Help! Connecting amplifiers together ? Lots of details provided.

J

JMJVK

Audioholic
Hello all. I have a rather simple and modest dual Stereo/AVR living room setup, but something is amiss in my connection strategy for a living room with two amps, which forces me to use a not-so-clear strategy for playback when using certain sources.

One practical example: I use a Western Digital streamer for much of my music and movie playback. The streamer is connected to the AVR with HDMI for movies, no problem there. But for music playback on the HK3490, I have to use an analog RCA connection: The stereo's two digital ports are already occupied by a link to a DVD player with a Toslink and to my SACD capable BD player using Digital CoAx, so I cannot use the WD's Toslink connection. The big caveat is that my streamer does not sport a good DAC like the stereo does, so sound quality is sacrificed, lest I use my optical disc media.

I'm about to change the audio gear stand, requiring a full dismantling and re-connect. I need help to connect my two amplifiers together, each as a possible digital source for the other. So I won't have to suffer with this problem anymore. Below is all the details I believe to be relevant. I'm hoping someone with a "fresh look" could identify an angle on this which could resolve my problem by changing the interconnects, or better yet, explaining to my how to properly cross-link my two amps so they both can be used as pre-amps for the other.

I have tried at one point to connect them using the "zone 2" of the AVR into one of the HK's analog inputs set to "Tape monitor", and I never got it to work. I'm usually pretty good with connecting gear, but I'm in a rut and need fresh eyes on this, even if it wounds my pride.




Here's my gear:

My Stereo setup:

* Harman Kardon HK3490
* 2 X JBL Studio 38II
* 2 X Reference Audio R50S

- Pioneer Rondo 2000 Turntable
- LG LGD435 DVD player.


My Home Theater:

* Harman Kardon AVR3600
* 4 X JBL Northridge E-60
* Reference Audio R550C
* 8" JBL Northridge SUB

- Sony BDP S5100
- Samsung BD-P1600
- WD TV Live media Hub 1TB #1
- Digital Cable & PVR box
- (Via SMB network) WD TV Live media Hub 1TB #2
- (Via Toslink) Creative SB X-Fi 5.1 USB


Here's how it's currently connected



Here the rear end of both devices:




I will subscribe to this post and closely monitor what happens here. Don't be fooled by my low post-count; I will be back and no answer or suggestion will go unread. Thanks to all who try to help.

:confused:


Edit:

Just did some test on the AVR --> HK connexion.

- Tried connecting AVR3600's digital coax out to HK3490's coax input, then reassigned one of HK inputs for coax input. No dice.
- Tried using AVR3600's preamp L+R outputs to HK's "tape monitor". again, No dice.

- Using AVR3600's analog "Tape OUT" to HK's "tape monitor" works, but it's a "hack" in my book. The signal is not affected by the AVR's volume or mute, but it is positively submitted to the AVR's tone and EQ settings.
 
Last edited:
P

PENG

Audioholic Slumlord
The stereo's two digital ports are already occupied by a link to a DVD player with a Toslink and to my SACD capable BD player using Digital CoAx, so I cannot use the WD's Toslink connection.
You could invest in a low cost external DAC headphone amp that accepts the WD's Toslink out.

Just did some test on the AVR --> HK connexion.

- Tried connecting AVR3600's digital coax out to HK3490's coax input, then reassigned one of HK inputs for coax input. No dice.
Have you read the relevant section of the manuals yet? It maybe possible that the digital out of the AVR would only work if the source is digital.

- Tried using AVR3600's preamp L+R outputs to HK's "tape monitor". again, No dice.
Did you forget to crank the 3490's volume up, and why tape monitor in particular, did you try the other analog inputs?
 
J

JMJVK

Audioholic
Thank you for looking into this.

- I'm not much of a headphone listener, I only own a modest pair Sennheiser 202s and I'm really trying to get the sound on my speakers.

- I have read the AVR'S manual. There's something which seems to escape my grasp; The Zone two setup instructions are rather lacking in detail, and I can't, for the life of me, find a way to make it work. In the end, a lot of time spent without any results. I'm very much willing to give it another go, if someone can coach me into it, though. My source was digital. My only analog source material are vinyls which play directly on the HK3490. Using the AVR's analog "tape out" is just the only way I've managed to get any result at all for the moment. I would much prefer digital transport.

