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Topic: Letritia Kandle Update-Carl Dixon |
Blake Hawkins
From:
Florida
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Posted 10 Aug 2008 9:25 pm |
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For DLD and anyone else who may be interested:
The two 6A3 tubes are triode power amplifiers, similar to the 2A3 which is still used by some audiophiles.
The tube manual gives the output of a push-pull pair
at 15 watts at 2.5% Total Harmonic Distortion
using fixed bias.
The 6A6 is a high mu twin power triode. Intended for use as a Class B power amplifier. The tube manual notes that with the units in parallel it can be used as Class A.
Interesting that the National Design uses 5 of them.
The 5Z3 is a heavy duty rectifier. |
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C Dixon
From:
Duluth, GA USA
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Posted 11 Aug 2008 7:06 am In all likelyhood...
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While I never serviced one of these amplifers, I did service kadzillions of amps made during this era. In addition, due to the fact that the National Guitar company greatly assisted Letritia's dad in the building of this incredible instrument; I do not believe it is unreasonable to assume there is NO other amp like this in existance; before or since. But I am not sure.
Based ONLY on the picture with no other technical input at all, the following picture and comments are what I feel may be close.
Note the following:
Rectifier tubes have only one purpose: To convert AC voltage to pulsating DC voltage. Power transformers increase AC voltage to a higher AC voltage BEFORE it is fed to the rectifier tube.
Also power amplifer tubes need very large DC current to drive speakers. This requires high DC voltages to deliever this current, Usually between 300 and 425 volts, depending on how much power a manufacturer wants to deliver to the speakers.
The transformer is the device that steps house voltage (110vac) to a much higher voltage, and the rectifier tube then converts this stepped up voltage to pulsating DC voltage.
Filters smooth this pulsatting DC to a smooth DC voltage. Otherwise the hum coming out of the speakers would be intolerable.
Triodes are always used in low noise situations, because tetrodes and pentodes are intrinsically "noise" producing entities; due to stray electons traveling at light speeds bouncing off the extra metal elements in tetrodes and pentodes.
However tetrodes and pentodes deliver more power. Thus they are almost always relegated to power stages, AFTER the very low "Pickup" signal has been amplifed enough to overcome said noise.
Note: The preamp tubes are encased totally in metal housings. This was an early method of trying to get rid of noise that vacuum tubes pick up from the air. These however were not practical. So they later came up with a way that the metal housing could be taken off and replaced easier.
Don' trun dem away. They have a pupose, I garownteeee ya!
So it appears to me, that the National company decided to have 4 twin, "low noise" triode preamp tubes; one for each input. Each input has its own volume control. So this appears to be a 4 input mixer in essence.
The "mixed" output is then fed to the 5th twin triode, where one of the triodes would serve as a post (driver) amplifer for the push/pull Power outputs stages; and the other triode would be used to invert the phase of the "mixed" signal, so EACH power output tube would ONLY supply high power current for one half of the amplified and mixed signal.
In this way you almost double the power. Or putting it in the vernacular: Class B (acutally AB1, later AB2), push/pull amp tubes. Later they came up with the most popular output tubes ever produced. IE, the mighty 6L6's. And later on there improved versions.
To get even more power out of these babies, Fender found a way to use 4 of them in a P/P/Parallel configuration; without having to double the DC voltage to 800 volts; which would have been just TOOO dangerous for techs to work on. Not to mention home repairmen that were not trained as well.
Fender then could say the power doubled. It didn't completely, but it came close. Ya could fry an egg on them in any case. Wow, did they get hot.
While 5881's and KT66/88's, etc, were further embellishments, the 6L6's (to this day) exudes a loving nostalgia in many electronic techs (including me) who lived and worked on 'em, thru that awesome explosional era of the early days of amplified sound.
Again, I am ONLY going on what I see in that awesome picture. I would LOVE to get a hold of the schematic. But I doubt if one could be found any where on earth. Particularly since I believe this to be a custom amp made expressly for this instrument.
I hope I live long enough to see this item, due to the fact that it is a part of something very dear to my heart.
