1951 Fender Pro.... terrible looking, sounds like gold!

This was a fun and interesting project. Came from Division Street Guitars in Peekskill, a great lil' shop run by my good friend Paul Decourcey. When it came to me it was, well, truly a barn find. Translation: absolutely disgusting. Barns are no places for instruments and definitely not a place to store an amplifier. This amp was badly water damaged on the bottom with plenty of mud to prove it. Some of the plywood had separated so much gluing and clamping was needed. Very time consuming and rather educational. I never realized how many layers of stuff are between the wood and the tweed exterior. More than I thought! And I also know, I'm not the man to do a re-cover job. Used a lotta Simple Green on this one.

He bought it on Reverb from a store in the midwest as a project amp. At least 2 other very good techs turned down working on it. I don't blame them either. If I wasn't a little nutty myself, I may have made the same choice. Amp was full of dead egg sacs from some unknown bugs and some of the wires had been chewed by mice. First order of business was to use a couple cans of compressed air outside just to get the nasties out. Next was the black mold. That and the mud is where I used a lot of Simple Green and a lot of towels, old toothbrushes.....gross man.

It also came with a replacement output transformer that was nice, but the wrong type. This amp had the transformer mounted to the speaker originally, but that old Jensen was long gone. So since this amp is so ugly and we're not re-tweeding it, we decided to just make it player friendly. I replaced the output transformer with a Heyboer tweed 8 ohm Bandmaster transformer availble through Mojo Musical Supply. Not terribly expensive and they are fantastic sounding transformers. I believe Mercury makes the proper '51 Pro part but it's much more expensive and we want to keep this amp affordable for re-sale. And truthfully, I like the Heyboer Iron I've used a bit better though my own amps are loaded with Mercury.

Power transformer was the original Triad. Bakelite fuse holder was broken in half and the power cable and switch were done. Replaced all that and grounded the poor thing!

No tubes came with it. Had to buy 3 6SC7 tubes. A word about those: at this stage of the game, they are risky to purchase. Most of the remaining tubes suck. A decade ago when I was really doing this I could buy a dozen for $60, reject 1/2 of them and still make my money of the remaining ones. Now they set me back at least $18 a bottle. Most I come across are microphonic or have a good hum going on. This one 2 outta 3 were passable, the third I used as the phase inverter. RING! It works but I advised Paul to get another one or buy a 6SC7 to 12AX7 converter on EBay. Other octal preamp tubes are plentiful, like the 6SL7 or 6SN7. For some old Gibson amps 6SJ7 tubes are cheap and plentiful. But, I'm not rewiring this amp for those.

The filter caps were all leaking. They had to go. Don't even bother turning an amp on with those old caps still in it. Throw them away right away. All the electrolytic caps had exploded in this amp. Also the original signal caps were all leaking, badly. I use polyester Orange Drop Spragues in the phase inverter and my favorite Mojo Dijon caps in the preamp. The input caps I left alone. No DC on those so why bother. I'm sure they leaked when they were new but that's a part of the sound so, leave them be!

Also replaced the power resistors with 10k 5 watt wire wound types and the load resistors with carbon composition like the originals. Amp was making those telltale spitting sounds. It's dead quiet now.

When he got the amp it had one of those ugly ass 70's Disco square magnet heavy 15" CTS speakers that belong in an Ampeg cabinet. Nope! Not for a tweed amp! Paul fortunately had this beautiful sounding and great looking Jensen from a 60's rather useless Epiphone amp that lives in his window. He bought the thing for the "someday I may need this speaker" factor. That someday is today and this amps just gives up a beautiful tone now....

It really needs a Telecaster. That is what this amp was built for. My '58 Jazzmaster loves this amp as well. That's a combination from heaven. Big, warm with lots of bite.

Nice and simple 2 channel amp with a single tone control. One channel is nice and dark and is set up for a microphone, the other has plenty of bite. Whenever I get a chance to show a Mesa Channel Switch reared youngster one of these amps I take it. They usually plug in and wonder where the 27 other knobs are but when they start playing something always happens: they start playing better. More grit? Turn the tone knob up and play harder. More clean, back off that pick.