- I cranked the volume, and chose "tape monitor" for two reasons; 1st, because it actually works, and second because while making my tests, it ruled out making some dumb mistake on input assignment. On the HK3490, The dedicated channels are Phono (used for vinyl), CD (used for BlueTooth receiver) and "tape monitor".
The other three channels are Vid 1, Vid 2 and Vid 3 are all programmable to use analog inputs 1, 2 and 3, Front analog, digital coax or Optical.



I've managed to take out four cables out from this mess, now that I have a working solution, but I still feel it's an amateurish "hack". I know people would probabaly use the "Zone 2" system, but apparently I have some kind of an intellectual equivalent to an "air pocket in the hose", and the pump just can't prime itself....
 
P

PENG

Audioholic Slumlord
Thank you for looking into this.

- I'm not much of a headphone listener, I only own a modest pair Sennheiser 202s and I'm really trying to get the sound on my speakers.
I wasn't suggesting headphones but usb dac headphone amp that can be connected to the analog in of your 3490, some of them actually have enough output to drive a power amp.
 
Swerd

Swerd

Audioholic Warlord
If I understand correctly, you want to be able to run digital connections from the WD streamer to both an AVR and a Stereo receiver.

Look over these mostly inexpensive accessories and see if any of them might be of use:

Digital Audio/Video Converters in the Home Audio / Video Department at Parts Express | 114

A/V Source Switchers in the Home Audio / Video Department at Parts Express | 125

Why do you want to use an AVR and a Stereo receiver in the same room? Why not use the AVR for both purposes? I noticed that you have different speakers run by each receiver and a phonograph on the stereo system. You can find ways to run multiple sets of speakers, and a phonograph on an AVR while avoiding the difficulties you now have.

I use a Western Digital streamer for much of my music and movie playback. The streamer is connected to the AVR with HDMI for movies, no problem there. But for music playback on the HK3490, I have to use an analog RCA connection: The stereo's two digital ports are already occupied by a link to a DVD player with a Toslink and to my SACD capable BD player using Digital CoAx, so I cannot use the WD's Toslink connection. The big caveat is that my streamer does not sport a good DAC like the stereo does, so sound quality is sacrificed, lest I use my optical disc media.

Edit:

Just did some test on the AVR --> HK connexion.

- Tried connecting AVR3600's digital coax out to HK3490's coax input, then reassigned one of HK inputs for coax input. No dice.
- Tried using AVR3600's preamp L+R outputs to HK's "tape monitor". again, No dice.

- Using AVR3600's analog "Tape OUT" to HK's "tape monitor" works, but it's a "hack" in my book. The signal is not affected by the AVR's volume or mute, but it is positively submitted to the AVR's tone and EQ settings.
 
P

PENG

Audioholic Slumlord
Preout of an AVR is meant to be connected to the inputs of a power amp. If you connect it to the input of another AVR (the 3490 is a 2ch AVR) such as the 3490 then you have to either remote the jumper and connect the preout of the 3600 to the main in of the 3490 (obvious that is not an option for you), or you connect it to one of the analog input such as the tape in, CD etc., and then you have turn you HK3490's volume to maximum, also not an option for you.

So the normal way is to do it the way you are doing, that is not a hack, it is the right way and should work the same if you use the CD input. Using a digital switcher as Swerd suggested is also good if you want to avoid the WD's DAC.
 
Last edited:
J

JMJVK

Audioholic
If I understand correctly, you want to be able to run digital connections from the WD streamer to both an AVR and a Stereo receiver
That's not quite my problem. The WD has a "ordinary" DAC, but I want to use my amplifiers' DACs. Because my stereo amp's digital inputs are loaded, I wanted to send more digital sources to the home theater AVR, and then have the one bit-stream link from the AVR to the Stereo for music playback, thus avoiding using the WD's dac which is required to use the stereo if I leave things as-is. (The HK3490' speakers are better balanced for music playback)

I have toyed with the idea of using a switcher. I actually have a half decent unit laying around, but given that my better half also uses this setup, I have to try and keep it as straightforward and simple as possible, or she's going to flip out and call me every time she wants to use it and can't figure it out.

