HK 730 Twin

I have a Harman Kardon 730 twin integrated amp. I am using the amp section on this integrated for power only. My preamp is a tube unit. The sound is astonishingly good. Any problems with this setup I should be aware of? Any one else have such nice results with this type of setup?
No problems. You're just doing what your ears and common sense is telling you to do. See here (I hope its OK to put link )
Yes that is true about the ears, It just sounds so lush and open. In comparison to my B&K ST-140 amp there is no comparison. The HK makes the B&K sound irritatingly harsh and super bright.
I use a Harman Kardon Citation 16A amplifier. I have never heard better. Used to have a very elaborate Mac set up, but it couldn't compare with the spacious sound of the Citation. Personally, I always hated Harman Kardon products, (for no apparent reason) so this was hard for me to swallow. But I am glad that I did. I use the 16A with a Citation 17 preamp and love it. This is my system for life. Old school and vintage to be sure, but so sweet sounding. You might try an HK/Citation 12, 16 or 19, as they are similar to your 730. The Citation gear was all hand made and used the finest available components. Enjoy.
I have an HK 930. One of best solid state receivers of all time. Nothing out there like it today.
The HK X30 receiver series seem to have become classics. I have a HK 430 and it is wonderfully musical within it's more limited power range. Word was when they were current products that Robert Fulton consulted on their design.

One word of caution on the Citation 12 amp for anyone considering that. It was very good into an 8 ohm load but not happy with 4 ohms. I used one with a single pair of Advent speakers in the '70s and all was well until I decided to try a Double Advent system -- the amp failed soon afterwards.
I bought a 730 in 1979 and still have it today although not in use now. I bought a Luxman receiver back in the late 80's thinking I was upgrading. that was a poor choice. Though the Lux got great reviews and sounded great in the showroom, it sounded terrible in my system with large Advent speakers.
I sold the Lux and returned back to my HK and used it until I stepped up to the high end stuff ie Conrad Johnson in the late 90's.
I have also used a separate preamp with the amp section of the 730 with good results. However the only reason I did that was because the preamp section of the 730 was not very clean anymore. This is due to age and the fact that solder joints were breaking down according to my tech who has maintained it for years.
I would love to recondition it back to original condition or maybe even mod it with some upgraded parts. But it would be more a trip down memory lane and probably not worth the $$$ put into it
Don't get me wrong. It was a fantastic receiver in its day and certainly among the best. Rated at 45 wpc, but in reality it benches between 65-70 wpc. It was my pride and joy for many yrs. However it will not compare with my system today. The CJ amps and preamps will blow the HK away. But they should considering the price difference. I would say that a properly functioning HK 730 will stay with or outperform anything $1500 or less. And it may do even better than that. It is that good.
BTW, the 430 is rated at 22 wpc. I remember when the salesman tried his best to sell me the 430 based on my room size.I believe it too is twin powered and it sounded very good too. But I had my heart set on the 45 wpc and so I walked out of the showroom with a brand new 730 and large Advent speakers. I was proud as a peacock. That was 30 yrs ago. Enjoy your 730. BTW, poke around over in AA at the vintage asylum and you'll find that there is someone who reconditions the 30 series. Enjoy
The specs in the manual for my HK 430 state: 25 watts minimum, RMS per channel, both channels driven into 8 ohms from 20 Hz to 20K Hz, with less than 0.3% THD.

This is a more straightforward set of specs than many brands provided at that time. Note that rating covers both channels driven through the full frequency band and with minimal measured distortion. While I'm not one to accept specs as the total indicator of sonic pleasures, to me at least HK's suggest good engineering.
Pryso, I thought it was 22 because I remember thinking at the time that it was a weird number. My mistake. Thanks for the clarification.
I have a mint 930, and some really cool "tech bulletins" that accompanied it from 1973-74.

I only listen to it occasionally, but it's a keeper.
I remember Nelson Pass commenting on HK amplifiers. In fact, the Citation 12 was one of his first 'MOD' jobs. He spoke very highly of their design and sound. I have an audio buddy who uses a Citation 12, with the DQ 10's. Very nice system. His preamp is a Citation 1 tube unit. I wish I had that preamp, the sound is incredibly warm, smooth and sweet. Makes you want to pour a good Brady or Scotch and listen for hours. I wasn't aware of the Fulton connection, but that really does make sense. The amps surely do have a unique sonic signature that keeps you coming back for more.

Have you ever opened up a Citation 11 preamp or one of their amps? The Build quality is outstanding. At least on the order of McIntosh. I don't understand why HK and Citation don't get more 'respect' in the audio community. Their product are all very robust and have excellent sound.