Bi-amping at last... running commentary

[Mr Nad]

Right, after weeks of deliberation, I've finally begun the process of bi-amping my system.

I'm going to be using two Amptastic Mini-T amps with 5A PSUs, and parts from Amazon and eBay, together with my existing Caiman+ which will be acting as the pre-amp.

One Mini-T will be powering the left speaker, the other the right speaker. To get me started, I bought new interconnects from eBay. I had been looking of the silver/gold Belkin PureAV interconnects, but there were none available when I was searching, but I did find normal Belkin PureAV interconnects (http://www.ebay.co.uk/itm/160660749861). Simply changing to these made a difference to the sound, improving the midrange and high frequency rendition, making it much more pleasant. I was surprised.

Next, I bought a couple of p!ss cheap phono splitters from Amazon (http://www.amazon.co.uk/gp/product/B0047JH2BU/ref=oh_o02_s00_i00_details). They work, but feel very cheap, so they will be replaced very shortly with something a little more substantial. They are being used to allow me to feed the amps' left and right channels with either the left or right channels from the Caiman+.

So, at the moment the system is bi-amped, but I'm still using one length of cable to feed both the woofer and tweeter of my speakers. However, it it clear that bi-amping has improved the sound making it more open and dynamic.

Later today I will be bi-wiring. Left channels from the Mini-Ts will be feeding the tweeters, right channels will feed the woofers.

I'm replacing the old Cambridge cable (which I think has something like 189 strands) with a more substantial 4mm OFC cable (http://www.ebay.co.uk/itm/350187678868) from ebay. I'm not sure how good this cable will sound, but I can say this cable does looks quite substantial compared with the Cambridge, so I'm hoping I will notice some improvement... I'll let you know later.

So far, I am impressed with what I've heard so far.

I'll try to post some pictures of my system, but I'm sure it will make some you you cringe.

[Stratmangler]

From your description you're not necessarily running biamped.
Have a look as this http://theartofsound.net/forum/showthread.php?t=5818

[Mr Nad]

From your description you're not necessarily running biamped.
Have a look as this http://theartofsound.net/forum/showthread.php?t=5818

I am vertically Bi-Amping:

In vertical bi-amping, a single two-channel power amplifier is used for each speaker. On channel feeds the LF bass unit, the other channel the HF unit.

I have one T-Amp feeding each loudspeaker.

Left Caiman+ output feeds T-Amp 1; Right Caiman+ output feeds T-Amp 2.

A splitter attached to each Caiman+ output allows me to feed that channel to both the L and R input of the T-Amp.

[Stratmangler]

I am vertically Bi-Amping:

In vertical bi-amping, a single two-channel power amplifier is used for each speaker. On channel feeds the LF bass unit, the other channel the HF unit.

I have one T-Amp feeding each loudspeaker.

Left Caiman+ output feeds T-Amp 1; Right Caiman+ output feeds T-Amp 2.

A splitter attached to each Caiman+ output allows me to feed that channel to both the L and R input of the T-Amp.

This led me to think otherwise
Later today I will be bi-wiring. Left channels from the Mini-Ts will be feeding the tweeters, right channels will feed the woofers.

[Mr Nad]

Apologies for the confusion. I can see how you misunderstood. Those words were chosen to try to explain that at the moment there is just one speaker cable between each amp and speaker. So although the system is bi-amped, it is currently neither vertical or horizontally bi-amped.

Bad choice of words, but I don't know which words I should use!

The cables are causing a stir... displeasure from the wife, delight from the children who think they are going to get their hands on the old cables (Wrong! that's going into the study.)

Sigue Sigue Sputnik - Love Missile F1-11 (12") has a new depth it it... I'm loving all this tweaking, and squeezing so much out of so little.

[DSJR]

Please check with Stan as to how the Caiman + will drive the load now it's effectively half what it would be normally. It's probably fine as long as the supply to the output stage/Gator is stiff enough..

In many systems, bi-amping worked for me - just depends on the products being used together :)

[Mr Nad]

...the load now [is] effectively half what it would be normally...

