Tortuga TPB.V1 Tube Preamp Buffer Review

[MakeMineVinyl]

Aren't tube enthusiasts just old peeps trying to recreate that 80s sound?

Huh? WTF does the 1980s have to do with tube sound, and 'old peeps'?

 

[MakeMineVinyl]

Tubes were obsolete by the end of the 60's ...

Come on, please!

The world is full of 'obsolete' things which are still being successfully used. I bet you might even own an 'obsolete' thing or two.

 

[MakeMineVinyl]

One of the reasons that tube swapping is a "thing" is that there are clearly audible differences between tubes. It's one of the aspects of the hobby where the hobbyist has some sense of control over the sound.

Some 30 years ago, I lived in Berkeley California, walking distance from an electronics shop that sold tubes, had a tube tester and a big NOS stock of tubes. I'd swap out tubes for my Stax Amp/Energizer [hybrid: J-Fets driving Triodes], later for an Ampex MX-10, [all-tube, ancient and very funky], Marantz 8B [glorious mid-range at the expense of everything else], and a 'starved tube' microphone preamp [another hybrid, op-amps driving the tubes, if I'm not mistaken]. Compared to the exclusively solid-state gear, the upper octaves of tube hybrid gear sounded more "rounded off" and there was a bit of soft clipping on peaks. A lot less 'grain'. The systems I'm using now, while extended as far as I can hear in the upper register, have few upper register resonances or audible hot spots. The Stax earspeakers were peaky on top, producing good "presence" and spatial effects. So were the speakers I was using for monitoring, little NHT bookshelf speakers. The Drop 6XX 'phones and the a/d/s 400 speakers in use now are as smooth as silk, driven by solid state gear.

The biggest difference with tube-swapping was in the upper registers. I'd use a Rat Shack tone generator connected to the inputs of the tube gear, connect the output to a cassette deck and look for differences in level. Also did this with various interconnects. There was a 5 db difference at 10K swapping out line level interconnects on the MX-10. The interconnects I made without shielding had the most treble, some old, thick Monster Cable stuff that was overloaded with di-electric had the least. I asked Jack Vad what was going on, he said "Send me a schematic". After looking at it, he called back, said "There's no cathode follower." I know what a cathode follower is now, didn't know then. This issue didn't happen with any of the other gear.

This all points to some of the more "Audiophilus Nervosa" aspects of the hobby. ASR would say tube gear has obvious, bad, distortions. I'm sure SET gear has oodles of distortion. I'm sure the kind of loudspeakers favored by SET enthusiasts have wonky frequency response. The sum total must be full of mismatched impedances and easily measured distortions. But all these "broken" aspects of design can be fiddled with endlessly until the golden-eared audiophile gets the sound he deserves for a price he really can't afford.

Personally, I'm dismayed that tube manufacturing has even descended to the point where they intentionally introduce distortion. In the days when vacuum tubes were current technology, the design goal of every manufacturer was to reproduce the cleanest signal possible with the least distortion. There was none of this 'tubes as tone control' shit as we have now. When I replaced the 12AX7A tubes in my preamp, I had to order 10 of them even though I only needed two so that I could find a reasonably matched pair out of the batch. That is insane. The problem is not tubes - its the current state of mind of tube manufacturers.

As for the preamp in this review, all I can say is that it seems to be a poster-child for the current 'tone control' tube mentality. Its stupid.

 

[MakeMineVinyl]

I seem to recall that many/most tube amp measurements show plenty of third harmonic (memories of many Stereophile tests). I suspect it's how these harmonics are evenly spread that can aid the so-called 'tube sound' in many *domestic* designs...

If the amplifier in question is push-pull output, than that type of circuit will tend to cancel even order harmonic distortion originating in that stage. Same thing with balanced circuits.

Funny thing is, tape recorders by their nature produce odd-order distortion almost exclusively. The more 'perfect' the recorder is, the more the even order harmonic distortion products are suppressed. As far as I've seen, nobody has ever commented one way or the other about tape distortion.

 

[levimax]

One of the reasons that tube swapping is a "thing" is that there are clearly audible differences between tubes. It's one of the aspects of the hobby where the hobbyist has some sense of control over the sound.

