Can solid state tape electronics equal their tube equivalents ?

[c1ferrari]

It's available on eBay, Bruce!

St. James Infirmary??

Search for vendor, "Satchmo Lives". It will ship out of Uganda, hehe

 

[stellavox]

My one cent worth

The title of this thread – “can solid state tape electronics equal their tube equivalents” suggests prejudice, so I can “shoot back”: “sure and handily beat them!”

But let’s start with a history of MY prejudice. As stated previously in other threads, I started out as a tubophile and directed all my “energies” towards that method of design and implementation. Then I “happened” across the Cello equipment which challenged these beliefs and altered my prejudice. I since realized that I had never had or taken the opportunity to listen to really well designed solid state (SS) equipment. From a tape playback perspective, this experience culminated in my King/Cello preamp. More later.

Now let’s examine tape electronics with a broad brush. The categories include 70 years worth of “stock” electronics supplied with the recorders both tube and solid state. Then there are what I’ll call the “accessory “categories, like many 1950’s, tubed “hi fi” preamps which had low level tape head inputs, and the few recent (10 years or so) tape playback (and record) equipment available from Manley, Bottlehead and others. Finally are what I’ll call “aftermarket” modifications made directly to the machines, into which I’ll lump the Aria electronics and modifications made by Tim Paravancini(sp?) and others. From a sonic perspective all of these electronics ranged from very good to the great term coined by my tape mentor U47: “abysmal minus”. From my own experience, a lot of decks including the tubed Ampex and a number of Studers do sound VERY nice.

Now let’s get into the sonics themselves: from personal experience. I have listed to a lot of different decks in a lot of good systems and enjoyed many of them. Of course, the problem is when I don’t enjoy something, the sheer number of intervening “things” make it impossible to determine the source of my irritation. So when possible, I use direct A/B comparison. This is NOT easy, especially with tape recorders – which are slightly larger than breadboxes – and, unless you are Ki Choi, can’t assemble many in one room. Through generous loans, I have had the opportunity to audition and compare the K/C (in my listening room) with certain “stock” decks; Ampex, Nagra, Lyrec and “accessory” preamps: Manley, Bottlehead. Through my electronics, driving Quad 63’s, in general I hear a wider, deeper soundstage and more of what I can only refer to as “slam”.

Why? – and I’ve got the body armor on here. Here’s the tube versus transistor thaang. Please realize that you have both the amplifying device itself AND the topology in which it’s used. From my reading I have to believe that every device and combination of devices and topologies have been explored – over the past 70 years! Much of what I see today is what I’ll call “minute implementation of secondary things" – shielding; grounding; vibration damping; decoupling, etc. , all of which can be important to reducing those last few decimal points of distortion, noise and items we haven’t quantified yet. And of course cable types and their inevitable interactions interfere.

I digress. For some reason which I can’t explain with any engineering finesse , I now feel that solid state can “take better control of a transient” – something to do with speed – hence time. Faster attacks and better control of overshoot. Seems to be especially noticeable in circuits requiring a lot of gain – hence preamps. Then there is the noise issue, which careful design and tube rolling can mitigate. Ah, the cachet of tube rolling: those were the days!!??

Finally, I must recount the interesting “tube prejudice” I’ve come across with a few preamp customers, and tire- kickers. The comments of one customer basically described the subset – something like; “I’m a tube lover and my whole system is tubes” - the undercurrent of which recalls the title of this thread. It took him a few days with my loaner, and subsequently a few minutes with a competing tubed unit to make up his mind. My point – there is a cult mentality here.

Lest I forget, and not necessarily a tube versus solid state issue; we (myself and U47 at least) have found that recording and playback designs can sound different within the same machine. Many (stock) machines seem to be more sonically neutral for recording than playback.

"Keep your Tails Out and your Heads Clean"

Charles

 

[RogerD]

The title of this thread – “can solid state tape electronics equal their tube equivalents” suggests prejudice, so I can “shoot back”: “sure and handily beat them!”

But let’s start with a history of MY prejudice. As stated previously in other threads, I started out as a tubophile and directed all my “energies” towards that method of design and implementation. Then I “happened” across the Cello equipment which challenged these beliefs and altered my prejudice. I since realized that I had never had or taken the opportunity to listen to really well designed solid state (SS) equipment. From a tape playback perspective, this experience culminated in my King/Cello preamp. More later.

