Thoughts on tubed preamps?

[SIY]

How basic and how far back do you want to go? DBT as a necessary control in any sensory experiment has been known for over a century and is discussed thoroughly in literally any introductory text on sensory science or experimental psychology. And just about any other experimental science like pharmacology, epidemiology, medicine, biology...

Audio people became more aware of it with publications like Munson and Gardner, JASA Volume 22, 675; 1950; Lipshitz JAES Volume 29 Issue 7/8, 482; 1981; Clark JAES Volume 30 Issue 5, 330; 1982; Lipshitz 8th International Conference: The Sound of Audio (May 1990); but the necessity of DBT as a basic control is subsumed under basic experimental design and pre-dates all of these references.

It's not that it's "better," it's that it's absolutely necessary for validity. It is the most basic of all controls.

 

[noobie1]

How basic and how far back do you want to go? DBT as a necessary control in any sensory experiment has been known for over a century and is discussed thoroughly in literally any introductory text on sensory science or experimental psychology. And just about any other experimental science like pharmacology, epidemiology, medicine, biology...

Audio people became more aware of it with publications like Munson and Gardner, JASA Volume 22, 675; 1950; Lipshitz JAES Volume 29 Issue 7/8, 482; 1981; Clark JAES Volume 30 Issue 5, 330; 1982; Lipshitz 8th International Conference: The Sound of Audio (May 1990); but the necessity of DBT as a basic control is subsumed under basic experimental design and pre-dates all of these references.

It's not that it's "better," it's that it's absolutely necessary for validity. It is the most basic of all controls.

I appreciate that you took the time to cite the references. Will take a look. I’m not doubting that sighted tests are unreliable. I’m just not convinced non-sighted tests are all that more reliable or if they are more reliable, it’s only under a narrow set of circumstances.

 

[SIY]

Fun trivia fact: people who are far more woke than I am are objecting to the term "double blind." Apparently the new approved term is "double masked."

 

[watchnerd]

And probably the main issue - how do I reconcile these opposing positions with myself?

I run my turntable through a digital DSP-based RIAA stage. I've used tube preamps and headphone amps combined with Class D power amps in the past.

How does one reconcile this?

Walt Whitman has your answer, from 164 years ago:

Do I contradict myself?
Very well then I contradict myself,
(I am large, I contain multitudes.)

 

[DonH56]

The (a) problem with the sighted vs. non-sighted comparison is that it has been around so long it is hard to think of a reference off-hand; it is simply "standard knowledge" to most of us. It's like asking for a reference that proved Maxwell's Equations or Ohm's Law. Or the definition of "red" (yes, there is one; no, I don't remember it off-hand).

The hardest part of a DBT IME/IMO is proper test setup. It is hard to do a good one that tests just the variable desired. It is essentially a "difference" test and not a "better" test; it is to distinguish between two (usually not more) test cases and not to tell us if one case is "better" than another.

When someone questions basic principles my usual response is to tell them to check out a basic college text and look it up. Or even Google it, or check Wikipedia, etc. The usual reply back is "you must not know it then and/or it must not be true". As I get older and busier I care less what others think about me, I suppose.

Back to work - Don

 

[greenpsycho]

I run my turntable through a digital DSP-based RIAA stage. I've used tube preamps and headphone amps combined with Class D power amps in the past.

How does one reconcile this?

Walt Whitman has your answer, from 164 years ago:

Do I contradict myself?
Very well then I contradict myself,
(I am large, I contain multitudes.)

Honestly, this is the most helpful answer. As you could probably tell, I was/am struggling in my original post in terms of how to juggle my desire for "the best" in all things (this is a personal fault of mine, and I usually defer to objective measurements). I think I'm turning a corner a bit after a good discussion with my wife in which she referenced food and the dining experience vs cooking. I had always approached sound/food reproduction as a science and the creating of music/food as the art, however, I'm beginning to realize this is probably not as cut and dry as I would like. In all things, there is sometimes a gulf between what is "accurate" and what "feels right"

Anyways, personal journeys and revelations aside, I have a loxjie p20 in my possession and a miniwatt n3 en route so I'll be evaluating both in the coming weeks. Even with a 30s listen on my koss portapro, I think the loxjie p20 is already going to flip my vote (can't wait until I hear them with my hd600's).

 

[Music&space]

I have been flirting with some cheap tube preamps on Amazon for less than 100$. I see surprisingly positive reviews and the fact that stock tubes can be replaced sounds quite nice as I can play around with the sound and significantly(?) improve its quality.

My set up consist of a Geshelli stack (Enog 2 pro and Archel 2.5 pro) which feeds a HE4xx and the Edifiers S3000 pro. So, I want the preamp to colour the sound in the headphones and speakers.

Do you think it is money worth spend, or will I be disappointed by them, hence better increase my budget to get something better? What is your opinion/experience with these or similar products?

