Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

OLD vs NEW tube amplifier circuits
OLD vs NEW tube amplifier circuits
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 15th March 2016, 02:18 PM   #1
lugnut is offline lugnut
diyAudio Member
 
Join Date: Aug 2011
Location: Austin TX
Default OLD vs NEW tube amplifier circuits

Is there much of a sonic difference between older (Williamson, GEC, Western,etc.)circuits than new (Tubelab, Millet, etc.)?? Is there really any inherent superiority or just personal preference? Do any circuits stand out above the rest?
  Reply With Quote
Old 15th March 2016, 02:20 PM   #2
SpreadSpectrum is offline SpreadSpectrum  United States
diyAudio Member
 
SpreadSpectrum's Avatar
 
Join Date: Nov 2007
Yes and no.
__________________
My Blog: http://tubeswithatwist.blogspot.com/
  Reply With Quote
Old 15th March 2016, 03:10 PM   #3
petertub is offline petertub  Sweden
diyAudio Member
 
Join Date: Jul 2015
Location: gothenburg,sweden
Quote:
Originally Posted by SpreadSpectrum View Post
Yes and no.
Thanks for the information.
__________________
My home is at www.tubular-well.se
  Reply With Quote
Old 15th March 2016, 03:15 PM   #4
SpreadSpectrum is offline SpreadSpectrum  United States
diyAudio Member
 
SpreadSpectrum's Avatar
 
Join Date: Nov 2007
Quote:
Originally Posted by petertub View Post
Thanks for the information.
With such a broad question, that is what all answers will boil down to. To answer it fully, you would have to write a book.
__________________
My Blog: http://tubeswithatwist.blogspot.com/
  Reply With Quote
Old 15th March 2016, 04:13 PM   #5
DF96 is offline DF96  England
diyAudio Member
 
Join Date: May 2007
And then someone else would write a different book!

The quick answer is that there is not much difference between the performance of a good design from 60 years ago and a good design from today, and any changes would be near or below the limit of likely human perception. There may be huge differences between a poor design of then and a poor design of today, as tastes in sound effects have changed somewhat: then people wanted 'good tone' but today they want 'slam' or 'soundstage'.
  Reply With Quote
Old 15th March 2016, 04:26 PM   #6
Doug Kim is offline Doug Kim  South Korea
diyAudio Member
 
Doug Kim's Avatar
 
Join Date: Apr 2008
Location: Maryland, USA
Quote:
Originally Posted by lugnut View Post
Is there much of a sonic difference between older (Williamson, GEC, Western,etc.)circuits than new (Tubelab, Millet, etc.)?? Is there really any inherent superiority or just personal preference? Do any circuits stand out above the rest?
I am no expert, but I have built 10+ different 300B SE amps for the last 25+ years.

To me, biggest sonic difference came from (1) output transformers and input or interstage transformer if there's any in the amp (2) tubes (3)power supply design. Even simplified WE91 style circuit and Tubelab constant current circuit did not sound much different.

I don't have proper measurement electronics, so I do not know about difference in THD, SNR, etc.
  Reply With Quote
Old 15th March 2016, 04:46 PM   #7
GoatGuy is offline GoatGuy  United States
diyAudio Member
 
GoatGuy's Avatar
 
Join Date: Dec 2012
Location: SF Bay Area
After reading this site for years and years, and remembering back to the days when slide rules were the bomb in calculating things for amplifiers… I'd say that most of the differences between the eras can be boil'd down to:

• economics of various parts
• esthetics of design choices
• fads and magical elixers
• sentimentality and purism

Economics is one of the 'real deals': inductors used to be cheap, now they're expensive. Capacitors used to be really expensive, now they're cheap. Commodity tubes used to be dirt-cheap, now they can be scores of Euros. Even solid-as-tanks resistors once were pretty expensive, then they got cheap. Now they're even cheaper, but no longer 'tanks'.

esthetics clearly is an evolving thing, but it is also does guide generational differences. Today, we have open-frame blue underlit tubes; people use gas regulators not for their practicality, but their telltale glow. Bespoke volume controls are au currant, but once it was silver-plated speaker banana jacks, and before that bakelite knurled knobs.

fads & magic has always been part of what defines the generational differences. Today the Aikido design (which is admittedly both novel and esthetically cool) is on the wane. Its still very good, but times change. Once it was SRPP (which no one can remember what the acronym means/meant). Before that there were cascodes and fairly unique common-grid designs lifted from the HAM folks. Times change. E'n the decision as to whether input or middle stages benefit from pentodes versus triodes (or FETs!) is contentious… and fluid.

sentimentality remains perhaps one of the most influential factors though. If we are honest, building tube equipment is a man's hobby, mostly. (Sorry, Katje! - you're extraordinarily special!) Just like rebuilding turn-of-the-century automobiles and trucks. (19th to 20th, not the recent one!). Design choices are very often rooted in original spec sentiments, then gradually 'honed' with decidedly later innovations. Sometimes openly, sometimes hidden below the hood.

