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View Full Version : Transporter vs. old Audiolab gain/sensitivity



bhaagensen
2008-04-15, 07:40
Hi,

Currently I have my TP connected via RCA to an Audiolab 8000S in pre/power mode which again is connected to an Audiolab 8000P and everything is bi-amped to my speakers. (I know, it's not true bi-amping, and although I at the time thought it was beneficial, I don't really know anymore)

I've decided I want to have a go at eliminating the 8000S and running the TP directly via RCA to the 8000P. One problem is I don't know the gain and sensitivity of the 8000P. The Audiolabs are from the original series produced in the 90's. The official data for the newer series are here:

http://www.audiolab.co.uk/model.php?id=3#

Does anybody know if the data for the old ones are the same? I tried google but it isn't always clear whether its the new or old ones being refered to. And I don't want to blow up anything. Also I had a look at

http://wiki.slimdevices.com/index.cgi?ConnectToPowerAmp

and although I probably could understand it, I would be glad if anyone could "just tell" the attenuation setting I need to use on the TP :)

Thanks for your answers.

Edit: I think I've seen claims that "the new ones are gained matched with the old series so they can be used together". But I cant find the reference again.

Bjørn

cliveb
2008-04-15, 09:17
I've decided I want to have a go at eliminating the 8000S and running the TP directly via RCA to the 8000P. One problem is I don't know the gain and sensitivity of the 8000P.

Does anybody know if the data for the old ones are the same? I tried google but it isn't always clear whether its the new or old ones being refered to. And I don't want to blow up anything.
Can't help you with the 8000P data you're looking for, but it's not actually necessary to know it.

1. Connect the TP directly to the 8000P.
2. Before powering up the 8000P, turn the volume right down on the TP.
3. Now switch on the 8000P, and start playing something.
4. Gradually increase the volume on the TP until you achieve the loudest playback you're ever likely to want. (If you get to full volume and it's not loud enough, you need an active preamp).
5. Note the dB attenuation reported on the TP's display. This is the amount of attenuation you need.
6. Power everything down, open up the TP and set the internal attenuation accordingly.

Provided you make sure you start with the volume right down, you'll be fine.

bhaagensen
2008-04-15, 11:48
Thanks for you reply. Sound like a good idea. But I don't know how well it would work. Assuming the amps specs are:

Input for full rated power: 1.0 V rms
Gain: 29.0 dB at 1 kHz
Rated output power: 100 W per channel into rated load impedance (8?), 150 W into 4?

I believe I would need to attenuate -6dB to get line level matching. Using only the TP builtin attenuation I really can not get very close to this, either -10dB or 0dB.

cliveb
2008-04-15, 12:46
Thanks for you reply. Sound like a good idea. But I don't know how well it would work. Assuming the amps specs are:

Input for full rated power: 1.0 V rms
Gain: 29.0 dB at 1 kHz
Rated output power: 100 W per channel into rated load impedance (8?), 150 W into 4?

I believe I would need to attenuate -6dB to get line level matching. Using only the TP builtin attenuation I really can not get very close to this, either -10dB or 0dB.
But how do you know what proportion of the 8000P's potential power delivery is actually needed in your system: ie. driving your speakers in your room, listening to your music at the sort of levels you prefer? Quick answer: it's almost impossible to know. Trying to work it out with calculations will take longer than just hooking the things up to see how loud you want to go and what attenuation is required. Once you have that info to hand, you can make some informed decisions about how to proceed.

bhaagensen
2008-04-15, 13:31
Trying to work it out with calculations will take longer than just hooking the things up to see how loud you want to go and what attenuation is required. Once you have that info to hand, you can make some informed decisions about how to proceed.

That makes sense (again). I'll try it and then ask further if things doesn't work out properly.