Well, another pre-amp & HT integration question...

I think I've managed to confuse myself. By adding a tube PA with a unity gain processor loop into my system I'll end up with the following signal path, right?

Digital Transport (Proceed PMDT) ---> DAC/HT Processor (Proceed AVP) ---> Tube Pre (TBD)---> Front 2-Channel Amp ---> Front R & L speakers

So even with a unity gain loop to bypass the PA when doing HT, won't I still have to futz around with both volume controls (AVP & PA) when listening normal 2-channel music through the tube pre-amp via the analog output of the AVP?

Thanks again,

Hi Thomas.
You will only need to use one volume control at a time. The HT Processor remote when using the HT and the pre-amp remote when listening to source units feeding the pre-amp.

There is no volume matching exc.

The only thing that you may need to do is to resest the gain balance between you surround channels one time when you first install. Just as you did when you first set up your HT Processor. The PRE-AMP may cause a slight change in the volume of you front left and right speaker when you first place the PRE-AMP in line. However this is no more than balancing your surround speakers as you did on the HT Processor set up. It will remain constant after that as you will not need to change anything (take out or add anything) on all following mode selections (HT OR 2 CHANNEL).

Here is how it works. With the processor loop.

On the back of the pre-amp you will have several inputs. Like CD, Video, AUX, Tuner, tape, exc. Then there will also be an input marked PROCESSOR (this is an input). You will take the front left and right speaker output from you HT processor to the Processor Loop input on the pre-amp.

On the back of the pre-amp there will be MAIN front left and right outputs that go to your amp. With Audio Research there is two sets of balanced, and two sets of single ended. On the CJ there is two sets of single ended only. The two sets allow BI-AMPING, EXC.

You will take the MAIN OUTS from the pre-amp to your amp/amps (AMPS IF BI-AMPING) for the front left and right speakers. When you select the Processor Loop setting your PRE-AMP simply removes all of the pre-amp volume control and pass the signal through to the amps, without any volume control supplied by the pre-amp. Your HT processor controls all volume.

When you go out of the processor mode your pre-amp now takes back the volume control and feeds the signal from what ever source you choose, from the PRE-AMP inputs (CD, Tuner, AUX, EXC.) to the same MAIN OUT'S to your amp/amps. NOW you are back in pure 2 channel with only the tube pre-amp in line.

The better units will do a very good job of the switching.

Of the two I mentioned Only the CJ will require you to ask for the unity gain cir. For what ever reason they have it as an ask for thing. The Audio Research comes with the processor loop already set up this way.

I wanted a tube Front end to feed my B&W 801N and this works great.

Hope this helps
...I follow all of the above fine (I think). I'm not concerned with cutting the pre-amp out when using HT, rather how to cut the HT controls out when listening to music.

When listening to 2-channel, I would be using the analog output of the AVP (DAC/Processor) to go into the new pre-amp. As such, the analog signal going into the pre-amp would be subject to the volume control on the AVP then again on the pre-amp. Right?

BTW, the AVP itself has a unity gain 'remote' set of analog outputs that I currently use to power my headphone amp. It allows the choice of using the main path, the remote path or both. I could probably use this set of outputs to alleviate the issue above (if there is an issue...).

Thanks again,

Hi Thomas

I will try to list the hook up.

DVD player--->HT Processor----> HT Processor left and right line level outputs---> Pre-Amp Processor loop input----> Pre-Amp main left and right output to amp/amps for front left and right speaker.

HT Processor Center, REAR left and right line level outputs to Center, REAR left and right amps and so on if 7.1 exc.

Select Processor loop on Pre-Amp use remote/HT volume control to contol volume.

When you select Processor loop setting on the Pre-Amp it will automaticly place itself in passive mode and have no effect on volume control. No setting or volume matching require. The only volume concerns is controlled by the HT processor.


Transport--->DAC---> CD input to Pre-Amp---> Pre-Amp Main left and right already to ftont left and right Amp. Exit Processor Loop, Select CD and now use Pre-amp remote/Volume to control volume as Processor is no longer in loop.

Works the same for a source equipment. To listen to what is hooked to the HT Processor select the input on the HT Processor for the unit. Select Processor Loop on Pre-Amp and use HT processor to control volume.

To listen to any source hooked to the Pre-Amp make sure the Processor Loop is not selected, then select the Pre-Amp input that the unit is hooked to and listen useing the Pre-Amp to control Volume.

You will most likely want to have 2 channel transport and such go straight to the Pre-Amp not the HT Processor. If the source player/transport is the same unit then the Digital signal goes to the HT Processor nd the analog outputs from player/Dac will go to the Pre-Amp direct.

