Volume levels with different amps

[Number 7]

I've noticed something slightly odd with my system: I've just replaced an old Arcam Delta 290 amp with an A28. Both have 70i'sh watts per channel output, but I was only using each as a pre-amp to an Arcam 100 watt per channel power amp. When playing CD's on the old set-up, the maximum on the volume I would ever use (and it was plenty loud) was about 1/4 up the scale. With this new system, I need to go to about 50 out of a max of 72 to achieve the same volume. Are these volume controls not linear, or have I missed something?

I know that on the A28 there is the ability to adjust the level of each source, but even maxing that for the CD doesn't help massively - probably only worth 8 on the 0-72 scale, so I'm still well over half-way up scale.

Any ideas welcome before I talk to the dealer.
Thanks

7.

[OldSkoolRS]

Different preamps can have varying amounts of 'gain' so it could be that the new amp isn't drving your power amp as hard as the old one, hence the lower volume. However it could equally be just the way the volume control works on the new amp (some aren't very linear or rather they are logarithmic but not very even in the way they control the volume). Another slim possiblity is that you are using low sensitivity inputs on the power amp, but I doubt this one as you've had it working OK before (unless there is a choice of two pairs of sockets on the back panel?) or perhaps there is a sensitivity control on the back of the power amp.

Either way, as long as it goes loud enough for your tastes and doesn't sound hissy (indicating not enough signal going into the power amp perhaps) or distorted, then it maybe isn't an issue.

[Graham E]

As I recall, Arcam use a log scale style gain control - so you have fine control low down, and bigger steps when loud.

[Toffer]

I have a similar ARCAM Delta 90.2 and the volume control is logarithmic.

[OldSkoolRS]

Generally speaking volume controls are logrhythmic, but some aren't very even in their execution....that's all I was trying to say. It is possible to wire a volume potentiometer so that the change in gain is more abrupt at one end or the other, but that's probably beyond the scope of this thread other than to say it is possible.

As I said above, if it gets loud enough for your requirements, then it isn't really an issue.