1963 Lesmann "Echo" Amp......No More Polkas for this Bad Boy
HTML-код
- Опубликовано: 16 окт 2024
- Recently, a generous viewer donated this amp to our channel as a video feature. Although a completely unfamiliar brand, it is a very unusual and well-made amp, intended for use with accordions. Several mysteries arose upon inspection: 1.) No input jack.....how did it ever communicate with an instrument? 2.) A mysterious UTC line-matching transformer 3.) The letters "VIB" and "TREM" on one control.....could it have both effects? 4.) The presence of the word "Echo" as part of its name......does this imply reverb? And more......that you'll have to watch to find out ;)
If these mysteries interest you, then please join us as we convert this very unusual old gem into a rocking guitar amp......with a killer tremolo. In addition, we will open a shipment containing another very unusual amplifier, sent by a viewer as material for a future video.
If you enjoy advertising-free videos like this, then please subscribe to our channel and consider becoming a Patreon patron at: / uncledougsvintageamps or making a PayPal donation to: dldcam@aol.com. We rely entirely on the support of viewers, not advertisers, and would appreciate your help. Also, like the viewers in the video, you can support us by donating vintage tube gear and components to be used in future videos. Thanks for watching !!! 
Видеоклипы
![[4K] Watch SpaceX Catch A Starship Rocket From Space!!! #IFT5](http://i.ytimg.com/vi/pIKI7y3DTXk/mqdefault.jpg)
![Oscar Maydon x Fuerza Regida - Tu Boda [Official Video]](http://i.ytimg.com/vi/_ymicn0_GYc/mqdefault.jpg)
NOTE: As a viewer noted, the tremolo seemed to overdrive the output tube(s) a bit. As a result, I increased the value of the resistor between the oscillator and grid from 100K to 220K. Problem solved :)
Whoa UD! The guitar fairy dropped a Legend Rock n Roll 50 on your doorstep!! That's the amp Billy Gibbons used to record ZZ Top Eliminator! Careful, that is one LOUD amp 📢🔊
Life is good 😎👍🏼
@@kickinvideo333 It is indeed, KV.....and it is truly LOUD !!
After watching one of your educational videos I understand why the vibrato did not work when connected to the grids of both output tubes.
The push pull circuitry cancelled it out!
When you moved the tremolo to only one output tube grid there was no cancellation.
@@Dennis-mq6or Thanks for the helpful input, Dennis :)
Even with the sampling and/or compression artifacts in the audio, the Lesmann is one of the best-sounding amps you’ve had on the bench. This one is a keeper and your mods made it so.
Wow, thanks so much, Hub :)
bump :)
+500 points for using "WFO" - cheers!
It came my old motorcycle days, Chris, but still seems appropriate :)
That amp is SICK! Bright, but with a full low end. And dem cats can Really Play!
Thanks, Dave. That's exactly what I aim for in voicing an amp.....and Jack & Ollie do the rest :)
Bless you Uncle Doug for sharing your wisdom with us!!! Our family loves your videos!
You're quite welcome, F1. Regards to you all.
This is certainly the best amp I've heard you build, the distorted character with the nice full treble and bass. It's everything you'd want, thank you for sharing.
Thanks, Jules. It had exceptional tone.
From Leo: My mother's accordion had a magnetic attached microphone that was hard wired into a long lead cable. A low Z microphone could explain that 600 ohm input. Nice work.
Thanks, Barb. I agree.
Barb Melle, it's interesting to note how many amplifier manufacturers in the late 50s and early 1960s were manufacturing amplifiers with labeled accordion inputs, amps that were marketed to accordion players. This includes Ampeg, Sano, Magnatone and all the various rebranded "Maggie's" such as Panaramic, Titanio, Giuletti and others. And yet, the actual pickups or microphone assemblies that would have been attached or fastened to the accordions themselves are virtually nowhere to be seen. I've bought a lot of vintage microphones at flea markets and ham radio Fest in past years, and although I would see lots of accordions at the flea markets they never had pickups attached.
@@goodun6081 I wonder why?
