[tubesforever]

I like to recap my projects after a year's time.  With some projects,  I keep my opinions to myself.  In other instances I find shards of success and I am happy to share my experience.  For me the journey is more important than the final destination.  

After one year's time, is the Clarinet a good value?  Did it deliver the goods?  Would I build it again?  Would I recommend it to a friend?   Would I recommend it to an audiphile with serious equipment and more money to spend than I earn in a lifetime?

Here is my opinion and you are encouraged to disagree with my findings.  What works in my system might bomb out in yours.  What I have found to sound great might make another run for the hills.  How will I judge this project five or ten years from today?

Here is my perspective on the Hagerman Clarinet line stage.   The Hagerman Clarinet half kit is a great project for anyone contemplating their very first kit build, their tenth build, or their thousanth build.  

Why would anyone consider this a great build for their 1000th build?  Jim's kit is well designed, the board is expertly laid out, the double board is extraordinarily durable for diy nuts like myself, and overall the unit responds with a sound quality that far exceeds its price.  
  
From a sonics stand point where does the Clarinet fit in the scheme of high end sound?  

In a stock configuration you can expect the Clarinet to sound delicious in every way.  Add a few parts upgrades in the right places and the Clarinet will match up to the top of the high end and not be ashamed.  

What I can say here definitively after a year of tweaking, parts rolling and tearing my hair out boils down to the fact that the Clarinet is one of the most cost effective line stages ever presented to the DIY crowd.  It is a fun and easy build for a beginner.  It is a worthy challenge for someone trying to perfect a highly revealing system, and it is serious taste of how music can sound more natural and life like.  For me the challenge of getting my Clarinet right was fun, affordable, and taught me a lot about what went into a tube line stage design.  

I would recommend without hesitation the Clarinet to a first time DIY builder, a pro, and anyone with any budget that would like to hear their recordings played back like music sounds in real life.

Will my Clarinet build be the best for everyone and every system?  Maybe yes....and possibly not.... my speakers might be different and my room and amp might sound more or less neutral than the system you own.  Perhaps your sources require different line stage parameters?  There are many reasons why a circuit design sounds either good or terrible in a system.  In the end, system matching is everything.

Therein lies the true beauty of the Clarinet.  Depending on the time and energy you are willing to invest in research, parts selection and tube rolling, I can say without equivocation that you can build a Clarinet that can outperform equipment costing anywhere from $300 dollars to $10,000 dollars.  

I took my Clarinet on the road and could system match it to any amp and speakers with just a few tube rolls.  In every case the Clarinet was far quieter than the other equipment I compared it against.  In fact in most systems you might think the Clarinet was not hooked up or in the wrong input selection...then the music starts, your jaw drops, you look at the other people listening with you.  At that moment everyone understands that the Clarinet is really in a different level than the 1-10k dollar equipment they have been playing in their system.  The Clarinet is that good!

If you want to know more about my Clarinet build please check out my previous posts on this board and feel free to email me for specifics.

Here is the bad and the ugly side to the Clarinet.....

For the bad side of Jim's design, I do not like the fact that the Clarinet reverses phase.  I really wish his system kept absolute phase.  How big a deal is phase reversal?  I am not exactly sure where I side on this controversy.  For some purists, they claim loudly and persistantly that absolute phase should remain positive from the signal generation to the speaker's movement.  

I have been asked by some of these purists what I think of phase and absolute phase?  Well from a wave length perspective if a microphone is 25 ft from the Tympany and Bass Drum and 6 ft from the second Violin section do you think the music's phase is correct at the microphone?  NO.  The signal does not enter a microphone in absolute phase so absolute phase cannot necessarily ever be achieved in a live performance or a recorded performance.

I am happy with the sound of my Clarinet and that is why I am on the fence regarding the issues of absolute phase response. 

Now for the ugly side of the Clarinet.....

Jim's Clarinet design requires 12AU7 tubes that are running squarely in the design specifications for the tube.  After one year my stock JJ Tesla 12AU7 short plate tubes were beginning to bleed.  What I began to hear was distortion in the midrange and upper midrange and a hideous 4-5k ohm squeel.  Jim calls it a whistle.

I just got in a fresh set of JJ Tesla 12AU7 short plates this week and inserting these into the circuit was very helpful.  The distortion and whistle are gone.   The point I am presenting is that you cannot throw just any 12AU7 or equivalent into the circuit and expect magic.   It needs to perform like new to work in the circuit properly. 

You will have to experiment for yourself if you want to evaluate how NOS tubes and variants will hinder or improve the sound.  In many cases I went back the the JJ Tesla's because the other tubes I own just did not keep the circuit as happy with the wide variety of music that I throw in its direction.  

