This Little Amp Is A Secret Weapon

[@valcotone]

hey Rhett, These are really cool amps. I was a previous owner of this actual amp and it was stock when it arrived here. It came from a friend of my fathers who used it as a PA in a hall for many years near Vancouver, Canada. I did some minor mods to it and swapped some capacitors. Like you noticed, the Mic1 + Mic2 channels are interactive and I actually bridged them so they run in parallel all the time (same result for both input jacks). The Phono channel was disconnected to reduce the load on the signal. I remember I used different input capacitors for Mic1 and Mic2 so one is a little brighter than the other. Mix to taste. None of these updates changed the fundamental character of the amp, and of course it may have been modified again since it left here. I sold it to the fellow in Alaska... amazing that it made it's way to you now. Have lots of fun with it!

[@markdouglas8073]

When I started playing as a teenager in the 70s, I saved up for the guitar first and it took about another year before I could get an amp. Until then, I started playing through my parents’ old stereo phonograph console, which sounded cleaner than this PA. These days I enjoy playing through stereo Katana Artists, which offer a tremendous palette of (non-tube) options. But no matter how far we have evolved technologically, I am reminded that experimentation and discovery, often even through happy accidents, are what leads us to legendary styles. Old tube amps have real character.

[@jeffery9]

weren't these popular in the mid 1980s with California Hardcore punk scene? 1950s military tube PAs?

[@RhettShull]

That is SO COOL that you found this video, and thanks for the information! I really love this thing, its a keeper.

[@Riffraff12571]

@@markdouglas8073 I LOVE tube PAs! I have a few and my Masco is the best of all. Mine is a late '40s 25 watt beauty with a phono top, such a crazy look. Channels 1 & 2 are bridged like this one with channel 1 darker and channel 2 brighter with more gain. You adjust channel 2 for the gain you want then bring up channel one to fill it in like you do with a jumpered Plexi. Just outstanding!

[@MoreMeRecording]

I think I remember being at a show at a Community Hall on E Hastings many years ago and seeing (hearing) this amp?

[@AlexanderXtcSlayin]

I like how quickly you just got into it and you didn’t babble about for 5 minutes like a lot of channels would have probably done. Great approach to the video retention technique 👍

[@cuteasxtreme]

On the other side of the coin, I almost didn’t watch this cause I already saw the short. Obviously I’m watching now tho so moot point

[@AlexanderXtcSlayin]

@@cuteasxtreme actually I think the whole video really did an excellent job of audience retention. Had a nice flow to it.

[@Superjet113]

Right on!

[@OldeDog_NewTricks]

Amen. I was trying to hear some LP tones in an Anderton video, and noticed it was 45 minutes long. After about 5 minutes of listening to those two clowns ramble on like a couple teenage girls I came here. Never did hear the guitars either lol😂

[@AlexanderXtcSlayin]

@@OldeDog_NewTricks I like andertons, one of my favorite channels lol. I expect the 45 minute videos from them. Similar to that pedal show, they make long videos also but they’re usually great imo. I like them mainly cause they stay on topic (focused on gear/tone). I meant that there’s a lot of channels that don’t do a good job of balancing the excessive talking and not enough showing. Especially at the start of videos. Yea it should never take 5 minutes into a video to actually see the product.

[@sepposyy]

I've been playing slide guitar more that 30 years and that is exactly THE SOUND what I've been searching. WOW

[@picksalot1]

This is a good candidate for a Capture by ToneX, or other similar device. You can bring the Profile/Model to a gig and the leave the actual Amp safe at home or in your Studio. You could also share your Amp Capture with the guitar community. 😎

[@brucesuitt993]

100% this. I would buy this profile in a heartbeat.

[@Kaptime]

Or NAM (Neural Amp Modeller) for a free and more accurate version.

[@therealjamesmarchant]

There are some captures from a projector amplifier on Tonex if you are interested.

