Can someone explain old combo amps to me

[coyote1]

So a couple things I can think of: first off (and this may be obvious, forgive me, I'm all about obvious) - artists back then didn't have the choices we have now, and had to go with whatever was available, affordable, or sponsor given - so you'll see a lot of odd choices perhaps for bass. Second, it all boils down to Leo Fender. He designed the first guitar amps that everybody used, and he didn't make much that was different about his "bass" amps or "guitar" amps. And in fact if I remember correctly it was a Fender Bassman circuit that Jim Marshall famously 'copied' for his first guitar amps. Now of course people understand a lot more about amplification and how you can design an amplifier to specialize for bass or something else, and you have more choices. But in the '60s it wasn't that different.

The reality is that it’s still not that much different. Take a bass amp, add a gain stage or two, and you have a (rock) guitar amp. Omit the extra gain stages and you have a jazz guitar amp. Add power and you have a louder bass amp. Etc.

So back then they worked with what they had. And remember, those were the days before every drum got its own mic and before stadium PA systems became a thing and before drummers hit as hard as they could….

 

[Pimpernel Smith]

As has been said, it's hard for anyone younger to imagine how crap the gear was, how little was available and how broke we were. Also, at the amateur level where I was, how ignorant we were about the science. This in England which was even more broke.

Absolutely right. And those kids today can't imagine how crap the amps were.

 

[ga_edwards]

Come to think of it, I still have several California-built mid-'60's solid-state Vox amps with six inputs: two for the Normal channel, two for the Brilliant channel, two for the Bass channel (and with tremolo and distortion on the Normal channel, mid-range boost with three settings for the Brilliant channel, and reverb assignable to either guitar channel). (Still my favorites among the guitar amps I've owned.)

Brother had an AC50 head with 4 inputs with a matching cab that he acquired from a friend for about £50 in the mid 90's. (Looking it up, it was either a mkii or mkiii). Amazing sounding amp once he got it fixed up and working, but a pig to lug around. He p/ex'd a few years later for a Marshall Valvestate 8080! He says he doesn't regret it, but I think deep down he does.

 

[Wesley R]

It’s been too many years ago now…but I remember everyone was “daisy chaining” their Fender heads. Bassman to Bassman, Bandmaster to Bandmaster, etc. I don’t recall my pals mixing different heads for example Bassman to Showman. So I think that what the Send/Rec labels were about(?). So some hapless roadie wouldn’t just blow the whole place up.

I too wound up with a Standel for awhile. It was a combo with two 15s. Not bad, especially after graduating from a St.George head with a Bandmaster bottom.

Standel made the Super Imperial, it was a combo with 2-15's. It was made to compete with the dual showman, and it did so really well. Priced at $100 below the dual and was louder and cleaner. If memory serves the speakers were labeled "free cone by Trusonic". I loved mine, yet wouldn't want another, and still have fond memories of my Dual Showman.

 

[portpc]

Standel made the Super Imperial, it was a combo with 2-15's. It was made to compete with the dual showman, and it did so really well. Priced at $100 below the dual and was louder and cleaner. If memory serves the speakers were labeled "free cone by Trusonic". I loved mine, yet wouldn't want another, and still have fond memories of my Dual Showman.

I had one of those when I was 17. I honestly have no idea where I got it from as much of the late 1970's were a blur... I do recall it was the best amp that I had used up to that time.

 

[SoulReflection]

One combo bass amp that I saw quite frequently in the SF Bay Area was Standell, an early solid state combo with 2x15 and pretty loud for the time, they had some reliability issues and quickly fell out of favor though.

My organist back then had a Standell that I really wanted. Guess I was lucky it wasn't for sale!

 

[DJ Bebop]

Standel made the Super Imperial, it was a combo with 2-15's. It was made to compete with the dual showman, and it did so really well. Priced at $100 below the dual and was louder and cleaner. If memory serves the speakers were labeled "free cone by Trusonic". I loved mine, yet wouldn't want another, and still have fond memories of my Dual Showman.

I had the 2x12 Standel “The Artist XII" A12B

Not my photo but the same one.
I liked it.

 

[Guitalia]

Brother had an AC50 head with 4 inputs with a matching cab that he acquired from a friend for about £50 in the mid 90's. (Looking it up, it was either a mkii or mkiii). Amazing sounding amp once he got it fixed up and working, but a pig to lug around. He p/ex'd a few years later for a Marshall Valvestate 8080! He says he doesn't regret it, but I think deep down he does.

I have a mid-'60's four-input AC-50 head that I could use as a toaster. The heat it puts out is incredible. Also have a Valvestate combo amp that sounds great. But my three solid-state Vox amps built by the Thomas Organ Co. in the U.S. are my favorites

 

[agedhorse]

The reality is that it’s still not that much different. Take a bass amp, add a gain stage or two, and you have a (rock) guitar amp. Omit the extra gain stages and you have a jazz guitar amp. Add power and you have a louder bass amp. Etc.

