A38 and Mono amping

[xedos963]

Hi there,
Can someone please enlighten me on the following.
Current setup:
CD23T
Solo Music (as pre-amp) with irDock
2x P38 with mono-link
Totem Acoustic Hawk

I've just picked up a DT26 for £155, which will also have to go via the Solo for now.

So my original 1 box solution has grown somewhat, as I can't help myself picking up nice kit for a good price!

So my final piece in the jigsaw is the pre-amp. I've been looking out for a C31, but prices are still quite hefty.

My questions are:

1. Is the pre-amp stage in the A38 the same as in the C31?
2. Can I replace my Solo Music and one P38 with an A38?
3. Will this give me the pre-amp stage I'm after and still allow me to mono-amp, or will there be any imbalance between the A38 on one side and P38 on the other?

I really do need to stop adding more boxes to my system! )

Many thanks for any feedback, experience and suggestions.
Simon.

 

[Clive197]

Hi there,
Can someone please enlighten me on the following.
Current setup:
CD23T
Solo Music (as pre-amp) with irDock
2x P38 with mono-link
Totem Acoustic Hawk

I've just picked up a DT26 for £155, which will also have to go via the Solo for now.

So my original 1 box solution has grown somewhat, as I can't help myself picking up nice kit for a good price!

So my final piece in the jigsaw is the pre-amp. I've been looking out for a C31, but prices are still quite hefty.

My questions are:

1. Is the pre-amp stage in the A38 the same as in the C31?
2. Can I replace my Solo Music and one P38 with an A38?
3. Will this give me the pre-amp stage I'm after and still allow me to mono-amp, or will there be any imbalance between the A38 on one side and P38 on the other?

I really do need to stop adding more boxes to my system! )

Many thanks for any feedback, experience and suggestions.
Simon.

1. The A38 Pre-Amp Stage is based on the C31 but is not quite the same.
2. Yes, but you obviously lose the Tuner.
3. The A38 and the the P38 are matched and work perfectly well together. I used this combination a couple of years ago in a Bi-Amp configuration, sound was excellent.

You think you hsve problems with boxes, my current system uses Cyrus (PreXPdQX, MonoX's, CDXT SE2 Transport, StreamX and a pair of psx-r's, making 7 boxes excluding BluRay, Sky+, 2 box Phono Stage and Turntable.)

Clive

 

[xedos963]

Many thanks for the advice Clive.

Yes, will loose the tuner, but the DT26 will give me what I need, as I only listen to DAB - shame I can't still keep the irDock, but will likely pair that with the Solo Music and a P85 I also have, for a secondary system, which is where I started out with the boxitis! ;o)

If the preamp stage of the A38 is close to the C31 then I'm sure it will give me the missing boost to provide a well balanced system. I'm already very happy with the sound I get from the CD23Ts RingDAC.

The only future change might be a CD37, when the CD23T decides to retire itself. But then I'd probably look at a music server or a combined BR thingy like an Oppo 95. Don't really have time to watch movies though, so always a pleasure to select a CD, slip it in and turn up the volume )

Regards,
Simon

 

[Clive197]

I used to have a CD37, great player. I'm just selling my Arcam DV-139 and have already replaced it with the Oppo BDP-95EU. Great Universal player, CD's sound nearly as good as in my Cyrus, so can recommend it.

Clive

 

[xedos963]

Just been checking the A38 manual and there's no mono-link on the rear panel - you know, that inch of bent coat hanger you get with your rather expensive piece of kit )
So although yes, fine for bi-amping, I'm still not 100% sure re. mono-amping.
Guess that because it has 2 sets of speaker outputs you just use both those for 1 chanel HF and LF.

 

[xedos963]

Can anyone definitively confirm my assumptions on this? - before I make what could be an expensive and possibly disappointing purchase.
To be clear, my intention would be to use an A38 and a P38 to provide pre-amp and mono-amp duties. As such I would be using all 4 outputs on the A38 as the mono amp for one speaker and the speaker 1 + speaker 2 outputs on the P38 for the other speaker (which I know is fine, as I'm already using 2x P38s to mono-amp).
Many thanks if someone can confirm this will work and be a well balanced configuration.

