UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Specific Vintage Equipment > Vintage Tape (Audio), Cassette, Wire and Magnetic Disc Recorders and Players

Notices

Vintage Tape (Audio), Cassette, Wire and Magnetic Disc Recorders and Players Open-reel tape recorders, cassette recorders, 8-track players etc.

Closed Thread
 
Thread Tools
Old 4th Jul 2010, 10:10 pm   #101
veffreak
Retired Dormant Member
 
Join Date: Jun 2010
Location: Latvia, Riga
Posts: 78
Default Re: Are 60's tape recorders an important part of the "60's sound?

Sorry, this is off-topic, but i wanted to jump in here a bit. Yes, these amps have controllable volume, but they sound nothing like the original Marshall designs from 60's and early 70's - most of the overdrive came from the power tubes, which gave the tone the rich and organic "crunch" heard on so many records, or in case of the earlier JTM's (KT66), Claptons "woman tone". After years of trying to get THE tone on lower volumes i don't believe in any modern technology gimmicks that promise to offer the same tone on low volumes. Attenuators and, even more, power scaling work very well as means to lowering the volumes to good live or band volumes, but that's about it. If the speakers don't get enough movement, everything starts to sound thin, flat, harsh, brittle and you can throw in almost any other negative attribute here. You can't go below 2w of output and hope for a good tone. And 2 watts are pretty darn loud if you dream about "bedroom" or "practice" levels, etc. That being said - a great 60's/70's non master-volume amp or it's clone attenuated or power scaled down to live levels is in a completely different league (unfortunately also price wise though). Some amps do sound great with something such simple as a PPI MV (post phase inverter master volume), but to my ear Marshalls don't fall under this category.

Kind regards,

veffreak
veffreak is offline  
Old 5th Jul 2010, 5:06 am   #102
TIMTAPE
Octode
 
Join Date: Jul 2006
Location: Perth, Western Australia
Posts: 1,965
Default Re: Are 60's tape recorders an important part of the "60's sound?

Quote:
Originally Posted by veffreak View Post
If the speakers don't get enough movement, everything starts to sound thin, flat, harsh, brittle and you can throw in almost any other negative attribute here.
veffreak
Veffreak,
Sorry to get technical again but speakers are designed to sound good over their entire useable range. A speaker that only sounds bad at low volumes has a fault such as a rubbing voice coil.

Subjectively though, our ears have a poorer sensitivity to the extreme bass and treble at low volumes, so just turning down the guitar amp or the stereo alters the sound to a thinner, often less interesting sound.

That probably covers why electric guitarists like not only the overdriven valve sound but subjectively loud too.

Actually, an overdriven magnetic tape has a sort of similar sound to overdriven valve amps. Somewhat compressed and with harmonics which on certain instruments can give a kind of turbo effect.

You have to distinguish between that as a tape effect and the sound of tape recorded to not distort. Most professional recordings aimed not to distort. So buying an analog reel to reel machine in itself doesnt automatically guarantee a certain "sound". It all depends on how you drive it.

In the same way, a valve amp working within its undistorted range essentially doesnt colour the sound either.


Tim
TIMTAPE is offline  
Old 5th Jul 2010, 5:42 am   #103
Kat Manton
Retired Dormant Member
 
Kat Manton's Avatar
 
Join Date: Jul 2005
Location: West Yorkshire, UK.
Posts: 1,700
Default Re: Are 60's tape recorders an important part of the "60's sound?

Hi,
Quote:
Originally Posted by TIMTAPE View Post
Sorry to get technical again but speakers are designed to sound good over their entire useable range. A speaker that only sounds bad at low volumes has a fault such as a rubbing voice coil.
Guitar speakers are designed to exhibit behaviours at high volume which would be considered undesirable in pretty much any other application.

Typically, the voice coil is shorter than for a similar size/power hi-fi or sound reinforcement speaker, such that when driven hard, there's less of the coil in the magnetic gap, resulting in non-linearities - distortion.