Now let’s examine tape electronics with a broad brush. The categories include 70 years worth of “stock” electronics supplied with the recorders both tube and solid state. Then there are what I’ll call the “accessory “categories, like many 1950’s, tubed “hi fi” preamps which had low level tape head inputs, and the few recent (10 years or so) tape playback (and record) equipment available from Manley, Bottlehead and others. Finally are what I’ll call “aftermarket” modifications made directly to the machines, into which I’ll lump the Aria electronics and modifications made by Tim Paravancini(sp?) and others. From a sonic perspective all of these electronics ranged from very good to the great term coined by my tape mentor U47: “abysmal minus”. From my own experience, a lot of decks including the tubed Ampex and a number of Studers do sound VERY nice.

Now let’s get into the sonics themselves: from personal experience. I have listed to a lot of different decks in a lot of good systems and enjoyed many of them. Of course, the problem is when I don’t enjoy something, the sheer number of intervening “things” make it impossible to determine the source of my irritation. So when possible, I use direct A/B comparison. This is NOT easy, especially with tape recorders – which are slightly larger than breadboxes – and, unless you are Ki Choi, can’t assemble many in one room. Through generous loans, I have had the opportunity to audition and compare the K/C (in my listening room) with certain “stock” decks; Ampex, Nagra, Lyrec and “accessory” preamps: Manley, Bottlehead. Through my electronics, driving Quad 63’s, in general I hear a wider, deeper soundstage and more of what I can only refer to as “slam”.

Why? – and I’ve got the body armor on here. Here’s the tube versus transistor thaang. Please realize that you have both the amplifying device itself AND the topology in which it’s used. From my reading I have to believe that every device and combination of devices and topologies have been explored – over the past 70 years! Much of what I see today is what I’ll call “minute implementation” of secondary things – shielding; grounding; vibration damping; decoupling, etc. , all of which can be important to reducing those last few decimal points of distortion, noise and items we haven’t quantified yet. And of course cable types and their inevitable interactions.

I digress. For some reason which I can’t explain with any engineering finesse , I now feel that solid state can “take better control of a transient” – something to do with speed – hence time. Faster attacks and better control of overshoot. Seems to be especially noticeable in circuits requiring a lot of gain – hence preamps. Then there is the noise issue, which careful design and tube rolling can mitigate. Ah tube rolling: those were the days!!??

Finally, I must recount the interesting “tube prejudice” I’ve come across with a few preamp customers, and tire- kickers. The comments of one customer basically described the subset – something like; “I’m a tube lover and my whole system is tubes” - the undercurrent of which recalls the title of this thread. It took him a few days with my loaner, and subsequently a few minutes with a competing tubed unit to make up his mind. My point – there is a cult mentality here.

Lest I forget, and not necessarily a tube versus solid state issue; we (myself and U47 at least) have found that recording and playback designs can sound different within the same machine. Many (stock) machines seem to be more sonically neutral for recording versus playback.

"Keep your Tails Out and your Heads Clean"

Charles

Hi Charles and thanks for your wonderful response.

I assure you, I can and do go both ways when regarding both SS and Tube tape electronics. My seemingly biased and slightly provocative phrasing of my title was intended in hopes of starting a informative dialogue on this subject. Your excellent response and input was just what I was hoping for. I hope someday to hear your K/C tape preamp.

Being retired I have to budget my disposable income and hopefully my Ampex upgrades will yield better sound. It matters if they do,but even then I get great pleasure in "doing" these upgrades or whatever the term is.

I have found that my SS Ampex has many qualities that I fully enjoy. Better articulate bass,more resolution, and a very fine presence and stereo image. The tubed 350's are fantastic,but as many can see I'm trying to voice them to have the best qualities of the SS design along with what they can offer. I don't know exactly if my goals will be achieved but it has been a lot of fun so far getting there.

 

[c1ferrari]

Charles,

Thanks for sharing your experiences and observations. I'm using a stock Studer A820 and cannot verify/characterize all of its performance parameters via test and measurement, but I'm working on it

What I can say is --in my system/room-- the stock Studer acquits itself marvelously; albeit, the signal is greeted by valves, downstream.

In my lifetime, I must make a pilgrimage to Master Choi...fabulous signature, btw, Charles

 

[Gary D]

I assure you, I can and do go both ways when regarding both SS and Tube tape electronics.:

Say What!

 

[stellavox]

Thanks Guys

A few December's back, Dick Sequerra addressed the holiday meeting of our Connecticut Audio Society. What I most remember most about his reminiscing was that: your hi fi system should be thought of as a "PLEASURE MACHINE". If it gives you pleasure - then so much the better: if not - then maybe you should find another hobby - (or reevaluate your prejudice).

CHEERS

Charles

 

[RogerD]

Say What!

