6 channel preamp???? (1 Viewer)

[Ben Hanrahan]

Anybody heard of a 6 channel preamp that can be used with outboard processors? Preferably the unit wouldn't have any processing which would add to the cost. I would like to get a dvd player with built in decoders (dts, dd,) and route the analogue outputs to a simple preamp which is basically only used for volume control and then straight to a power amp. The reason being, I only use my system for home theater, and when playing music, I use my dvd player. I'm somewhat surprised that nobody else has come out with a product like this.

Also, is there a way to build my own preamp(s) if only for volume control purposes?

Ben

 

[Ron Shaw]

Of course you can build your own. Its done all the time. It just depends on your skill and motivation. You should be able to find a lot of info on the net. A book I recommend is from National Semiconductor called 'Application Specific Analog Products'. A lot of good examples of almost any type of analog circuit.

 

[Ken Woodrow]

If you're leary of building your own, a good solution is the Sony TA-P9000ES. It's a 5.1 analog preamp with two 5.1 inputs, independent channel volume control, and some other features. It was designed to handle the analog inputs from SACD players but would work with any 5.1 analog sources. It's $700 retail, $500 street. There's a couple on E-Bay right now.

- Ken

 

[Ben Hanrahan]

Thanks for the advice. The sony is an option buy somewhat defeating the purpose as it's relatively expensive. What about an integrated amp with 5.1 channel ins??

 

[ThomasW]

Just buying a ganged 6 channel volume control is going to be expensive, let alone ganged 6 channel input/output switching. It would be almost impossible for the average DIYer to build something like the P9000ES for less than the $485 that is the price from http://www.oade.com

 

[Ben Hanrahan]

Thanks for the advice guys, I didn't know this product existed until now. Do any of you feel you get a better sound with a built in decoder in your dvd player vs running an optical/coax to your receivers decoder?

Ben

 

[ThomasW]

I've never used the decoders in either my DVD player or HTPC. Everything is done by the pre/pro

 

[Ben Hanrahan]

Well, I was in a local hifi shop and the salesman told me that using the dvd players processor sounds better because there is less digital jitter. I didn't really think I'd hear a difference until he A B'd the 2 different configurations, the dvd with built in decoder sounded much better, clearer, less fatiguing. He explained that when you go from dvd player to processor you're adding an extra DA conversion which adds jitter to the sound. He was right.

Ben

 

[Ken Woodrow]

Ben:

That's not the complete story. Usually, you go from the DVD player to the processor with a digital (S/PDIF) connection. With this configuration, the processor handles the decoding and the digital-to-analog conversion and the DVD player acts merely as a transport. With an analog connection between the two, the receiver may in fact redigitize the input in order to apply bass management or other digital signal processing, UNLESS you set the receiver to analog direct mode. To make a true comparison, you'd need to compare it in direct mode without the extra DAC in the receiver.

I'm not sure which config. is most susceptible to jitter -- it probably depends on the quality of the DACs in the processor vs. those in the DVD player. Some processors and DACs have their own timing circuitry that eliminates any jitter introduced by the transport.

I know from my experience with a Toshiba SD-3205 and a Sony DB930 receiver that my receiver had better DACs than the DVD player. The sound quality was better with a digital connection b/n the DVD player and receiver than it was with an analog connection between the two, even when I set the receiver to analog direct mode (thereby eliminating the second DAC).

- Ken

 

[Kevin McCurdy]

Ben,

I tried something similar to what you described using my Panasonic RP91 and my Denon 3300. I have the RP91 connected with an optical cable and the analog outs going into the 8.1 channel inputs on the Denon.

I flipped between auto and ext in's settings on the Denon and I noticed a difference similar to what you described encountering at your local hi fi shop. When using the analog in's or ext input on the Denon the sound seemed to be warmer and fuller.

I put in the avia disk and ran the test tones using the analog inputs and noticed that the spl's were about 2db lower on the Radio shack meter? This may account for my perceived difference or maybe the fact that the RP91 is about 2 years newer than my receiver and possibly has better dacs, I'm not sure but I know I heard a difference.

 

[Ben Hanrahan]

Kevin,

that's cool that you were able to hear the same results! So, will you be keep your setup going with the dvd's dac?? WHat dvd players are out there with built in DD and DTS??

Ben

 

[Kevin McCurdy]

Ben,

I've pretty much been using it both ways, the ext in's for music and auto for movies. My system is pretty much dedicated to movies and I've been hesitant to go through and change any of the settings because others in the house use the system when I'm not around, so I leave it in auto for simplicity to detect whatever may be sent to the receiver.

I decided to hold of making any changes until I get the 950 at that point I'll make the decision and I'm almost certain it'll be the 950's dacs.

There are a lot of DVD players that have both DD and DTS built in decoders. My last three DVD players have all been Panasonic (U120, RV80 and the RP91)and all of them(I believe) had built in decoders for both formats. It's listed in the specs of the player and usually on the front panel as to whether or not it will decode the formats. The other option needed if you want to pass the analog signal to the preamp is analog outputs.

In the end I believe the difference I heard was probably caused by the age difference of my two components (my receiver is almost three years old) and the best performance will be had by using the internal dacs of the prepro or receiver as others have pointed out. If your trying to setup a system I would place more emphasis on getting a quality prepro or receiver. As always in the end it's up to you to decide what you like best.