(Compare the specifications for some guitar speakers with similar size/power hi-fi, sound reinforcement or bass speakers. The parameter to look at is 'Xmax', the maximum linear excursion. It's a lot lower for guitar speakers.)

Guitar speakers also have a thin, light cone; when driven hard it ceases to work as a piston and "cone break-up" occurs. More distortion.

They don't sound the same at low and high volume, by design. They sound better the harder you drive them.

(As I'm getting the equipment and software together for loudspeaker measurements anyway, I might find time for an experiment, more out of curiosity than anything. If I drive my 'greenback' loaded 4 x 12" cab with a low-distortion solid-state amplifier and use a microphone which will handle high SPL without introducing non-linearities, what I measure will be largely down to the speaker alone. I'd expect different distortion figures and a different distribution of generated harmonics at low and high volume.)

Regards, Kat
Kat Manton is offline  
Old 5th Jul 2010, 6:54 am   #104
veffreak
Retired Dormant Member
 
Join Date: Jun 2010
Location: Latvia, Riga
Posts: 78
Default Re: Are 60's tape recorders an important part of the "60's sound?

Timtape, i have to agree with Kat Manton - guitar amps, cabs and speakers are somewhat goofy, when compared to what hi-fi equipment is built for. I also have to add that guitar amps by no means sound anywhere the same also when not overdriven - "clean" - and even more different when getting more into saturation. There's a huge difference between my JTM-45 (big, round, bold, very bassy (even with bass at 0), a bit on the dark side, but still detailed) and my 18w (lot less punch and bass, more high end detail, brighter) even when talking clean and through the same cab/speakers and there's even more difference to say black face Fenders (scooped mid-range, can get too bright at times - but love these when they saturate). Hi-Fi amps are built to be ideally transparent (which the ones that are built well maybe even are - and hence sound very similar) - guitar amps are, i think, made to color the sound by purpose. A DI electric guitar signal is true horror to the ears, with exception of some really good semi-acoustic and archtop guitars. And i suspect a really really transparent and clean amp would keep the same flat lifeless character to the electric guitar if played on a hi-fi amp, completely clean. Many amps, like some marshalls have some (what guitarists call as) "hair" to the sound even when at lower, clean volumes - a slight hint of overdrive, that adds some harmonic content - a nightmare if a hi-fi amp would do it, but a great "feature" for a guitar amp.
And for the speakers (thanks to Kat Manton for the technical explanation, which was educating for me, as i didn't really know the technical reasons for this difference between hi-fi and guitar speakers) - if they'd really sound the same or even remotely close when on low or high volumes, then if you'd record say a greenback on low volume and then on high, adjust the levels, play it back on the same levels - they should sound the same. I have done this experiment myself, a couple of times, trying to achieve just that - great tone on low volumes. It is not possible due to the necessary speaker movement. To my ear, what happens is, the speakers and the sound together, gets too detailed or even more "transparent", it begins to sound what you'd hear from an overdriven tube amp played through a hi-fi speaker, which shows the true nature of distortion, which is terrifying. The same goes for clean - it starts to sound like the DI tone of the electric guitar. Guitar speakers "wash it out" and make it smooth due to their "inferior" construction in some ways, which Kat explained. But in this application they can't be beat by any hi-fi speaker. I've tried also that. I have some old 70's japanese Sansui speakers here, their woofer is about 12" i think - so i though it would be worth the try as it's old and i thought maybe it would be less precise, etc. and the woofer has the typical guitar speaker diameter. The results were just as dreadful as any other Hi-Fi speakers i've tried. I didn't try to push them to "live levels" as this would probably destroy them, especially with all the peaks that flat out tube amps can put out. And i think this is also the reason why all the promises of the marketing departments from several manufacturers about a great tone on low volumes from their next product is mostly just that - marketing - there's no way around a guitar speaker and there's no way around moving it heavily to get great tone. I think this will be solved as soon as someone figures out how to make the speaker behave in a similar way on low volumes. But that would afaik go a bit against laws of physics


All the best,

veffreak
veffreak is offline  
Old 5th Jul 2010, 7:17 am   #105
TIMTAPE
Octode
 
Join Date: Jul 2006
Location: Perth, Western Australia
Posts: 1,965
Default Re: Are 60's tape recorders an important part of the "60's sound?

