Class A power for bi-amping

[Fangio]

Someone convinced me to refoam a pair of 127A's for him, and to extra motivate me he also brought a stereo tube amp that I got lent for a week or two.

It's a Mastersound 845 compact made in Italy, he is the german distributor, and it has approx. 10x the value of the L166's that I'm currently using to try it out. So far, so good – sounds wonderful, but I consider to try it also in my bi-amp setup for the MF/HF/UHF part of the 4343's, because it has a power amp only mode.

My question is, how much translate 20W Class A (thats what he said it has, the website states even 30W Class A, probably at 4 ohms) – in normal output watts? Probably suffice to run the upper part of the 4343's I'd think, compared to the 150W/ch at 8 ohm Citation 16 for the LF part?

Is there a rule of thumb for that? Thanks.

[timc]

Watt is watt. Class A, B or other.

However Class A tends to have a fuller, richer sound thand equivalent powered A/B designs.

But when it comes to how loud they play, its the same.


-Tim

[Robh3606]

20 watts is 20 watts. Doesn't mater if the amp is class A, AB, B or D. It's just a power rating. If by design you get more headroom or one clips more gracefully than another that's a different issue.

I have used 100 watt Crown PS-200 for the top side with 4344 and have very rarely had them clip on snare snaps and percussion. It was loud but nothing crazy. Using the PS-200 is only about 6db more headroom. I would definately give it a try. What do you have to loose unless of course you like it.

Rob

[rs237]

Hello Fangio,

watt = volt * ampere, whether it is from a tube amplifier or a transistor amplifier. Because Röhrenvertärker soft clipping is the recoverable volume greater than that of a transistor amplifier with the same nominal performance.
My English is too poor to better explain it, I send you a PM in German.

regards
juergen

[Ian Mackenzie]

Fangio,

It also depends on ther size of your room and your listending preferences.

Remember that if wind up the L pads you will also improve the headroom by at least 3+ db, In this situation the 20 watt amp will appear as 40 watts. With the gains of Bi amping it will be the equivalent of a standard 120 watt amplifier. ie very loud.

The bass amp is a good choice and this is where the power will really benefit.


Ian

[Fangio]

It also depends on .. your listending preferences

Usually at moderate levels, I do have neighbours.. but last long weekend when Rich was here some felt the need to remind me later that I'm not alone in da house

Remember that if wind up the L pads you will also improve the headroom by at least 3+ db, In this situation the 20 watt amp will appear as 40 watts. With the gains of Bi amping it will be the equivalent of a standard 120 watt amplifier. ie very loud.

Thats what I somehow figured, thanks for the confirmation. In bi-amp mode I'd rather have to throttle it a bit, is my feeling.. together they should blend in well. Will report

...would definately give it a try. What do you have to loose unless of course you like it.

That might actually become a prob.

[Allanvh5150]

Having said that 20watts = 20 watts, why does a 60watt tube guitar amp, blow the dooors of a 200watt guitar amp?

[Mr. Widget]

Having said that 20watts = 20 watts, why does a 60watt tube guitar amp, blow the dooors of a 200watt guitar amp?

Because door blowing isn't quantifiable.

Now on the other hand, if you took an SPL meter and actually got a higher reading from the 60 watt amp that would be due to the fact that a triode amp will typically clip in a much more musical way and you are likely driving the speaker with over 200 watts of distortion from that "60 watt" amp.


Widget

[johnaec]

...a triode amp will typically clip in a much more musical way and you are likely driving the speaker with over 200 watts of distortion from that "60 watt" amp.

+1

John

[Allanvh5150]

Because door blowing isn't quantifiable.

Now on the other hand, if you took an SPL meter and actually got a higher ............


Widget

I knew that Widget, but I had to ask the question. My main hobby is building class A, A/B and simul-class A+A/B guitar amps. I am currently working on a bunch of amps and crossovers using tubes, for the home theatre that I am working on. They will alos keep my house warm

[Robh3606]

Everybody knows quitar amps go to "11"

Rob

[Allanvh5150]

Everybody knows quitar amps go to "11"

Rob

Only the good ones

[toddalin]

Everybody knows quitar amps go to "11"

Rob

Enjoy!

http://members.aol.com/chiprowe/gotoeleven2.wav

[Fangio]

Will report

Well, the amp (and the woofs) were picked up – yesterday. "Unfortunately" the owner didn't make it to my place earlier.. After using it for my top end for almost 3 month I do understand the appraisal for these huge 845's. Very nice and precise sounding tubes, interesting experience. And an amazing eyecatcher too. Too bad these amps loose almost half of their value (4.5k) within the first 12 month, on the way from 'new' to 'used'.