Why are tube amps better? (1 Viewer)

[chung]

Saurav:

Speaking of opamps... next up on my fiddle/tweak list is using a FET and a resistor between the opamp output and the V- supply, to act as a constant current source and bias that opamp into class A with about 2-3mA .

When it comes to opamps for preamp/line-stages, here is my simple advice: NE5534/NE5532. That's probably all you need to know about opamps for audio.
It seems like you are adding a FET follower to the output of the opamp. How are you closing the feedback loop? Why FET? I don't see any benefit at all in what you are proposing. What load are you driving into?

 

[John Kotches]

Duke:
Recording Industry Association of America.
The "RIAA" curve is an equalization curve applied to the master prior to writing to vinyl. It rolls off the bottom and top end. The more LF information, the wider the groove must be. The more HF information, the finer the traces to be followed. By equalizing each end of the spectrum you make the job of the phono cartridge easier (HF) and extend the playing time of the record (LF).
The RIAA could be described as a having a "mid-range" hump, but it's really intentionally rolled off at each extreme. At one point, there were several different curves used to cut LPs from various labels, and the RIAA curve was agreed on industry wide at some point in time.
Phono stages do 2 things: One, apply the inverse to the recording curve to get a flat frequency response and Two, take the MM or MC level signal to typical line level.
Regards,

 

[Saurav]

I thought the RIAA compensation curve boosted the bass and attenuated the treble. In other words, the information on the record had teh bass attenuated and the treble boosted. Not a U shape or A shape.

Why FET? I don't see any benefit at all in what you are proposing. What load are you driving into?

About 100K. The idea is to add a path from the opamp output to the V- rail (doesn't have to be a FET, could be just a resistor), so that the current draw on the opamp increases, and it moves into class A. Any DC offset introduced is taken care of by the coupling caps. And the amount of current needed is calculated from the maximum voltage that the opamp output swings, and the load that it's driving.
I don't know if I'm making any sense here. Anyway, the FET turns this into a more constant current load, using only a resistor wouldresult in the current varying as the opamp's output voltage changes.

 

[Saurav]

That post came off as sounding more disgruntled than I intended

 

[chung]

Saurav:

The RIAA compensation is done in the feedback loop. I know there are other ways to do it, but that was the schematic that I built.

I don't think you answered my question. It is critical how the loop is closed: whether you treat the output of the opamp or the FET source as the output as far as the loop is concerned. I don't think you have thought through this issue, with all due respect .

 

[Arthur S]

Does anyone else remember the $10,000 Bob Carver amp challenge? He bet $10,000 that in 24 hours he could modify one of his earliest solid state amps to sound like any tube or other kind of amp. Holed up in a motel room he tweaked his little solid state amp as needed. As I recall, in double blind listening tests, he met the challenge.
Now under the Sunfire brand name he makes at least one (and I think more) amp that has 2 sets of speaker outputs, one called Current for a "warmer, more open tube sound", and the other called Voltage "for a faster, more dynamic solid state sound".
There have been reviews of these amps and the frequency response with the Current (tube) output is nowhere near flat.
However people achieve the kind of sound they like is their business. IMHO solid state is the preferred way to go for the vast majority of listeners, including most of those who consider themselves "golden ears".
Artie

 

[Stephen Houdek]

As a music lover and guitar player I will step in and say the musical difference between tube and solid state is much more apparent in the guitar world depending on the type of music you play, but the tube changing hassle and reliability makes SS the hands down winner.

 

[Saurav]

Boy, you do sound grumpy

My apologies

 

[Joe Casey]

Let's not go there, I've had someone else tell me that too, that I grew up listening to crappy records so that's why I like them. I find it mildly offensive that people cannot accept that I simply enjoy the sound of vinyl more.

I couldn't have said it better. Some people are into sterile SS music reproduction, whereas others prefer the musicality of tubes and good vinyl. To each his/her own. I don't knock the SS crowd, and I expect the same in return.

 

[Duke H]

Ah, yes...this old debate! How is vinyl inferior to, say CDs, DVD-As, SACDs, HDCDs, etc.? How can you get better than the original? Answer-you can't. Sure, vinyl has hisses and pops, but that's part of the experience! As I've said before in other threads, digital is great, but when you convert analog to digital, I feel it comes off as sounding a bit sterile. Not bad...just sterile. Also, if digital recording is so much better than analog, how come many artists still insist on recording to analog tape? I love DVD audio, but I still listen to a lot of vinyl.

Here's another question...say I bought the Mona Lisa, and didn't like the fact that she doesn't have eyebrows. Add a little black paint, and vola...a nice Burt and Earnie style unibrow! Did I improve the painting, or bastardize it? It depends on who you ask. Now, how about this: Aerosmith goes into the studio, and records a kick-ass album, onto a very cool retro reel to reel deck. The album is then "digitally mastered," and released on, say, CD and SACD and Vinyl. Here's the catch: the vinyl is not digitally remastered. So, which copy is closer to perfect? Wouldn't digitally converting an album intentionally recorded with analog equipment be bastardizing the artist's original intent? If so, wouldn't that make the CD the equivelent of our lady Lisa's Unibrow?

 

[Steve Zimmerman]

onto a very cool retro reel to reel deck

I think you've captured the essence of tubes. Very cool, very retro.