Hey little Brother, do what the man says ;

"Keep your Tails Out and your Heads Clean"

 

[RogerD]

A few December's back, Dick Sequerra addressed the holiday meeting of our Connecticut Audio Society. What I most remember most about his reminiscing was that: your hi fi system should be thought of as a "PLEASURE MACHINE". If it gives you pleasure - then so much the better: if not - then maybe you should find another hobby - (or reevaluate your prejudice).

CHEERS

Charles

So true! Charles

 

[DonH50]

Hi Don
My phono stage is a LCR 600 ohm passive EQ, drive by WE 437A and transformer, and I will have no more new ideas to replace them for more better. for tape's EQ filter is more simple than RIAA should be more easy to design but the only different thing tape need calibrate, that is why I keeping the deck's original design for easy calibrate and I am planning to design a 6922 differential in-put to a passive EQ for a 4 track play back (6922 much cheaper than WE437A, need more tubes still OK) on a Revox PR99 transport (replace with a 4 track head) to play with those pre recorded 7 1/2 4 track tape which bought from Ebay although they are not as good as 2 track but has more choice
tony ma

Thanks Tony,

...and a big "duh!" on my part for forgetting the different tape EQ issues. When I did this, I had fixed on a standard metal tape formulation so hard-wired the EQ. I did build a switched EQ circuit for a friend, but it was a nightmare trying to control switching glitches (pops) with the tuube circuits.

 

[DonH50]

Hi Don,

Regarding the SS circuits...were you able to hear them I like differential balance circuit topology...personally, the valve expense and heat are justifiable

Wow, that was hard to read on my hi-res notebook, Sam! Old eyes...

Do you mean hear the difference between SS and tube circuits? Yes, usually, though by the time we got them both dialed in the difference was essentially inaudible with real source material. The tube circuits had a little more hiss, and the SS a little more fllicker ("popcorn") noise, but in use they were virtually identical sound-wise (measurements readily showed numerous differences). The SS circuit used HV transistors for their large area and low noise, the final tube circuit Nuvistors (I think) instead of the usual 12AX7 etc. found in most all preamps back then.

 

[tony ky ma]

Wow, that was hard to read on my hi-res notebook, Sam! Old eyes...

Do you mean hear the difference between SS and tube circuits? Yes, usually, though by the time we got them both dialed in the difference was essentially inaudible with real source material. The tube circuits had a little more hiss, and the SS a little more fllicker ("popcorn") noise, but in use they were virtually identical sound-wise (measurements readily showed numerous differences). The SS circuit used HV transistors for their large area and low noise, the final tube circuit Nuvistors (I think) instead of the usual 12AX7 etc. found in most all preamps back then.

Don and Sam
IMO those extra repro preamp can sound better than the stock amp is not the reason of tube or SS, I guess because it is shorten the sound path wire and less of contact points. of cause material and design also a main issue but those R2R decks especially pro recorders they design for recording and editing not only for play back, so with a lot of switches, sound path cable from head to amp and to switches and meter, mono and stereo, input and repro,SYNC etc. selectors final to out put socket. even Studer's design all amp plug in to the main broad create too many contacts. by the result of modification can prove this matter.
To me tube and SS they sound different that is for sure but can't say which one must be better. different tube will have different sound , maybe SS will be the same but you can't change it easily for ABX test. 12AX7 and 12AT7 are the most common use in deck's amp but I like 6922 and 5687 better, my favor is WE437A but cost too much
tony ma

 

[c1ferrari]

Gary D and RogerD...

Hey little Brother, do what the man says ;

"Keep your Tails Out and your Heads Clean"

You guys are TOO much...you could be the Smothers Brothers of RTR Forum

 

[c1ferrari]

Don and Sam
...shorten the sound path wire and less of contact points.
tony ma

Excellent design considerations, Tony

 

[c1ferrari]

Wow, that was hard to read on my hi-res notebook, Sam! Old eyes...

Do you mean hear the difference between SS and tube circuits? Yes, usually, though by the time we got them both dialed in the difference was essentially inaudible with real source material. The tube circuits had a little more hiss, and the SS a little more fllicker ("popcorn") noise, but in use they were virtually identical sound-wise (measurements readily showed numerous differences). The SS circuit used HV transistors for their large area and low noise, the final tube circuit Nuvistors (I think) instead of the usual 12AX7 etc. found in most all preamps back then.

Hi Don,

Hope this will be easier to read In an earlier post, you mentioned, "...some of the SS circuits blow every tube circuit I've seen out of the water, but those tend to be hard to find and cost according to their complexity and use in high-end decks."

