as not many were sold in N. America
I miss mine

hunter

 

[dyche01]

Really?? Hmm. Maybe I should give the HK-730 another shot. I actually never even tried driving the speakers with the HK amplifier. I just pulled the jumpers and connected the pre-out to the McIntosh.

BTW, thanks for the reply!

 

[hunter00]

If your hk730 hasn't been recapped it will not perform its best.Truly dual mono in construction, with two separate power transformers and power amplifier boards, the 730 renders stereo images very well as my hk930/630 do.My units ive maintained/recapped .the 630 has been with me since the 1970's my first stereo receiver.
The best combo I found with the IMF's were the last pic,a pair of dynaco mkiv mono blocks/pas 2 tube preamp.those made the IMF's sing !!!

hunter

 

[dyche01]

If your hk730 hasn't been recapped it will not perform its best.Truly dual mono in construction, with two separate power transformers and power amplifier boards, the 730 renders stereo images very well as my hk930/630 do.My units ive maintained/recapped .the 630 has been with me since the 1970's my first stereo receiver.
The best combo I found with the IMF's were the last pic,a pair of dynaco mkiv mono blocks/pas 2 tube preamp.those made the IMF's sing !!!

hunter

Interesting. You are literally the only person I've heard advocate the use of low power amps with the IMF speakers. For comparison, the ALS40's are 8-9 dB less efficient than the Dynaco A-35's and Altec Madera's I use with my old tube gear.

I will have to test this out myself.

 

[hunter00]

You are literally the only person I've heard advocate the use of low power amps with the IMF speakers

Well the Dynaco MKiv monoblocks are rated at 35-40wpc which is nothing to sneeze at considering their tube watts.I last had the IMF's in my bedroom system{16x14} with the monoblocks and they would shake the room if wanted.The Dynaco's have good iron and one trafo per channel they can rock pretty good with great detail.

hunter

 

[dyche01]

Well the Dynaco MKiv monoblocks are rated at 35-40wpc which is nothing to sneeze at considering their tube watts.I last had the IMF's in my bedroom system{16x14} with the monoblocks and they would shake the room if wanted.The Dynaco's have good iron and one trafo per channel they can rock pretty good with great detail.

hunter

I like the sound of that!

My current listening room is 13.5' x 12' and the 100 wpc McIntosh fills it up with a lot of room to spare. I will see how the 40 wpc of the HK compares.