Veffreak I agree with what you say here but it would have been a much shorter thread, but perhaps not nearly as interesting, if you had declared your interest in the influence of 60's tape machines on the electric blues guitar sound from the outset. We've taken a very long detour to finally get to the question you apparently were really interested in.

In short my reply would be, with the distortion already introduced by the overdriven valve amp, plus the amp's inbuilt speaker, any extra distortion introduced by a pro tape machine, operated within its limits, would be inaudible.

Thanks Kat for that info about the contribution of the guitar amp's speaker to distortion at higher levels.

Cheers Tim
TIMTAPE is offline  
Old 5th Jul 2010, 7:44 am   #106
veffreak
Retired Dormant Member
 
Join Date: Jun 2010
Location: Latvia, Riga
Posts: 78
Default Re: Are 60's tape recorders an important part of the "60's sound?

This is true - it was a big detour and i hope i didn't step on anyones feet by not getting more into specific from the get go - as i already explained - initially i had assumed the tape recorded would play a significant role here, but in the course of this thread i was taught otherwise. Though the tape recorder definitely adds some individual character it seems to be almost irrelevant in contrast to all the other aspects and factors - like first and foremost - if it's recorded together in a "live setting" or separately, isolated and on individual tracks, etc. Thanks for all your input and for the great discussion!

All the best,

veffreak
veffreak is offline  
Old 5th Jul 2010, 8:34 am   #107
Valvepower
Octode
 
Valvepower's Avatar
 
Join Date: Aug 2008
Location: Rayleigh near Southend-On-Sea, Essex, UK.
Posts: 1,852
Default Re: Are 60's tape recorders an important part of the "60's sound?

Hi,

Yes Kat Manton is bang on, as guitar speakers and amps are breed on their own. The guitar speaker has it’s roots in the larger 10-12 Inch Radio/PA speakers, which were around in the 50’s, I suppose the Celestion G12 being the best example.

Guitar amplifiers have a tailored response to get the required sound; this is less of an equalization network but the use of parts in the circuit to give a HF lift and LF cut. The tone controls are fairly basic and nearly all passive – in the past I tried active tone controls and they didn’t sound right. The power amplifier in not to dissimilar to those found in 50’s and 60’s hi-fi amplifiers, but with less or no feedback (this in some circumstances required less amplification stages in the power amp) and lower value coupling capacitors. The best examples being the Marshall/Fender, Hiwatt, Orange/Matamp & Vox.

The Matamp book is useful to get an insight into guitar amps and there design
http://www.matamp.co.uk/book.htm

This book by Mo Foster is an interesting read as well (I think it’s out of print, but I believe it may be back in print soon – can be found second hand though)
http://www.mofoster.com/author_17watts.php

Terry.
Valvepower is offline  
Old 5th Jul 2010, 11:14 am   #108
brenellic2000
Octode
 
Join Date: Aug 2006
Location: Rye, East Sussex, UK.
Posts: 1,647
Default Re: Are 60's tape recorders an important part of the "60's sound?

Just to reiterate what is said much earlier, Celestion recognised that their modern speaker cones didn't 'sound right' and lacked that '60s sound'. They discovered some unused G12s and by using laser doppler interferometry recreated the G12 cone movement in a new 'Vintage 30' cone, alongside their new Sidewinder range of guitar speakers.

If you can't find any intact G12s, look out for some intact Celestion 'Vintage 30' from the late 1970s.

Dave - I supect most drop-out in the 1/4 track A77 is due to oxide accumuating under the head shroud - inaccessible to cotton buds - badly affecting No.1 track. That's my only gripe about A77's!

Barry
brenellic2000 is offline  
Old 5th Jul 2010, 1:56 pm   #109
jamesperrett
Octode
 
Join Date: May 2007
Location: Liss, Hampshire, UK.
Posts: 1,870
Default Re: Are 60's tape recorders an important part of the "60's sound?