[@IanYoung-ko4ws]

When Felix Pappalardi did a deal with Sunn amps to equip the newly formed Mountain they mistakenly sent Leslie West a Sunn Coliseum P.A. head. Leslie apparently took one look at it, plugged his Les Paul Jr. into one of the mic inputs and turned up the gain. Incredible overdrive ensued, plus the amp had an output volume so Leslie basically had a master volume control as well as the most incredible tone and sustain.

[@JEEJ_MUSIC]

The Queens of the Stone Age/Josh Homme fan community has been lighting up recently with posts about these projector amps as being a source of these quirky, fuzzy tones. I think we're on the edge of this style of amp becoming a huge trend in the world of tone chasing. Great video!

[@maxpeck4154]

It's been a niche thing for a while. Check out Tex amps if you haven't. Definitely protector amp inspired but sort of crossed with a Vox. They're holy grail territory for me. Super cool

[@Reverend_Taco]

Now there’s gonna be no chance of me finding one 😢

[@patpuckett240]

Blake Mills and many others have been using bell and Howell,etc projectors as amps for years

[@JohnsDough1918]

On which forum?

[@incredifunk]

Old tube driven record players are where it's at.. That is not a projector amp. Not sure why people are saying that. Did you did you see a projector with it? It's a p a set up basically but also used 4other purposes... I've had 1 4years

[@lichen8855]

What everyone really wanted to know: What does it sound like running a Bad Monkey into it? What a sick amplifier!

[@jamesrabic5380]

😂😂😂 Fantastic channel crossover! 🍻

[@douglasdort]

Please run the bad monkey thru this! You know Rhett has 2. One to keep and one for sale/ trade

[@toddmayer6859]

@@douglasdort ....... No disrespect ... but somehow I don't think Rhett needs to monkey around with this amp

[@sub-jec-tiv]

🤦‍♂️

[@Riffraff12571]

When you run an OD or boost in front of them they tighten up and sound more Marshall than Tweed. AWESOME recording amp and a secret weapon in a lot of studios because harp players have been using these forever. They typically use the 10W & 8W versions. Totally giggable when connected with a Power Station.

[@nedward5871]

Yes! I had a Bogen CHA-33 Challenger from the 50s and it is amazing as a guitar amp. Hand wired point to point, beefy transformers, and these are going for peanuts. I got mine for $250 3 years ago. These are the vintage amps to get right now! (note - I sold mine so I don't have a horse in this race).

[@VinceWhitacre]

Challengers make killer guitar amps.

[@VS-wg3ld]

Glad someone has learned about these amps. I've had one for about 16 years and love it. Octal tubes are something different.

[@anthonysilva5312]

Man !! A vintage amp that comes with a bass player!!! ❤

[@subtletyandnuancerules]

Bogan P.A. amps come with one as well. It’s called the Boggy Man. I had one as a kid and was conflicted about it sounding like one but was embarrassed about it not being an actual guitar amp. I also wasn’t exactly proud of the 12” speaker I got fried (Capacitor got me!) while disconnecting outdoors from a found cabinet of some sort just sitting in my (Also found.) antique bookshelf. I was just trying to get some noise out of an electric guitar with no lute. I got it, but it was not the ideal situation-cooked with no lute.

[@mattbrillhart2922]

When I lived in Ohio briefly, I found a Hi-Mu amp. Sounds Japanese but made in USA in 80’s-90’s IIRC. Had to sell due to money issue, but the small combo was the best amp I ever played. Always be willing to try unknown amps as they might surprise you.

[@Ryan_Q3L]

This sounds so great. I love that natural warm and wooly overdrive.

[@Somers_Alaska]

.

