Phonograph cabinet Guitar amp

[Volitions Advocate]

*Heading you off before you get all pedantic on me for not calling it a gramophone*

So a few years ago my wifes grandmother who had alzheimers had a fall and was sent to long term care.  She ended up selling her house and most of the the things that were in it went to family. (old sofas etc)

One thing she got was one of those massively heavy phonograph cabinets made of solid walnut, (or something stained to look like walnut) and a vast collection of vinyl that contains mostly Barbara Striesand, Anne Murray and Richard Simmons albums.

Anyway, the massive thing has been migrating around with us from apartment to apartment and now to our home that we bought 3 years ago.  It's been a TV stand and a Makeup table and whatever else.  It's now sitting in the basement among our storage doing nothing but holding a pile of crap on top of it.  My wife always hinted at wanting to make a nice entertainment centre out of it.  Pulling off the old fabric and replacing the speakers, making a shelf int he middle for the electronics in the living room, that kind of thing.  I've had my eye on it for years wanting to make a guitar amp out of those old speakers and the amplifier inside.  We've never played the records on it because the centre post on the turntable is broken off, but I do know it works, I tried it.

Well we were cleaning up our storage to take some stuff to the salvation army when I asked her about it, and she gave me the go ahead to pull everything out of it, so long as she got her entertainment centre in the end.

So there's my next project boys,  I'm excited about it.    I dont' have any pictures yet, but I'll take them in the morning when I get home from work ( after I take all the junk that's piled on it off )

Has anybody here done this? Would love some pointers and input.  I know a thing or two about DC theory now, but I'm no expert.  I'm sure pictures of the actual unit will help.

I hope to pull the speakers, and the amplifier out,  I'm not sure yet if the amp is in the same housing as the turntable, but I'll find out.  I'll take the grillcloth off the cabinet and use it in the cab I'll build for it I think.  I hope to keep the same visual aesthetic once the amplifier is made, to remind me of its origin.  And if I can salvage the phonograph itself I'd like to wire up the output to a TRS jack or a couple of TS jacks so I can plug it into my recording interface and have a nice listen to some vinyl in my studio space (and maybe actually start buying some vinyl)

Help me out here.  I'll post pics. later.
In case your'e wondering.  It's one of the bigger units.  a bit bigger than this one, but same idea.

UPDATE:  Finally got pics taken.  I'm not so sure its a tube amp unfortunately.

If this turns out to be all around useless, at least I can de-solder all of the nice vintage components and keep them for future projects.  Verdict withheld for the moment.  Need to find out more about this thing.

 

[Volitions Advocate]

Reserved for WIP updates.

 

[Cagey]

Reminds me of my grandmother's stereo. Almost identical piece of gear. It got thrown on the bonfire when we emptied her house. She lived far enough out in the country that you could pretty much burn whatever would burn without a crowd of rabid environmentalists showing up to eat your liver and use your intestines as headbands while they marched on the nearest city that had a news truck.

My guess is you could spend a helluva lotta time and money making that into something useful, and if it didn't match your current decorating scheme (which would have to be '50s art deco), it would be a massive pain in the shorts. The record player/gramophone/turntable is useless, of course, as is the amplifier. The speakers aren't even worth talking about. So, if you gut all that crap out, what are you left with? A heavy, unwieldy cabinet.

Now, maybe you appreciate the design of the thing, it matches your other stuff, and don't plan to move it once you have it in place. In that case, I'd consider replacing the speakers with something useful, and modifying it so those doors in the middle opened up to a small area where you could put a useful amp. Perhaps a Quilter? Lotsa watts, good sound, small size, etc. Something like that, anyway. Then, you'd have a practice amp that looked like furniture when it was all buttoned up. Chicks (read: wives) hate musical gear in the living room, but if that could fit in with everything else, you'd have a strong argument for having practice gear in what's likely the most comfortable room in the house. Can't beat that with a stick. Although, keep in mind you have to share that room so you may not get the use you'd want out of it.

 

[Volitions Advocate]

oh, I'm not trying to make that whole thing into a guitar amp.  I want to rip the guts out of it and turn THAT into a guitar amp, and build a new cabinet for it, something actually wieldly.  I've heard of people doing similar projects and really liking the sound of what they get.  Something real bluesy at a low volume.  Not looking to compete with my rivera here, just something to give a different sound that I can throw a mic in front of and record.