This thread has really grown over the weekend!

I thought I could add a couple of things from my experience running a recording studio.

First, so much of the sixties sound is in the feel of the playing. You need to think about what sort of styles the musicians were brought up on. There was no heritage of heavy rock and pop music as we know it had only been around for less than 10 years. Many of the players had started off playing jazz or rock'n'roll and that influence is important in the playing style - even if it isn't obvious on the final product.

At our studio I mainly recorded young bands but one session we had an older drummer who had started off in the beat boom of the 60's. His style didn't actually suit much of the modern music that the band was trying to record but as soon as they started playing a 60's cover I could hear the genuine feel that he had. He was playing with a regular grip rather than the straight grip that is more common these days but this was only part of the sound. The very slight difference in timing was just as important.

The other interesting thing was working with some of the old multitracks from Pye studios. This was probably from one of the first 8 track recorders in the UK so I guess the engineers were still working in the same way that they would have worked with 2, 3 or 4 track machines. The sounds on tape were virtually finished and no extra equalisation or compression was needed to make the songs sound great. About the only thing I had to add was a touch of reverb. I would say that the sound had very little to do with the recorder used but everything to do with the layout of the musicians in the studio, the acoustics of the studio and the playing style.

James.
jamesperrett is offline  
Old 5th Jul 2010, 4:35 pm   #110
veffreak
Retired Dormant Member
 
Join Date: Jun 2010
Location: Latvia, Riga
Posts: 78
Default Re: Are 60's tape recorders an important part of the "60's sound?

Thanks for the contribution, jamesperrett! Of course you're right - much of it is in the players fingers and the whole recording context - this seemed to be if not the consensus, then at least the main tendency. I myself am a guitarist, so it's sometimes easy for me to believe in some voodoo tape recorders that add the 60's flavor (this was my initial assumption)

Regards,

veffreak
veffreak is offline  
Old 5th Jul 2010, 5:43 pm   #111
dave walsh
Dekatron
 
Join Date: Jan 2006
Location: Ramsbottom (Nr Bury) Lancs or Bexhill (Nr Hastings) Sussex.
Posts: 5,814
Default Re: Are 60's tape recorders an important part of the "60's sound?

That's well summed up James P/VF. Starting from the original VF tape recorder thesis and working through all the fascinating technical detail that has been contributed, the sound is still [overall] a psychological product of existing/modified equipment, the physical recording enviroment, a culmination of playing skills and "Something in the Air". The Thunderclap Newman [Microphone?] hit was just a late Pete Townsend spin off although it captured the atmosphere of the times like, say, Summer in the City or " Are You Going To Sanfrancisco". Watching Ray Davies [and Dylan] this weekend, I was reminded that [at 16] Dave Davies got an early lead fuzz tone by simply razor blading a small speaker and playing through that. The spirit of the sixties. This generated a whole teenage minor industry [aimed at preserving loudspeakers] involving electronic fuzz boxes and circuits in Practical Wireless/Electronics that everyone scrabbled to build. My friend at Salford Electrical Instruments [Heywood] built a few of these that [finally] worked. What few people realise now is that the 60's sound was being inadvertently "learned" and bashed out very effectively [live] at relatively low wattage by bands amateur and professional [not a lot of difference at first] using very limited gear by comparison with todays Stadium Rock approach by one guy in a pub with a backing track machine. Dave W

Last edited by dave walsh; 5th Jul 2010 at 5:48 pm.
dave walsh is offline  
Old 5th Jul 2010, 9:44 pm   #112
Dave Anderson
Retired Dormant Member
 
Join Date: Apr 2010
Location: Slough, Berkshire, UK.
Posts: 113
Default Re: Are 60's tape recorders an important part of the "60's sound?

"Are 60's tape recorders an important part of the 60's sound?"