No worries!  The JJ Tesla 12AU7 short plate is very affordable and easy to obtain.  It actually sounds very balanced and very robust.   I bought mine from Tubes and More which is where Jim has you buy the Hammond transformer, tube sockets, and the stainless hardware.  These are on sale this month for $7.95 each.  Buy a few extra if you plan to build a Clarinet.  You will be very happy to have some extra's stashed away.

When it comes to line stages I am done looking and I am done tweaking.  The Clarinet I have today is everything I want and then some.  It is everything I don't want and then some.  By that I mean that the Clarinet has an honesty and neutrality regarding the signal.  It does not make the signal overly warm, give it excess bloom, or act as a tone control.  Rather I find it to be fast, articulate, expressive and flat out impressive.  It will make the hair at the back of your neck stand up regardless of the source you throw its way.

I hope others will post in here and state the parts they are using and how they like the results based on their systems.  This is what makes DIY so much fun.  I will tell you that my Clarinet passes every one of my acid tests with room to spare and these acid tests are not an easy thing for most line stages to accomplish.  

After a year I can confidently state three things about the Clarinet.  First I am glad I built it and I would be eager to do it all over again.  Second it easily matches and exceeds the sound of 5-7k dollar line stages I have compared it against.  Third, Jim Hagerman and this board are about the best support group you could expect to find in the DIY arena.  

I realize there are lots of other great kits out there.  I would chose the Hagerman kits for this simple reason.  I think that you could do a lot worse and hear a lot less for the dollars and time you plan to invest.  I am certain you will learn more about circuits and meet some great new friends.  

If I were to rate the Clarinet I would rate it as follows.

Ease of build.....a perfect 10
Support during and after the build.....a perfect 10
Kit design and board layout.....a perfect 10
Circuit design.....a 9 due to the phase reversal.
Parts quality and overall cost......6 for the recommended stock components
(9 if you are willing to kick in a few extra dollars for upgraded passive component parts).  

Satisfaction?  That is up to you, your motivation, and your willingness to explore.

For me the journey is done until Jim emails me about a new design--a fully balanced, absolute phase line stage kit.  Then I am plugging into perfection.  Jim????  Can I count on you to do this?

Happy Holidays to everyone here at the Hagerman board.  A special thank you to everyone who contributes here--we are stronger and better for adding our voice to improve or perfect Jim's great designs.  

Thanks Jim for all the help, the support, and the excellent DIY designs.  I am a better person for building a Hagerman kit.  That is a testimony to you.  I know your life has had its ups and downs but I hope you continue to enjoy rubbing elbows with the DIY contingent.   We admire your committment and your dedication to building affordable and excellent sounding gear.

Cheers!

[dangerbird]

Damn,, that was a good read,,, is it really that good?

[tubesforever]

is it really that good?

It depends on your research, your parts selection, and how you measure overall success for your project. 

Personally, I was not out to build a great sounding 500 dollar kit.  I wanted to rub elbows with the best line stages I have access to hear and compare.  Instead of 400 dollars of parts I spent closer to 900 dollars.  It was money well invested.  I achieved the measurement of success I had set for my project.  In fact I was pleasantly surprised at the level of sound that is achievable with Jim's designs.

DIY is bliss when you have Champaigne tastes and operate within a beer budget.  In the normal marketing model, a manufacturer would need to sell my under 1000 dollar Clarinet to a dealer for between 3000 to 4000 dollars.  If the manufacturer could not get this price then eventually they will need to close their doors. The dealer would need to retail it for 5500 to 6500 in order to keep the lights on. 

You can see why I am drawn to DIY.  You can achieve excellence for pennies on the dollar.  Our economic model is far different than a high end manufacturer. 

In stock form the Clarinet is a very capable and satisfying piece.  That is with the pcb mounted rca jacks and all the switches and pots as specified in the build sheet.  Build it as Jim lays out in the manual and for someone hoping to get a taste of the high end they will not be disappointed. 

If you build a Clarinet, you will find it very easy to voice and improve the sound to match what your system requires.  As I spun in and out various tubes and passive parts I could sense the sound was better for this genre and worse for that genre.  I could tune up a Clarinet for any system or musical genre.  The Clarinet is adapable. 

Is the Clarinet a perfect design?  I know of at least one contributor here that did not find enough gain for his DAC.  He loved the DAC so his line stage is now a different circuit design.  There is no one line stage that will work for all of us.

Is the Clarinet this good?  I would recommend the Clarinet to anyone who desires a taste of high end high fidelity sound reproduction regardless of their budget, their experience, or their overall systems. 