The big ass cabinet itself is destined for pretty much exactly what you described.

As far as whether or not the guitar amp will end up as something actually useful or not?  Well I'll learn a lot doing it won't I?

Like I said, I'll throw up pics, My unit is a lot bit less fugly than that thing.  More 70s than Art Deco.

 

[Cagey]

Ok, I misunderstood your intent.

If you've already got a Rivera, you're a million miles ahead of the game and I wouldn't even consider wasting time trying to repurpose the amp in that cabinet. There are both input and output impedance issues you'd have to deal with, and it's not a trivial task. Trying to resolve those isn't worth the trouble. If you want to do an inexpensive experiment, go to Radio Shack (or someplace like that) and get a 1/4" to RCA adaptor. Shouldn't cost you more than $5. Use that to plug your guitar into any hifi unit that has a phono input. See if you're happy.  Without even being there, I can guarantee that if you crack a smile at all, it'll be to laugh at how bad it sounds. You'll wish you'd saved that $5 for a six-pack of [your favorite beer].

We tried doing this sort of thing more than once 100 years ago when we were dead-broke grasshoppers. It just doesn't work.

 

[Volitions Advocate]

Awesome. I actually already have a handful of those things.

I'm still gonna do it.   If for no other reason than to learn.  But I'll take your advice to moderate my expectations.

Same principle as the worthless squier neck I have that I'm going to do a refret on.  I'll never use it in a guitar. the pocket won't fit, and its an awful neck.  But i'll help me learn a bit and get some practice.

 

[Cagey]

Same principle as the worthless squier neck I have that I'm going to do a refret on.  I'll never use it in a guitar. the pocket won't fit, and its an awful neck.  But i'll help me learn a bit and get some practice.

Where do you think I learned to level and dress? How about re-fretting? You don't do it on vintage Martins or Gibsons. You get people to dig out old cheap crap from under their beds or in their closets/attics/basements and promise to make them better for little or no money. Trust me: you may not be the dresser of doom, but with many guitars it's not hard to improve them even if you're a piker. So, you practice on those until you feel good about what you're doing, then you attack better instruments when you're not so worried about screwing them up.

It takes time, but eventually you get good at it. It's mainly a patience thing, plus proper tools and techniques. Oddly enough, in my experience even the guys that are bad to passable at it return results that are better than the original. If you've ever tried playing a guitar in your life, you know what's good and that's what you try to deliver.

 

[Volitions Advocate]

Well put.

 

[mayfly]

Just jumping in here before I read the entire thread.  Sorry if this has already been discussed.

Before you do anything, have a look at the electronics.  Sometimes those old cabinet stereos had GREAT EL84 TUBE AMPS in them.  These things, although low power, sound GREAT FOR STEREO.  Some  upgraded speaker components and an input for your CD player, iPod, airport, whatever and you'd have a killer setup.

DON"T GET RID OF THE TUBE GUTS.

I'll go back and read the rest of the thread in a bit 

 

[mayfly]

Just read the rest of it.  My advice is not to try to make a guitar amp out of the stereo.  You're going to spend a bunch of time and energy and not end up with anything useful.  It's a much better idea to:

1 - replace the speaker drivers.  I can offer some advice here.
2 - have the electronics gone over and made right.  This is a project in itself and you'll learn a lot by doing it.  AND you'll have a killer stereo/entertainment centre/amp for your DAW etc in the end for your efforts.  A LOT better than a pile of parts that is not a guitar amp.
3 - The gramophone record changer is cool, but if you don't have any records, you could ditch it and regain that space.  Don't throw it away; put it up on one of those free lists instead - you'll get some action and you won't contribute to landfill.

BTW, in my experience these things are divided into three parts:

1 - gramophone (usually a gerard) is separate
2 - preamp and tuner is a separate piece as well.  This is the par you see
3 - stereo power amps.  An other separate box, mounted down low in the guts.

First step would be to take the back off and take lots of pictures.  Then I'm sure I'll have more comments. 

 

[Volitions Advocate]

It surrounded by boxes and stuff at the moment. I uncovered it to look inside, and it's an Electrohome Dielcraft.  I'm guessing manufactured sometime in the late 60s or early seventies.  Probably right in your backyard somewhere Brian.  Kitchener most likely.  Before Electrohome moved away from furniture and consumer electronics and started doing commercial and industrial electronics.