So, I was seeking clarification if the solid state circuit was inherently "superior" as it was a solid state design.

Anyway, would you please elaborate on the last segment of the quote, i.e., What's hard to find and costs accordingly

Thanks!

 

[stellavox]

Let me finish airing my dirty laundry..

Couple of items came up in subsequent off-line discussions:

Technical: power supplies. I've also found that the "stiffer" you can make the power supply, the better the dynamic range and imaging appears to become - especially if you can separate the supplies for each channel. Implementing stiffer supplies to power solid state designs is easier mainly because of the much lower voltages involved and their components taking up much less space. If you troll (trawl?)the DIY (Do-it-yourself) resources you'll find many references to "super regulators" which offer this "stiff" regulation along with lower inherent noise. Sorry - perhaps I should define what I mean by "stiff". Broadly, this is some kind of a regulator that doesn't change it's output regardless of input (power line) or output (load) variations and offers a VERY low impedance to its load - kind of like a battery. All the Cello preamps (and early Levinson and Krell and Spectral) utilized a power supply / pre-regulator in a separate box with additional "super regulation" in the preamp (second box) itself.

And on the matter of sonic prejudices; there are three "characteristics" that I listen for - tonality (flat frequency response) - dynamic capability and sound-staging. Perhaps more importantly, I weight these three characteristics 1/3 - 1/3 - 1/3. Most systems do OK with tonality. Dynamics is(are?) interesting in that many systems I have heard do fine on the small scale, but fall apart on large scale especially forte classical. What torture does "Arnold Overtures" put your system through (and as I've also said before - if you don't have it get it - immediately - next purchase)

Sound-staging is a whole other issue. Being an old fart, I started my "career" listening to Mercs and Shaded Dogs - and now realize that from them I learned AND remembered AND appreciate the three-dimensionality imparted by room reflections (time cues). This effect pretty much disappeared in the mid 60's when multi-channel recording became de rigueur, and I'd opine that many brands and generations of equipment, especially speakers, have been produced without "knowledge or appreciation" of this aspect of sound reproduction. From a musical genre perspective, rock and a lot of pop music appear to be the biggest offenders - I'd say the reproduction rating here is dynamics 50%; tonality 45% (especially the ablility to go low), with imaging 5% - as long as there is some semblance of left-right.

I'm done - Nurse, where ARE my med's!

Charles

 

[RogerD]

Charles I enjoy reading your comments, very insightful and very agreeable to my experiences. I have always loved the shaded dogs and Mercury records, as they have a quality that only can be found on some classic recordings of today,there are exceptions. What I really like is to listen to the different tape machines that were used in the original recordings. Most were Ampex 300's I believe, but I think Mercury Records did use 35mm film. (http://www.nytimes.com/2009/09/25/arts/music/25fine.html). It is a shame that the present generation will not be initiated, like we were,my dad buying records such as these when they were issued. The beautiful sound that filled our parents houses when we were growing up.

The soundstaging is an exceptional part of these recordings, but also I look for the ability to hear the ambient and inner detail captured in these recordings. I think this is where tape shines as the best electronics allow you to get involved emotionally because everything is revealed.

Couple of items came up in subsequent off-line discussions:

Technical: power supplies. I've also found that the "stiffer" you can make the power supply, the better the dynamic range and imaging appears to become - especially if you can separate the supplies for each channel. Implementing stiffer supplies to power solid state designs is easier mainly because of the much lower voltages involved and their components taking up much less space. If you troll (trawl?)the DIY (Do-it-yourself) resources you'll find many references to "super regulators" which offer this "stiff" regulation along with lower inherent noise. Sorry - perhaps I should define what I mean by "stiff". Broadly, this is some kind of a regulator that doesn't change it's output regardless of input (power line) or output (load) variations and offers a VERY low impedance to its load - kind of like a battery. All the Cello preamps (and early Levinson and Krell and Spectral) utilized a power supply / pre-regulator in a separate box with additional "super regulation" in the preamp (second box) itself.

And on the matter of sonic prejudices; there are three "characteristics" that I listen for - tonality (flat frequency response) - dynamic capability and sound-staging. Perhaps more importantly, I weight these three characteristics 1/3 - 1/3 - 1/3. Most systems do OK with tonality. Dynamics is(are?) interesting in that many systems I have heard do fine on the small scale, but fall apart on large scale especially forte classical. What torture does "Arnold Overtures" put your system through (and as I've also said before - if you don't have it get it - immediately - next purchase)

Sound-staging is a whole other issue. Being an old fart, I started my "career" listening to Mercs and Shaded Dogs - and now realize that from them I learned AND remembered AND appreciate the three-dimensionality imparted by room reflections (time cues). This effect pretty much disappeared in the mid 60's when multi-channel recording became de rigueur, and I'd opine that many brands and generations of equipment, especially speakers, have been produced without "knowledge or appreciation" of this aspect of sound reproduction. From a musical genre perspective, rock and a lot of pop music appear to be the biggest offenders - I'd say the reproduction rating here is dynamics 50%; tonality 45% (especially the ablility to go low), with imaging 5% - as long as there is some semblance of left-right.