@@donaldheitger6731 , like I said, it's a perplexing question. Perhaps the inclusion of accordion inputs on all those amplifiers was merely being hopeful on the part of the amp manufacturers, that they would be used for something other than loud rock and roll guitars. Certainly Ampeg founder Everett Hall detested rock and roll, and made every effort to *not* accommodate rock and rollers or anybody with long hair, any bands that were coming through the area and might have been interested in visiting the factory, and so on. This definitely put a dent in Ampeg's sales figures, until Hull was finally put out to pasture in the late 60s. Anyway, perhaps the anticipated, hoped-for (chuckle) glut of pickup-equipped accordions just never materialized. The old- guard musical equipment manufacturers we're slow to see that the rules of the game, indeed the entire game, had changed. And then the music market got really soft around 1969 and a whole bunch of manufacturers went bankrupt.
@@goodun6081 I have a Farfisa "Transicord" amp (Solid state, sadly) with an accordion input. The connection looks a bit like a tube socket, actually.
This amp sounds great Uncle Doug! You seem to just have the knack of knowing what to do! Great stuff!
Just wonderful to see Casey having a great time playing with her intoxicating toy, like a little kitten!
Thanks so much, Neville. She really is a sweet little kitty :)
Thant was a super cool trouble shooting video! Thanks for taking us along in such detail..can't wait for the next one!
You're welcome, DY. I hope you enjoyed the trip.
that's gotta be one of the very best sounding amps that you have had on your channel, thank you for doing your thing!
Thanks so much, PS.....glad you liked it :)
I’m always waiting for your next tube amp extravaganza!!!
Thanks my friend!
You're welcome, Bill. This one features a rare gem, for sure :)
Thank you. A good video.
Knowing electronics and knowing audio amps seems, at least sometimes, two separate areas of understanding.
Thank you, again.
I would say that tube circuits are a somewhat arcane but still popular sub-category of electronics, Glen.
I'd be "less of a man" for not watching this Lesmann amp video. Thanks Uncle Doug.
Thank heavens you watched, ¿. You're welcome.
@@UncleDoug what's the best way to contact you to donate hardware? I'm considering getting some reissues of 1965 Fender guitar amps but not sure how they stack up to the originals. I hear they make them in Mexico now. Not sure whether to get a Princeton or Deluxe Reverb. What do you recommend?
Is that a ‘ Nes Lesmann ‘ or a ‘ Les Nessman ‘ amp?
If I were you, I would find a nice Silverface Princeton or Deluxe Reverb from the late 60's, early 70's. Their circuit is virtually identical to the Blackface versions, yet the price is about the same or lower than a reissue.....which will have PCB's, 1/4W resistors, and all sorts of corners cut to keep cost down. Give me your e-mail address and I'll contact you directly.....but make it a fresh comment. This one is buried too deep to find tomorrow.
@@UncleDoug your recommendation is much appreciated Uncle Doug, and this leads me to ask, if the price is nearly the same, and the circuit also nearly identical, then why not opt to buy a new reissue which has the added benefit of tubes that have not depleted any of their life cycle? Not questioning your wisdom, just trying to understand where you're coming from. Admittedly, I'm partial to the aesthetics of some of the reissues currently available in some of their limited edition versions.
Outstanding workmanship. Circuit and cabinet!
Thank you very much :)
Aluminum is difficult to drill because of it ductility and softness causes a constant contact with the cutting edge of the drill face. Probably to save on drill bits during manufacturing.
beautiful work as usual Doug . love the way you share you experimenations.
Thanks, Barry :)
Lolol “I’m going to wait till the 4th of July to plug this thing in” 😂😂😂.
Glad you liked it, Dean :)
Uncle Doug Yes I did, like your sense of humor. Good to see you back! I’m a electrical nit wit but am fascinated with old tube radios and amps. I love learning about them and your vids are the best. Really love your tutorials, you make them fun and very understandable even for the electrically challenged!
Thanks, Dean. We appreciate your time and interest.
Afraid
Doug, I really appreciate that you don't get mired down in the theory when deciding to do some mods & are not 'afraid' to just launch in with the knowledge & experience you have and do the good ole trial and error method. It makes it easier for us others to understand that you don't have have a road map, just some common sense. tube circuits are very forgiving so even if you make a 'mistake' most tubes will recover...even red-plating output tubes as long as you don't leave them that way for too long.
Thanks, Glen. I encourage all budding techs to use trial and error at every opportunity. Once you gain experience and knowledge, the trials get better and the errors become much less frequent :)
Check out Mr Carlson's Lab he gives good servicing advice for the hybrid Legend amps the semiconductors are easily destroyed, good advice for anyone not used to working on this type of amp
I am not strongly inclined to work on the hybrid circuit, John, but if I do, I will keep your suggestion in mind.