I wound up bolting the new output transformer to the chassis and adding a 1/4" Switchcraft jack so you can plug this amp into any 8 ohm cabinet of your choosing. Also this amp is cathode/self biasing. You can simply drop in any matched pair of 5881, 6L6 or KT66 tubes of your choice and jam out. That's the fun/madness of these early tweed amps. Endless choices! You can make decisions about your tone on the fly. New amps they pretty much make the choices for you. No thanks. But ya know, those new amps are good for getting you there. A real amp like this is good for the one who has already arrived dig?


                                                         Mandatory photo with a Tele:

So if you want to see this amp, hang ten and make the drive to Division Street Guitars in Peekskill NY. Great shop and Paul may even sell it to you!

JB 

Oliver B120

Ok. I stole this photo. It's not mine. I neglected to shoot this amp when I had the chance.

These are uncommon. Very good studio bass amp. About 50 watts with 2 6EU7 tubes and a pair of 6L6 tubes. It was noisy and weak. Solution was change the power tubes which were shot, re-bias it and replace the main filter can which had burst. I replaced it with 2x 220@350V caps in series for a total of 110uf @ 700v. Added bleeder resistors across them as well.

Also grounded it and removed the 'death cap'. My customer doesn't enjoy getting shocked and nor should she!!!

This one belongs to 75 dollar bill as well! Do check them out! One of my favorite bands in Brooklyn, or this world for that matter! I love me a band that can get a big sound with little tube amps. They are that band. Hypnotic, dreamy, driving, wild and never too freaking loud that you can't sail with them!

https://75dollarbill.bandcamp.com/
Click here^^^^^^^^
Thank you! JB

1974 Marshall 100 watt Super Lead (model 1959S)

Oh yes. The ticket to hell, or heaven depending on your point of view. This came to me with complaints of noise and poor volume. The owner runs it with only 2 of the 6550 tubes at 50 watts. He was certain it was dead tubes. These are big amps and I can make good dough on a tube sale for them. Caps too...

But the filters were all new and it's a good job too! And the tubes all tested great. Amp was only drawing about 6ma per output tube. So just a good cleaning and re-biasing is all it needed to get going. Also replaced the 100k cathode resistor in the cathode bias tone stack. It had drifted to 130k and this is common. Check that one if you have spits and crackles!

This particular one was modded to behave like a JCM800. Good job too. Nice, creamy and nasty distortion at any volume!

I was a 100 watt Marshall player for years. This is one of the last really attractive ones with the 60's styling. After that they went the way of the cheap looking President Ford/Carter suit. Boxy, ugly and ready for the CBGBs punk Los Angeles heavy metal era. Part of the early Marshall amplifiers appeal is it's beauty. They are some of the best looking amps on the planet. Notice how well it goes with my Persian carpet? Yes. Psychedelic all the way.

JB

Magnatone Varsity

Not much to say about this little amp, I believe it to be made in the 40's, probably before it was called "Varsity". These are one of my all time favorite recording and yes, performing amps. I have a later mother of red toilet seat ones. Just lovely sounding. Not super gainy tweed Champ nasty, just a good sweet overdrive.

This one arrived DOA. Belongs to my friends in 75 Dollar Bill: (click invisible link below!)

https://75dollarbill.bandcamp.com/


Click here^^^^^^^^^^^^^^


They love these little amps and so do I.

Probably about 4 watts max. They have the classic 3 tube setup: 5Y3 rectifier, 6V6 power tube and a nice 6SJ7 pentode for the preamp.

The problem? Just dead caps. This amp is close to 70 years old. Caps die. Tubes were all NOS, I sold them to the band a few months ago and now this little amp simply rips. Has a new Jensen alnico speaker with barely enough room in the cabinet for the tubes to fit! But it works so.... And it sounds great. Not usually a fan of those new Jensens but in a darker sounding amp like one of these, they work really well.

Go try one, maybe buy one! These are a bargain. Not a "Champ Killer" or anything like that, they have their own thing going on. Perfect bedroom amp!

JB

Maestro Fuzz!

Not much to say about this job. It was simple and fun. Just needed to wire in a new AA battery holder as the original was broken. Thankfully the transistors were still good. After the first blast I knew, oh man this is a good one. They are all a little different, some just plain sound too garbage like, this one sounds just trashtastic enough and not one bit trashier. Like a real beat poet rather than a pimp.