Why do you want to use an AVR and a Stereo receiver in the same room? Why not use the AVR for both purposes?
The AVR sounds great, but has no Phono segment, and I listen to vinyl everyday. Further more, I like to listen to music in a A+B mode (Stereo channels, duplicated) with four speakers. The AVR force either 2 way stereo, or I have to use various DSP modes which all force the mid into action. (Harman's chief engineer should be fired for omitting a 4 channel "A+B" mode). Anyway, so that mid is not a full range speakers, it's a 70Hz~20Khz, which is great for dialog clarity in movies, but it seriously mucks up things for music playbacxk, because the other four are full range (Best does 21.1Hrz, worst is 23Hrz), and I dislike the "odd one out": It kills certain harmonics, and colors certain instrument's lower-mid notes. Pianos, cellos and clarinets suffer horribly.

Thanks for taking the time to help. Swerd.


I was almost tempted to actually use a switcher (instead of 3490's jumper) to switch between the 3600's Pre-out and the 3490 pre-out then back to the 3490 amp-in, but decided against it because I think I may create more hiss and hum by adding impedance/capacitance imbalance at such a critical phase. I'm going to search fro Zone 2 tutorials on Youtube and see if I can get my head wrapped around this.

Thank you very much, Peng. I'm feeling a little less guilty about the "hack", but I'm not defeated yet.
 
Steve81

Steve81

Audioholics Five-0
The AVR sounds great, but has no Phono segment, and I listen to vinyl everyday. Further more, I like to listen to music in a A+B mode (Stereo channels, duplicated) with four speakers. The AVR force either 2 way stereo, or I have to use various DSP modes which all force the mid into action.
Couple thoughts that may help to simplify things:
1. Phono preamp ala the Emotiva XPS-1. I'm not a vinyl guy, so I can't make recommendations on less costly models, though they certainly do exist.
2. Utilize Zone 2 to create your A+B mode.
 
J

JMJVK

Audioholic
Utilize Zone 2 to create your A+B mode.
Edit: I'm done looking into it. It require the source to be analog on my particular receiver. This means the Zone 2 capability is useless to me.

I guess I'll have to use it as it is. It's quite workable, but it just feels "not right" because the signal is affected by EQ and tonality settings. (I tend to lower the bass on it for night time movie watching).


Thank you all folks. I appreciate your input and patience. Hopefully, I'll make up for at some other time.
 
Last edited:
Swerd

Swerd

Audioholic Warlord
Inexpensive phono preamps for moving magnet cartridges (less than $100) are widely available. There are far too many to know them first hand, but I suspect that many are up to the job. I can recommend the one I use, an Audio Technica PEQ3. I bought mine several years ago when they were widely available in the US. A Japanese import is still a reasonable price. I found no audible difference between mine and the built-in phono section of an older Denon AVR I had been using.

Your HK 3490 stereo receiver has PREOUT and MAIN IN RCA jacks. Normally they are connected directly to each other by two jumpers, but you can remove the jumpers and run the PREOUT from your 3490 (see page 9 of the 3490 manual) to the Front Left and Front Right input jacks on the back of your AVR 3600 (in the 6/8 Channel inputs). That way the HK 3490 functions as a separate preamp that sends signal out to the AVR 3600 amp section. Any audio source connected to the HK 3490 can be played through the AVR 3600 amp section.

If you want to run this the other way, run the ZONE 2 OUT jacks from the AVR 3600 to the MAIN IN jacks on the HK 3490.

There seems to be other options on the back of 3600, including ANALOG4 OUT (may function like a tape loop), and digital COAX OUT (for sending a digital signal out from the 3600 to the 3490. See page 6 of the AVR 3600 manual.

There is more to those manuals than I can download and read now. I hope one of those options works for you. Good luck :D.

I sometimes find these manuals don't explain everything in adequate detail. It may be useful to try a connection or two, and find out by use what works and what doesn't work for you.
 
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J

JMJVK

Audioholic
Options and what works

Current scheme

Right now I'm somewhat resigned to using the AVR 3600's "Analog 2 out" to the HK 3490's "tape monitor in". This doesn't look or sound as "pure and straightforward" as a "digital out --> digital in" connexion, but it's a working solution for the moment. It allows playback of the streamer's music files using the AVRs DAC, amplified by HK. It's comically twisted, but it is better than messing with the streamer's output menu and using it's onboard DAC whatever the chip is.



Here's what I've got as "potential solutions" so far:



AVR 3600's "digital out --> HK 3490's digital in" Doesn't work


A quite "pure and straightforward" proposition. Problem is that for some incomprehensible reason, it just doesn't work. I'm puzzled by this problem, and just can't figure out what's wrong. The video link in the next paragraph mentions doing Zone 2 using a digital link another amplifier, (3:54), but only working with analog sources.