The upshot was, don’t go around with your probe AC-coupled in the high voltage bits and then zap the SS bits with the charge still stored in the probe’s or scope’s coupling cap.
Correct being unaware of this hazard could end in tears
@@hubbsllc , and although it's not a hot chassis, transformerless amplifier, an isolation Transformer on either the amplifier's power cord or the oscilloscope's power cord might be a good idea.
Wow, that amp sounds great. Probably one of my favourites. Thanks, Doug.
You're welcome, Andrew. Thanks !!!
Nice job. The mystery transformer is in the anode circuit of V1B. It is therefore an _output,_ providing two isolated secondaries: 25K at the same level as the primary, probably a few volts, perhaps to drive a slave power amp, and 600 ohms to drive a studio mixing desk directly. Or maybe they are the send and return to and from the missing echo unit? Both are tapped off before the volume control of course. It is a feature, not an anachronism, and IMHO you should leave it wired in. Anyway the primary is part of that anode load and can't be removed without shifting the operating point of V1B. The 25,000 and 600 ohms are impedances, not DC resistances, and 600 ohms was a common standard for audio back in the day. I still have some 600 ohm stuff from the 1980s.
The amp is overloading far too early. I would increase the 56K grid input resistor to say 100K, or maybe raise the cathode resistors to 4K7. At least you should remove that resistor you put across the 25K primary.
The Echo and VIB remain mysteries. VIB must mean vibrato, but you need severe phase shifting to even approximate that. What was switched differently in the VIB and TREM positions?
Thanks for all your helpful comments and suggestions, EJ. I will definitely keep them in mind.
Uncle Doug The more I think about this the more I think it must be the echo send/return. It fits right in with the current-drive current-out nature of reverb springs (=> high source impedance, low target impedance), and it provides gain (sqrt(25,000/600)) to compensate for the lossy transducers.
Fantastic work again Uncle.
I had a Minerva 415W tube radio from 1940s, once belonging to my grandparents. It was sort of working while I was at high school, some 35 years ago, with a beautiful warm sound, but then ceased to work, thanks to my stupid uncle for leaving it under a dripping roof. I am a bit electronics hobbyist, but these tube setups were like Chinese to me. After watching you videos and digesting the information you provide with that friendly and couraging voice, they are not total aliens to me anymore. My first project now is to bring that beast into life again, hoping to find proper replacements for her already too old and beaten tubes of course. Thank you again for sharing loads of information with us.
You're quite welcome, LS. We're glad the videos are helpful and wish you the best with your project. Be careful !!!
This amp sounds so genderfluid. You should add a switch to select the adequate pronoun.
HAHA!(8-). Glad I didn't just take a swig of coffee. I'd have blown it all over the monitor.
True, it's a hybrid - why force an arbitrary decision? Maybe a "metro intensity" control - leans this way, then that way. =)
I'm shopping for a 68-position switch to allow for all possibilities, Λογος :)
@@PipeCat1965 , "leans this way, then leans that way"..... sounds like a definition of vibrato to me. I remember this line from a blues song, "She got Elgin movements from her head down to her toes / she rakes in a dollar most anywhere she goes / she's got it, Elgin movements from her head down to her toes / she rakes in on a dollar, most anywhere she goes......"
And if you know what's meant by "Elgin movements", you're showing your age.
@@goodun6081 All I wanna know is, was the crown set of lever set? Beyond that, I've had to put up with "Inca block" movements most of my life...
Great video Doug. Worth the wait for sure. Hope you and the gang are all well.
Thanks, Rob. Never better !! You too, I hope.
The Lesmann rocks ! Great project, totally enjoyed the video. Thanks, Pedro.
You are quite welcome, Pedro. Thanks so much !!!
Great work on the additional circuits. I really like Simple green for cleaning and it leaves a nice shine that is not glossy
Ya know, Doug...its surprising how much difference just having clean, proper power supplied to the amplifier(& fx) makes. I bought a 3-light outlet tester and it showed the outlets I use had live & neutral swapped.
So I swapped them to their correct spots on the outlet and buttoned it back up. I swear to you that killed 90% of my hum issues. I couldn't believe how much hum I was getting.
First, I was getting hum from the outlet itself due to the backwards live & neutral. Then I was getting EMI hum from it when I got anywhere close to it with a guitar. Finally, I was also getting hum from my cheap pedal power supply.