 

[Mark.Yudkin]

I'm not quite sure what you mean by "mono-amp". The "mono link" is merely a rear-panel equivalent of a splitter cable enabling you to use both channels of the stereo amp to amplify the same signal using a normal interconnect. The P38 cannot be bridged: it cannot be used as a monoblock. If your speaker supports biamping, then you can use the two channels of the ampliifer for that. Using the speaker 1 + speaker 2 outputs is simply biwiring, a more expensive version of using thicker wire, not a means of obtaining addtional amplification.

 

[xedos963]

Yes, I've got a little confused as you can tell. Indeed I mean using the mono-link in order to maintain seperate channels of amplification to left and right, as per page E-14 of the Arcam manual. But rather than need a P38 for each side, to use it for one side and use the integrated amp in the A38 for the other sidel. So one side would be as per E-14 and the other taken directly from the A38 speaker terminals - as per the "Bi-Wiring" diagram on page E-9. The aim is to have seperate amplification for left and right, not to obtain more amplification. I've read that this can be beneficial and wanted to try it and see if I could hear (or think I hear!) a difference. Not relevant to this question, but as info. I already use 2 wire runs for the LF speakers - i.e. 2 cables lightly twisted together with 1 Milty plug on each end of the run - as I'm using Totem Tress which is a thinnish cable. Hope this makes sense - difficult to describe without a photo or drawing.

 

[larkone]

The A38 will be receiving a stereo signal and is also your pre-amp so there is no way of sending just one channel to this and the other to the P38 as this does not have a pre-amp. I think what you are trying to do is bi-amp. For this you need to connect left and right speaker outputs on A38 to HF on left and right speakers and take a stereo pre out to the P38 and connect left and right speaker outputs to the LF on the left and right speakers.

You can only achieve the solution you are describing and what is described on page E14 if you have one A38 and two P38s. With one A38 and one P38 you need to wire it as per the bi-amping diagram on page E8. The mono links then are only relevant to the P38 in the situation described on E14, they are not relevant to the A38. Both solutions are very clearly described in the manual so that you do not get it wrong - the danger is trying to do something that is not described in the manual.

 

[xedos963]

Thanks, yep so the answer is as anticipated really - can't be done like that. Fortunately I do have 2 P38s, so can achieve a hopefully good result - the reason I've been looking into making an A38 act as both pre-amp and power amp in this manner is because I originally started out with just a Solo Music, as a 1 box solution, so things have got a little out of hand now, with the stack I've ended up with...
irDoc
Solo Music
DT26
CD23T
P38
P38
But then with the prices I've managed to pick this quality kit up for second hand, it's a problem I'm happy to live with )

 

[xedos963]

Well as luck would have it I've just managed to offer a good home to a C31 for a very fair price, soooo...

Now planning to have the CD23T and DT26 into the C31.

LH out from C31 into first P38 and into LH Totem Hawk using speaker 1 and speaker 2 outputs.

RH out from C31 into second P38 and into RH Totem Hawk using speaker 1 and speaker 2 outputs.

Keeping the LH and RH channels separate like this will hopefully ensure the best sound quality.

Anyone with any experience / advice / thoughts on this?

Is there any theoretical advantage, or should I just stick to "normal" bi-amping with one P38 driving LH and RH LF and the other the HF?

Simon

 

[larkone]

You have a choice - go with a possible theoretical advantage and there are arguments supporting both configurations or try both and trust your ears to make the choice.

 

[Mark.Yudkin]

The theory is that the LF places a heavier power demand, which increases distortion, which is most perceivable in the MF. This leads to the "usual" LF / MF-HF split.

My guess is that with the Totem Acoustic Hawk's being two way speakers with a 2.5kHz crossover, the above considerations will not be applicable, the MF being with the LF on the same 140mm woofer. This would speak for having one amp per channel, to give you slightly more power for those moments of ear-drum splitting misanthropy.

In other words, you should just experiment with both options and take whichever you feel works best.