Old school Power amplifier for bass

[Bob Lee (QSC)]

If you ever check out a CA9 you will know right away why they are the best power amp ever made for bass guitar. Crest on the CA9 according to people in the know say that Crest did something a little different in the design of the feedback loop if memory serve's me correct to enhance bass response, anyhow whatever it was it worked.

Have you ever compared a CA amp with one from Crest's beefier line, the Professional Series? That would be interesting.

 

[svtb15]

That just clouds waters for the folks here that don't yet have experience with a wide variety of upper tier gear..

My 1073 sounds different than my api 512, 550 and Em500.. yet all of then are " flat".. I have a pair of old Quad Eights.. that are different...

Touting mic pre's is much easier from a marketing perspective, which is one reason why it's done.

 

[seamonkey]

For those who want "All Class-AB" signal path but want all the benefits of Class-D should look at:
Technology | Self Training | Training & Support |
Yamaha

It has all the features of Class-D like longer parts life and reliability, higher efficiency, and some reduced weight.
From signal input to output is it all Class-AB. There' no doubt about that. The patent clearly shows this.
The power is an SMPS connected to a Class-D amp, the this Class-D is used to drive the rails of the Class-AB. The power supply has the same waveform as the amplifier but for the worried consumer, it's only going though Class-AB from input to output.

It has all the same measurements as any good amp in any class. It just has the marketing claim the signal path is pure Class-AB.

Essentially added complexity, cost, and weight just to say the signal path is Class-AB

It's always fun to see what marketing can do to satisfy purist.

 

[svtb15]

I never have done that compare. But I had some old 7001 Crests a long time ago.. They were beasts..

Amps that i currently have are a MA1200 and old Showco modded Crown PSA2... When on out on a gig and have the crew i will usually use the Ma1200.. The PSA2 is just too much for anyone to lift these days.. Its power per channel may not be as much as current day amps on its weight per watt.. But it sure lets you know it is in the house. Its 900+ watts will leave bruises on your body from the punch .. While other 900 watt amps seem somewhat loud.

It must be that they RATE amps differently these days. I did a thread last week and No one was able to clarify how amps are rated today. it's all very hush hush by builders form what users wrote me on the side .

Have you ever compared a CA amp with one from Crest's beefier line, the Professional Series? That would be interesting.

 

[Bob Lee (QSC)]

A lot of people mistake higher gain for more "oomph," which is why a CA - Pro Series comparison would be so interesting.

 

[agedhorse]

For those who want "All Class-AB" signal path but want all the benefits of Class-D should look at:
Technology | Self Training | Training & Support |
Yamaha

It has all the features of Class-D like longer parts life and reliability, higher efficiency, and some reduced weight.
From signal input to output is it all Class-AB. There' no doubt about that. The patent clearly shows this.
The power is an SMPS connected to a Class-D amp, the this Class-D is used to drive the rails of the Class-AB. The power supply has the same waveform as the amplifier but for the worried consumer, it's only going though Class-AB from input to output.

It has all the same measurements as any good amp in any class. It just has the marketing claim the signal path is pure Class-AB.

Essentially added complexity, cost, and weight just to say the signal path is Class-AB

It's always fun to see what marketing can do to satisfy purist.

This is a kinda-sorta sort of argument, because if you look at the output signal you will see some PWM leakage from the tracking supply. In fact, I am confused which company owns this technology. This is the same thing that Lab Gruupen does with their class TD amps (TD stands for tracking class D supply). There may be enough difference in the mechanics to co-exist, but both suffer from the same challenges with regard to PWM residuals... one of the chief reasons why class AB purists say they can't stand class D. [Irony not lost]

This tracking rail design is a logical extension to Hitachi's original IP with regard to class G, where in Hitachi's approach, the high tier operates linearly with the lower tier operating linearly at saturation minus about 5 volts) The power savings is due to the reduced linear voltage drop at high power. This does not generally suffer from any additional noises or artifacts because the tracking is linear and related to the signal.

 

[BassmanPaul]

Thanks for refreshing my crappy memory with your excellent description of Class H Bob. As I read it all came back to me. How long the information will stay is another matter!