The 1960's was well before the arrival of the subjectivist school of thought when testing hi-fi components. When I started reading hi-fi magazines in the late 60's/early 70's reviewers measured everything. Amplifiers were judged on their performance by results gained on the test bench. Likewise, nobody thought a turntable could be 'heard'. It only turned the record. We all thought then that the transducers were the real influential factors; the speakers, the cartridge etc.

Then the biggest can of worms was opened up. Reviewers started saying they could actually hear differences between amplifiers, tuners and turntables. Then they turned to cables, equipment stands and mains supplies. Wasn't it Peter Walker of Quad who said an amplifier should be "a straight wire with gain" or words to that effect? Add nothing to the sound and take nothing away.

In the 60's hi-fi reviewers spent little time actually listening to equipment and most of the published review was an evaluation of technical performance using test instruments (not ears). So, I doubt very much if reel to reel tape recorders were reviewed in a subjective way using in depth listening tests. Some decks may 'win' a test against similar opposition on wow and flutter figures or perhaps frequency response. The 'losing deck' may well have sounded better but who would know, or care?

I like to think reel to reel tape recorder manufacturers tried to build neutral-sounding machines that neither added nor took away much from the recording but as the reviewing techniques were somewhat one-sided (test bench-based) one would probably never know. Indeed, I doubt very much whether reviewers or customers thought their 60's tape recorders had any 'sound' at all.

So, are 60's tape recorders an important part of the 60's sound? Well, they probably were but it was unintentional. Like many 'hi-fi' products the all-important magazine review was won on the test bench, not through listening tests. If it measured well it got a great review. Nobody thought about subjective listening tests until the late 70's and early 80's.

Most people laughed when it was suggested some amplifiers 'sound' different to others. Likewise I am sure the thought that a tape deck had a 'sound' would be too risky for any magazine reviewer in the 60's. He would fear loss of all credibility to suggest such a thing.

Dave
Dave Anderson is offline  
Old 5th Jul 2010, 11:00 pm   #113
dave walsh
Dekatron
 
Join Date: Jan 2006
Location: Ramsbottom (Nr Bury) Lancs or Bexhill (Nr Hastings) Sussex.
Posts: 5,814
Default Re: Are 60's tape recorders an important part of the "60's sound?

I agree with that very good analysis of the "listening to test tone records" school of seventies Hi Fi reviewing Dave [ie ignoring the music]. However VF starts to explain [by post 27*] that it's the contribution [or not] of different TR's in getting the studio "sound" onto the vinyl product that is his factual focus as a musician, or at least that's my interpretation. As you say, it may not be vital or exclusive-except things had to be simple or experimental-no 24 track resource.
An example of what makes "the sound" is an accident like a guitar leant against an amp feeding back on "A" [which opens "I Feel Fine"]. What could the test reviewer do with that?
In that sense TR home playback in the subsequent HI Fi era is less significant in itself. Perhaps the word "creating" should be in the title as well. Thinking about it, I presume that many of the studio machines and ancillary mixer boards etc would have pre-dated the sixties anyway
like say the early three track recording gear at EMI.

Cheers, Dave W
dave walsh is offline  
Old 6th Jul 2010, 12:09 am   #114
neon indicator
Retired Dormant Member
 
Join Date: Jun 2010
Location: Co. Limerick, Ireland.
Posts: 1,183
Exclamation Re: Are 60's tape recorders an important part of the "60's sound?

Quote:
Originally Posted by Dave Anderson View Post
Nobody thought about subjective listening tests until the late 70's and early 80's.
Nonsense. It wasn't the priority. Subjective listening tests established limits to strive to. Subjective listening tests on their own are useless. The subjective listening tests in HiFi mags in late 1970s and 1980s were largely coloured opinion as they were not double blind trials, thus mostly worthless.

Quote:
Originally Posted by Dave Anderson View Post
Most people laughed when it was suggested some amplifiers 'sound' different to others. Likewise I am sure the thought that a tape deck had a 'sound' would be too risky for any magazine reviewer in the 60's. He would fear loss of all credibility to suggest such a thing.

Dave
you know what?
By the early 80s HiFi magazines were largely rubbish.

A subjective listening test is OK if it's double blind. But much has become opinion and snake oil.

