Old Movie Theater Tube Amplifier?

[MarkA]

[EDIT: Mods, if this would be better in another sub-forum, please feel free to move it there!]
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Last week at an out-of-town jam session, a harmonica player brought this, along with a relatively nondescript Kustom (modern, not old-school) cab with a woofer and a horn. Said that he got the amp, along with an old film projector (with its super-bright bulb and everything) for a pittance recently.

He asked me if I knew anything about it -- aside from the obvious (I see tubes and stuff), I did not, but I told him that I'd ask here. The amp was pretty loud and sounded better (richer, smoother, better defined) than whatever he was using before and a good deal better than just running his mic into the PA.

Any insights from you all? I could see something like this as easily being repurposed into a sweet guitar amp or (depending on how it handled the lows) a low-wattage bass amp.

Thanks in advance!
-Mark

 

[MarkA]

Okay, clicking on the top photo to enlarge it (and looking at it, now, on my laptop screen and not on the small screen of my phone or in dingy bar light) I can see the logo, Filmosound Amplifier. A quick Google search turned up some eBay listings -- haven't taken the time to try to match his, exactly, but it looks to be potentially worth a good deal more than he paid for it (and the projector and whatever other stuff he got with it). The company Bell and Howard Howell is mentioned and, going by one of the listings, the idea of repurposing these for guitar or harp is not that unusual!

I'll let him know to look into that much!

 

[rodl2005]

Bell and Howell???

 

[MarkA]

Heck, now that I have a name, the googles are turning up a wealth of info on the amps. Still, any insights, experiences, anecdotes are welcome.

Bell and Howell???

You are correct! Edit impending.

 

[Goatrope]

It’s cool. 2 pairs 6V6 and a pair of 12AX7? Fascinating!

 

[kevmoga]

It’s cool. 2 pairs 6V6 and a pair of 12AX7? Fascinating!

Guitar players have been all over these things for a few years now. Check out folks like Anthony Wilson, Blake Mills, and I think Ry Cooder may use one too. Prices are reflective of growing interest. No idea how they would work as low wattage bass amp. My understanding is most put a preamp in front or mod what serves that role in the original amp.

 

[10cc]

I’ve used one of these old Masco PA amps for bass and it worked wonderfully. Of course it had been modified slightly for bass.

 

[spiritbass]

I’ve used one of these old Masco PA amps for bass and it worked wonderfully. Of course it had been modified slightly for bass.
View attachment 3361621

What happens when you flip the "motor" switch?

 

[two fingers]

Paging @agedhorse .....


From what I gather he was doing theater sound when we switched over from silent pictures.

 

[spiritbass]

Paging @agedhorse .....


From what I gather he was doing theater sound when we switched over from silent pictures.

 

[beans-on-toast]

Filmosound 385 or 388, about 15W. Nice little amp that can be modded to use with an instrument.

 

[10cc]

What happens when you flip the "motor" switch?

I’m not really sure. It was back lined and I just plugged and played.

 

[beans-on-toast]

Here is the 385 schematic.

I'd carefully check the conversion for instrument one. Like the tone stage. Can use 1M pots in the EQ, easier to source.

 

[GretschWretch]

I still have a couple of old McIntoshes from the 1950s that used pre-amps in front of them. One was my first "bass amp." Sounded okay, and pretty loud for the times.

The fact that these amps may rate at only 15 t0 25 watts may not be the deal-breaker it would have been in earlier times. With good FOH sound they would be great as stage amps.

 

[agedhorse]

Yeah, that's a Bell & Howell "Film-O-Sound amplifier, that was a trade name for a series of home and non-theatrical projection equipment. They never got into the 35mm projection market but did build commercial/military versions of 16mm machines. At one time, they may have been owned by the Singer sewing machine company, but my memory is hazy on the details.

There were lots of small amps like this bilirubin the 1950's and 60's.

 

[spiritbass]

There were lots of small amps like this bilirubin the 1950's and 60's.

Another butchered victim of spell-check? My maternal grandmother was also in the movie business for a while. She played piano accompaniment to silent movies. That lady had an incredible repertoire!

 

[Slevage]

What happens when you flip the "motor" switch?

Probably turns the motor on.

 

[spiritbass]

Probably turns the motor on.

I was setting up @10cc for a 'flippant' response, but he didn't take the shot. My guess would be starting the projector?

 

[xaxxat]

Lots of videos on youtube on making these amps useful. Change the caps, remove what you don't need and then let it rip.

 

[mmon77]

Usually these kind of amps will work for guitar. Mods normally involve changing the input so it will work with high impedance guitar pickups, and possibly changing components in the tone stack to be more guitar appropriate. Some also play with the negative feedback circuit.

I did something similar with an old Hammond organ reverb tank amp. Mine was EL84s and 12AX7s, so its similar to the old Marshall 18 watt amps. This one would probably end up being around 50 watts.