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gary
07-08-2008, 10:33
Do older valve amps lack the speed to handle more complex music

I have been told from several sources that valve amps are brilliant for reproducing vocals and acoustic types of music but can fall down where more complex music is involved.

Is this just a preconcieved notion of valve amps in general or is there some reason for this pipe and slippers assumption, ie were older amps prone to this and if so what have your experiencies been.

Gary

lurcher
07-08-2008, 11:02
IMHO:

Its a complex question, there are very good old valve amps, and there and not so good ones. There are very good new valve amps, and not so good ones.

Its harder to produce a good valve amp than it is to make average solid state one. Normally to make a valve amp that does all the things you want requires a good design and good components. Generally that expensive. Some imported amps now get close by being built with lower costs, but they still need additional work to be at their best.

I personally think there have been a lot of valve amps that produce the sort of sound you refer to, and many people want that sound, and expect it, but its a feature of the design, not inherent to valves themself.

The classic way of getting the sound you mention is by slew rate limiting, 6sn7 common cathode driving 300b is a good example.

A lot of the old designers knew exactly what they were doing, electronics in the 50's was far from an inexact science, but I guess it was possible to get away with a lot in audio if the best source you had tailed off over 10kHz

gary
07-08-2008, 11:15
IMHO:
A lot of the old designers knew exactly what they were doing, electronics in the 50's was far from an inexact science, but I guess it was possible to get away with a lot in audio if the best source you had tailed off over 10kHz

I have had a look at some of the books on subject through the link posted by mike in diy section of this forum and the science part of it is a bit beyond my meagre understanding of it, I am curious to find out where this pipe and slippers reputation comes from as it would seem that for many valves are way better in performance to sand amps.

lurcher
07-08-2008, 11:22
I have had a look at some of the books on subject through the link posted by mike in diy section of this forum and the science part of it is a bit beyond my meagre understanding of it, I am curious to find out where this pipe and slippers reputation comes from as it would seem that for many valves are way better in performance to sand amps.

I would guess in many cases it came from the same place where the idea that DD turntables were not speed stable, and idler drives rumbled. From manufacturers trying to convince people that the sound their nice new solid state amps made was how it should sound, and not hard, harsh, and nasty, which was how it was actually sounding.

jandl100
10-08-2008, 06:55
Do older valve amps lack the speed to handle more complex music

Gary

Hi Gary - have you seen my thread here? ... http://theartofsound.net/forum/showthread.php?t=916

There's nothing at all "pipe & slippers" about my Leak Stereo 20!

Primalsea
10-08-2008, 09:55
Yep the Leak ST20 is one of the most transistor sounding valve amps that I've heard. It seems to have almost all of the strengths of both technologies. However Leak made a few stinkers as well.

I think the pipe & slippers idea came from 2 places:

If you read any technical books or papers from the 50 &. 60 they're very stuffy documents which gave the impression that the writer was the kind of guy who would go home and don his slippers, light a pipe and listen to old fart music.

Before the TS theory was developed speaker drivers were less than optimal and enclosures where designed by trial and error. Treble units weren't fantastic and to extend bass response techniques were used that often gave slow ponderous bass.

Everything I've read about amp design at the time took into account that the amp must have full bandwidth of 20Hz to 20Khz. Although I guess some designs were limited to less than this in order to make the amp unconditionally stable.

All this is IMHO however and there are people on here a lot older than me who may know from 1st hand experience. Any Sliver Surfers out there??

lurcher
10-08-2008, 12:10
Everything I've read about amp design at the time took into account that the amp must have full bandwidth of 20Hz to 20Khz. Although I guess some designs were limited to less than this in order to make the amp unconditionally stable.

From the Radiotron Designers Handbook 4th Ed 1953

"A high fidelity a-f amplifier should have nearly constant amplification over the whole range available to the most critical listener - from say 30 to 20000 c/s. There is no serious difficulity in designing such an amplifier, but it can only be usefully applied when being fed from a wide-range source and excites a wide-range loudspeaker system.

...

If a particular equipment is to be operated always at comparatively low levels (e.g. dinner music) or in noisy location, reduction of the frequency range is quiet correct and may even be beneficial.

...

Amplifiers for other than wide-range high-fidelity are usually designed to meet the requirements of the average listener, with a frequency range (at maximum orchestral level) of about 45 to 15000 c/s, which may be still further reduced to about 70-13000 c/s at typical levels for home listening.

...

In commercial quality-produced equipment the frequency range is often restricted to the extreme. By this means non-linear distortion and hum are reduced to a bearable level without expense. Unfortunatley, frequency range can only be extended, while remaining free from obvious distortion, at a cost which rises at a rapidly increasing rate - largely due to the loudspeaker. It is important to reduce the distortion before widening the frequency range."

I guess in the 50's and most of the 60's the people who could afford this stuff tended to smoke a pipe and wear slippers when at home.

http://hem.bredband.net/b202639/images/apparatus/Lycklig%20QUAD.gif

Togil
10-08-2008, 12:26
But then those same "Pipe and Slipper" types were persuaded by Quad that their new Current Dumping SS amps were better ( in fact perfect )and I don't think they objected very much ; in Germany valve amps from the States ( Marantz, Macintosh ) were very popular for a short while in the mid-sixties until people noticed that they had to change valves, adjust bias etc and SS took over from then onwards

lurcher
10-08-2008, 12:37
The current dumping quads were from about 1975 onwards, the 303 covered the period I think you are talking about.

The Grand Wazoo
10-08-2008, 14:37
From the Radiotron Designers Handbook 4th Ed 1953



I guess in the 50's and most of the 60's the people who could afford this stuff tended to smoke a pipe and wear slippers when at home.

http://hem.bredband.net/b202639/images/apparatus/Lycklig%20QUAD.gif

This particular guy looks like he's smoking TWO pipes!!


.......smoking in stereo & listening in mono.
:steam:

Primalsea
10-08-2008, 15:24
Good point Lurcher on the Radiotron book, I haven't read that I must admit.

I must therefore concede that some of the older valve amps were curtailed at the frequency extremes.

:doh:

lurcher
10-08-2008, 15:50
Good point Lurcher on the Radiotron book, I haven't read that I must admit.

I must therefore concede that some of the older valve amps were curtailed at the frequency extremes.

:doh:

I think the way things work means that history remembers the good ones.

If you have a few spare weeks and don't mind a 25Mb PDF, Pete Millett scanned RDH here http://www.pmillett.com/Books/RDH4.pdf

Mike
11-08-2008, 15:50
Or for a host of other stuff ranging from 'interesting' to 'hurt your head' try here: http://theartofsound.net/forum/showthread.php?t=584