[@arbiagolli9297]

Rhet always surprises us with new finds. The guitar community loves you Rhet 🤩

[@musicbyclay4919]

Agreed. Rhett is the man, and I watch every new video released instantly

[@rondelio8562]

Great tone!! Who woulda thought?? LOL Did you know that Terry Kath of Chicago did something like that back circa 1970 and was included on their Chicago Transit Authority album, the track is Free Form Guitar. Terry ran his guitar thru a Bogen PA head and into an amp from there. Worth a check out. As usual, a great video and highly informative. Thanks for your contributions!!! 👍

[@robertclarkguitar]

I've got a late 50s early 60s hand built entertainment system. All from a then new Kit you could buy. It is massive. It is HEAVY. Each speaker cabinet has massive speakers. Legit. I want to say they were 12s or so. Anyway tweeter too or smaller mid. The cabinet is teac I think. Did I mention heavy?? It's all scratched up now as it traveled from base to base with my family. It sits in my daughters workshop behind my studio. I opened it up since I got into guitar late in life and it's loaded with tubes. Loaded. And the power supply is massive. Has an old tuner and real to real along with a record player. I wonder if I could plug into the unit by adding if there isn't one an input jack to the board. Hahahaha. Has knobs so cool and vintage. Again it's massive and heavy!!!!!!!

[@keiranbradley3238]

If it's got a "mic" input you could convert it to 1/4 inch, these old units have massive transformers which is where the "magic" is imho?.

[@robertclarkguitar]

@keiranbradley3238 Sadly the house I mentioned with the old heavy stuff my uncle left when he passed is all gone to my now ex son In law. He will junk it. I'm sure. My goodness if I had room I'd keep it. I cannot move it. Lol.

[@keiranbradley3238]

@robertclarkguitar Sorry to hear that you lost you uncle,,,,,,,,,,,,,,,,not the ex son-in-law!. Sounds like a moron if he would send an old gem like that to land-fill!.

[@robertclarkguitar]

@keiranbradley3238 my daughter bought the house. Then after a few years sold it with all the family memories and 'Junk ' to her ex and his family. To his credit that kept my grand daughters room the one she's raised in but now in another home with me she's got 2 rooms. Lol. Anyway yeah. He told me he was going to dump all the stuff. I get it , it's junk to many but my step dad and his uncle built that heath kit in 65 I believe. It was 3 huge pieces. 2 cabinets and one main console. When I say heavy I mean heavy. You and I would renovate it and show it in living room or even studio. When I was 7 til 17 it was traveled base to base with us as when my uncle had my dad pick it up we used it. The record player mainly and the sound was always so deep and incredible clarity. I remember once a friend told me his dad had one and they sold it for several k as they were extremely rare ... again as far as I know it just sits in the back wood garage enclosed to the back of the house. There's tons of stuff , mainly from up to 90 but so many small unused unopened tools and man stuff lol as he was mechanic and wood working as well as into hifi back In the day. I have a couple tools I kept and a few old school electronics .meters etc.

[@adrianolabusta6620]

you are in my opinion the most fun to watch guitar channel on youtube you have the ability to explain these topics like other channels but you have theatricality to your videos and they feel like music videos or professional ads most of the time big props from where you started keep it up

[@lidj16]

Love this tone! The way the distortion breaks up is so unique.

[@steverodgers9372]

Why don’t we hear music like this anymore? I just sent this video to my 20 year old son and he said that ROCKS!!!

[@Avatar7x7]

Rhett, - When you started playing slide guitar that's when I thought "Okay there it is" that's the magic ! also it sounds killer when you cleaned it up and has this subtle break-up tone ! Derrick Trucks would love this amp !!!

[@AndrewMasters]

This video is insane. That tone is outrageous.

[@snapfinger1]

Similar products are 1958 Bogen PA. Lafayette Electronics stereo receiver kits & early ‘70’s Sansui stereo amp w/ 1/4 input. Sculpt your own sound.

[@hgostos]

I like how the paper tag in front of the speaker cab moves in sync with the air pushed by the speaker. Great!

[@IamMusicNerd]

I love unique stuff like this. I can’t think of any music I play that would be that dark and muddy, but I can totally see why people that play that kind of music would love it.

[@mericland]

The tone outta that thing is insane.

[@DivKid]

Love this! I have a 1950s factory PA amplifier that I had tech add a little work to which brought it in line with a guitar input and gain + master volume. It's 20 watts but still stupidly loud. Great to find these unique items and re purpose them.

[@BertSummersell]

Hey Rhett, you seem very passionate about everything you are doing and I think your audience really appreciates that. Love the Channel.. Thanks.