Hope to see more of these again. I dig it!

JB

Trace Elliot Velocette. Oh, modern, amps. Why so lazy?

Had one of these on the ol' desk today, a Trace Elliott Velocette. I remember when these first hit the scene. The crazy 90's "there are no good cheap tubes except EL-84s being made so let's make little boutique sorta VOx sounding sorta Marshall sounding amps" era.

This amp came to me dead. No sound, no lights. Fuse was good, I had a hunch it was an internal fuse or the filament was dead. I haven't seen one of these in years but last one I worked on had a filament line issue.

 All tubes test good, high voltage is good. Yup, too much Bimoze on the filament line.

What's a Bimoze? I really don't know. I just like saying that.

So anyway, these amps are built in the typical modern fashion. With a crappy mother board where most of the components are attached. This includes your tube sockets as well. I never liked this. I'm not opposed to p.c. boards, but come on. Hand wire those tube sockets will ya? It's just better and more reliable. I know, I know. It cuts into profit. I'll shut up.

So the filament line comes off the power transformer into a connector that gets connected to the p.c. board that gets connected to another smaller connector that has wires going to 3 other connectors that connect to each tube. See something wrong with this sentence? It's a run on sentence and I say connector way too many times.


Photo of where the filament line connector meets another connector. Look at all that hot glue..... Got real handy with a razor today. Also notice the heat stains around the smaller black connector.

The underside:

This amp isn't very hard to get apart, that I appreciate. I just turned down working on an amp that I knew would be a nightmare. Life is too short.

More underside:

Hard to tell but wherever there is high current, there are cracked solder joints. This means filament line, high voltage line and speaker. Best to just touch up all of them while you are in there. Also touch up joints on jacks and pots. You can see what I'm talking about if you have a magnifying glass.

Connectors removed:

I wound up hard-wiring where the connector went to connector #2 on the first power tube. Lights on!

But..... after I put the amp back together, the other 6BQ5 tube wouldn't light up. Whack a Mole on such a simple amp! That connector was bad as well. In order to un-solder these connectors you need to remove the tube sockets. Um, EFF THAT!.

So I wound up removing all of these crappy connectors and hard wiring all of the sockets on the other side of the board. Now this little feller makes music. And sweet music it does make. These are really nice sounding amps. Almost has a 'gypsy jazz' quality to it. Warm and dry, cuts nice. They are cathode biased so you may pop in fresh tubes at will.

Speaking if which, one tube did start red-plating. They were just horribly mis-matched so I popped in one that was close. The only sets I have are JJs. Lovely sounding but I popped in 2 sets and they both started red-plating! I don't trust JJ EL-84 for class a operations. They are great for a Blues Jr properly biased but even in this amp, I don't like the risk.

Modern tubes.....bah.

I do like the styling of this amp. It looks like a cross between a vintage British racing car and a French bicycle.

Laziness #2:

Why write the serial number in pen?:

Can you read that? Oh well.

I would love to get one of these and gut it entirely then build a proper amp inside. But even stock, yeah, I would gig with this amp. It's strong point is that sweet, friendly voice it has. More my style then a Fender Pro Jr, which is a similar amp in some ways. I'm a huge fan of cathode bias. The sound produced is infectious.

JB

1975 Marshall Super Lead!

 Well, here is the beast of rock nation.

  These amps are from the days when things were innocent to the point of being kinda dumb. Rock stars didn't wear ear plugs in these days.

  I was once coaching a group of kids for an after school program where they had a rock band. They played well. The final performance was to be for their parents at the end of the term. They were figuring out the order of the set and decided to put "Hotel California" 3rd out of 4th. I approved and said "yeah that's perfect timing for people to put their cigarette lighters in the air like this" They replied rather baffled: "people used to put their lighters in the air????"

  I said "oh man, you kids will never have any idea how disgusting a rock n roll concert once was." One of the fathers looked at me with a nod and said "yup."

  So these amps are some of the greatest inventions in modern history, or should I say, a great piece of evolution. Marshall merely copied Fender and his tweed Bassman amp and made it louder. Much, much louder. I've owned several of these, the first being a 1977 50 watter, the next being a 1974 100 watt Super Bass. Then I went through a series of Plexis. A 1966 Super Pa, '67 Super Lead, '67 JTM 50. These are hands down my favorite amps. The early ones simply look gorgeous. Heck, they made Jimi and Cream even more attractive to look at. That Gold face, black cabinet and silver grill along with Persian carpets screamed psychedelic.

