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Pre-amp to receiver?

If I play a CD , and connect  a  Denon  CD player OUT to Dynaco PAT 5 preamp IN , and then the preamp OUT  to a CD IN of an Optimus STAV 3000 receiver( which has no connector in back to separate the receiver's preamp and amp) I  seem to be able to use both the Dynaco tone controls and also the Optimus tone controls to effect sound through speakers.

The questions are two...1) since the Optimus has its own quality of preamp, which of course does not rise to level of Dynaco PAS 5,  will this mean that no matter what quality signal the Dynaco is inputting into the Optimus receiver CD input, that signal will  degraded to however  the Optimus receiver preamp would handle a direct CD IN signal without the Dynaco, or will it be improved  isomewhat due to an added emphacis on some frequencies or the ability to discern those frequencies or whatever by the Dynaco?

2) if the above is audio anathema,  as i suspect, is there a correct way to bypass the receiver's preamp (with a receiver that does not have the two small metal connectors in the back to disengage its  preamp from amp) and insert the Dynaco 5 as the tone controls?

I googled this question but the net seemed to provide confusing or inadequate response.

Thanks to anyone who takes the time to read and/or respond..




saitta22
saitta22 OP
8 posts
 
donvito, 

....understood, but  to belabor the issue, still curious from a tecnician as whether it is electronically sometimes acceptable and producing good results to connect a preamp to a receiver's preamp since so far my receiver has not fried and the music from the speakers has improved noticeably...

....but will connect it eventually to an amp



imhififan's avatar
imhififan
2,181 posts
 
although it wouldn't bypass the volume and tone control on the receiver, connect the PAT5 to one of the Tape Monitor loop on the receiver, so you can switch the PAT5 in or out by just pushing a button, as long as you don't turn the PAT5 volume too high it should be fine.
If you can diy, modify one of the tape monitor in/out to pre-out/ power-in is the best way to go.
saitta22 OP
8 posts
 
imhififan,

...first of all...nice handle!

 and thanks for, pardon the pun, input...

so since , in one configuration at least, and i believe in your suggestion,  my dynaco preamp is going into optimus receiver's preamp and the sound from the speakers has improved, does this mean that electronically somehow the receiver's  preamp electronic innards  that deal with the incoming source signal ( beats me what that would consist of....i guess resistors or whatever) somehow they don't get fried by the Dynaco's  additional input and somehow improve their stretch or capability of the optimus preamp electronics?

I have read that it is audio anathema to hook a separate preamp into a receiver preamp  in ALL situations...is that because one is rolling the dice as far as damaging the equipment while never improving the sound so why do it ...,or is it rolling the dice, sometimes not damaging equipment ,and sometimes improving the sound?



imhififan's avatar
imhififan
2,181 posts
 
I believe the PAT5 helps to trim off some high frequency "hardness" of the CD signal. Many years ago, I bought  a used ARC sp-6c tube preamp via audiogon, just to make sure everything works, I hook it up to one of the line input of my receiver, I got the same result like yours, CD sounded much better!
However, connect the preamp direct to the poweramp section and bypass those tone and volume control from the receiver, the sound was further improved.
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