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2 channel tube preamp for a HT receiver?

I would like to improve the sound of a Harman Kardon AVR7000 receiver, connecting the CD and turntable to a 2-channel tube pre-amp and then to the receiver, for using the receiver just as an amp for stereo music, and keep the DVD connected to the receiver and 5.1 channels for DVD and Homecinema.
I have Dynaudio speakers (4 ohm - 87 db) so I need lots of amp current to drive them.
The receiver has 5 amp outputs and 5 preamp inputs (2 front, 2 rear and 1 center), interconnected with an external switch, as if the two sections of the receiver, amp - preamp, were internally separated and externally connected with that switch.
I thought to connect the 2-ch outputs of the preamp to the front channel preamp inputs of the receiver, but I doubt if, this way, I shall loose the front channels for DVD playing ( the DVD is connected to the receiver).
I also thought to connect the preamp to a L-R line input of the receiver, video 2 for example, and keep the receiver amp-preamp sections, but I think that this this way I will not get much improvement.
Do you think I can get noticeable sound improvement doing this way, or I am wasting my money?
How can I connect the preamp and the receiver?
Thanks
manuel_
seth
38 posts
 
Connect the front L/R outputs of the reciever to an Aux or Video input of the tube preamp. Then connect the preamp outputs back to the receiver. Set the volume on the preamp to 12noon and balance the output of the receiver to that for 5 channel use. You could then use either the receiver or the preamp volume knob to control 2 channel volume.

That said, I doubt you'll get much of an improvement from doing this as you are more or less just layering two preamp sections on top of each other. If you have a separate preamp/amp combo for the two front channels then reuse the receiver for the other three channels then you have a nice purist path to the main speakers and a slightly degraded signal in the front for 5 channel use.

Hope this makes some sense.
edesilva
768 posts
 
Try this thread--http://forum.audiogon.com/cgi-bin/fr.pl?bhome&1033239358&openusid&zzEdesilva&4&5#Edesilva

One concept is use one set of DVD outputs to go to 2CH preamp, and the other set to go to HT Rcvr. The FR/FL pre-outs from the HT Rcvr can then be run back thru 2CH preamp. Requires adjusting 2CH pre to preset volume to match HT surround volumes, but something like that might work for you.

Using this setup, for 2CH audio, its DVD->2CH Pre->Spkrs. For HT, the DVD runs through both the HT Rcvr & the 2CH Pre, but sound quality there probably isn't as much an issue...
marakanetz's avatar
marakanetz
5,473 posts
 
it is much simplier to browse a used market for Plinius 8200 integrated 175W/ch amp and build a separate 2ch than strangle yourself with receiver setup.
there also more powerful integrated amps for a budget price on the market that will bring you much more performance.
tpao
3 posts
 
With your current set-up and an additional pair of high quality interconnects, you can interface the tube pre-amp with your AVR 7000 using the using the front L/R channels of the 5.1 inputs reserved for external processors. You can do this using either the pre-amp outputs OR the tape output loop IF it monitors the function switch. The latter allows you to use the HK's volume control solely, and the former gives you more vlume adjustment flexibility & probably better sound. Just be careful not to overload the HK's inputs by setting the volume control too high. You'll have to play it by ear (pun intended) :-)
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