[@bluzzjazz]

Rhett, your fuzz pedals are now jealous. That thing sounds awesome, especially for recording where you want a certain coloring of your tone.

[@joeloschiavo1237]

So about 30years ago a bud of mine bought an old (even then) RCA pa head The only thing we had to do was use a quarter inch adapter to the 3 pin Canon input The tone was sooooo amazing crunch Love it to this day as one of the best ever Oh yeah I bought it from him

[@bridgestreetdesign]

Leslie west of mountain used a pa head instead of a guitar head and got a massive tone.

[@goodun2974]

It was a Sunn PA head.

[@bridgestreetdesign]

Yes that’s right. He was expecting a guitar head but when he opened the box they had shipped the wrong item. But he gave it a whirl and since it basically had a master volume he got that amazing tone he was known for.

[@bristolfashion4421]

I remember playing my howm made guitars through a mono Philips cassette recorder. It sounded great, too! To hear the guitar, you had to press play and record together and then you were monitoring the recording signal. The guitar massively overdrove the tiny little soldi-state onboard amp and it sounded (from a certain perspective) fab !!

[@stevendavidson391]

That amp sounds amazing. That break up is killer

[@russellzauner]

ahhhh the sounds of soft clipping and naturally squishy compression instead of the dulcet velvet fog of smooth emceeing it's set to deliver heart squeezing tone fluid

[@gabrielbrum9416]

We need to someone to start making these again because i NEED one, this is awesome i think is my new favorite amp

[@amberyooper]

If you really want to hear it's bass response, plug it into a 15 inch speaker. The Fender silverface Dual Showman head used a 2-15 cabinet back in the day. A friend that I was in a band with back in the 1990s had one of those, but it was too loud to use in the local venues...

[@jtmotenz]

Rhett, I’ve been running my guitar through a 60s reel to reel tape player, using the tube preamp inside. I can then connect the output to my clean guitar amp, and it sounds absolutely wonderful. Anything that has a tube preamp, a input, and an optional output will work. Mine has 4 tubes, two 12AX7s, and two 12ax7 family tubes.

[@knowl1969]

I literally felt transported back in time when the slide playing started!

[@vitalsound1727]

Of all the comments you get I’ve followed this channel for the genuine love of everything around the channel

[@AndreAmeli]

Here in Brazil, in the late 60's and early 70's a local brand called giannini (the same as jimmy page's craviola) produced a series of amplifiers based on the 60's fenders. Basically the story is that they had a fender in their hand , they sent a letter to Fender in the USA asking for the schematic, and in return they received a letter with ALL the schematics of all fender amplifiers! I have one called giannini thunder sound, based on bassman, it sounds very similar to the amp in the video, lots of bass, mix of marshall and tweed!

[@Mike_Spor]

Any chance you are going to profile it? That would be sweet. Thanks Rhett. Sounds really killer for my style.

[@JonFrumTheFirst]

'Guitar' amps were just audio amps slightly modified for use. Many old guitar amps had vocal inputs as well, and they were all basically the same circuit. Audio is audio when you're not trying to be slick. Go through the old RCA tube amp books and you can see the circuits, and how similar they were.

[@RobertBakerGuitar]

That thing sounds SICK!

[@tomi-jon8798]

I LOVE rooting through the electronics bin at my dump and finding cool crap to plug into. I have gotten some amazing vintage gear there and brand new iPad no joke...in the box new.

[@goodun2974]

I found a pair of Heathkit mono- block tube Hifi amplifiers with original Genelec KT66 output tubes for free in the E-waste dumpster.

