Altec Novice

[Eric23]

Has anyone had any experience of the very old Marantz model 1,2,3,4 and 5 monoblock power amps? They are meant to be quite nifty (that's UK English for 'good')

Also Western Electric stuff!!

[joyspring]

MikeInNH:

There is somehing that is more musical, more mellow...I don't know....Maybe it's the type of music I play....I don't know...but there is SOMETHING there.

<font size="2" face="Verdana, Helvetica, sans-serif">It may very well be distortion (harmonics in addition to the fundamental) on musical transients from the SET amp when it demands more energy that its output devices cannot produce that you may be hearing.

Yes, even with vinyl LPs, transients may easily reach +20 dB peak-to-average, particularly on classical and acoustic jazz, especially on percussion and piano.

+20 dB is two orders-of-magnitude (100x) higher power than average; even +16 dB is 40x.

Here's a very non-technical explanation of dynamic headroom, and why - provided you have a low noise floor amplifier - you can never have enough power:

Soft to Loud: The Nature of Power and Dynamic Headroom

A small excerpt:

"Moreover, what many of us don't realize until we hear it, is that clean undistorted loud sound often does not sound that "loud." The key here is that in most of our home listening, there are small amounts of distortion caused by a lack of dynamic headroom. It's the distortion that makes it sound "loud" in a domestic setting."

SET (and tube amplifiers in general) have different harmonic content than solid-state amplifiers when overdriven, but it's still non-linearity and addition of harmonics to the original signal nonetheless.

Fine for a musical instrument amplifier; however, that's hardly what anyone would consider `high-fidelity', which I would assume means `faithfulness to the original input signal' to most.

Eric23:

I currently own a Bryston 4BSST 300-watt amp.

<font size="2" face="Verdana, Helvetica, sans-serif">Incredible amplifier: apart from its high quality build, WIDE power bandwidth, generous power supply, etc., its key feature that renders it as exceptional is its very low noise floor (under -110 dB noise below full power, 20 hz - 20 kHz). I'm not so certain I understand your desire to replace it.

Its output topology renders it relatively immune to highly reactive loads as well - Brystons are well known for their ability to drive nearly any loudspeaker system.

You often see Bryston 4Bs in mastering control rooms. Note that you'll NEVER see an SET amp in that type of professional critical listening setting, even with high-efficiency monitors.

The lack of dynamic headroom and attendent potential for harmonic distortion at average listening levels are faults, not virtues.

BobR

[joyspring]

To all:

A clarification on my last post:

"The lack of dynamic headroom and attendent potential for harmonic distortion at average listening levels are faults, not virtues."

should read:

"The lack of dynamic headroom and attendent potential for harmonic distortion on transients at average listening levels are faults, not virtues."

Harmonic distortion on transients is the point I am attempting to address in this thread, but I believe that distinction is lost for many on this forum.

Needless to say, having ample, undistorted power is a primary, basic means of ensuring sufficient dynamic headroom. It is also a basic element of good sound practice and system engineering/design.

Eric23:

Speakerdave has Model 19 components requiring rebuilding in another post:

http://www.hostboard.com/cgi-bin/ult.../f/3729/t/1518

Constructing your own enclosures may be a nifty means of saving on shipping expense and using the windfall on having GPA rebuild the components to new spec.

BobR

[RonSSS]

Bob,Loudspeaker efficiency plays a huge role in all of this, corrct?
Normal listening levels with a 100dB/1W/1M speaker will only require average power levels of less than a watt. I have measured this.
While I agree that 8 watts isn't enough, especially if the bass becomes demanding, a 35watt tube amp will do just fine.
Also, transformer coupled tube amps do better job with transients, because if the driver stage has balls, the output stage can be driven into Class A2 which adds significantly to the dynamic headroom.
Also, it is more than possible to build SET amps with even 50 watts of power. You just don't get to use 300b's.
About 300B's....I love them. But I also feel that at least some of their sound is due to the fact that they tend to be microphonic. If you look at my avatar, it's a PP 300B amp that makes near 40wats at 1% THD Transformer coupled BTW. The tubes are so michrophonic, you can almost yell at them and hear it in the speakers. Folks with low efficiency speakers never hear this.
Ron

[Hornluvr]

I mostly drive my Model 19 with a pair of Radio
Craftsmen C500`s from 1952. They are the old Williamson type amps, PP, 10 Watts from a pair
of KT66`s in triode mode. Boy, they can play real
loud, and audible distortion is not an issue either.I never have the feeling of lacking power
even with modern formats like SACD or DVD-Audio.
Regards, Martin