mono amplifier speaker connection

[Sansiiro]

I am very happy to be in this forum, since I always get good feedback here.

My inquiry today might not be most sophisticated one, but nonetheless.

My XTZ-Edge amplifiers have a mono mode, so I can use two amplifiers at once.
But using mono mode I must connect ALL (8) binding posts, which forces me to use two sets of cables (which I don't like).
However I use Audioquest Rocket 22 cable, which has 2 positive and 2 negative separately isolated strains in one cable.
Regularly these 2 strains are peeled and merged at the ends, resulting in one positive and one negative plug.
So I am curious to use this cable with 4 plugs on the amplifier end.

Here's my question - is it safe to use 4 plugs only on the amplifier end, but let the strains on the speaker end of the cable be merged together
as they are?


30479


Veiko

[Barry]

I am very happy to be in this forum, since I always get good feedback here.

My inquiry today might not be most sophisticated one, but nonetheless.

My XTZ-Edge amplifiers have a mono mode, so I can use two amplifiers at once.
But using mono mode I must connect ALL (8) binding posts, which forces me to use two sets of cables (which I don't like).
However I use Audioquest Rocket 22 cable, which has 2 positive and 2 negative separately isolated strains in one cable.
Regularly these 2 strains are peeled and merged at the ends, resulting in one positive and one negative plug.
So I am curious to use this cable with 4 plugs on the amplifier end.

Here's my question - is it safe to use 4 plugs only on the amplifier end, but let the strains on the speaker end of the cable be merged together
as they are?


30479


Veiko

If you read XTC's information for the EDGE A2-300: https://www.xtzsound.eu/edgea2300?lng=en#!/EDGE-A2-300/p/384936051, it is not at all clear if the two outputs can be paralleled up when in 'mono mode' (see the second diagram: "Bi-Amping Setup"). I suspect not, but if your speakers have four terminals and use links, then you can use the amps in mono mode with your cables if you use all four wires (strands) and remove the speaker links.

[Sansiiro]

Thank you Barry.
I suspect the same, so I spent time today changing these cables, to give them four plugs at each end.

To my surprise, when peeling the insulation there was a lot of oxidation present.
Must be because I once tried cleaning them with vinegar.
30482

However the end result is like this.30483

But the evaluation is not easy. Once I fired the system up with the "new" cable, I got the
sensation, that the sound is more stressed. But maybe it is just me, that is stressed.
Perhaps the amps need time to warm up? And by that time I am unable to recall how it was
before, and I can not A-B it, because I have changed the cable.

Also - for some time (before today, when strains were merged) I used the system as not intended - exploiting only one set of outputs of each monoblock (intended is 2 sets). And I liked it. But I have noticed this, that when you KNOW
you are doing something "wrong" you tend to be more forgiving of your system, more tolerant and
relaxed. As opposed to when you try to exploit the "A-game" of your system, you are expecting a lot,
and not pleased so easily. So there is that to consider, if you can follow my thought.

So many SQ improvements are hard for me to track and point finger at. At any given moment there could
be so many factors, starting from myself and ending with synergy of certain products, which I also change
quite often. This unpredictability leads me to rely on some "scientific theory" of what "should" be best.
Which creates the absurd situation, when instead of listening ones system one might search "logical" answers from
internet forums and youtube. And that might not work, reviewers have different opinions and so on.
But we do want everything to be right, and sound right and so on.

So now I am listening the system that is cabled up the right way, but I have a suspicion that it sound more
stressed than before, when I was using only half of the power of each monoblock.

Atleast I just had a good idea - I can A-B it, if I remove the plugs and stick bare wire and merge them into the amp terminals.

It has been very good sharing my experience with you.
I believe I will soon write about my findings having A-B-d two different ways of connection.
Have a great weekend.

[Lawrence001]

Here's my question - is it safe to use 4 plugs only on the amplifier end, but let the strains on the speaker end of the cable be merged together
as they are?

Veiko

Reading the manual I don't think you should. They are 2 separate channels that mirror the input signal from one input, not bridged mono. If you join them at the speaker end you are joining 2 separate channels together. With many amps this might damage them, if you haven't you are lucky.

"In mono mode, the input Signals at the left and right RCA Input are accumulated and both Output channels will reproduce this accumulated Signal. In case only one Input channel is used, the Signal from that channel will be distributed to both Output channels. e.g.- Use the stereo mode when using the amplifier in a regular stereo system.- Use the mono mode when using the amplifier for Bi-Amping with a single speaker"

You either need speakers that have HF and LF inputs (4 sockets,) or just use one amp not 2. Your previous method might be marginally better as it places less strain on the power but I think the ice power boards have separate power built in each board, therefore it makes no difference so just use one amp.

[Sansiiro]

Very interesting.
I suppose I should also try with just one amp.

But I would like to test the difference when connecting 2 amps with 4 plugs VS with 2 plugs on amplifier end.

a) So we have established that I should not merge cables on the speaker end (4 from amp to 2 in speaker, (with jumpers)).

b) I also somewhat established that 4 into 4 sounds stressed to me (4 from amp, 4 into speaker (without jumpers)).

c) What I have used, and what I liked was 2 from amp (supposed to be 4) and 2 into speaker (with jumpers). No apparent damage there.

d) What I have not tried but I am curious about is to merge the wires on the amplifier end (2 from amp (instead of 4), 4 into speaker (without jumpers).
Would that be safe?

I know using 2 outs from amp basically equals only using one amp, but I hope that using 2 amps with halved power has sonic benefit over using one with full power.

[Barry]

Yes, option (d) would be safe, it is essentially the same as option (c), provided the outputs not used on each amplifier are loaded with an 8Ohm resistor.

There is another option which you might like to try, using both amplifiers in 'mono' mode. As far as I understand it, when 'mono' mode is engaged, one of the channels (of the nominally two-channel amplifier) is fed via an inverter, which makes that channel 180 degree out of phase with the other channel. That means double the voltage appears across the two red speaker terminals. All you need to do is connect the speaker cable to the two red sockets. How you wire the speaker cable to the speakers is up to you, i.e. with or without jumpers.

[Sansiiro]

I believe I will try the "d" option out then.
I will take proper time for that, to get the sense of what is the difference.

This fiddling with them plugs is bit stressful, I should say. I always thought that oxidation would
occur more on the bare wire, but for some reason I find it much more from under the (original) isolation.
Some of the screws in plugs are failing and I also keep breaking the singular threads.
It would be a solution to buy a new cables, but since I am probably going to buy a new amplifier also,
I am postponing that.

About using two red terminals on the amp in mono mode - that certainly sounds interesting.
Just to be absolutely sure - that would be using normal speaker cable (2 lines) and both of them lines
would be connected to the red (plus) terminals of the single amp, that is in mono mode, and to a
single speaker - one to plus terminal, and another to minus (?).

Thank you for your time

[Barry]

I believe I will try the "d" option out then.

About using two red terminals on the amp in mono mode - that certainly sounds interesting.
Just to be absolutely sure - that would be using normal speaker cable (2 lines) and both of them lines
would be connected to the red (plus) terminals of the single amp, that is in mono mode, and to a
single speaker - one to plus terminal, and another to minus (?).

Thank you for your time

Yes, that is correct.