So I fixed the outlet and that killed the power hum and the EMI hum. Replacing the power supply got rid of that hum/buzz, as well(and the last 10% of excessive hum). I honestly couldn't believe how much buzzing & humming I had prior to fixing the outlets.
Now, it's quiet as a mouse. I can crank the amp up 100%(gain & volume maxed) and it hums less than it did at even 25% before. When I plugged in after fixing it all, I was ecstatic, to say the least. 👍
That's great news, JC. Thanks for sharing :)
Incredible Job in all respects. I learn more watching you than any other electronics teacher on the web, no kidding. I think it's your background teaching to young persons, who seldom brook messy explanations without eye rolls ;) You talk slow with well chosen words..they sink in: thank you. The pets breaks are hilarious. You inform, you inspire, you amuse.....Uncle Doug you rule!
Wow.....thanks so much, Uhoh. I really appreciate your kind analysis and comments.
Just an awesome resurrection Uncle Doug!! That’s a real nice natural breakup in the LesMann!! I like it when a plan comes together..
Thanks, Luth. So do we :)
Great troubleshooting & mods UD sounds top notch! Thanks for sharing that was very entertaining!
You're welcome, James......glad you liked it :)
Fascinating unit you got there. I introduced a friend from university to your channel a couple days back and now he's a huge fan of yours. He wants us to build an amp someday.
Greetings and keep up the good work.
At 18:00, looking at your simple hand drawn output circuit, there's no negative feedback? I would have thought they'd want a cleaner sound for an accordion. Since you're going to be modifying this unit anyway, you could put in a switchable negative feedback circuit, also known as a presence control. Maybe you could even use the rotary 3-way switch for that function.
Thanks so much, Mr. TM. Our best to you both.
That's a good idea, GU. Thanks !!
@@UncleDoug , you'd also have to experiment to see which way the negative feedback gets hooked up without causing a feedback squeal, from positive regeneration or oscillation. That might be fun to show people in a RUclips video! Good for peoples learning curve.....
I think most of us have heard what a positive feedback loop sounds like, GU. It would make a memorable and informative video segment.
So glad you are still doing repairs and posting videos! This is one of your best, all are your best!! The Tolex reminds me of the 60s Valco-Supro amps! The Gibson Crestline models also used similar Tolex. The cab reminds me of a 90s Fender Blues Jr.. someone at Fender must have known of this amp. You enlighten everyone of just how many unusual amps were made and still exist. To mod this vintage jewel was no mistake! You brought it to a wonderful condition for playing. It sounds great! Thanxz
Wow, thanks so much for all your very nice comments, ATL. We really appreciate them.
Great video Doug.. You have a lot of tube Amp knowledge. I’m quite envious my friend!
Thanks, Tony. Don't be envious. If I can do it, so can you,
Not sure about that Doug! I’d love to have your knowledge my friend..
A lot of great troubleshooting and a great restoration. Thanks for sharing.
You're welcome, Larry.
Just amazing! Wow what you can do ! Thank you !
You're welcome, Curtis. Thanks !!!
I once bought a Cordovox accordion from strangely enough, a woman named Maggie. This thing was massive. It had an amplifier unit like this one, mounted in a cab. along with 2 x12" Fender speakers and a twin cab. which housed a huge point to point wired chassis with hundreds of caps and resistors. Each note played on the accordion itself had a dedicated circuit. There was a large umbilical cable that ran from the Accordion to the circuit board that also housed a ton of 6X8s , it also included a volume pedal. So, there you go.
That sounds like a huge amount of circuitry and equipment......for an accordion, Tim.
And spectacular certainly describes the tone you are receiving
Thanks, David. That's our goal :)
Uncle Doug I played about 1000 bar gigs in the 80s using a Legend 50 - same amp as you have there. It was.a small company in Syracuse NY. They had no idea how to price their product and went belly-up. I have a schematic I can send you it has a foot-switchable clean/dirt channels and some other useful features like a line out. Mine does not have a reverb tank. It is insanely loud. Mine has been sitting in my garage for 20 yrs.
I have a schematic, TF, but thanks for the offer. The amp seems to work just fine, and is indeed horrendously loud......louder than either of the 50W Marshall amps featured in recent videos. I will be including an audio test demonstrating its remarkable volume and tone in a future video. It has no effects other than an effects loop with volume controls.