[alpa6]

I find it interesting you got a squeel with those jj's.I too tried them after 8 hours i got a midrange buzz.I swaped them out with a well worn set of electro harmonix tubes and 95% of the buzz went away.I swaped out the jj gz34 for a sovtek 5ua4.I then got a good clean tube rush sound.
Not bad mind you but it's there.I did expect this as i had researched this beforehand.I do expect tube based system's to have some noise.Jim's design thankfuly has no 60 hz buzz.My bottlehead foreplay has this it used to drive me nuts.Even after several fix's and mod's.
I stuffed mine with kiwame's and auricaps.I also added some connex rca's.What i got in sound quality simply floored me.
At my listening position the tube rush is impossible to hear until you go 50% volume.
I simply use my piccolo at its highest gain setting so i stay under the 50% volume threshold.It's dam quiet at this setting.As good as i could of hoped for.
The greatness of this product comes from useing it as a whole system.I have a clarinet,cornet 2 and piccolo system.
It will be the last system i buy for at least 10 years possibly for life.It's that good!
The only thing i'm thinking of getting is jim's amp's.I have so many vintage tube peices that i'm wondering do i really need another.
What i really wish is that jim had a set amp project.You reading this jim?I have  a few pp amps and would be wiling to try another of his great designs if he ever tried a set amp kit.

[wdi]

I do not like the fact that the Clarinet reverses phase.  I really wish his system kept absolute phase.

Tubes, isn't this corrected by swapping the red and black connections at the speakers, or am I confusing this with polarity?

[tubesforever]

isn't this corrected by swapping the red and black connections at the speakers

Absolute phase is a tough critter.  The proponents say that it must be maintained from the source through to the speakers. 

Lets say you decide to take a listen like I have.  The reverse phase goes into your amp which then provides the signal going to the speaker.  If you reverse the phasing at the speaker outputs, then your speakers are moving in when they should be moving out.  This creates a sonic disaster of major proportions. 

You could build IC's that reverse the phase from the preamp to the amp.  However in a common ground device that means you are plugging the common ground from the preamp into the amps right and left inputs and then the stereo signal is going to the amps common ground.  This seems counter-intuitive to me.

I know some tube manufacturers back in the 70's would have a preamp with phase reversal and an amp that reverses phase and would claim this brings the signal back to proper phase.  I am not sure I buy into this for the same reason as the IC situation I listed above.

I love the sound of the Clarinet so for me the issue on absolute polarity is not a major thing.  For some it is a deal killer.  I would love to have a differential balanced line stage from Jim.  Then using the Trumpet would make perfect sense. 

I hope some of this helps.  I would not pass on the Clarinet because of phase reversal.  As I mentioned even in a recording the phase response of the instrument is never captured in perfect phase. 

Cheers!

[hagtech]

For a first order correction, yes it is as simple as reversing the speaker leads.  That gives 100% polarity correction.  When the cone (or panel) is supposed to push and compress the air, it does.

However, there is another issue that is related, so we may as well talk about it.  In a single-ended design such as the CLARINET, the non-linearity of the amplification function has a dominant 2nd order, which means the gain of output versus input is in the shape of a "J" rather than a straight line.  Ok, a very slightly curved line.  Distortions levels are pretty low here.  But imagine for a moment a strong "J" shape.  This means the waveform above the zero crossing point is amplified a little more than the waveform below.  That's all fine and dandy by itself, but what happens when you put two amplifiers in series?

If a preamp and amp have "J" curves for transfer functions, they can either add together to become a stronger "J", or oppose and become an "S".  That's right!  Two 2nd harmonic type distorting amplifiers in series cancel out the 2nd orders and generate a 3rd instead.  This is true only if they are equal and opposite, but there is still some residual cancellation and additions even when not equal.

Hence, a preamp that preserves polarity is one thing.  Having it match distortion characteristics with the amplifier is another.  Do they add or cancel?  It is a complicated system matching issue.  Which is dominant, the preamp or the amp?

jh

[tubesforever]

Jim thanks for explaining this in greater detail.  It is somewhat over my head, but this will get me to research more about phase angles and how SRPP effects absolute polarity. 

I cannot reverse the speaker outputs on my amp.  If I do the speaker is pulling in instead of pushing out.  This causes a huge suck out in the sound quality.   That leads me to think that the absolute phase is not 180 degrees reversed. 

As I have mentioned, I have concluded that the Clarinet sounds worlds better than the purely passive preamp functions of my previous Precison Fidelity C7, my hot rodded passive buffered preamp, my Bedini 6677 preamp, my purely passive Dale Vishay stepped attenuator preamp and a variety of high end preamps I have sold over the years.