Except that it’s nowhere near that simple with any of the better quality amps.

 

[KellyC]

The open back combo design provided a place to stash your weed, which has been made obsolete with the liberalization of marijuana laws.

 

[brianrost]

Whole bands plugging into one amp happened with a lot of bands composed of teenagers who were financing their music careers with lawnmowing money. But the multiple inputs in amps usually were meant to make the amps more versatile for a single player.

Definitely the amps made in the 50s and 60s that had inputs for microphones with separate volume controls were intended to be used as simple PA systems. Some amps had phono inputs for hooking up a turntable. Ampeg even had accordion channels on some amps. People did use these features. The change to single channel preamps (so one amp per signal source) happened in the 1970s and 80s which is also when PA systems began to be much more sophisticated.

Peavey sold a combo in the 1980s with four input channels. The Rhythm Master 400 was not sold as a keyboard amp, but actually meant to plug in multiple string instruments. With 210 watts into 1-15”, it was probably aimed at the country market…plug in your Tele, your steel, your Martin and your fiddle…but it didn't last long on the marketplace. Peavey’s steel guitar amps were all single channel.

Acoustic Image made two channel combos with mike inputs on one or both channels, complete with phantom power. One application was for upright players using both a pickup and a mike on their instrument. However, the second channel could be routed to an outboard power amp or powered speaker. That way a second instrument or microphone could be controlled from the combo but the audio routed out to a a different amp/speaker.

The Roland Cube Street EX is set up with two channels that can accept either a guitar input on 1/4” or a mike on XLR in addition to having a stereo line input for adding a keyboard. I use one for busking, bass in one channel and vocal mike in the other. It has a unusual two amp linking feature where running cables from each amp to the other allows all six channels to be amplified through both units.

 

[WI Short Scaler]

The first amp I ever had was hand-me-down Panaramic with a 12" speaker in it. It looked an awful lot like this one but was more beat up, my dad had hauled it around for many years using it for his accordion/polka gigs. I had a guitar and a bass and played them very loud, and very terribly, for a few years.

I can't speak to the tone but I know it was loud enough to play music along with a drummer friend. We were both terrible but thought we were on the road to stardom. And since this was used for many years of live polka gigs over a drummer and 2 or 3 horns I'm pretty sure it was loud enough. It was still working in the late 90's the last time I saw it at my dad's. I wonder what happened to it? I'll have to ask.

My first "real" bass amp was this SG System monster. I don't have any photos of mine, this was a stock web image. It was loud and heavy, paid $75 dollars for it. It had a 15" and 2-10" speakers in it. The case was built to repel cannon-fire. Did I mention it was heavy? And awkwardly huge. The amp eventually died and I used a borrowed Peavey head for awhile until I got a Peavey combo with a 15" Black Widow speaker in it.

I'm a big fan of newer, lighter, gear.

 

[bigdaddybass12]

Just for a different perspective, the kids like me who were learning bass in the 80s had a bit of an advantage with the availability of Peavy combos. They didn’t sound all that great, but they were less expensive

yeah but HEAVY !! I believe "Peavy" spanish for Heavy !! Had a friend loaned me his TNTxxxx, Felt like it weighed 150 lbs!

 

[Guitalia]

Definitely the amps made in the 50s and 60s that had inputs for microphones with separate volume controls were intended to be used as simple PA systems. Some amps had phono inputs for hooking up a turntable. Ampeg even had accordion channels on some amps. People did use these features. The change to single channel preamps (so one amp per signal source) happened in the 1970s and 80s which is also when PA systems began to be much more sophisticated.

Peavey sold a combo in the 1980s with four input channels. The Rhythm Master 400 was not sold as a keyboard amp, but actually meant to plug in multiple string instruments. With 210 watts into 1-15”, it was probably aimed at the country market…plug in your Tele, your steel, your Martin and your fiddle…but it didn't last long on the marketplace. Peavey’s steel guitar amps were all single channel.

Acoustic Image made two channel combos with mike inputs on one or both channels, complete with phantom power. One application was for upright players using both a pickup and a mike on their instrument. However, the second channel could be routed to an outboard power amp or powered speaker. That way a second instrument or microphone could be controlled from the combo but the audio routed out to a a different amp/speaker.

The Roland Cube Street EX is set up with two channels that can accept either a guitar input on 1/4” or a mike on XLR in addition to having a stereo line input for adding a keyboard. I use one for busking, bass in one channel and vocal mike in the other. It has a unusual two amp linking feature where running cables from each amp to the other allows all six channels to be amplified through both units.

All true. My six-input Thomas Organ-era Vox amps were certainly designed for maximum versatility for either single or multiple musicians. And my solid-state Gibson Les Paul combo amp (preamp head unit plus powered cabinet with four 12" speakers and two 10" horns) has two channels, each with two inputs (high and low impedance, the latter clearly intended for use with the mildly wacky Les Paul Recording and Personal guitar models).