The only other marking I saw just said "Carter" at the bottom of the gramophone.  Havent' looked into that yet.

There's too much crap around for me to take the back all the way off, and I didn't have much time, so I'll try tomorrow.  All i can say at the moment is that I saw cobwebs.  lol.  I think it already has 1/4" jacks in the back for a tape machine.

 

[mayfly]

Sounds cool.  Those 1/4 jacks could be just the ticket for your DAW.  It probably has tape sends as well  :headbang1:

 

[mayfly]

BTW, you didn't happen to see one of these in the back did you?

 

[Volitions Advocate]

I didn't get a good enough look yet.  Tomorrow should be better. the kids are off with their aunt for most of the day.  So i'll have some me time to screw around.

Also.  Sorry.  I know your name isn't Brian,  It's been awhile since I've been around here, not sure where I picked that up.

 

[Volitions Advocate]

Some pics uploaded.

 

[Great Ape]

HEY!! Are any of those Richard Simmons LP's still around? HEY!!  :icon_biggrin:

 

[mayfly]

oooo - transistors!  So Modern!!!

ok, the guts are probably junk.  You could try it to see if you get a signal through.  But if you don't get anything useful out of it I'd build a little preamp/input switcher thing and run that into an inexpensive tripath type amp.  Done.  Well, maybe a little D/A as well if you want to use it with airplay or something.  Could be a fun little project.

Regarding the components, I would not save the electrolytic caps - they are dried out and useless.  Wrong voltage for tube amps anyway. The old carbon comp resistors are not great either.  The polystyrene caps (I think I saw some) are pretty cool.  Faceplates and cosmetics are worth re-using.

Here's some resources on cheap but good stuff to stuff into it:

Amplifiers etc.  I would not bother with anything over 30 watts:
http://www.parts-express.com/cat/audio-amplifier-boards-modules/3464

An excellent D/A:
http://www.parts-express.com/pe/showdetl.cfm?partnumber=310-332

Some speakers:
http://www.parts-express.com/cat/home-audio-woofers-midranges-tweeters/13

and of course check the deals page!:
http://www.parts-express.com/term/clearance_center_factory_buyouts

Have fun,

Trevor

 

[mayfly]

BTW, that little chassis with the passive components and wires going in and out of it at the bottom of the unit is likely the crossover circuits for your speakers.  I see that it's a 3 way system (cool!).  If it were me I'd keep the same speakers for now as changing them involves baffles and calculations and design and crap and just stick a cheap amp out front of the crossover circuit.  Then you're up and running for under $20 bucks.  Use this amp:

http://www.parts-express.com/pe/showdetl.cfm?partnumber=320-332

or this one if that's too powerful
http://www.parts-express.com/pe/showdetl.cfm?partnumber=320-330

If the speakers are blown, then you'll have to solve that problem.  But for now that's what I'd do.

 

[Volitions Advocate]

I'll check for them ape. Let me know if you want one of them

I'm quite sure the amp actually works.  I've had the FM going in it.  I'm quite surprised at just how clean the amp/receiver looks though.  I guess being mounted on its side helped, especially looking at the crossover on the bottom and how dusty it is.

Not sure what to do next.  I wish I knew more about circuit design.  I took a class in my degree program that was geared toward audio, but all we really did was the equations for ohms law and some other stuff.  Most of the circuits we did were just the ARDX tutorials for Arduino,  Learned how to use a relay and an IC and couple of other things on a bread board.  But I'm pretty much in the dark and don't know where to start to expand my lernin'

Parts express has some great stuff, I've browsed there often at JacktheHack's recommendation. (that was years ago, is he still around here?)

 

[mayfly]

well, if the amp works - use it!  The only trick will be routing different inputs into it.

If it were me I'd just use the tape returns, then put a switch in front of that.  Don't use the Phono input - it will have the RIAA eq curve on it.

Update...

BTW - don't plug anything into that little chassis on the bottom.  From what I can tell (Your wiring diagram is kinda fuzzy) those are all speaker outputs.

Are the tape inputs really run into the photo section?  Maybe the RIAA curve is applied there....  You'll have to take it apart to see.