Nice job Doug those wiring alterations certainly paid off and we learnt a bit from you, thank you............................................Berni
You're welcome, Berni :)
I'm late again thanks to a big storm Sunday, just got internet service back. Interesting amp and repair solutions. Great sound.
Sorry to hear of your problems, Andrew, but glad you liked the video. Thanks !!
Jack's playing is really coming along. He Shook Us All Night Long!
He and Ollie have been jamming a bit......on the back fence at midnight :)
I just brought home my second Lesmann amp today from Minneapolis and the previous owner still had the accordio-organ that came with it. I got a demonstration of how it works. The accordion is likely an import that Lesmann added their patented electronics to. There's a hefty interconnect cable and the tone is quite pleasant-not the cheesetone you'd get from a Farfisa or a Vox organ. It is in very nice condition and had been owned at one time by a person who used it for his performances of Persian folk music. I suppose that there had to be some sort of power supply to run the electronics so I'll have to see if the mic plug has any live pins.
Very interesting, Robert. Thanks for sharing.
What a great amp! Well done Uncle Doug.
Great video again. Can’t get enough of it. Thank you so much.
You're welcome, III.
Great job! You turned landifill into a fantastic sounding amp!
Wow.....thanks, John.
Damnit, now I have to go listen to More Than A Feelin' by Boston! Nice work, Doug- you really know how this stuff works!!
There are worst things to listen to, Laura. Thanks so much :)
I am glad I found you Uncle Doug. You have taught me so much. I can't thank you enough. Thanks to Rusty too!
We're glad too, VW. Welcome to our channel. We hope you feel at home here.
Nice job! I really like the breakup the amp has.
Thanks, Larry :)
Ach, now I see. What we here we is the newest of all tube biasing technologies. Bluetooth cathode biassing of the second triode :)
Excellent work and great result. That amplifier was not just saved but it was reinvented.
Thanks, 9W :)
A little late,,,but,,,, I know there is a tear running down the cheek of some old squeeze box player but gotta say the re-du on this one came out just great. Nice job pal.
Thanks so much, Carl :) One man's loss is everyone else's gain......
Interesting cooking, Uncle Doug, nicely done. Shame there isn't a schematic available, it would be interesting to see how exactly was this amp wired up and what the VIB-TREM switch did. Thanks for the awesome video, as always.
Matthew
You're welcome, Matthew. I would love to find a schematic......but so far, none have been discovered.
I miss Rusty. It was so fun to watch him act as your foil. He was a good dog.
He was indeed, Matthew. We miss him a lot.
What a great sound she makes. Great job and the echo section sounds excellent too. If only the Lesmann crew knew what was going on in post accordian USA.
Thanks so much, James. Little did they know :)
very cool mods and a nice tone to match the cab :)
Thanks, PN :)
Very Thorough.
Another fine job and example for us amateurs.
Thanks, Evan.
Great work sir! Love your informative videos and your keen insight.
Glad you like them, David.
Great Video Uncle Doug!! I like the sound of this amp better than the last one!!
Thanks, Big Joe.
I love the breakup in that amp! Nicely done!
Thanks, Matt :)
to my ears that sounds great so does the tremolo really nice clear treble & clear bass output so a great amp now but a hell of a lot of work to achieve that.but you certainly did i would buy that & be most happy with those tones wonder how it would perform with a fuzz & reverb added lol but clearly a fine amp with top tones & you can hear it start to break up nicely great post doug peace...
Thanks, DJ. Glad you liked it :)
Sound fantastic. Nice Bass response. You been practicing !!! Great Job as always.
And you left me thinking about the feeding the grids for the outputs directly. I would think the problem you were having with the second tube is an out of phase problem if you pump them both directly. That would explain why one works and the other doesn't. The other is 180 off.
Thanks so much, Bert :) You could be right.
Man that sounds good. Well done uncle Doug!
Thanks, Angelo.
Great Job Uncle Doug! I think it sounds great converted to a guitar amp. I knew if anyone could make sense of that beast it was you. I like your showing your thought process and experimentation with the circuit. I never would have figured it out. BTW I did send the tubes it had in it, They were wrapped in some white foam padding and taped inside the cab. hope they didn't get tossed.
BiogDave
Thanks so much, Big Dave, both for your nice comments and your donation of the Lesmann amp. Yes, all of the tubes you sent were used in it.
WOW @15:15 !!! It's GREAT to see Aerovox Caps , as I worked at Aerovox around 1998. Also my mom worked there for over 15years 🌴😎👍
They were a commonly used cap back in the day :)
Love your show, Uncle Doug! The amp sounds great after your skilled care.