Some 30 years ago, I lived in Berkeley California, walking distance from an electronics shop that sold tubes, had a tube tester and a big NOS stock of tubes. I'd swap out tubes for my Stax Amp/Energizer [hybrid: J-Fets driving Triodes], later for an Ampex MX-10, [all-tube, ancient and very funky], Marantz 8B [glorious mid-range at the expense of everything else], and a 'starved tube' microphone preamp [another hybrid, op-amps driving the tubes, if I'm not mistaken]. Compared to the exclusively solid-state gear, the upper octaves of tube hybrid gear sounded more "rounded off" and there was a bit of soft clipping on peaks. A lot less 'grain'. The systems I'm using now, while extended as far as I can hear in the upper register, have few upper register resonances or audible hot spots. The Stax earspeakers were peaky on top, producing good "presence" and spatial effects. So were the speakers I was using for monitoring, little NHT bookshelf speakers. The Drop 6XX 'phones and the a/d/s 400 speakers in use now are as smooth as silk, driven by solid state gear.

The biggest difference with tube-swapping was in the upper registers. I'd use a Rat Shack tone generator connected to the inputs of the tube gear, connect the output to a cassette deck and look for differences in level. Also did this with various interconnects. There was a 5 db difference at 10K swapping out line level interconnects on the MX-10. The interconnects I made without shielding had the most treble, some old, thick Monster Cable stuff that was overloaded with di-electric had the least. I asked Jack Vad what was going on, he said "Send me a schematic". After looking at it, he called back, said "There's no cathode follower." I know what a cathode follower is now, didn't know then. This issue didn't happen with any of the other gear.

This all points to some of the more "Audiophilus Nervosa" aspects of the hobby. ASR would say tube gear has obvious, bad, distortions. I'm sure SET gear has oodles of distortion. I'm sure the kind of loudspeakers favored by SET enthusiasts have wonky frequency response. The sum total must be full of mismatched impedances and easily measured distortions. But all these "broken" aspects of design can be fiddled with endlessly until the golden-eared audiophile gets the sound he deserves for a price he really can't afford.

Wouldn't it be easier to just use EQ rather than feed the signal though a box like this with the only adjustments being changing tubes to the wrong type that don't work correctly in the circuit?

 

[oldsysop]

Sand some of that hard digital edge off your DAC’s output

 

[MakeMineVinyl]

Wouldn't it be easier to just use EQ rather than feed the signal though a box like this with the only adjustments being changing tubes to the wrong type that don't work correctly in the circuit?

An EQ wouldn't introduce distortion, which I think is the reason this type of distortion box exists. Audiophile mentality always seems able to find new depths of non-logic.

 

[Robin L]

Obviously , not the type of product that goes down well here. The interesting question isnt "Why buy this?"- but "Why buy this not something like https://www.amazon.co.uk/SENUCN-AUD...=1&keywords=tube+buffer&qid=1626085359&sr=8-5 ?" Or, put another way, what does $1600 get you here that $30 doesnt in something like the linked product- lets be honest, it cant be any worse!

I say it's worth testing, if only for the sake of comparison.

 

[Geert]

This review made me wonder if any audiophool would fall for this amp. Guess what...

From https://wallofsound.ca/audioreviews...passive-preamp-and-tpb-v1-tube-preamp-buffer/:

"Everything becomes more relaxed, effortless and flowing.
I heard cymbal splashes become “cleaner” and much more vivid (thank you, tubes), and marked improvements in realism, very noticeable with pianos and vocals – everything sounded less like a recording, with more depth and focus.
I can say with confidence that this is the best preamplification I’ve lived with to date.
While it seemed unassuming at the outset, the more I learned about the TPB.V1, the more impressed I became".

 

[Robin L]

Wouldn't it be easier to just use EQ rather than feed the signal though a box like this with the only adjustments being changing tubes to the wrong type that don't work correctly in the circuit?

Wouldn't cost enough, wouldn't have enough distortion. If you want this specific species of awful sound, you gotta pay.

 

[Robin L]

If the amplifier in question is push-pull output, than that type of circuit will tend to cancel even order harmonic distortion originating in that stage. Same thing with balanced circuits.

Funny thing is, tape recorders by their nature produce odd-order distortion almost exclusively. The more 'perfect' the recorder is, the more the even order harmonic distortion products are suppressed. As far as I've seen, nobody has ever commented one way or the other about tape distortion.

I've seen it. Have read many times of producers/engineers/musical artists bouncing their "sterile" digital productions to analog tape in order to take advantage of analog tape's soft limiting. Of course, one could simply use a digital compressor/limiter tweaked just so, but I digress.

 

[MakeMineVinyl]

I've seen it. Have read many times of producers/engineers/musical artists bouncing their "sterile" digital productions in tapes in order to take advantage of analog tape's soft limiting. Of course, one could simply use a digital compressor/limiter tweaked just so, but I digress.