My sincere thanks to all who played a role in bringing this "one of a kind" treasure back to life. It looks incredible for its age.
May Jesus richly bless Letritia, Paul and John, for their contributions to this amazing bit of musical history.
c.
_________________
A broken heart + † = a new heart. |
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David L. Donald
From:
Koh Samui Island, Thailand
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Posted 11 Aug 2008 7:28 am
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Carl thanks also for your additional info.
I am not sure that you know,
but I have been building, moding and refurbishing tube guitar amps
for the last 6 months,
including 5881's and 6V6 6L6 units.
And I restored an old '57 Harmony that came my way.
You are spot on all except that little 'always'
about triodes in pre-amps, a minor point.
There are several amps that use at least one
low power pentode for a preamp stage,
often the 1st, for a warmer sound.
Not a lot but less than always. 
The trick with pentode noise is getting the
screen voltage right relative to Anode/Plate voltage.
I am about to bread board one for design testing.
I would love to see this National /Dobro amps
wiring, likely point to point, inside, both before and after.
Certainly the preponderance were triodes in practice.
I am curious if they did any tone control with various
pickup windings vs having some interesting signal cap choices
for EACH preamp coupling to the summing amp.
Or is it all the same.
I would use a slightly more high pass cap for the bassier tunings,
and more low pass bottom for the brighter ones etc.
Carl thanks again. Always a pleasure to read your posts.
God speed on your trip.
_________________
DLD, Chili farmer. Plus bananas and papaya too.
Real happiness has no strings attached.
But pedal steels have many! |
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C Dixon
From:
Duluth, GA USA
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Posted 11 Aug 2008 7:59 am
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Ty David
_________________
A broken heart + † = a new heart. |
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C Dixon
From:
Duluth, GA USA
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Posted 11 Aug 2008 1:15 pm
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A few more tidbits about amplifiers back in the 30's and 40's; that may be of some interest to enquiring minds.
1. Large speakers did not have permanent magnets back then. The beast did not exist. Rather, they used "electro magnets". And this was achieved by using a vital part IN the amp's internal Power Supply to create this electro-magnet.
If you look closely at the picture of the back of the speaker (pictured earlier), you will see the word "field". This was a place for the field coil part number, since it was separately replaceable. It was this coil that when fed with current from the amp's P.S., that created the magnetism that allowed the speaker to work.
While this was ok, engineers later realized that under the best of circumstances, "field coil" speakers were more noisy than permanent magnet speakers. Plus, their location could be dangerous. Thus today all speakers use permanent magnets. It added considerable weight, but the results are better.
2. "Fidelity" was NOT of concern in those days. So these amps were FAR from not only HI-FIDELITY, but "stereo" and "surround sound", etc, was NOT even a gleam in any engineer's eyes. Thus, output transformers were small. Their response was probably NO greater than 300-4KHz at best, believe it or not.
But one does not miss something they have never heard or seen.
In addition, engineers had not created "feedback" circuitry as yet, as well as other sophisticated circuits; to overcome "crossover" and "intermodululation distotion". So using LO-FI output transformers greatly diminished the problem, since they were inherently incapable of passing much of the distortion itself
As engineering progressed into the days of HI-FI, and later stereo, then of course the entire audio engineering "psyche" changed.
3. Finally, Class A power amps (while a minisculs few had them, and most of these were lo power amps), the overwhelming majority of musical instrument amplifiers, always used Class B, P/P power tubes. It was only in later years, that engineers have taken a second look at a power amplifer operated in pure Class A.
The advantage to this is:
1. NO crossover distortion (when one tube is shutting down and the other one is starting up.)
2. NO intermodulation distortion. (Two or more signals "beat" with each other, and causes a small distorion in the ouput, that seasoned ears CAN hear!)
Or putting it in layman's terms "A sweeter tone".
The dissadvantage is:
Only half of the power can be obtained with a given Power Supply.
This malady, has been the nemesis of audio engineering from the onset.
Solid State proved a mecca for this. Due to the fact that solid state devices ARE current driven devices; whereas vacuum tubes are voltage driven devices.