--Steve

 

[Saurav]

This is probably not going to get resolved here, since it hasn't been resolved for the last several decades. I've said this before - if anyone is in the San Francisco bay area and wants to see what 8W amps and a $2K total budget can do, you're welcome to drop by my place. I don't think I have the best system possible in that budget, but I think it's pretty decent. Sure, it's cool and retro to have the tubes glowing in the dark, but that's secondary. I just happen to prefer the sound of the tube amps I've heard more than the SS amps I've heard. And my priorities lean towards the rhythym and flow in music rather than tonal accuracy and detail, and factors like soundstage and imaging are fairly unimportant to me.
Question: Have you recently heard a quality R2R or vinyl setup? I'm not talking about what our parents used to own, but modern gear. I'm also not talking about turntables that cost in the 4 or 5 figures, there are pretty decent 'tables being made today for as low as $200, and very good 'tables can be had for under $1K new.

 

[Duke H]

Does anyone know where and for how much I can get one of those needles that doesn't touch the record? I think that they use a laser or something similar, much like a CD player. If anyone has one, what does it do to the sound quality, as far as pops and hisses are concerned?

 

[John Sully]

Question: Have you recently heard a quality R2R or vinyl setup? I'm not talking about what our parents used to own, but modern gear. I'm also not talking about turntables that cost in the 4 or 5 figures, there are pretty decent 'tables being made today for as low as $200, and very good 'tables can be had for under $1K new.

I listened to a vinyl setup a friend of mine put together a few years ago (few < 5 years). I believe that he was using a Technics SL1200 since he is into DIY techno music, but he tried to convince me that vinyl sounded better than CD. We A/B'd several tracks on recordings he had on both vinyl and CD. I heard all the old bugaboos that made me sour on vinyl after CD was introduced:

• Excessive HF noise.
• Clicks and pops.
• Rolled off high end.

It has always been possible to put together a very good vinyl system for a reasonable price. One of my favorites was the old AR XB with a mid grade Grado cartridge. My first decent turntable was a Stanton belt drive unit which had an arm tuned to the 681EEE. This was an excellent sounding combo, but I decided to upgrade because I wanted something which would turn off when I fell asleep while listening instead of running the cartridge against lead out grooves all night long. I tried several different combinations and eventually settled on a Sony BioTracer single play table with a Grado cartridge. Most of the other units I tried were prone to problems with tracking warped records or had LF feedback problems when listening at high volumes. The BioTracer arm was very good at minimizing these problems and was especially good at tracking warped records -- and warped records were a real problem in the '70s since most records came from the plant pre warped.
There really has been no advances in vinyl playback systems for many, many years. The various types of arms which attempted to damp feedback and improve warp tracking were the last hurrah of vinyl. Currently decent players such as the Regas use technology as old as the hills (belt drive with a synchronous AC motor). This is an excellent technology for running a turntable as long as your 60Hz is 60Hz and is stable. Both this technology and regulated DC motors (as used in direct drive turntables) can provide excellent results. Arms and cartridges have changed not a whit in 30 years, it is still important to get a good match between the arm and cartridge to optimize warp tracking and bass response. And of course, as always, a good phono pre amp with high quality RIAA EQ is still important. However, all of this technology was basically perfected in the 60s and 70s, with the pinnacle probably being the phono stages designed by Tomlinson Holman (of THX fame).

 

[Saurav]

Ah yes, Holman's phono stages, especially the one in the NAD 1020/3020. That's legendary. I've heard great things about AR turntables too, never owned one though.

There really has been no advances in vinyl playback systems for many, many years.

What about tonearms/bearings and cartridges? I don't know enough to comment on that, but I do know that the sound I get out of my Rega table/arm is in a totally different league from what my 70s Pioneer belt drive can produce, with the same cartridge and phono stage. It's possible that the technology hasn't changed, but IMO the availability certainly has. Most people trying out vinyl these days have something at the level of a Rega or an MMF. These seem to be several notches up from the run-of-the-mill turntables from the 60s and 70s, based on my experience with a few of them. I'm not comparing state-of-the-art back then to SOTA now.

 

[Danny Tse]

I have worked with Technics' SL1200 turntables when I was a volunteer DJ at my college' radio station (Cal State Hayward's own KCSH), and I think they are OK. The SL1200 is not build to be an audiophile turntable; it's build to be a DJ turntable. In fact, the SL1200 is THE turntable to won if you work in a club and need to spin vinyl. The current issue of Wired magazine selected the SL1200 as one the most important "instruments" in music making, for what it's worth. The SL1200 CAN be made into a audiophile turntable, but factor in the additional cost, why not just get a Rega or a Music Hall to start?

 

[Larry B]

Joe:

I do read specs, but my ears are the final judge...Some people are into sterile SS music reproduction, whereas others prefer the musicality of tubes and good vinyl. To each his/her own. I don't knock the SS crowd, and I expect the same in return.

I'm with you. (Although currently, I do use SS.)

Larry

 

[Joe Casey]

Larry,
I actually use a combination: a tube pre to liven the sound of 800W SS amps driving 84db efficeincy speakers .

 

[Larry B]

Joe:

800 W. Yikes! What speakers do you use? And while you're at it, please tell me about your entire system.

Thanks.

Larry

 

[Aslam Imran]

Tube gear is not necessarily better than SS gear. Its just different sounding. In fact specwise or on paper tube gear is worse than SS gear. It just sounds better to the human brain (yeah brain not ears) due to some inherent distortion characteristics that is only found in tube gear. In fact there are several reasons one might not want to use tube gear.

1) Tubes have life, after which you will have to change and re-bias (the amps) and most definetly end up with a different sound than the last one. This could be a blessing to the guys who love tweaking (tube rolling) the sound of their gear.

2) Mostly low power outputs.

3) Tubes are prone to noise due to the inherent microphonic nature of tubes.

4) Tubes color the sound (in a good way) more then SS gear. They typically have distortions over 1%.

So for guys that love consistent sounding gear that can be calibrated and left alone to enjoy for years to come, tubes are not the way to go.

All that said, I love tube gear myself more than SS gear, so no offense to the tube lovers out there.