Hope this with previous post helps clear things up
Hi Thomas
In your last message you state that you would be using the analog output from the AVP to the Pre-Amp.

Is the analog outputs fixed level outputs. By this I mean there may be outputs for the DAC'S that may not have volume control. If it does then you wound take that to say the AUX,orCD input on the Tube Pre-Amp. BE SURE THOUGH THAT IT IS A FIXED LEVEL OUTPUT. You woud be useing it like any other input and then the Pre-Amp controls the volume

If you are talking about you main speaker outputs then they would have to go to the processor loop in. Then the Process will control volume.

If you want to get a gain from a Tube Pre-Amp you need to be able to get an analog fixed level signal from the DAC (may be by way of fixed level analog output from the AVP) to a Pre-Amp input, for it to use as an incoming signal.

I would check the owner manuals to see what you have.
Hi Thomas
Just seen you new Post and I am not up on what the Proceed AVP will do, so can not help much there. But the last post connection should work on most systems.

Hope my last post will help. But not sure why you would run the 2 channel source to the AVP at all. Go straight to the Pre-Amp inputs with your analog outputs from the player or the DAC which ever you use.

For me I wanted the Tube Pre-Amp sound for 2 Channel. Again to me both the Audio Research and the Conrad Johnson is so much more musical than my Lexicon MC-1 that I want to remove the Lexicon out of the 2 channel mode. I also did not want to have to switch the interconnects each time. With the above the surround processor is removed from the system allowing total control of the 2 channel from start to end with only the 2 channel system in line.
Thanks for all your input. It's much appreciated. Here's the way my system works and why I'm having the questions:

Source - Proceed PMDT, this is a DVD/CD transport, digital output only with cards for progressive scan video output. It also acts as a video switcher to take in output from other video devices and translate them also to 480p output. Sounds great with redbook CD. So all source material goes through this unit.

DAC/HT Processor/Pre-amp - Proceed AVP, this does everything, D/A conversion, surround sound, normal pre-amp functions.

So to add a regular two channel pre-amp, it has to come into the path after the AVP in order to receive an analog signal. The source for DVD home theater and 2-channel CD is the _same_. Thus, the conundrum with how to isolate the control functions of the AVP while still using it as a DAC to send analog output to the proposed tube pre-amp.

It can be done, it's just how tedious and how much signal degradation will be involved. If only I has the space and $$ for two complete systems...


I can't fathom the benefit of running out of the AVP to yet another preamp. You don't need any more gain, nor input switching. I'd think you'd either do something in lieu of the AVP or call it a day.
Sorry, this thread is a continuation of an earlier one. The goal was to integrate a tube pre-amp into the system for use when listening to 2-channel music. This would be followed by tube monoblocks for my front R & L speakers.

I like the tube sound but only have space for a single system that has to do double duty between HT and music.

Here... I have the exact setup with the exception that my pre-amp is a Mark levinson 380S


The PMDT Transport has multipule digital outs, the AES/EBU goes to my DAC (soon the BE ML 36S) and I also have a Ensemble Digiflux BNC going to the AVP.

The AVP main Left right go to the ML 380S pre-amp as it has a unity gain called SSP this is specifically made for this reason, to incorporate HT in a 2 CHN environment.

My PMDT by-Passes the AVP and goes directly to the ML380S when I listen to CDs.

Can't ask for a better setup

So you use the AES/EBU output to a 2-channel DAC and from there to the ML 380S and on the the amps. You program the PMDT to route CD's to that output, select that input on the PA and completely bypass the AVP, right?

That's sweet, now I get to shop for a new DAC as well as a PA and maybe even a (heaven forbid) turntable. Then I have to get the wife a present to cover my ass.

Have you heard anything other than what's on the Madrigal website regarding the AVP upgrade and potential SACD playback on the PDMT/AVP combo?


>>So you use the AES/EBU output to a 2-channel DAC and from there to the ML 380S and on the the amps. You program the PMDT to route CD's to that output, select that input on the PA and completely bypass the AVP, right?,,

correct, there is noting to program on the PMDT, all outputs are enabled at all times, you just have to select that input on the preamp that is feed by the DAC, to bad on the DAC, just sold mine and picked up the ML36S.

Lots of rumours on the PMDT, there is something coming up on the PMDT, however, I think it will start with the possibilty of DVD-Audio.

There is also the AVPII coming next year...not sure what it will offer. But I have to say I am thrilled on the PMDT's performance..based on Levinson's No37 transport..and now with it PVP feature...excellent !