  This one is a later model from '75. All original except someone added an fan which it doesn't really need. It's also been converted to 6550 tubes. Big sound with those tubes. I do prefer EL-34 tubes in these but, this is one ballsy amp.

The blue cap is from this amp, find me the date code:

  28th week of 1975. Now by this point in rock history, the stars were demanding amps to be brighter and have more distortion. This one isn't a Master Volume model, but it's dangerously bright. I don't like that. I prefer the sound of the earlier Plexi models. But, this is easy to alter. Just take out the damned bright cap across the volume knob on the bright channel. In this amp it's a .005. Try a 50pf or 100pf. Or leave it out so you can actually turn the treble knob up! I left the circuit alone cause this works for the owner.

  Also try taking a patch cord and putting between the low input on the bright channel and the high on the normal channel. I used to do this. I'd turn up the normal channel then add the bright channel for just a bit of hair.

  When this amp came to me it sounded terrible and had a nasty hum with plenty of crackly junk going on. I re-capped the power supply, changed a couple bad load resistors and cleaned it thoroughly. Also removed all the pots and cleaned the chassis where they are mounted to. This is routine. It gets gunky back there and causes problems cause this is where all of your signal path gets grounded to. Clean it. It will only take 5 minutes! Then make sure everything is nice and tight. Screws, nuts and bolts. Marshall amps, unlike Fender amps have mechanical grounds. In other words, the grounds aren't soldered to the chassis. They are soldered to lugs that are bolted to the chassis. For quietest operation, clean them all.

  I replaced the output tubes with Sovtek 6550 tubes. The plate voltage in this amp is 525V! I wouldn't trust any modern EL-34 tubes with that kind of juice. I'm running these at a conservative 35ma each. The preamp tubes, 2 were RCA, one was a Telefunken, all 12AX7 of course. I left them alone except for cleaning the pins which were filthy. They sound great and no modern tube can match these. I don't know what the good people at Telefunken were doing but, their 12AX7 had a 100k+ hour life span. And this was a smooth plate version, highly sought after. As per usual, that tube had both sides pretty close to being matched. I've sold dozens of these and use them in my own amps. It's rare that I get a mis-matched tube, even at this age!

  Also replaced the broken handle:

  Some before shots of the old caps:

  The filters are pretty easy to replace except for this one which feeds your preamp tubes. Fortunately by this point they put a longer ground lead on it so you can just pull it up from the chassis, unsolder it and solder in your new cap.

  In this particular amp I took some liberties with the power supply. The main filters rather than use the stock 50x50 caps I chose to use 350uf caps built by JJ. In series this gives you a total of 175uf. The next stage I went with the stock 50x50 caps followed by a 32x32 feeding the phase inverter and 16x16 for the preamp tubes. My customer wants that thunderous low end. JJ builds drop in replacements that go up to 800uf! That's pretty extreme. I've built a couple Plexi clones that used this high of a filter and gotta say, nothing wrong with a tight bottom. I chose to use a much smaller 16x16 for the preamps just cause that's what the old ones use. It's a bit faster response supposedly.

  So it was great to breathe life back into this fine amp. I miss the days when it was normal to rock one of these with a couple 4X12" cabinets. Voice of god I tell you! Nothing sounds this good to me. And the funny thing is for those who have a prejudice against these due to the years of bad music made by hair metal guys. These 4 input heads are actually a low gain amplifier. They can be FANTASTIC jazz amps. There is so much tone and they respond so well to your touch. I don't care for the later 900 and 2000 series at all. As my former boss Steve Melkisethian at Angela instruments said: "I know bad taste when I see it!" He refused to sell those 900 amps when they came out and he sold a lot of Marshall. I'm on the same page as he is.

  See.... what else can I say about these? I worked on a Dumble once. Belonged to Robben Ford. I couldn't understand for the life of me why people pay $40k for one of those when these just sound so much better! I'd take one, sell it and buy a few Plexis myself, or pay for a nice vacation.........yeah, that's what I'd do.

JB