From Gold plating, painting edges of CDs, Oxygen Free Copper wire (all decent wire is oxygen free or it's brittle), Litz Wire for speakers (Skin Effect at 15kHz Ha ha ha) and much more madness has crept in since Engineering, Physics, Mathematics and proper testing has been replaced by "opinion" dressed up as subjective listening tests.

There were MANY different 60s sounds.

The one sought would be more to do with playing style and mistreating Valve amplifiers than anything to do with Fidelity or Recording equipment.

The "best" amplifier for fidelity to the original performance *is* like a piece of wire with gain. That is basic incontrovertible physics.

There is nothing in the real of audio signals that can't be measured.

Obviously a double blind subjective test with different volumes and content is needed to compare compression techniques and see at what point increased low frequency, high frequency response is pointless, a minimum audible level of distortion for various kinds of distortions and other imperfections.

Once the limits are established for a suitable sample of listeners with double blind subjective tests, then test equipment is entirely adequate to measure the performance of equipment. To believe otherwise is to deny the scientific method, physics, mathematics and engineering. You might as well tell people green coloured cable works better. Without double blind subjective test, the green cable WILL sound better for a significant number of people (More than 10%, maybe more than 20% of non-engineers). But if the listener can't see if green or some other random colour is used, they will claim even slightly poorer sound is better if assured it's the special Green cable.

Last edited by neon indicator; 6th Jul 2010 at 12:17 am.
neon indicator is offline  
Old 6th Jul 2010, 12:43 am   #115
veffreak
Retired Dormant Member
 
Join Date: Jun 2010
Location: Latvia, Riga
Posts: 78
Default Re: Are 60's tape recorders an important part of the "60's sound?

Quote:
Originally Posted by neon indicator View Post
painting edges of CDs
This is a new one to me and a really good one! What was supposed to be the benefit of that and what might be the enlightening explanation for this? (just out of curiosity)

What i gather from many amp builders, including pro's being educated engineers (though they are a bit careful about stating this in public with their name under the statement), is that not everything can be measured. An interesting phenomenon, for example, is also something that might be made from the same wood as the benefits of painting edges of CD's - "burn-in". While it's equivalent "break-in" that is attributed to speakers is undeniably an important factor to the sound, burn-in is pretty much nonsense from the point of view of an engineer or any person educated in physics. Caps, in theory, should "burn-in" in the matter of milliseconds, the same goes for other components. But still many builders (including pro engineers) swear there is a noticeable difference after 20 or even more hours of "burn-in" (through old speakers that are well broken in). It is nonsense according to what is being taught, but on the other side there has been no in-depth research of the changes in caps on the molecular level during burn-in. I personally don't believe in it - i think it's the ears that "burn-in" with time - we just get accustomed, but who knows. Since i recently read stuff on string-theory and m-theory i've remembered again that nothing, even our understanding of physics isn't bulletproof - never say never - it's just an incomplete model of reality that is being improved all the time - don't confuse physics with religion.

Best regards,

veffreak
veffreak is offline  
Old 6th Jul 2010, 12:52 am   #116
veffreak
Retired Dormant Member
 
Join Date: Jun 2010
Location: Latvia, Riga
Posts: 78
Default Re: Are 60's tape recorders an important part of the "60's sound?

Ok, i just found something about it in this article (a great and funny read): http://www.theaudiocritic.com/downloads/article_1.pdf
"CD treatment" is Nr. 9 - i'd say one of the best!
veffreak is offline  
Old 6th Jul 2010, 8:32 am   #117
neon indicator
Retired Dormant Member
 
Join Date: Jun 2010
Location: Co. Limerick, Ireland.
Posts: 1,183
Default Re: Are 60's tape recorders an important part of the "60's sound?