Thus, with a SS Power supply of only 5 volts (but very high current delivery capability), one can achieve extremely large power outputs, with NO output transformer at all. So what goes in comes out.
The downside was: Transistors had very low "transient" times. Whereas vacuum tubes have almost instantaneous transient times. This means that in the early days of solid state amps, they suffered greatly from poor "dynamic range".
IE: being able to go from a very low level power to a very high level power in a nano second. Tubes have NO problem doing this at all. Thus the crack of a new bass string the instant it is picked, going into a tube amp, comes OUT of that tube amp. And the music lover CAN hear it, and loves it.
But that same crack coming out of the first SS amps, was a thud instead. Some of you many have experienced this in amps like the first Ampeg SS amps. EVEN though they WERE more powerful.
Thankfully, as engineers created ever faster transistors, they were able to greatly increase their transient times. But under NO circumstance can ANY SS device be as fast as a lowly vacuum tube. But they can come quite close now.
So don't let any one fool ya. They both have their advantages and their disavantages.
For whutevah it's worth.
David, thank you for sharing with us what you are doing in electronics. Wish we lived closer, we could have a ball talking about things MOST people could not care less about. 
c.
_________________
A broken heart + † = a new heart. |
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C Dixon
From:
Duluth, GA USA
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Posted 13 Aug 2008 5:50 pm
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I spoke with Letritia last night, to reconfirm our up coming visit. She told me that her husband is no longer able to drive. She has not been able to in a long time. She said, "We never go anywhere."
So Hazel and I are going to take her and Walter (her husband) out to dinner, Wednesday night August 27th. What a thrill that will be. Wow
May Jesus bless this dear couple. Just think, in their 90's. She will be 93 in November. And he is a bit younger than her. But at that age, WHO is counting?
It is hard to imagine, seeing someone you have not seen in 60 yrs. Wow. Praise Jesus they are still with us.
I told her about this thread, but for some reason she has lost her AOL connection. I hope she can get it back soon. It would be nice to know that she can see something lauding her and her achievments after soo many years of giving to others. Along with her awesome contributions to the Steel Guitar.
Wonder if Scotty and the SGHOF knows about her? HMMMMMMM
c.
_________________
A broken heart + † = a new heart. |
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Ron Whitfield
From:
Kaaawa, Hawaii, USA
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Posted 13 Aug 2008 6:32 pm How 'bout it, gentlemen?
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Sounds to me like our fellow forumites in the Chicago areas should be more than happy to invite the couple out on occassion for a show/dinner or whatever, to enjoy themselves and some good conversation with other steel players.
I know I'd be jumping at the chance! |
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John Norris
From:
Peterson Strobe Tuners, Illinois, USA
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Posted 15 Aug 2008 10:19 pm
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| Drew Howard wrote: |
| Absolutely amazing. How much did Letar weigh with the amp and cabinet? Doesn't look light! |
The weight of the Grand Letar itself is 265 lbs.
When packed in the custom built original National case, we're talking close to 400 lbs...
Many people seem interested in the amp, so here's more info:
Here's an overview...
The power tubes are Raytheons, the preamp tubes are for the most part from Sylvania and the tube guards were built by the Fred Goat Co. in Brooklyn NY...
Here's a view of the amp's undercarriage and some of Jeff Mikol's work. The transformers were built by the Hadley Company out of Ventura CA, later of Los Angeles, CA...
But the most intriguing part of the Grand Letar was yet to come...
John N
_________________
John Norris
Peterson Strobe Tuners
- Celebrating over 75 Years of Tuning Products in 2024! |
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Frank Freniere
From:
The First Coast
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Posted 16 Aug 2008 11:54 am
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| This is really turning into a cliffhanger. I agree w/ Ron Whitfield's comment - I'd love to meet Ms. Kandle, too. |
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Rick Campbell
From:
Sneedville, TN, USA
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Posted 16 Aug 2008 1:11 pm
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| I bet that guitar pictured in the start of this thread would cook a mean steak. |
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Richard Sinkler
From:
aka: Rusty Strings -- Missoula, Montana
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Posted 16 Aug 2008 2:38 pm
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WOW!!! 