But, with the exception of a few amps designed for specialty applications such as those you presented, the overwhelming majority of amps have been designed for one musician/one amp use since the early '70's.

 

[DJ Bebop]

Definitely the amps made in the 50s and 60s that had inputs for microphones with separate volume controls were intended to be used as simple PA systems. Some amps had phono inputs for hooking up a turntable. Ampeg even had accordion channels on some amps. People did use these features. The change to single channel preamps (so one amp per signal source) happened in the 1970s and 80s which is also when PA systems began to be much more sophisticated.

Peavey sold a combo in the 1980s with four input channels. The Rhythm Master 400 was not sold as a keyboard amp, but actually meant to plug in multiple string instruments. With 210 watts into 1-15”, it was probably aimed at the country market…plug in your Tele, your steel, your Martin and your fiddle…but it didn't last long on the marketplace. Peavey’s steel guitar amps were all single channel.

View attachment 5449164

Acoustic Image made two channel combos with mike inputs on one or both channels, complete with phantom power. One application was for upright players using both a pickup and a mike on their instrument. However, the second channel could be routed to an outboard power amp or powered speaker. That way a second instrument or microphone could be controlled from the combo but the audio routed out to a a different amp/speaker.

View attachment 5449165

The Roland Cube Street EX is set up with two channels that can accept either a guitar input on 1/4” or a mike on XLR in addition to having a stereo line input for adding a keyboard. I use one for busking, bass in one channel and vocal mike in the other. It has a unusual two amp linking feature where running cables from each amp to the other allows all six channels to be amplified through both units.

View attachment 5449167

That's how my dad used his Ampeg B15n.
It didn't make a difference even though there was 3 inputs but only 2 channels of control. He would run his Wurlitzer piano, a mic or two, or a mic and a guitar, and use it as a mic locker, drink and ashtray stand all at the same time! Then when his was done, throw all the cables, mics and his portable bar in the Fliptop cabinet and throw the whole sugaree in the trunk of his Caddy. Never once ripped the speaker after many years of abuse.

 

[coyote1]

Except that it’s nowhere near that simple with any of the better quality amps.

Is this where the secret sauce, magic smoke, and voodoo come into play?

what do you consider the best-ever bass amp? What is the general structure of that amp? Is it something other than one or more preamps, a tone stack, and a power amp? Perhaps it has an effects section? Please describe how otherworldly that amp is compared to, say, my old Marshall Major or my current Hartke HA3500.

 

[agedhorse]

Is this where the secret sauce, magic smoke, and voodoo come into play?

what do you consider the best-ever bass amp? What is the general structure of that amp? Is it something other than one or more preamps, a tone stack, and a power amp? Perhaps it has an effects section? Please describe how otherworldly that amp is compared to, say, my old Marshall Major or my current Hartke HA3500.

The Voodoo is the designer's understanding of player's wants/needs, their intent and skill at executing the design.

IMO, there is no "best amp", there are many different amps that better address each player's desires and personal tastes. For example there are players who think the Marshall Major is the worst amp ever and players who think it's the best amp ever. That's life in a nut shell.

 

[matthewbrown]

The Rural Electrification Act’s effect began in the late 1930’s and slowed down during WW2. About 1/2 of all American farms had access to electricity after WW2 and most had electricity by the late 1950’s.

Much of it was 110V AC and 30A service was common, expanding to 220V service then getting larger. During this time, the US adopted the 120/240V service in combination with 240V, 3ph delta and 120/208V, 3ph wye and 208V, 3ph delta services that most are common today. (Plus 277V/480V wye and 480V delta).

I wondered if musical amplifiers as consumer items were marketed the way Fender guitars were: Like mass market cars. It seems like they were, and it would be hard to market them to folks who lacked the electrical service to supply them with the power the amps needed.

 

[matthewbrown]

Yeah, I have had little success finding out how MUCH electrical power the average American home had on hand immediately after WWII. It wasn't much before that, mainly because i don't think that there were lots of affordable appliances that used lots of electricity, primarily refrigerators and electric ovens/ranges. I'd love to find out more about this.

See Aged Horse's post on this topic for some interesting info.

 

[SoulReflection]

In the mid to late 60s, the best I could do gigging was a 60W Dynaco and a 2-15 D140F cab. It was a Sunn clone.

I have to add my thoughts on the volume wars that followed.

Groups like mine did not have much problem with loud drummers. The bass rig I had was fine with those drummers, a guitarist that had a 20 to 30w amp, an organist that played a B3 through a Leslie and a low volume PA for singers and horns. I believe the wars started when the guitarists began using 60 to 100 watt amps, like mine. At that point, everyone had to "crank it up", IMHO.