I've done that a couple times too. My recorder is all vacuum tube so it adds back some even order distortion along with the saturation effects.

 

[solderdude]

How many people will have bought this ?
Are they still using it ?
Does it 'improve' the sound to them ?

the inside:

https://www.audiocircle.com/index.php?topic=145836.40

 

[DHT 845]

I know 2 guys that record their CD on tape recorder and listen from tapes. That is irrational but who cares. Tube buffer is the same story.
I own SET amps that I adore (together with transparent front end and easy to drive speakers). SET amps are far from reference SINAD

 

[Robin L]

I've done that a couple times too. My recorder is all vacuum tube so it adds back some even order distortion along with the saturation effects.

View attachment 140702

The old KPFA building had these Ampex r to r machines all over, all the studios and the music library. When I started there in 1988 some people were still using tape, digital editing hadn't quite happened [it was not really available to most people back then] and KPFA continued to use whatever still worked. When they moved, there were a few Otari reel to reel decks, but most folks already moved on to DATs and there were a number built into the studios.

 

[Maxicut]

Tubes were obsolete by the end of the 60's ...

Tell that to nearly every band & recording studio on the planet lol

 

[Phorize]

Aren't tube enthusiasts just old peeps trying to recreate that 80s sound?

No, that’s casting the net very wide. I have an affinity for 1940s to 1960s valve designs, especially the Williamson/gec designs. They were very good in their day. That’s not the same thing as someone who pays for one of these things, or buys the cringeworthy high end stuff like audio research gear. Valve gear used to be objectively designed and available to diy enthusiasts at everyman prices.

 

[Goldmann]

There must be something desirable about introducing these kinds of distortion for a lot of people. It's easy to quickly dismiss their claims about the quality about some piece of gear they love, when looking at measurements, and I've had heated discussions with audiophiles about these things in the past. I've also listened to various setups comprising of record player, tube pre- and power amps playing into big horns, line arrays or other "flawed" speakers. I must admit, that I kind of get their point. Some of the setups were very "detailed" and exciting to listen to. Others were very lush and relaxing. Off course, these characteristics were present all the time, and while it complimented some recordings and musical styles, it made others sound terrible.
Then there's the fashion aspect of it, which is kind of hard to argue with, and which they often won't easily admit to.
Perhaps a company such as TC electronic or Line6, with their extensive insight into sound modelling, could design an audiophile/hipster "box" to be inserted into your low distortion HiFi setup, which could emulate these kinds of aberrations. Add a lot of harmonics, some compression, some hissing, microphonics, some random subtle pops and crackle. Place the DSP it in a nice wooden case, perhaps with some lightbulbs on top, old school dials and buttons, but with digital I/O.
It would take some very clever marketing, perhaps using words like soul, life, "authenticity", freedom (in the US at least) from digital harshness, but it would be considerably more flexible for the end user. They could simply adjust how much they wanted of this or that kind of distortion, without having to buy new equipment all the time. Perhaps they would even dial it down over time, and end up enjoying some of the recordings as they were originally mastered.
I recognize my somewhat arrogant tone, but it could honestly be quite helpful to a lot of people. Even us objectivists, could appreciate a few of the effects on some recordings. The struggle towards lowest possible distortion, does not always give you the best musical enjoyment of a specific recording IMHO. I use a lot EQ, and have even created custom EQ versions of some of my favorite albums. Dynamic compression and EQ is also very handy when listening at low SPL.

 

[Maxicut]

...When they moved, there were a few Otari reel to reel decks, but most folks already moved on to DATs and there were a number built into the studios.

DAT tape was the worst... the rolloff from hell lol

 

[MerlinGS]

. I my memory when CD player or DAC had solid state and tube buffer output I always prefered solid state. I used to own sonic frontiers preamp that I liked, but it was over 2 decades ago. But I understand that some audiophiles want to "enrich" the sound of class D amps with crap like this buffer.

One can purchase belt driven CD Transports costing thousands of dollars and Tube DAC for thousands of dollars. Contradictions have rarely been a concern in high-end audio.

On a slight tangent, I just remembered a conversation I had with an audio engineer for one of the most respected (in high-end audio circles) tube amplifier manufacturers. I asked him why he designed tube amps as opposed to SS, he explained that it did not take much work to design a transparent SS amplifier that could deliver high wattage while also providing low output impedance, conversely, tube amp design required more thought (if transparency and high level performance were a goal) and thus was of more interest to him.