I also prefer it over the Pass Xono, Manley Steelhead, Thor, and even the expensive Wave Light preamp. 
Basically this means I would need to spend more than 7,000 dollars to get a preamp that sound better but would it be a lot better or just better in one area or another.

Perhaps the biggest thing I find with the Clarinet is that it does the entire frequency response better than my other preamps.  My Clarinet had no weak areas.  I had to do some comparisons side by side to really trust my ears.  It is easy to build something and feel it sounds as good or better.  When you actually compare side to side and get feedback from your friends then you know you are onto something special.

Your explanation of the slight curve on the phase makes sense to me. 

As I clearly stated, I don't buy into the argument that absolute polarity is necessary.  There is a lot more phase variance due to microphone technics, distance of instruments to the microphone and recording engineers that purposely alter phase to create a 3-D sound field.

For me I am really happy with the Clarinet.  I would build another without hesitation.  The only thing better would be a balanced Clarinet.  Then I could justify the Trumpet and start looking for a decent balanced amplifier.

Happy Holidays Jim!  You are a true DIY hero!  Your Clarinet sounds amazing and it is the stand out piece in my system.  Everything sounds better when connected to the Clarinet.  I cannot think of a better reason for someone to try one for themselves.  If anyone is on the fence, start saving up your nickles dimes and quarters.  The Clarinet will not disappoint you unless your sources have extremely low voltage output.

Happy Holidays everyone!

[ronpod]

Greetings Jim and Jim,

This is a fascinating discussion that is at the heart of why DIY is so fun. The introduction of 2nd order gain transfer functions as described by Jim, which provide a revelation in component matching objectives, reminds me of when I first saw Spock on an early episode of Star Trek playing 3 dimensional chess. Guess this also gets to the heart of why engineers use transfer functions to manage frequency and variable gain characteristics.

The RIAA shaping circuits emphasize and de-emphasize based on frequency. But what is described above is a different form of signal shaping based on variable gain of a signal at a discrete frequency. The elegant explanation of the "J" gain curve is reasonably grasped. But doesn't the "J" gain characteristic change as you range up and down the frequency spectrum? If this is so, it certainly complicates component matching to achieve euphonious bliss. (Hence, the need for the before mentioned transfer functions.)

I have reason to believe that a Clarinet is in my immediate future. If so, I have an interest in selecting parts that compliment my system. Are the transfer functions of a Cornet2 and a Clarinet in series complimentary? (Rhetorical question, I know.) Should I be concerned about part selection knowing that these two components will form my front end? It has been previously stated that the tubes are the most predominate parts that color the resultant sound. I realized that I may be overly concern about part selection; but I am want to muse over every detail to fullfill my DIY quest. I will post pics of my "possible" Clarinet build as soon as my personal anticipation morphs into reality.

Thanks for providing many hours of entertainment and enjoyment!
Wising you a Merry Christmas and a Happy New Year.

Ron.

[hagtech]

But doesn't the "J" gain characteristic change as you range up and down the frequency spectrum?

Only indirectly, via intermodulation distortion.  The "J" is an amplitude function, not frequency.  The larger the signal, the greater the distortion.  Smaller signals have less distortion proportionally.  SET power amps are the classic example of this, and clipping representss the ultimate "J" kink in a transfer funciton.

How does it affect frequency?  Not at all, for single frequency tones.  Each one comes out distorted equally for a given amplitude.  However, when tones are mixed you get an additional effect.  Add a high frequency tone on top of a low one.  As the LF heads towards the top of the "J", the distortion of the HF riding atop gets lower.  The LF tone continues and eventually head back through zero crossing and goes negative, toward the curvy part of the "J" function, where the HF tone is now compressed.  This is IMD.  You can therefore have too much of a good thing.  That nice 2nd order distortion that "warms" up a sound, also causes new tones to be created and screws up the treble, causing a loss in resolution.  For me, I find it as a lack of ability to separate instruments, they all start to meld together.  So there is a balance here.  In the case of a CLARINET, even though it is a 2nd order distorter, it does so very gently (less than 0.1%).

jh

[analog97]

Hi again to all.  I am still experiencing what I believe to be a tube "squeel" in my Clarinet and it is driving me buggy!!  This thread discusses this, so I did a search and am posting here for help.  I have finally done some tube rolling and here's what happened:
1.  The Ei 12AU7's that I started with about 2-3 years ago squeel the worst!!  They seem pretty bad.
2.  Tried recently Sylvania 12AU7's and found they began to squeel after a few hours of play, but no where near as bad as the Ei's.
3.  Tried RCA clear top 12AU7A's (supposedly these are very low noise) and after about 30-40 hours of play (not continuous), they are giving me that same, intermittent, high-frequency squeel, but again, somewhat less than the Slyvanias.