All this time I was avoiding this thread just thinking it was a misplaced health update placed here instead of OUR EXTENDED FAMILY. While it does cover this lovely lady's health, it goes way beyond that. What an incredible instrument and history lesson. And that amp, just beautiful.
I WANT ONE 
My prayers go out to her and her husband and I hope too that fellow Chicagoans (is that right?) take an interest and make sure they are alright. I know I would.
Thanks for bringing this bit of history to our attention.
Did I mention I WANT ONE!! |
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John Norris
From:
Peterson Strobe Tuners, Illinois, USA
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Posted 24 Aug 2008 11:17 pm
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A lot of work has been done on the Grand Letar since the last post, the back neck pickup has been repaired...
Some attention paid to the chrome, although its difficult not to damage other artifacts such as the original 1930s speaker grille cloth...
The biggest job which loomed large during this job was the built-in light-show, something which is unique to any instrument of this vintage. We believe it is the first ever instrument of any type with such a feature, certainly pre-dating the Rickenbacker light-show guitar by several decades.
When Paul first acquired this 1937 guitar from Letritia Kandle, there were four elements to it:
1. The quad neck National console guitar
2. The custom built 4 channel National amp
3. Some kind of dimmer rack
4. A mysterious looking padlocked box.
We first had a look at the dimmer rack...
Four large pots accompanied by rows of ON/OFF switches...
The rear side of this unit had a number of A/C sockets and a matrix of banana sockets, which reminded me of hot-patches on old-fashioned dimmers I had seen in theatres in Europe and North Africa in my days as a lighting tech on tours.
Opening the unit revealed four separate rheostats and a mess of perished and decayed wiring...
Our lead tech at Peterson, Sue Haslam, soon had it rewired and polished up...
The next thing to do was to find out what was in the mysterious locked box beside the amp...
Paul had to use boltcutters to open it...
Inside was a motor driving a train of gears linked to two copper plates...
...one of which had a number of wires connected to it...
Having a vague idea as to how this unique aparatus worked, we proceeded, Sue rewired the wheel, we ordered new banana jacks...
Using period correct 1930s StroboConn gear oil (used on the very first tuners made by us in the 1930s), we brought the motor back to life after over 50 years of inactivity...
The Bodine Motor Co. is still building motors today, still at the same location in downtown Chicago.
The more we dissembled the guitar, the more hidden lighting cavities we found, and the more rotten cable we uncovered...
Glass panel after glass panel revealed more and more lights...
All had to be checked and rewired...
...then we discovered 24 lights under the fretboard...
...we thought we were almost done, until another 64 were revealed all around the apron of the guitar...
After work lasting weeks on over 160 lights on several circuits, we were getting very curious as to how (or if) the guitar would perform, so after patching the various cable looms to the rheostats and, in turn, to the mysterious motor driven apparatus, we threw the power on ..........................DISASTER!....... one of the rheostats started to burn, we had made a mistake in the dimmer patch.
Luckily Sue was able to save it, so after correcting the patch and testing the fretboard...
We carefully started to re-assemble the restored Grand Letar...
...until every cable was connected and every screw and bolt was fastened...
Then holding our collective breaths, we turned out the lights, fired up the amp.... and then we threw the switch on the light-show ............................................................................................................SHOWTIME!!
As the mysterious motor began to turn, the lights began to alter their hue beautifully by themselves, and Paul stepped forward to play the first notes on the legendary Grand Letar, awakened from a slumber of 58 years...
You should have been there.... !
John N
_________________
John Norris
Peterson Strobe Tuners
- Celebrating over 75 Years of Tuning Products in 2024!