Examples on Amazon are the following:

SUCA-AUDIO Tube-T1 Preamplifier, Vacuum Tube Amplifier Buffer Mini Hi-Fi Stereo Preamp with Treble & Bass Tone Control for Home Audio Player (6K4 Tubes): https://www.amazon.com/gp/product/B07Q656449/ref=ox_sc_mini_detail?ie=UTF8&psc=1&smid=A18L48XDTDF0CW

AIYIMA Audio 6J1 Tube Preamplifier Bluetooth 5.0 HiFi Treble & Bass Adjustment Audio Preamplifier DC12V Amplifier Preamp for Home Theater System (Black+Bluetooth 5.0): https://www.amazon.com/dp/B07TX89D9...lja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ&th=1

Dilvpoetry 6K4 Vacuum Tube Amplifier NE5532P Chip Preamp 2 Channel Treble Bass Stereo Buffer Preamplifier(Silver):
https://www.amazon.ca/gp/product/B07HP38P9G/ref=ox_sc_mini_detail?ie=UTF8&psc=1&smid=A27GP0EZAO17FR

 

[levimax]

I have been flirting with some cheap tube preamps on Amazon for less than 100$. I see surprisingly positive reviews and the fact that stock tubes can be replaced sounds quite nice as I can play around with the sound and significantly(?) improve its quality.

My set up consist of a Geshelli stack (Enog 2 pro and Archel 2.5 pro) which feeds a HE4xx and the Edifiers S3000 pro. So, I want the preamp to colour the sound in the headphones and speakers.

Do you think it is money worth spend, or will I be disappointed by them, hence better increase my budget to get something better? What is your opinion/experience with these or similar products?

Examples on Amazon are the following:

SUCA-AUDIO Tube-T1 Preamplifier, Vacuum Tube Amplifier Buffer Mini Hi-Fi Stereo Preamp with Treble & Bass Tone Control for Home Audio Player (6K4 Tubes): https://www.amazon.com/gp/product/B07Q656449/ref=ox_sc_mini_detail?ie=UTF8&psc=1&smid=A18L48XDTDF0CW

AIYIMA Audio 6J1 Tube Preamplifier Bluetooth 5.0 HiFi Treble & Bass Adjustment Audio Preamplifier DC12V Amplifier Preamp for Home Theater System (Black+Bluetooth 5.0): https://www.amazon.com/dp/B07TX89D9...lja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ&th=1

Dilvpoetry 6K4 Vacuum Tube Amplifier NE5532P Chip Preamp 2 Channel Treble Bass Stereo Buffer Preamplifier(Silver):
https://www.amazon.ca/gp/product/B07HP38P9G/ref=ox_sc_mini_detail?ie=UTF8&psc=1&smid=A27GP0EZAO17FR

I would be concerned that these pre-amps are actually cheap SS amps with "tubes for decoration", I don't know specifically on these but I have seen this reported for similar products. Free advice and worth every penny is if I was going to get another tube pre-amp it would either be a well know vintage one or a DIY project. I would also be very skeptical of "tube rolling" .... if a tube pre-amp is working right it is not going to sound different than a SS pre-amp working right.... "rolling" in a different tube that sounded different would most likely indicate the tube is not working right in the circuit. In any case good luck and have fun.

 

[cryptout]

I also use a cheap tube pre (fx-audio tube-01) in my otherwise very clean (Atom + D50s) headphone setup. Messing around with tubes is fun. There is a huge tread on another friendly forum about this cheap pre. (search: FX Audio 6j1 tube preamp - a $31 wonder)

 

[cryptout]

if a tube pre-amp is working right it is not going to sound different than a SS pre-amp working right

You are right about that, but the idea is to get a bit of pleasant distortion from the tube pre. So in a purist way it degrades the signal but many people find that it adds something.

 

[beefkabob]

I did a sighted listening to a tube rogue audio amp versus some Japanese class A amp. The rogue audio sounded muddy on vocals and great on electric guitar. If every instrument had a separate track on the recording, putting the guitar through a tube to make it even grungier might be fun, but it's just messing around with the sound. Find if messing around with sound and electronics is your hobby, but not fine if listening to music is your hobby.

So I think it's an utter waste of time to get anything with tubes.

 

[majingotan]

You are right about that, but the idea is to get a bit of pleasant distortion from the tube pre. So in a purist way it degrades the signal but many people find that it adds something.

Subjectivist calls it "sins of omission" and "sins of commission". I use the Schiit Saga preamp with 5692 red base tube with little penalty in "sins of omission" (audibly transparent sounding, zero microphonics, inaudible noise floor at unity volume, little to no penalty in microdetails) but has good amount of "sins of commission" (wider soundstage, mids are a hair thicker with no hint of muddiness, slight increase bass impact but without extra decay, no treble roll off). Can't really A/B volume match it with the 120 dB SINAD passive mode since the tube mode is noticeably louder right after I flick the switch. Caveat Emptor: the difference is splitting hairs where I have 100% confidence that if I can volume match the modes, there would be ZERO difference in sound

 

[watchnerd]

I have been flirting with some cheap tube preamps on Amazon for less than 100$. I see surprisingly positive reviews and the fact that stock tubes can be replaced sounds quite nice as I can play around with the sound and significantly(?) improve its quality.