Thanks, OS :)
Nice job, good gritty breakup! I like it, cool sounding trem.
Thanks, Ron :)
Ripping good stuff as always. You'll be happy to know that I repaired a Fender Deluxe Reissue amp this morning. Just a couple bad solder joints on the primary 12AX7, but it's my first tube amp repair. ( Oh the braggin' there'll be)
Thanks, Mr. CC. Congratulations on a successful repair :)
Uncle Doug , AGAIN... you amaze me! You are TRULY a great teacher and builder! By the way , the logo on that amp kinda looks like the one on the Stage Right Amp.
Thanks, Wayne. I think the logo is the only similarity :)
Another fun and educational video Uncle Doug! The final product sounds fantastic! My girlfriend now asks me if there are kitties in the videos since I told her the wonderful story about KC. I also bought her cat the same A frame house with heated pad as a present. Neither of our cats like the house, but the heated pad is a hit with the fur balls
Thanks, Andy. KC sends her regards. She is probably too fat to fit in the little A-frame house now.....but she loved it back when she was starving and otherwise homeless.
@@UncleDoug You're a good man, truly. Beyond all the amazing educational things you share with us, how a person treats the little critters says a lot about a person.
Great Job Uncle Doug!!!!! Sounds Great!!
Thanks, R1.
Hi, It would be great to have all 3 tremolo controls together. Thanks
Thanks again Big Dave. Nice rewiring Uncle Doug. Thanks for sharing!
You're welcome, Daniel.
Just started watching. Could it be that this is one of those situations where, like other electric accordion setups, this was part of a stereo setup, thus the "echo" in the title?
Little further along and why not just remove the ext speaker control and put the jack there? Just thinking out loud.
It could be, Brad. I've seen other amps in which the term "echo" merely implied that there were two separate speakers. You'll see what happens to the external speaker control :)
I want more man! Great video!
Thanks, FW :)
Uncle Doug.... I pulled out my trusty copy of the Vintage Guitar 2019 Price Guide to look up the vaule of your latest aquisition the rare Lehmann Echo Amp. It appears that these are so rare that they are not listed in Vintage Guitar guide. I did find a mention on this amp in the Poka Man's Guide On Vintage Poka Amplifiers. It looks like this amp's value is at $2 due to it's common gray case. I hope this is helpful to you. Thank you for today's video! David
Perhaps you need to consult the Pokemon's Guide to Vintage Amplifiers. Put Detective Pikachu on the case! (But don't put me on the case; if I sat on that vintage amplifier cabinet, sturdy though it might appear, it still might collapse).
Wow.......much more valuable that I every dreamed. Two dollars !!! Easy Street, here I come ;) Thanks for doing all this research, Dave :)
I’m glad you inspect your amps before plugging them in and turning them on!!! As usual, a fun video.
Thanks, AB :)
Nice work Doug looks/sounds great! That thing is as old as me omg!
Thanks, HS :) Talk about old.....I was a senior in high school when it was built.
Im quite sure that speaker is glad to be rescued from polkaland to rockland,great vid and sounds awesome!
I have a feeling you're right, Ted. Thanks.
Nice work 🎉
Thanks :)
Amazing sounding amp. That's the sound EVERYONE is looking for!
Wow......high praise indeed, George. When I "voice" an amp, this is the tone I seek, and I'm so glad that you like it too. Thanks !!!
Trying to think through what was going on with the distortion issues by applying the tremolo signal to both tubes. My guess is the trem signal was creating a cross-over distortion situation. By applying the trem signal to one tube, it minimized the cross-over distortion to half of the push-pull swing at the point where the one tube cuts off. At the low setting, the bias swing is lower and not pushing the tubes into cross-over distortion, and at the higher intensity, the cross-over distortion is "silenced" as the one tube is pushed into cutoff (the "quiet" phase of the tremolo swing).
Just spitballin'
Very interesting analysis, TP. Thanks !!!
Got to love RUclips, I had.to research you again even as a subscriber.
I'm thinking the Lessman amp may have been born in a garage as a venture by Searles and Studeman that never fully took off. If it had, or if they had focused on guitar amps instead of organ amps, we might be coveting vintage Lessmans as much as vintage Fenders. That strong bottom and clear top end give it a tonal quality that anyone would envy. I'd have one in a nanosecond, but only after it had gone through Rusty's workshop first.