[@mikevukas9818]

Thanks Rhett, great video! I happened upon a Calrad PA amp several years ago. I put it in a cupboard and forgot about it. Recently I found a great tube amp tech and had it serviced and 1/4” jacks added. What an amazing sound. Here are the specs: 6CA4 - Rectifier 12AX7 - Preamp 6BM8 - Power X2 (Electro-Harmonics) 7 watts each Currently running it through a single 12 cabinet with a Celestion. If you can find one it’s a great addition to your arsenal. Cheers

[@earle4370]

Very cool amp. I picked up a late 50's, early 60's Stromberg Carlson Signet 22 a few years ago. Same thing, it was love at first chord. My SC was modded by Dan Lurie of FYD amps before I bought it and I'm not afraid to gig with it. Dan modded the amp so that when you plug into channel one, you can cascade one channel into the other getting those super high gain tones. That and these little PA amps are just cool looking!

[@nathanbrown816]

You could hook up two Leslie speakers to this thing if they're 147s. I noticed the 6 pin amphenol connectors. If you can wire it up according to the 147 pinout schematic, you can have a footswitch on the floor to control two Leslies while the amp is providing power to the Leslies.

[@ishko108]

this one's gotta lotta soul. you're a lucky one, rhett, to be able to find such stuff without traveling to other continents.

[@loudtim265]

Amazing. I have a reel-to-reel from the mid-50s that sounds absolutely phenomenal with a guitar in and external speaker, although the little 5ish” internal speaker sounds great too! It’s not loud enough for anything more than a pub gig , until you mic it up….

[@jtmotenz]

Haha I literally have the same thing too. Is yours in a portable case with a handle on it?

[@randallbargar348]

That old school growl sound- love it!

[@AndiPicker]

That amp sounds the way I always think a good fuzz should sound.

[@patrickgauthier3464]

Thought the same

[@vincentl.9469]

@@patrickgauthier3464I guess now the values of any left will go up! personally I would not bother

[@johnhutchinson1260]

I have a similar Masco PA head I bought 25 years ago. I just pulled it out after sitting on a shelf for almost as long. SWEET! Thanks for the reminder. Loves Fuzz too. Glad I already have mine before this video drives prices up :)

[@hifijohn]

The mic input is made for a few millivolts so the output from a guitar will drive it into heavy distortion.

[@unclesixer]

This is funny, ever since i was about 18 I have known this... my uncle had a crusty old tube PA, turned up past 6 or 7, the guitar tone was magic. I was in a music store and fell in love with a blackface champ (65?) a couple years later. Basically, we all grew up hearing overdriven tube/analog gear as "the sound of rock n roll"... doesn't really matter if it is fender or marshall or whatever... clipping power tubes and all the wonder that goes with it is a beautiful thing. I also owned a marshall 2555 for years, loved the huge tone of the distortion, but never properly heard the magic of its power amp section until shortly before I sold it... put in earplugs and dimed it on the clean channel (I had thought it had unlimited headroom clean, turns out, the headroom ran out slightly above painful levels). At any rate, old stuff is good. Take care of it and it will continue to serve its purpose for many more years!

[@JagStar]

I’ve got a Bogen PA amp from the late ‘40’s or early ‘50’s that sounds amazing. It needs some TLC so I’m probably going to do a video next fall or winter and tear into it and really get it into shape. A tip, that is a big secret, is to look for these PA amps from the mid ‘60’s and harvest the tubes. During that time they used really great Millard output tubes and often Telefunken preamp tubes. I have another Bogen PA amp from around 1968 that had five Telefunken ribbed plate 12AX7 preamp tubes. Those go for stupid money on the ANOS market and I got the entire amp for under $150 Canadian and the tubes are in excellent shape.

[@warrenmusic]

The secret is out… damn. I use a Newcomb H-25 PA amp. It was modified by Mitch Carroll in Visalia, CA. It’s basically the 25w clean version of this. Also 6L6s. Mitch told me it sounds like a Tweed. Having never played a Tweed, I can’t say but it has beautiful clean headroom before it gets broken up. When it gets cranked it’s absolutely hairy in a way that isn’t like any pedal/amp I’ve ever used. Three channels but I can’t tell the difference between each. It’s also super bassy so I’m usually maxed out on the treble and will use a blues breaker/klon style booster to push it. It got stolen and then I bought a second one from Mitch. The second I bought I ended up trading for a Jazzmaster after the police recovered my original stolen amp! These amps are still at flea markets and on eBay so people who know how to work with tubes should check them out!