Intellectual avocation (not in the bullet list) is also another significant factor. Many of the people who congregate here have both remarkable intellectual talent and the desire to dig deep, deep into the analytic underpinnings of abstract electronic engineering and physics theory. For many, just to understand, to 'grok', and to then design from the ground up - NOT depending on copying others' designs - is hugely satisfying. Evidence that all that studying, noodling, calculating, driving the wife nuts, is worth it.

Just like (mostly) gentlemen who are maybe bankers or attorneys, or civil construction generals, but who in private life have cultivated a life-long hobby of fine cabinetry and woodworking, or musicianship, or photography and printmaking, or crafting something really oblique like fountain pens, or cuckoo clocks, or distilling whiskey on a tiny scale. It consumes the wan hours of a lifetime, and the results, the creations are tangible. Evidence of intellect. Good stuff.

And guess what … all those things are also influenced by the prior 4 bullets.

So that's what influences the generation-to-generation designs of … everything.

GoatGuy
__________________
John Curl's Golden Rule…: 100 kHz bandwidth, 3 μs risetime, 100 W mean output, 100 V/μs slew rate, 2 Ω dynamic load, 20 amp min current source/sink
  Reply With Quote
Old 15th March 2016, 05:00 PM   #8
richwalters is offline richwalters
diyAudio Member
 
richwalters's Avatar
 
Join Date: Sep 2003
Location: Alps:Tube amp designs over 150W, SMPS guru.
Quote:
Originally Posted by DF96 View Post
And then someone else would write a different book!

The quick answer is that there is not much difference between the performance of a good design from 60 years ago and a good design from today, and any changes would be near or below the limit of likely human perception. There may be huge differences between a poor design of then and a poor design of today, as tastes in sound effects have changed somewhat: then people wanted 'good tone' but today they want 'slam' or 'soundstage'.
Very correct...basically the old schematics remain true..Having built many powerful MI/HiFi UL amps from 1960 to ?; the biggest significant change on my bench is boxes of under performing New Edition made power tubes, poor materials, poor annealing/outgassing and worst, their sales flannel claim the performance as their predecessors could do; but no; the 6550 is a good example of a tube NOT to push. That dupe tube is closer to a 6L6, though there are many who use 6L6's way above 470V B+ in UL.
Electrolytic caps have definitely improved; as has the understanding of the CCS in designs; but those of us who use GNFB, will soon realise how accommodating and powerful the closed loop is, in trimming so many evil parameters. Component tolerances, Hum & noise; thd; damping factor; and so on.
I suffer from Tinnitus; but can still hear what'ain't right....
rich
  Reply With Quote
Old 15th March 2016, 05:25 PM   #9
smoking-amp is offline smoking-amp  United States
diyAudio Member
 
smoking-amp's Avatar
 
Join Date: Dec 2001
Location: Hickory, NC
The old advice, or admonishment, to "linearize first, before applying feedback" has entered a new dimension:

1) old grid 1 drive
2) new (g2 and g1 hybrid or "Crazy drive")

No amps using it yet however. Will someday be realized.
(after doing taxes, clearing deadly trees from nearby river for kayakers, after clearing brush from some property I need to sell, to pay those taxes, after solving high blood pressure problem .....) Well, maybe next year.
Attached Images
File Type: jpg rsz_26lx6_p.jpg (51.4 KB, 487 views)
File Type: jpg rsz_26lx6_crazydrive_55v_5,4vs.jpg (71.9 KB, 478 views)

Last edited by smoking-amp; 15th March 2016 at 05:28 PM.
  Reply With Quote
Old 15th March 2016, 05:35 PM   #10
billshurv is offline billshurv  United Kingdom
diyAudio Member
 
billshurv's Avatar
 
Join Date: Mar 2014
OLD vs NEW tube amplifier circuits
Quote:
Originally Posted by smoking-amp View Post

No amps using it yet however. Will someday be realized.
I still reckon the enhanced triode mode that Tim deP used back in the mid 90s was a form of hybrid drive. Just not enough round tuits to work out what he did.
  Reply With Quote

Reply


OLD vs NEW tube amplifier circuitsHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
CAD for Tube circuits NZkeith Software Tools 19 16th October 2014 01:10 PM
H11F1 Switching in tube circuits ToefistJU Tubes / Valves 7 16th March 2013 06:11 AM
LTspice and simulating tube circuits? markusA Software Tools 19 15th August 2011 02:04 AM
Standby voltages for tube circuits. ashok Tubes / Valves 23 25th September 2009 09:02 PM
amplifier circuits madan Solid State 27 23rd November 2005 11:08 AM


New To Site? Need Help?

All times are GMT. The time now is 01:42 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio
Wiki