Last edited by John Norris on 26 Aug 2008 8:45 pm; edited 4 times in total |
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Jonathan Shacklock
From:
London, UK
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Posted 25 Aug 2008 3:45 am
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| Incredible work guys, CONGRATULATIONS! |
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Bill Hatcher
From:
Atlanta Ga. USA
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Posted 25 Aug 2008 4:42 am
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| Amazing!!!!! |
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b0b
From:
Cloverdale, CA, USA
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Posted 25 Aug 2008 9:25 am
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| <gasp!> Absolutely breathtaking! Beautiful! |
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P Gleespen
From:
Toledo, OH USA
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Posted 25 Aug 2008 12:24 pm
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Wow! They sure don't make 'em like THAT anymore! That's freakin' amazing!
Great photo-documentation, too.
_________________
Patrick |
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Rick Schmidt
From:
Prescott AZ, USA
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Posted 25 Aug 2008 1:00 pm
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| This thread is really a great story with a fantastic payoff! Thanks so much for documenting this for us! Who new such a thing existed!!! |
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Ron Whitfield
From:
Kaaawa, Hawaii, USA
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Posted 25 Aug 2008 5:44 pm We have the answer to - "Will it play in Peoria?"
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And it's obviously a resounding YES!
If this isn't the greatest thread ever in this forum's entire history, then please point me to it!
I'd give anything to be in attendance when Ms. Kandle finally get's to see and hear her beautiful playmate again, and for me to hear it as well. Getting to play it myself might be a tad much to ask, but since we're dreaming...
Using this monster as a template, it shouldn't be too great a task to replicate similar/better versions for sale! |
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Mark Durante
From:
St. Pete Beach FL
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Posted 25 Aug 2008 5:50 pm
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Oh my God
Are you bringing it to St Louis? |
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Frank Freniere
From:
The First Coast
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Posted 25 Aug 2008 6:05 pm
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| These last pictures are stunningly beautiful. Fabulous work by Paul & John. Can't wait to hear about Carl's visit w/ Mrs. K. |
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Blake Hawkins
From:
Florida
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Posted 25 Aug 2008 6:54 pm
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It is way beyond any instrument I've seen.
Thanks John, Paul and all your associates for
letting us see this awsome project.
All of that using 1937 electrical and electronic techonolgy.
A museum quality restoration job! |
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John Norris
From:
Peterson Strobe Tuners, Illinois, USA
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Posted 26 Aug 2008 1:37 pm
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| Quote: |
| Are you bringing it to St Louis? |
That would be up to Paul Warnik, do you think we should?
John N.
_________________
John Norris
Peterson Strobe Tuners
- Celebrating over 75 Years of Tuning Products in 2024! |
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Paul Warnik
From:
Illinois,USA
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Posted 26 Aug 2008 2:50 pm
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| Mark Durante wrote: |
Oh my God
Are you bringing it to St Louis? |
Yes Mark my friend
The Legendary Grand Letar will be on display at the
Peterson Electronics Booth at Scotty's show
This may be the most excitingly awaited appearance of this instrument since the 1938 trade show in New York when it first appeared upon it's completion
And here is an interesting story about that straight from Letritia:
In 1938 the National Dobro Corp shipped the newly completed Grand Later to the New Yorker Hotel for a musical trade show with Letritia also in appearance there to demonstrate her talents on instrument-In the course of playing it in a room filled with listeners Letritia said she happened to look up out into the audience and see there one of Her Idols-None other than The Legendary Alvino Rey-She became immediately thrilled with the prospect that she would be able to meet him-But had to continue on playing Her tune-When she finished playing the number and looked up again ALVINO WAS GONE
And Letritia never had the chance to meet Him again
What would have made Him leave so hastily 
My guess is Alvino witnessed something there that shook him up-Not just Her playing but Grand Letar itself Remember this was 1938 and Gibson had no console model steel guitar of any type or even offer one with legs until their 1939 catalog-same goes for Epiphone-and Rickenbacker was years away from anything but lap steels from what I have researched-Yep I say Alvino was a bit miffed at what National-Dobro and Letritia Kandle and Her Father had done before the all others 
SEE YOU IN ST. LOUIS
BTW-We could use a little muscle from a few able bodied volunteers to help John and I unload/load the Grand Letar on Thursday and Sunday afternoons from the van
Anyone who helps out with this will be allowed to take a turn at playing this historic instrument
Thanks In Advance
PW |
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basilh
From:
United Kingdom
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Posted 26 Aug 2008 5:10 pm Superb restoration,
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An absolutely incredible instrument credibly restored incredibly. Huge kudos to all.