[@FunkyELF]

The Pedal guys just did a show where they plug into all kinds of things like megaphones, tiny alarm clock sized Bluetooth speakers via aux jack,... You can get good sounds out of anything. Between that video, the Jim Lil videos about amplifier tone stacks and all the new capturing stuff... I just think nothing matters except what you like.

[@harshtruth9148]

In 1992 I was 12 years old and my Father bought me my first USA Fender Stratocaster. Also a Fender 2x12 tube combo. Originally we had a Techniques stereo with record player and It was tube powered. On the back It had a Guitar jack and the thing sounded just like this. It was from the 80's and I believe I still have it. I should try it.

[@partriotsfight5039]

Some of the old accordion amps from that era are friggen incredibly insane. I had a friend who used a Magnatone or something like that and it really was unbelievable. Ok I talked to him and he said it was called a tone master 214

[@johngerson7335]

Amped made a huge single 15" combo with multiple input jacks. The accordion input was the best one lol.

[@goodun2974]

​@@johngerson7335 , you mean *Ampeg*, and you are probably referring to one of the Gemini models.

[@johngerson7335]

@@goodun2974 You are correct, and it _was_ a "Gemini". Thanks for pointing out my typo, l hadn't noticed.

[@goodun2974]

@@johngerson7335 , Blame auto correct or predictive text programs. I always do! Sometimes I'm even being truthful!

[@johngerson7335]

@@goodun2974 lol 😆 ! Have a good one man!

[@jhoskins5630]

I own a few Mascos, used them for harp, those amps are around 18 watts, not 40.

[@cosmossunshine9120]

I did a gig with Steve Kimock a couple of weeks ago and he was rocking a projector amp and a blackface Fender. It was the first time I’d seen such a thing. Sounded incredible

[@andersf324]

Sounds great, Rhett! Back in the early 80's I had no money so I ripped the tube amp out of an early 60's Wollensak reel-to-reel that had been discarded. Sounded fantastic and I ended up gigging with that for a couple of years. Love those old quirky amps!

[@TK-fk4po]

Sounds fantastic! It reminds me of the microphone Jack on my Gibson GA-6 from 1957 which I bought about 12 years ago for 500 bucks but see that they are now up to 1500 to 2000.

[@amberyooper]

I've been modifying old Bogan PA amps for guitar use for a number of years now, you can really get some performance from those old amps, and you can voice them like most of the amps of the 1960s if you want to. I'm not much of a guitar player, but I'm pretty handy with a soldering iron... :-)

[@nerdyonthegreens]

Initial tones are incredible!

[@jfro5867]

Sounds fabulous even through my headphones. Must be sublime in person

[@zellarecords6195]

You need to look up Getchell Amplifiers. Bobby Getchell has been doing this for years, he has all kinds of amps like this, old PA amps, old film projector amps, old radios turned into amps.

[@dbutler721]

Great amp, and a great player. Sounds amazing and inspiring as usual. Put together an album please. Better yet, put together an album and make a documentary while you’re doing it. Thanks for all the content over the years.

[@johnmac8084]

I always think these cage amps look really cool with the cage off, so you can see the tubes & transformers. Of course, if you are gigging it, you need the cage on to protect the tubes, but in the studio it's fine. Sounds fantastic.

[@julianmorrisco]

About 30 years ago I pulled apart an old phonogram. I wired a guitar jack straight into where the phono stylus/pickup went into the system and the overdriven phono preamp, designed for a non standard cartridge (I use the term loosely as I’m pretty sure it was never a cartridge designed to be replaced, you changed the needle rather than the whole cartridge, I believe). Anyway, I plugged my Les Paul Deluxe in and the most amazing, creamy, distortion I’d ever heard came from the two 8 inch oval speakers. I knew nothing about guitar amps - I had a pretty awful Yamaha 100 watt solid state combo - but I knew I’d found my sound. The phonogram, now sawn in half to remove the record cupboard and the legs were sawn off, was destroyed in a flood and I’ve chased that sound ever since.