If I'm getting this right, this means the AVR can digitize an analog source signal and forward it to another amplifier as a bitstream, but the same AVR can't forward a native bitstream source "As-is" to another amplifier. Am I alone in thinking that this is twisted and doesn't make any sense ?


AVR's Zone 2 via RCA analog out --> any of the HK 3490's analog input Doesn't work

After a fair bit of searching, I've come to believe that on my AVR, like many AVRs of it's vintage, Zone 2 only works when the source material is analog. Apparently, digital sources can't be carried to Zone 2 in any way. That sounds like a most stupid design decision, but (Audioholic's own review seems to confirm this about my amp (3:45). Apparently Onkyo AVRs of the same year also had the same caveat, so it's not just a Harman thing. (Found this out on an official Onkyo AVR setup video) It kills the Zone 2's usefulness and makes it into a kind of "what the .... where they thinking of ?" thing, but, I digress... The whole reason for me wanting to bridge these two amplifiers is precisely to send a pure and unadulterated bitstream from one amp's source to the other amp.


Using a dedicated phono pre-amp or HK3490's pre-amp signal to the AVR for playback Wrong playback amp

Sending the Phono signal to the AVR is also a no-go. The AVR's sound is great when the source is multi-channel, like a movie or concert DVD, but I'm looking for good, 4 speaker playback from a stereo source, and the AVR just can't do it.



Switchbox between the "HK 3490's Main-in" and the pre-outs of both amps. Scary, kills remote usability.

I have an old RCA switch. It was meant to use two sources on a single amp input, and allowed inter-connecting the two sources for recording purposes. There are resistors in it on one side of the PCB. There may be diodes on the other side of the PCB, but I can't see under it, and because it would require manual switching, I'm not interested. Thought I'd upload photos just for the heck of it:

View attachment 13099View attachment 13100View attachment 13101



So the best potential I have is:

Daisy chaining the HK's signal to the AVR and back again to the HKs "Main-in". Scary but potentially workable

"HK 3490 Pre-out" --> "AVR 3600's FL+FR analog in (from 8 channel analog RCA inputs)" then going back to "AVR 3600's analog pre-out" --> "HK 3490's Main-in".

I'm not certain it's a good idea. I'm afraid it may add jitter, impedance and capacitance or bring out other unforeseen negative consequences. These lines sound to me like they should be "pure" and respect some kind of industry standard or some logical design ideal, but I'm not knowledgeable enough, and know nothing about these signals' potential for interoperability.

Any Ideas/comments ?
 
Last edited:
J

JMJVK

Audioholic
That option would be fine to play my records on the AVR, and doing away with the stereo, but the thing is, I want the sound to be amped by the stereo, because of it allows playback using 4 speakers (A+B). Unfortunately, my AVR does not let me do this. It forces artificial 5.1 and 7.1 modes using a bloody DSP, and lacks the option for mirroring FR+FL to FSL+FSR.

Looking at the gear you linked, I had a moment of clear thinking: I will simply purchase a new streaming and SACD capable BD player, hook-it to the stereo and use that to stream music to it. It's a minimal cost solution and should satisfy my needs.


Thanks to all who've contributed to this thread. Sorry if the solution is somewhat anti-climactic
 
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Steve81

Steve81

Audioholics Five-0
That option would be fine to play my records on the AVR, and doing away with the stereo, but the thing is, I want the sound to be amped by the stereo, because of it allows playback using 4 speakers (A+B).
Hi there,

The DACs I linked aren't related to playing records on your AVR; that would be a phono preamp. As mentioned, you'd run the Toslink cable to the DAC, and then analog interconnects from the DAC to the 3490. Of course, if getting another SACD/BD player will get the job done for you, so much the better.
 
J

JMJVK

Audioholic
Of course, if getting another SACD/BD player will get the job done for you, so much the better.
Well, getting a BD player is the most inexpensive route, and it will eliminate the need to switch the audio out settings on the streamer.

I was so focused on getting a link between the amps... I hate myself for not thinking about using a BD player sooner. Meanwhile, I'll use one of my current units and just switch the outputs when I need too. (The better half never uses those, she only uses the streamer, so she won't hit any snags due to settings she doesn't understand...)
 

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