:scratch:

This is where my understanding of electronics/electricity/loads/current/voltage/physics falls apart. Can you explain how the load is halved?

That aside, I have now completed the process, and the differences are subtle. Listening to Tubular Bells II (which is always my test of choice) I am aware of much better separation and rendition of the instruments.

Tubular Bells II is a complex mix of instruments, but right now I can hear them so much more clearly, and the way they fade in and out is much more gradual. It's the audio equivalent of switching a monitor between 16bit and 32bit modes.

Pleased so far, but I'll need to test with a wider range of music before giving a final verdict.

[DSJR]

Stan should explain better - in this particular instance - but if the Mini T has a 20K input impedance per channel, then doubling up, which is what you're doing, will show the Caiman + a 10K total load per channel. This will put a little more loading on the Caiman's output and it depends on this unit's abilities at driving long interconnetcs as to how effective it is. I think this was another of the thoughts regarding the Gator board and, as I said above, Stan will confirm..

You won't do any harm whatsoever, but it would be nice to know what's exactly happening...

[Patrick Dixon]

This is where my understanding of electronics/electricity/loads/current/voltage/physics falls apart. Can you explain how the load is halved?


Actually the load is doubled - it's the impedance that's halved.

[Mr Nad]

Aarrgh, doubling, halving, loading, impedance.

These are words I understand in completely different contexts. But put them in the context of an electrical circuit and my mind frazzles! :steam:

I have never got to grips with parallel and serial circuits. Current and voltage. :scratch::scratch::scratch:

[wee tee cee]

Lenny,
I can recommend the splitters from maplin. I went through a couple of cheap amazon jobs, one of which literally disintegrated, the other fried and an amp!!!!
Try not to get tied up in the technicalities...trust your ears.
Tony.

[Mr Nad]

Thanks Tony. There's a Maplin not too far away, so as soon as I have the chance I'll be popping down there. Suddenly, my day became very hectic, so I've not had the opportunity to listen to as many tracks as I would like to put the new arrangement through its paces.

Perhaps tomorrow, though I'm the Sunday Chef...

[Mr Nad]

Well, what can I say?!

The improvement is much better than I has expected. I'm currently listening to a wide range of tracks - BAD, Van McCoy, Alison Moyet, punk, pop, instrumental, 70s, 80s, 90s music - and the clarity is superb. Even at lower volume levels the instruments are well separated, lifelike, and tuneful. Much moreso than with just one amp.

A highly recommended upgrade I would say.

The only problem is that now I know what speaker colouration is. I have to change their position now, but that really will drive the wife closer to snapping.

[electric beach]

I have to change their position now, but that really will drive the wife closer to snapping.

http://theartofsound.net/forum/picture.php?albumid=65&pictureid=396

We drive these alternately with a 1.5W SET amp or a Mini-T amp. Tell your good lady that this is the target, that should put your tweaking in a different perspective :lol:

[Mr Nad]

Nice horns.

If I had anything like that, I guarantee either the children or the animals (possibly both) would disappear inside together with untold toys...

I can move one speaker, but the other is currently sandwiched in an undesirable corner.

[wee tee cee]

Lenny,
Just out of interest how hard can the mini t x2 drive the f3s. I have the same speakers and find them a pretty good partner for my t amps.
Also, have you tried bi-passing the volume pot on the caiman and using the amps, a bit like a croft pre-amp with the dual pots.....

[Mr Nad]

@wee tee cee,

1 Mini-T sounded sweet with the F3s, and they went very loud.

With 2 Mini-Ts they seem to go much louder, and I find myself turning the Caiman down a little. It used to be at 9 o/c, but now it's at 8 to 8:30. Everything is much tighter and better controlled, and the bass is greatly reinforced. In fact, the bass it now so much less flabby, that I really must reposition the speakers. They have become a tad too boomy. Just a few inches forward and it would be better, I think.

The two Mini-Ts and cable upgrades have been well worth the time and £££. I am no expert, and my ears are not as refined as many here, but the difference is obvious.