[@julianmorrisco]

BTW, the phonogram was made sometime in the 50s.

[@davidriley4895]

I had absolutely no idea of this concept, but I love the end result. And I was shocked by the price. I was thinking at least triple that. But then again, I knew nothing of these things. Nice job.

[@patpuckett240]

Oh, they just doubled in price

[@CyrielBouckaert]

Here in Belgium (and the most part of Europe), people used to play their electric guitars through Geloso or Philips or SBR or other PA-amplifiers or even their radio's (I still do). There weren't much other options; there was Dynacord in Germany making guitar amplifiers (but they were also quite PA-ish), and since the late 1960's, we got our own (as wel as British and American) 'real' guitar amps.

[@dutchmetalmaniac]

when you rollerd the volume knob open you you made the smile on my face bigger.😊 that amp sounds FAT. great machine. congrats!

[@TheLakeJake3]

Volume dial turn in the intro was cool as hell

[@memphishancock6483]

I've been using the amp out of an old 1949 HMV record player. 6v6 preamp breaks up real nice with a boost pedal

[@whatwouldhousedo5136]

I've seen a few converted film projector amps around- they sound amazing.

[@Michael-bm8hi]

Try and get a Mascot 110 or 112. Those are modern interpretations of this amp. Marble Amps in The Netherlands builds them. The package comes in an unmatched quality, even the transformers are handbuilt. I have the 110 and really love it.

[@caseyholford]

Really came alive when you exhibited it on the slide work. Thanks for showcasing it. I have a Bell & Howell projector amp that sounds pretty sweet on guitar. Those are fun if you ever run across one.

[@bennybenmorrall236]

When I was a young man my band played at Pogo Studios under Mark Rubel. He had an RCA PA amp that sounded unbelievable… Huge gain! I guess he used it a lot of HUM’s Downward is heavenward. Cool find!

[@madsenamplification]

Rhett, have you ever checked out the TAVA (truth about vintage amps) podcast? I think you’d like it is. There’s definitely some PA head love over there.

[@justinguitarcia]

Skip is one of the ogs who shed a light on these years ago, hes modified a ton of these

[@Neosuburban]

I had an old McIntosh rack mounted lab amplifier from the 50s that was the same way. It had a bunch of different windings on the output transformer that could match impedance from 2 to 128 ohms. I made a little solid state preamp for it and used it as a harmonica amp in 1980s through a 15" Altec Lancing speaker cabinet that I also built.

[@jimsalman7257]

When repurposed for guitar, an old tube PA amp like this effectively becomes a "high gain guitar amp, built before high gain was even a thing". The big reason: PA amps are designed to take an input signal from a microphone, not a magnetic guitar pickup. And a microphone signal is much, much weaker, requiring more gain in the preamp section in order to drive the power section to full output power. So, when using a guitar, it doesn't take much to overdrive PA amps into glorious tube distortion.

[@tubularbill]

I have owned a lot of really good amps and I work on amps as hobby. This might be the best sounding gain driven amp I have heard in along time. Wow that has push. The gain is due to the head room clipping. Awesome.

[@swingarmer]

I just located the schematic and like the supro, gretch etc it uses the paraphase inverter with 190 volts on the on the 6sc7 plates 47k load resistors .02 coupling caps and 270k 12k and 270k on the see saw :) Its that extra gain in the power amp that make the paraphrase sound so ballsy! There is also 340v on the 6l6 plates and 300v on the screens. I'm going to build one! Thanks for posting!

[@pugforce8315]

Thanks Rhett 👍

[@ceeph36]

Cool Amp. I have a 1948 Stromberg Carlson 100 watt PA amp. It has 4 preamp tubes 2 12ax7 and 2 12ay7 the power tubes are two big coke bottle shaped KT88's (I think). I have never been able to get it working it blows the the rectifier tube every time you power it on. I inquired about getting it fixed a few years ago but the guy wanted an arm and a leg to just get it back to stock much less mod it for guitar. I figured it was more than the amp was worth but if these things start skyrocketing may have to get it out and have it repaired and maybe make a little money off it. I bet it would sound awesome and should have unbelievable clean head room as the circuit isn't designed to distort talk about a great pedal platform!!