I'm done - now where ARE those meds!

Charles

 

[DonH50]

Hi Don,

Hope this will be easier to read In an earlier post, you mentioned, "...some of the SS circuits blow every tube circuit I've seen out of the water, but those tend to be hard to find and cost according to their complexity and use in high-end decks."

So, I was seeking clarification if the solid state circuit was inherently "superior" as it was a solid state design.

Anyway, would you please elaborate on the last segment of the quote, i.e., What's hard to find and costs accordingly

Thanks!

Yes, much easier to read, thanks!

SS is not inherently superior, no. In fact, if you dig into the physics, the distortion series of a tube is factorial, and that of a transistor is exponential, so in theory tubes have lower distortion! In hindsight, my statement was too strong, and it's good you called me on it. Virtually every tube circuit I have seen, save the custom one I built and perhaps a couple in some pro decks, are single-ended. That lowers their power-supply rejection (they are more sensitive to power supply noise) and common-mode rejection, and leads to higher distortion than typical SS circuits which use differential (opamp-type) stages. It is also more difficult to get high gain out of tube circuits, meaning less loop gain to let feedback do its job. (Many tube circuits are quasi-open-loop.)

The circuits I am thinking about required extreme care in design, used complementary HV RF transistors to provide high gain with lots of headroom and low noise, and in some cases were fully-differential. Biasing got more complicated, and of course only the best components were used. The only decks I remember that utilized all of that were the ML-modified Studers, though I am sure there were/are others. They were not cheap. You can do most of that with tubes, but the circuits become much more complex and harder to realize thus I have not seen many (can only think of a couple).

So, in theory you should be able to build similar circuits using tubes and transistors, but in practice it is difficult. HOWEVER, and IMO, a decent tube circuit offers great headroom, low noise and distortion (especially relative to the tape and head itself), and is fairly simple (albeit you do need that durn HV supply). The SS circuits IME tend to be a bit more complex and with higher gain comes the requirement for more care in design and layout -- they are easier to screw up (can I say that?)

Does that help? I am being wishy-washy partly because it has been so long since I dabbled; I remember the results, but not the details, sorry! - Don

 

[c1ferrari]

Does that help? I am being wishy-washy partly because it has been so long since I dabbled; I remember the results, but not the details, sorry! - Don

Oh, hell yes!

 

[fas42]

Technical: power supplies. I've also found that the "stiffer" you can make the power supply, the better the dynamic range and imaging appears to become ...

And on the matter of sonic prejudices; there are three "characteristics" that I listen for - tonality (flat frequency response) - dynamic capability and sound-staging. Perhaps more importantly, I weight these three characteristics 1/3 - 1/3 - 1/3. Most systems do OK with tonality. Dynamics is(are?) interesting in that many systems I have heard do fine on the small scale, but fall apart on large scale especially forte classical. What torture does "Arnold Overtures" put your system through (and as I've also said before - if you don't have it get it - immediately - next purchase)

Sound-staging is a whole other issue. ... From a musical genre perspective, rock and a lot of pop music appear to be the biggest offenders - I'd say the reproduction rating here is dynamics 50%; tonality 45% (especially the ablility to go low), with imaging 5% - as long as there is some semblance of left-right

As Roger stated, some excellent points. With power supplies there is almost no limit to the benefits of refining what happens here: as far as I'm concerned, a piece of gear with excellent power supply and so-so audio circuit with always be greatly superior to another with so-so power and excellent audio

Dynamics, the obvious giveaway of a system not up to scratch, usually because the aforementioned power supplies are too crippled for various reasons.

Where I would disagree is about pop and rock. These recordings are typically more "difficult", they are also a form of torture because at times they have been deliberately engineered to exaggerate various qualities, which systems find hard to reproduce correctly. Obvious examples are highly emphasised reverb, and manipulation to create huge acoustics; if playback is not up to scratch they can sound very mediocre, but if the system is firing on all cylinders they can sound absolutely amazing, and overwhelming!

Frank

 

[DonH50]

p.s. Just to be "me too", I also appreciate your insights, Charles, thank you! - Don