Pre-Out options from receiver to tube amp

[dlapointe]

I have searched these forums (admit there are a few posts I'm sure I've missed), and I haven't been able to find an answer to a problem I have:

I have an older Onkyo receiver which does not have pre-outs. I currently have a pair of Klipsch corner horns which I use with an old Scott tube amp for vinyl/cd, and I would love to use them for my home theater - problem is that they sound horrible when connected directly to the Onkyo. I have been able to get them to work when using analog input from my dvd (the Onkyo has a line-out option for one of the video modes), however when I select the optical or coax digital input I lose it.

Is there any other way to get the digital signal to my tube amp (I've seen that somebody suggested using the tape line out), or is the only option to upgrade to a receiver with pre outs?

Any thoughts much appreciated

 

[markw]

"Is there any other way to get the digital signal to my tube amp?"

No. Your tube amp can not, never did and never will be able to handle a digital signal. It's analog all the way, baby. You gotta go through a DAC somewhere along the way.

 

[dlapointe]

just so I understand - after the incoming digital audio signal is broken up by the receiver, it is still a digital signal that gets sent to the speakers? I know my amp can't handle a digital signal, but I thought that by the time the signal was sent to the two front speakers (via the speaker output jacks) it was analog at that point, and I was wondering if I could run that through the tubes...

 

[markw]

"it is still a digital signal that gets sent to the speakers?"

Amazingly, you answer this yourself in the sentence following this question.

No, it's analog by that time. The receiver contains a digital to analog converter (DAC), which, as the name implies, converts those digital ones and zeroes into a waveform that our ears can recognize as sound.

You might want to spend sometime reading some of the articles explaining some of these basic principles and the workings of this hobby that are available on the main page of this site. They are really quite informative.

 

[jcPanny]

Pre-Amp signal levels

just so I understand - after the incoming digital audio signal is broken up by the receiver, it is still a digital signal that gets sent to the speakers? I know my amp can't handle a digital signal, but I thought that by the time the signal was sent to the two front speakers (via the speaker output jacks) it was analog at that point, and I was wondering if I could run that through the tubes...

There is a big difference in the analog signal levels at the pre-amp stage of the receiver and the amplified output though they are both analog. The pre-amp/processor function of your receiver is what converts the dolby digital singal to independent analog signals for each channel.

At the pre-amp stage the signal level is in the range of 100-200 millivolts (0.1-0.2 Volts).

An amplified output that is driving 50 Watts into an 8 ohm speaker is outputing 2.5 amps and 20 Volts to the speaker.

Do not try to connect the receivers amplifier output to the input of your tube amp!

 

[jaxvon]

No, unfortunately, the only option I see is to get a receiver with pre-outs. There are plenty of lower priced units that will do what you want and have pre-outs. I suggest that you check out the less expensive models from Yamaha's RX-V line. The newer 657 and 757 units have XM compatability, as well as a host of other features, and most importantly, great pre-outs (something Yamaha receivers are known for). I think the RX-V657 would work fine for your purposes, and its MSRP is $550, but you can most likely get a deal on it at your local dealer.

 

[Thunder18]

A not so elegant solution

Could he possibly use an automotive grade audio line-out convertrr to match output voltage from the output stage of his receiver to the input stage of his tube amplifier?

I have a '93 Nissan Maxima with the BOSE sound system and because it includes no pre-amp outputs and also because they run high current 1 ohm amplifiers, there was no way to add another external amplifier and subwoofer. I ended up using a line-out converter spliced into the speaker cables going to the rear speakers and then connected the converter to the external amplifier via RCA cables after dialing in the output level at the converter.

 

[mtrycrafts]

Any thoughts much appreciated

Come in from the cold and join the 21st century in audio gear. Even used will serve you better than what you have.

 

[jaxvon]

Mtry, why must you rip him for having tubes? I personally think they're great for listening and enjoying. I know they aren't the highest of fidelities, but by god they sound good.

 

[mtrycrafts]

Mtry, why must you rip him for having tubes? I personally think they're great for listening and enjoying. I know they aren't the highest of fidelities, but by god they sound good.

Now where on earth did you read that I was banging his tube gear???
You seem to jump to unwarranted conclusions from a harmless statement. The tube aspect didn't even come to mind but now that you mention it, I have nothing against them. A personal preference issue, isn't it.

His complex problem needs a simple solution, modernization.

Try not to read what is not in print, OK??