[@eldjr1104]

Wow.. Reminds me of my old Bogen Challenger 35-watt P.A. amp. I added a 1/4-in and out and an old 12" speaker. It was just like this. Big-time Grang. Nice find.

[@jex2762]

I just did the same with a french PA Bouyer ST20 from 1963. The circuit looks like 5b6 tweed Bassman (20w cathode bias)

[@oldasrocks9121]

Uncle Doug, the Guitaralogist, Ron Carter and other KZbinrs do PA amp conversions often and well. These are also go to amps for harmonica players with dynamic mics. As you have discovered some of them can be real rippers

[@meanmr.mustard]

Yup, ..love hearing slide guitar👍🏻.

[@esmfotoz]

That second volume is almost like a "gain 2", cool. It's kinda fizzy for sure, got that "cousin-of-fuzz" sound, interesting.

[@GermanFafian]

Sweet! we have a friend here in Avila, Spain. Who recovers old tube P.A and radios to be used as guitar amps. Nice guitar btw 😋

[@TM-jo4wz]

I got a Bogan pa amp in 1970. Sounded great. Kinda like yours. Wish I still had it!! I think it burned in a fire at our practice house in 1973. Really don’t remember. Been a while.

[@tone1798]

Congrats on this wonderful find! Really sounds great! In your hands this amp sounds like something I believe is unique! That tone! Thanks for sharing Rhett!!!

[@michaelpatrick6950]

At the beginning, Terry Kath used a Bogen PA amp. Listen to Free Form Guitar on the CTA album.

[@karlaparussel6804]

20+ years ago I went into a guitar and amp shop looking to buy a Fender Champ. Walking into the shop I noticed they had this really old tatty looking bedroom guitar amp in the window. I tried the Fender Champ but it wasn't the sound I was looking for. The shop owner suggested I try the amp I had noticed walking in. I thought why not, old valve amps can sound nice clean. So I plugged in and it sounded amazing, especially when paired with another guitar the shop owner suggested might be more suitable. I ended up buying the amp and a Japanese Fender strat 62 reissue for the same price I was going to spend on the Champ. The guitar had lots of high end mods, so I effectively got the amp thrown in for free. When I opened up the back I found it was all hand wired with a Celestion speaker. The amp is a Rosetti Lucky 7 amp manufactured by Supersound. After searching online I got in contact with the son of the person who used to own the company. He said it was circa 1960, or a couple of years earlier. But also that the company owner worked with a couple of people who later went on to create Vox and the AC30 and that this design was a precursor to it.

[@teresathomley3703]

The dirt coming outta that amp is lovely.

[@mikebri5274]

If I'm not mistaken, Lezlie West of Mountain used a PA amp from the 60's for that classic tone he got on "Mississippi Queen".

[@goodun2974]

It was a Sunn PA amp; Sunn made actual guitar and bass amps as well.

[@scottyvalero3691]

I recently bought a Stromberg Carlson AU 29 late 40s PA amplifier. I work at an electronics recycling plant, and I found it there in really good condition, but non-functioning. I bought it for 20 bucks. Dropped it off yesterday to have it fixed up and converted to a guitar amp.

[@scottyvalero3691]

Update: got it back and it sounds killer

[@JohnQGuitar]

@@scottyvalero3691 I have a similar amp by Stromberg-Carlson. WOW.

[@noahpelty6765]

Glad you dig it, man!

[@TheElrondo]

I'm normaly not in overdrive guitar tones, but this thing sounds very musical even at high-level. Maybe it's the combination if your fingers and the amp. And yes the first impression i had: It sounds like a projector amp converted for guitar.

[@zb9141]

Just be sure it's electrically safe. I restored a similar one some years ago and was a bit worried about how close the wires of the mains input were to some other stuff. Also, it was possible to touch some hazardous parts of the circuit through openings made as handles.