Quote:
Originally Posted by veffreak View Post
for example, is also something that might be made from the same wood as the benefits of painting edges of CD's - "burn-in". While it's equivalent "break-in" that is attributed to speakers is undeniably an important factor to the sound, burn-in is pretty much nonsense from the point of view of an engineer or any person educated in physics. Caps, in theory, should "burn-in" in the matter of milliseconds, the same goes for other components. But still many builders (including pro engineers) swear there is a noticeable difference after 20 or even more hours of "burn-in" (through old speakers that are well broken in).
Well, if it is demonstrated as significantly* noticed by a suitable sample** of people in "Double Blind" trials, then I will believe it exists and that we don't yet know the physics.

(* i.e. more than simply throwing a dice would give)
(** i.e. young ears, old ears etc in enough quantity)

The interesting thing about the 10 lies is that almost all have a grain of truth.

1) Using a long run of thin Bell Wire or Magnet wire has significant resistance, and thus will work with 100V line speaker in a small room but degrade a 4 Ohm triple speaker + crossover (tweeter, mid & Woofer). At VHF I use 0.5mm enamelled copper wire for coils. Tinned copper is poorer. At UHF I might use 1mm lacquered silver plated wire (high enough frequency and steel instead of copper core works as well) because the current is mostly on the surface. These effects are hyped to excuse the over-expensive cables. Gold on connector is to prevent corrosion and both halves (plug & socket) must be gold or the Tin or Nickel is attacked galvanicly. Gold is actually a poorer conductor than Silver or Copper.

2) There is nothing "better" about Valves (Tubes). However at higher volume levels (beyond what the amplifier should be used at) a Valve amplifier may soft limit and Transistor amplifier may clip. Soft limiting can sound pleasant on some types of content. No content sounds good on clipping. The solution is to have a correctly specified amplifier for the volume (loudness) required. As discussed earlier the deliberate over-driving of valve amplifiers is part of the live performance quality of certain rock/pop content. It can be perfectly duplicated in diode array analogue limiter or DSP, or by "close mic" to the Guitar Amp loudspeaker.


3) Analogue is Better than Digital.
Well sometimes it is. It's not inherently better. To improve analogue you need ever lower Intermodulation, less distortion, flatter frequency response and linear phase that looks only like a delay and sufficient Transient response. At some point the imperfections can't be heard. To improve digital you need higher sampling rate, lower clock jitter, monotonic ADC/DAC and sufficient bits resolution. At some point the imperfections can't be heard. What was state of the art to get 15kHz bandwidth as good as best analogue in 1975 was Thousands of Pounds. Now it's about 50c. Spend the less than equivalent money now and you can have 110dB of dynamic range and over 30MHz of bandwidth. That means you can get a digital processing system good enough to connect to aerial on one side and class D direct to loudspeaker at other end with only an analogue low pass filter 35MHz (100MHz sampling) on input and 25kHz low pass on the loudspeaker (1MHz sampling).

more later ...

Last edited by neon indicator; 6th Jul 2010 at 9:01 am.
neon indicator is offline  
Old 6th Jul 2010, 11:10 am   #118
Roger13
Retired Dormant Member
 
Join Date: Jun 2006
Location: Wrentham, Suffolk, UK.
Posts: 508
Default Re: Are 60's tape recorders an important part of the "60's sound?

Dave,

"Most people laughed when it was suggested some amplifiers 'sound' different to others. Likewise I am sure the thought that a tape deck had a 'sound' would be too risky for any magazine reviewer in the 60's. He would fear loss of all credibility to suggest such a thing."

However, reviewers did lose all grasp of reality eventually. When they started sticking little bits of cooking foil under their turntables and professed to 'hear an improvement' I stopped buying magazines..........

Cheers,
Roger.
Roger13 is offline  
Old 6th Jul 2010, 11:17 am   #119
neon indicator
Retired Dormant Member
 
Join Date: Jun 2010
Location: Co. Limerick, Ireland.
Posts: 1,183
Default Re: Are 60's tape recorders an important part of the "60's sound?

Continued...