Thanks so much, Randy. I understand that the Lesmann company was a successful and well-known accordion manufacturer, so their production of amps like this was intentional, rather than misguided foolishness ;) Now that Jack and Ollie have demonstrated its excellent guitar-related qualities, however, it does appear that they missed the boat......since accordions, like dinosaurs, faced merciful (for us) extinction, while guitars lived on.
Hi Doug,I dont think this is an accordian amp. I believe it to be an amp dedicated solely for adding trem and Vib to another amp to be placed several feet away (Satelite amp). The Lesmann would be fed by a fixed cable with a phono on the end fed from the reverb out (or something similiar) so you could get your main sound with your regular amp and then blend in the Vib amp to taste.I had a Gretsch and a Ampeg that both performed just like this (except they provided Reverb).Funnily enough,they were both from 1963 also.Just my theory.Take care,love your vids!
That's an interesting theory, Winny, but since Lesmann was strictly an accordion company, and there was no provision of either tremolo or reverb in any of their circuits, it seems unlikely.
Please be careful if you are going to check this out with an oscilloscope, you can damage the transistors if you go from the high voltage tube section to the transistor section. The oscilloscope can store high voltage across the test leads and discharge it across the solid state components if you go from one to the other. It' won't be an issue of you discharge the probe by grounding the tip. Beautiful wood case on the donor amp. Keep these videos coming!
Thanks, Christopher. I will keep your warnings in mind.
wow this is why i love your projects ,you made this old amp a very nice playable guitar amp,the cab in the legend is just beautiful to say the least ,I would use linseed oil on it for sure ,I really love linseed I use it on all my rosewood guitar necks and on all my customers rosewood necks it really works well ,nice demo on the lesman you really did great work on it thanks for sharing your great craft .cant wait to do my own amp work on my amps ,just waiting rto get what is needed 1st on the list is your current limiter ,esr ,variac ect wont start until i have these items
Thanks so much, Joe. I will definitely keep your recommendation of linseed oil in mind. Best of luck when you start working on amps.
I Really like the sound of this amp Top Notch
Thanks, Jim !!
Practically a re-design Doug and lovely work as usual. I often wonder with these 'tankless' projects if reverb could be added perhaps using two (extra ?) tubes in oscillation with a C-R ('tank') network...the so called "Vib" maybe had this ?
It's difficult to add reverb without upgrading the power transformer, Dave. You're better off using a Fender 6G15 or pedal.
Seems to sound really good with lots of crunch
Thanks, JB :)
Hi Doug, If I remember correctly..... That sealed 600 ohm transformer was used in some class-C radio transmitters, military, broadcast and ham ! Maybe as far back as the late 30's !!
So ex surplus stock, so much built in UK from military teardowns
👍👍 nice job in restoring everything Sir Doug 👍
Thanks, Jim :)
Nice work Doug! I'm curious as to why the tremolo works the way it does in your final revision. Is it some firm of power tube bias wiggle?
I don't recall where I attached the tremolo output, Kley.....but it was probably to the cathode of a pre-amp or phase inverter tube
I remember seeing one of those many years ago ... and as I remember the input cord was just as you guessed and plgged right into the acordian ... and it was a pretty loud rig also
Thanks, Martin, especially for confirming my suspicion about the cord.
What a transformation! If I had a grumbly- dirty old man sounding amp back when I paid $125 for my Super -Reverb (guess when that was), I might still have good hearing. I love it !
What's that???......I can't hear you. Thanks, Griffin :)
The advantage to cutting the corners on the control panel over drilling is not having to set up the drill press or a punch and simply shearing the corners off as you shear each panel in the same session at the same station. It also lessens the chance of snagging those corners on the cabinet vinyl when the chassis is installed, and peeling them up or gouging the vinyl.
Thanks for the explanation, TN.
that echo sounds really good!...
Thanks, YR :)
Great tone !
Thanks, SP.
I always enjoy watching you mod these amps into great guitar amps, please keep the videos coming, oh and a Merry Christmas and Happy New Year to you and your family for 2019.
Thanks so much, Simon. Likewise to you and your family.
Also, that amp probably has never sounded better in all it's life, well done!
Thanks, Astro :)
Great video! Your great at explaining stuff! Thanks!!
You're welcome, Russ. Thanks !!!
WOW sounds great UD
Thanks, Mr. T :)