If your intent is to do tube rolling, these are all hybrid tube amps.

In my experience, hybrid tube amps aren't as susceptible to differences in tubes / don't sound much different with tube changes, compared to pure tube amps. So if your intent is to play around / "improve the sound" hybrids are less likely to fill that role.

 

[watchnerd]

I did a sighted listening to a tube rogue audio amp versus some Japanese class A amp. The rogue audio sounded muddy on vocals and great on electric guitar. If every instrument had a separate track on the recording, putting the guitar through a tube to make it even grungier might be fun, but it's just messing around with the sound. Find if messing around with sound and electronics is your hobby, but not fine if listening to music is your hobby.

Similar effect on horns (sax, trumpet) as on guitars, in my experience. It can be a pleasurable effect.

But on piano...meh...

 

[majingotan]

Similar effect on horns (sax, trumpet) as on guitars, in my experience. It can be a pleasurable effect.

But on piano...meh...

That's why I would rather go with a properly engineered hybrid tube amp than a full input and output tube stage since my preferences is only a tinge of tube flavor. Going excessively on tube just sounds wrong to me

 

[pkane]

That's why I would rather go with a properly engineered hybrid tube amp than a full input and output tube stage since my preferences is only a tinge of tube flavor. Going excessively on tube just sounds wrong to me

Here you go: https://www.audiosciencereview.com/...us-bluetube-v2-adjustable-hybrid-preamp.8795/

Objectively, it's not a bad preamp when used with the tube disabled. But you can turn in as much of the 'tube' effect as you want, and it shows in measurements. When listening, I find a transparent SS preamp or no preamp subjectively better, but that's just me and my preferences.

 

[majingotan]

Here you go: https://www.audiosciencereview.com/...us-bluetube-v2-adjustable-hybrid-preamp.8795/

Objectively, it's not a bad preamp when used with the tube disabled. But you can turn in as much of the 'tube' effect as you want, and it shows in measurements. When listening, I find a transparent SS preamp or no preamp subjectively better, but that's just me and my preferences.

The distortion values on that thing in tube is insane. Definitely not my cup of tea as well. Like I mentioned earlier, the tube mode on the Saga is nothing like that distorted as measured here. That also confirms why I barely hear any subjective difference against passive mode, but unfortunately tube mode is slightly louder than passive hence I can't volume match A/B them without another unit and a switch box.

 

[Wes]

Hey all, I'm slowly building up my system and my next big purchase will most likely be a preamp (linestage technically). I'm typically pretty firmly in the solid state camp, and would consider myself an objectivist, however, a lot of the features I need in a linestage come via the audio research LS line. True, there is a newer Bryston preamp that offers some comparable features, I guess my question is: would this group consider anything with tubes immediately off the table because they might measure not as well as solid state components?

And probably the main issue - how do I reconcile these opposing positions with myself? I'm sure that audio research gear sounds great, but I honestly (and weirdly) feel like I'm betraying some of my own beliefs.


edit: should mention some associated gear. Linn LP12 fully kitted out, PS Audio Direcstream Jr, Bryston BHA-1. Emotiva Stealth 8, hifiman HE-400S, Senn HD600, Beyerdynamic DT990, hifiman HE-6, etymotic er4xr

I hate to redirect this thread back to the OP's question, but he wants certain features.

The Audio Research LS models are often available used and can easily be resold for little or no difference in price. They are high quality units, and ARC will service everything they ever made. The tubes in a pre- will last at least a couple of years, and not use a lot of power (as an amp would). The more recent units have run time meters to tell you if the tubes are nearing end of life (or getting "soft").

Bryston has a very long warranty and is also high quality.

If you are a renowned audio engineer, you can make your SS amp sound like any other super spendy amp in a day or two of non-stop work...

Can you list the features you need or want?

 

[watchnerd]

That's why I would rather go with a properly engineered hybrid tube amp than a full input and output tube stage since my preferences is only a tinge of tube flavor. Going excessively on tube just sounds wrong to me

The comment wasn't about the topology.

The comment was about whether the stereotypical tube distortion characteristics were euphonic or not.

 

[SIY]

The comment was about whether the stereotypical tube distortion characteristics were euphonic or not.

Serious question: what are they? I've designed/built/worked on a lot of tube amps and preamps over the years and never saw anything consistent in their distortion or overload characteristics.

Likewise, I've heard people say that tube amps are bright and forward and others say that they're mellow and laid back.