4) The Double Blind Trial (AKA ABX). needs no more comment!
Quote:
Here’s how you smoke out a lying,
weaseling, obfuscating anti-ABX hyp-
ocrite. Ask him if he believes in any
kind of A/B testing at all. He will
probably say yes. Then ask him what
special insights he gains by (1) not
matching levels and (2) peeking at
the nameplates. Watch him squirm
and fume.
5) Negative Feedback can be bad. No feedback is bad.
In fact "Negative Feedback" can be integral to one stage (cathode resistor or emitter resistor or source resistor is in fact negative feedback). If Negative feedback is well designed on a well designed amplifier it make it better. If you have push pull with no bias on the devices then negative feedback won't fix it as you need much more open loop gain than closed loop gain and an "off" device has zero gain. However for a "performance" effects unit this distortion might be as valid as an over driven valve amp (IMO cross over distortion sounds nasty, always). A second issue is Transient Response.

If the filters are too steep (system band pass to stabilise feedback or prevent tweeters burning out, or graphic equaliser or tone controls) then static tone tests are OK, but the negative feedback does nasty stuff with a 10Hz +10dB signal that is nearly a square wave (rise time equivalent to 15kHz to 30KHz). A Cymbal crash will distort. This is not an inherent problem of negative feedback but a bad design. You should not see "ringing" on step impulses with edges at highest frequency and repetition rate of lowest frequency.

6) Burn in.
Burn in should be done at manufacturing to catch defects and "infant" failures. If equipment was tested at Manufacture then an ABX test will reveal no difference, and even "raw" off the production line probably not at all on electronics. Has it been demonstrated on loudspeakers with true double blind trial? So yes, "burn in" is needed, but not for the reasons some suggest.

7) Biwireing is nonsense, an illusion. There is value to an Active Crossover before the PA output. Then of course Tweeter, mid range and Woofer need separate cables and amplifiers. The Active crossover has to be tailored for the cabinet design and loudspeaker drivers in use. This is where the silly idea has come from.

8) Power conditioning needs no comment. If your PC needs it then it doesn't meet FCC /CE standards and you can in EU demand money back, manufacturer's warranty is irrelevant. I have photos of CE approved PC PSU with the filter parts needed by ANY SMPSU missing and four wire links instead of the RF chokes. A Linear PSU never needs it. It must be built-in to any valid design of Switch Mode PSU for Audio.

9) Snake oil of highest order. I have suspicions as to the origin of this myth.

10) Golden Ears. No further comment needed. Perhaps the origin is in Audible differences not obvious from specifications and the need to sell magazines as HiFi gear got better in late 1970s and the reviews got boring. If a double Blind trial identifies a difference, it can always measured with test gear. There is no magic.

I don't decry the use of anything to achieve a type of "sound" in performance or production. All can be artistically valid (e.g. Hendrix etc). But the final recording and master recordings should be all at best fidelity, without colouration. If recording a live sound as listener would hear at a performance, then you need flat, quality microphones, mixing recording and post production that adds nothing and takes away nothing. In this case simple "pan pot" of many microphone to create a stereo image is worse than two crossed cardiods at a typical listening position (or dummy head with electret capsules for headphone only listening). Ideally multiple microphone/multitrack needs variable delay to left and right channels coupled to L &R levels for true stereo image. The simple volume only pan-pot creates a lifeless and poor stereo image.

The listener's player, Amplifier and speakers should be without colouration, highest fidelity as the decision as to style and colouration of the sound has already been made by Artists and Production. Any further colouration would detract from most content.
neon indicator is offline  
Old 6th Jul 2010, 1:20 pm   #120
jamesperrett
Octode
 
Join Date: May 2007
Location: Liss, Hampshire, UK.
Posts: 1,870
Default Re: Are 60's tape recorders an important part of the "60's sound?

Quote:
Originally Posted by veffreak View Post

What i gather from many amp builders, including pro's being educated engineers (though they are a bit careful about stating this in public with their name under the statement), is that not everything can be measured.
I'd disagree with this. If it can be heard then it can be measured. However, you may not be able to see a difference with conventional, simple measurements. You may need to think about the problem a little more and measure some of the less obvious parameters to find out what is really going on.

James.
jamesperrett is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 7:50 pm.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.