Please excuse the correction of salient issues, but it shouldn't be let stand as a fact, so, just for posterity's sake, I'll beg your indulgence whilst I interject...
On the subject of the amplifier Carl said:
| Quote: |
| 2. "Fidelity" was NOT of concern in those days. So these amps were FAR from not only HI-FIDELITY, but "stereo" and "surround sound", etc, was NOT even a gleam in any engineer's eyes. Thus, output transformers were small. Their response was probably NO greater than 300-4KHz at best, believe it or not. |
That quote is wrong, stereo existed in recordings from 1931 and had been experimented with before 1930. The fidelity of the 1934 EMI Abbey road session recordings (made by Alan Blumlein, an EMI research engineer, whose contribution to the invention of stereo sound is only now starting to be appreciated,) of Sir Thomas Beecham conducting the London Philharmonic Orchestra is far from 300 to 4Khz that Carl intimates is the norm for that era..It has been digitally restored to the original quality and has proven to be virtually full range, not sonically in a dynamic sense but definitely falling within the normal criteria for "Hi Fi" As a recent BBC broadcast of the original has confirmed.
Carl's timeline of audio development is somewhat incorrect, but that's excusable as the invention was over here so probably wasn't even noticed "Stateside"
But MANY an engineer's eyes gleamed long before that guitar's amp was constructed..
Just "Google Alan Blumlein , or go here to read more about the TRUE history of Stereo and Even Surround Sound which Alan Blumlein patented in ..... 1931
The salient point are
| Quote: |
| Blumlein lodged the patent for "binaural "sound, in 1931, in a paper which patented stereo records, stereo films and also surround sound. |
By 1935 it was concluded that amplifiers and speakers with a frequency response of 20hz to 20Khz would be needed to accurately reproduce recorded sound. in the UK by the late 30's that goal had been achieved by Both the BBC and EMI with the aid of Blumlein and his fellow engineers..
Ooops, I forgot to mention Harvey Fletcher and his research assistant Winston Nelson.
| Quote: |
In 1933, Fletcher and his research group had successfully transmitted a live performance at the Academy of Music in Philadelphia over AT&T telephone lines to Constitution Hall in Washington, D.C. The audience in Washington had been invited to hear a concert of Bach, Beethoven, Debussy, and Wagner by the Philadelphia Orchestra. They sat facing a closed curtain, behind which they believed the actual orchestra was playing. In Philadelphia, the assistant conductor was leading the orchestra, while in the back of the Washington hall, Maestro Leopold Stokowski used a control unit to manipulate the amplifiers of the three-channel system so that the dynamic range of the sound coming from the speakers went beyond what was possible from the signals in Philadelphia. By adjusting levels, Stokowski could make parts of the orchestra come in higher and lower as he saw fit. It was a convincing demonstration of the possibilities of live stereophonic sound reproduction. When the curtain parted at the end of the performance, the people gasped to find a bank of loudspeakers producing the music, not a live orchestra. A few years later, Fletcher’s team returned — this time with a four-track optical film recording technique that offered greater fidelity and dynamic range. Fletcher specifically requested the orchestra to play Stravinsky’s Firebird Suite because its rich harmonic structure and thundering climaxes showed off the system’s advanced technology.
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See THIS
_________________
Steelies do it without fretting
CLICK THIS to view my tone bars and buy——> |
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basilh
From:
United Kingdom
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Posted 26 Aug 2008 5:21 pm
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Paul, I'd say your assessment
| Quote: |
| I say Alvino was a bit miffed at what National-Dobro and Letritia Kandle and Her Father had done before the all others |
It's quite plausible and probably was one of the motivating factors that led to all the development work Alvino did. So, This guitar is responsible for quite a large part of the development of the pedal steel, If, it did give Alvino a bit of a jolt.(Metaphorically speaking) |
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