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    the safety precautions around high voltages.

Is there much point in tube preamps? (This isn't a troll)

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#42
:rofl: :rofl:

Too funny SY

Although Gentlemen,
this has given an opportunity for so many different and common perspectives to be shared in one place. I appreciate the eye opening that would probably have taken many years to figure out on my own!

Regards//Keith
 
#45
Many integrated tubeamp are by nature simply a poweramp with passive attennuator, and it works because of the high impedant input of the tubes, right?

Some "simpler" tube poweramps have lower sensitivity, maybe because of lack of a gainstage...and they are designed with high gain tubepreamps in mind...some of the best tubepreamps have high gain, right?

In some occations with very high sensitive speakers it may be different

In general, if your speakers are lean in bass, you may need a preamp
Or if your speakers have plenty in both ends, you may get away with passive attennuator

Just thoughts, nothing conclusive 🙂
 
#48
dsavitsk said:


I'll agree with rdf, but also add that it doesn't matter. The opamps, if they are there, are, what the economists call, sunk costs. The recording is what it is. If you are at an art museum, just because some painting probably could use some restoration and is a little duller than it might be is no reason to not bother putting on your glasses to look at it.
Click to expand...

Doug, Wow.. Can I quote you on this, it's the best summation in a nutshell of why I do what I do in a long, long time...

😀
 
#52
This snippet of a point from EVA in a power supply thread evoked me to take my gloves off.
QUOTE from EVA:- <Audio bussiness is pure fashion, the looks and the exotic story behind the product are far more important than anything else.

Performance does not matter. Tubes provide very poor performance for nowadays standards, yet there are a lot of enthusiasts imitating the past, either because they miss the tube gear that was in fashion when they were young, or because they want to know those tubes that they have heard wonders about but were already obsolete when they were born.

Anyway, you are not likely to see smps and tubes mixed in the same design because smps were not in fashion when tube gear was and tube people are just seeking pleasure by imitating the past (sound is actually not important)>. END QUOTE


okay..... what'you recon..I'm a tube amper because everyone who's listened to my amps say they prefer the sound. So do tubes provide very poor performance ??...no they don't. Although that thread is about smps in tube amp psu's (which I'm a strong advocate of) she is quite wrong in her assumptions that SS doesn't get mixed up with tubes. Morgan Jones regulary uses tranny stuff in psu's and CGS's.
I use a preamp to correct so much poor quality tone stuff around even from satellite sources......which is full of SS. The odd CD disk is also prone. Okay it's a broadcasting studio fault which have consoles full of TL071's and 5532 amps. Perhaps a dash of RF thrown in.
So any more to throw the towel in ? I guess from EVA's post that she is implying we tubers are a bit eccentric with our obsession with the past glowing technology. But it continues to serve us very well.

richj
 
#53
Well, no. Eva has no scientific ground on which to justify that contention. Tubes are trivially capable of objective performance well exceeding any known scientifically proven metric for 'blamelessness'. It's up to Eva to prove 0.0001% distortion is 'better' than 0.001%, and good luck to her. Compared to most speakers even mediocre tube topologies are 'blameless'. Can they also be, and often are, used as thermionic Aphex Aural Exciters? Oh ya. My personal voodoo open to amendment is audible performance hinges on three orthogonal vectors: objective measurements, simplicity, part quality/layout. By definition circuits heavy in op-amps - complex circuits in simple packages - start with a huge hit on the complexity side. The ideal circuit achives perfect measurements with a single simple active element. The basic linearity of tubes gives them a jump in that respect. But then I could be high on Bear Whiz Beer.

For 20 years I would have been right on board with you but broadcasting is rapidly changing. Economy of studio construction favours commodity hardware and many new stations are based on digital encoding at the source with LAN distribution. Microphones commonly plug into A/D converters, CDs are ripped, even transmitters have AES/EBU inputs. It's not your father's radio station anymore.
 
#55
SY said:
and maybe even some bandwidth limiting.
Click to expand...

Some (Van Alstine) go as far to limit the bandwidth, owing to power supply issues, or so they imply.

I can listen to vinyl for hours, but get pretty distracted with digital media, and even though my much hot-rodded GFP-565 sounds great, I still prefer my Audio Research SP-8...(which probably condemns me to some ring of Dante's Inferno).
 
#56
SY said:
Hey, Rich, would you like to see a schematic of a commercial tube power amp with smps from... 1977?

http://www.davidberning.com/support/ea2150b
Click to expand...
Hang on, the psu section of that Berning amp doesn't have smps..B+ which is the bone I'm picking......the rest of all discrete bias stuff = okay but all that for 150W-> an overkill ?

I still maintain and challenge the thought that tube amp performance is inferior to todays standards.

Okay Eva you've got it right..There is a brand of solid state power amp on the market that has a double triode stuck in the front panel just with heaters glowing and not connected to any other part of the audio circuit. Okay everyone says'"nice stuff looks good & sounds good"...but the tube is only bluff......and people buy it.

I leave the readers to make their own conclusions !! mine is darned clear.

richj
 
#59
SY, Yup, the power amp circuitry, looks like half-bridge voltage mode. Wasn't long after before Dixon followed up with current mode ...if implemented this could have saved much of the "pre destroying caption" with the "failure parts of this amplifier"...true grit but makes interesting reading. One could take it for a typ TV of the era.
There is absolutely nothing wrong with a bit of smps in hi-fi tube amps. If one has confidence in putting it all together then fine. The lower impedance current sourced regulation vastly improves B+, the holding up on a heavy beat note impulse and a host of other things.
My previous remark regarding tube performance, an excellent slew rate can be acheived with an amp built with ex video tubes, hence the Citation is a very well famed amp. The E80 RF tube series and others can equally take on a enhanced mosfet. ..so fairs fair..

I still drive and fire nostalic steam loco's.. By ther'e way, we get more people loaded in the carriages than those loco's driven by solid state.


r:-
 
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