Tubesforever talked about the JJ's fixing this.  Any other thoughts?  Hey, maybe it's not even the tubes causing this.        

[PatOMalley]

I have found the RCA cleartops to be noisy as well.
Any Holland made Amperex 12AU7 type from the late fifties to early mid 60's.
They can be had. They cost money but will last a long long time. They are worth it in the sense that $20+ a pop every few months equals the best NOS there is.

Or for new production try a set of TAD 12au7's.

Also. The rectifier on the Clarinet can make a difference in taming noisy au7's Try a Bendix in the rectifier slot and the tubes you now have may quiet down.

Hi again to all.  I am still experiencing what I believe to be a tube "squeel" in my Clarinet and it is driving me buggy!!  This thread discusses this, so I did a search and am posting here for help.  I have finally done some tube rolling and here's what happened:
1.  The Ei 12AU7's that I started with about 2-3 years ago squeel the worst!!  They seem pretty bad.
2.  Tried recently Sylvania 12AU7's and found they began to squeel after a few hours of play, but no where near as bad as the Ei's.
3.  Tried RCA clear top 12AU7A's (supposedly these are very low noise) and after about 30-40 hours of play (not continuous), they are giving me that same, intermittent, high-frequency squeel, but again, somewhat less than the Slyvanias.

Tubesforever talked about the JJ's fixing this.  Any other thoughts?  Hey, maybe it's not even the tubes causing this.      

[analog97]

Thanks, Pat.  I was beginning to wonder if I was nuts and what I was hearing (that darn squeel) was caused by something other than a tube.  Seems you have to wait at least 50 hours or so to decide about a tube's performance.  I popped in another set of 12AU7's and am waiting.  Thanks.

[hagtech]

The squeal is caused by cathode-heater insulation leakage.  I run the circuit with quite a high level of offset, which is also why I chose the 12AU7 for such duty.

Tubes with better vacuum and cleaner insulation work best.  There is no way to know except via testing.  Theoretically, the cold war era tube production was best in this particular area, as the quality for cathode and insulation materials were at their peak production and purity. 

It is the second tube that is in question.  One quick cure is to swap tube positions.

jh

[analog97]

It is the second tube that is in question.

Thanks, Jim for confirming it is a tube.  Problem is, I must have tried 10 tubes, 3-4 different 12au7's and 7a's.  I have learned that the Clarinet tubes are FAR more critical than the Cornet2 tubes. 

From the front of the Clarinet, the second 12AU7 is further back?  Thanks again and best wishes.

[fatty]

Hi Jim,

Is there a purpose to running that much offset ? I was just about to do a Clarinet kit but now I am having second thoughts---I have a very large supply of NOS 12AU7's but I don't feel like going through that squeel type problem. It's bad enough just trying to find quiet tubes without the dc offset issue.

Thanx,
Jack

[bummrush]

Just checking ,but in this day and age,are those the correct prices,at his site,i cant hardly believe it.

[hagtech]

Yes, second tube from front.  The one near rectifier.

jh

[tubesforever]

Worried about the squeel....heck, just change out the tubes.  It takes mere seconds.

I have found the JJ 12AU7 provide excellent sonics, have no squeel when they measure new and good. 

These are under 10 bucks a piece.

Try your favorite 12AU7 in space one and use the JJ in space 2 and I bet you are happy as a clam.

The dynamics, the SET magic, the linearity of this line stage are outstanding.

I love the sonics. 

Don't ever be affraid to spin some tubes in this thing.  It sounds outstanding and at the price it really might be untouchable. 

I applaud Jim for designing such an outstanding line stage.  I want one balanced!  Jim can you do this and maintain the SET magic?

[analog97]

Tubes and Jim,

After trying about 10 or so 12AU7's in the Clarinet, I conclude:

1.  They all had squeel.
2.  Generally speaking, the squeel took at least an hour to reveal itself.
3.  The squeel was always intermittent.
4.  The squeel is a genuine PIA.
5.  NONE of the tubes that squeeled in the Clarinet had bad sonics in the Cornet2 (this is what threw me).  Why in the heck would that be?  I tried a lot of tubes, Ei's, RCA clear-top 12au7a's, GE, Sylvania, some 6680's and 5963's. 
6.  The squeel sounds very similar to a high-pitched electric light bulb on a dimmer...ever hear this??
7.  I will order some JJ's and give it another shot. 

Thanks again for your experience and help.