• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Ancient Valve Amp and Rola Speaker PLEASE HELP!

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Gday
I must firstly thank all that helped me resotre my yamaha p2200. I must say before i begin, that the p2200 was my first "major" attempt at anything to do with amplifiers. So here is my first valve amp....
Little help needed,... or suggestions... is this just junk or shall i restore it?... I mean is it worth the metal it is made of.. it did work before it sat in the shed for 25 years. now it looks a bit rusty. it is a very old amplifier radio. My dad's grandfather bought it. Yeah work that out! The old wooded case (jukebox style!) I will restore, but the amp section has seen better days. I need suggestions on restoration and if it is worth bothering with. My first problem would be, could i earth the metal case? It was not originally earthed, but these days anything metal must be earthed..
This amp was originally made in Melbourne Australia. I have cleaned up the dirt a bit since i took the pictures. Everything seems OK. Just a lot of rust and old cords (look suss)
ANyway have a look at the pictures there a lots of detail. I dunno maybe someone needs some valves or an old speaker.
Thankyou
priscared at hotmail.com
daniel
 

Attachments

  • old amp case front.jpg
    old amp case front.jpg
    38.5 KB · Views: 196
First thing's first, any commerically built Australian made gear isn't worth the metal they build it on except for looks and charm.

Unless it's pre-1940's like the early battery/AC sets in cabinets or ones that which were made overseas then imported, RCA, gramophones, etc.

Remember it's the American made units that are popular in terms of money flow.

Without a doubt if it is intact, it is definatley worth the time and money to restore it, the Aussie made sets still sound great.

Remember, if the front-glass is intact DO NOT WASH IT, DO NOT BRUSH IT and DO NOT TOUCH IT or RUB it...

Leave the glass somewhere safe in a vertical position, if you even let it lie down on something the lettering of the glass dial face will rub off very easily and you'll waste yet another many fools dial plate.

If you don't have a glass front however than the unit after restoration won't exactly fit the original look in the living room.

You can rub back the chassis where there are rust spots and either kill-rust them or paint the thing black or whatever.

To rub back the transformer be very careful with the windings as you don't want any sort of metal dust or shavings in there, the best thing to do would be to write down the taps on the bottom and label the leads with white sticky-tape and a pen or pencil, then desolder them and take the thing out of the chassis by undoing the four nuts, being careful to take note where the washers are in relation to the top or bottom of the chassis, then remove the top plate of the transformer and rub it back with a bit of sand paper, soak it in petrol and then finish the sanding off, then repaint it black or whatever, then go do the actual transformer's E core outer edges, a nice steel brush does this fine, be VERY careful though.

If it has a label then it's up to you wether you want to keep the transformer as it is, but beware that with time, moisture will get rid of it just as easily as Aussie cockroaches can with speakers..

Always!!! hang up your speakers from vintage sets or whatever on the wall with a nail through one of the mounting holes, I can't stress this enough.

I've noticed though that some cockies are vigilant and will go up on the wall just to eat the paper cone, so keep spraying that Mortein around your shop.

---- About the design ----

It looks like a fairly simple fully-octal coke-bottle unit which is reminiscent of the 1940's sets in Australia.

The biggest problem for replacing components will be tubes and capacitors, these 1940's sets use "two" numbered tubes for receiving and preamplification to the 6V6 tube (common as output tube in these early sets).

---- Word on Mains wiring ----

You noticed and asked if you should earth the chassis or not, my word is that if you don't know how to wire up 240v in these sets then you don't have the expertiese to fiddle with these sets.

But if you're infact gullible enough to mess with a death trap then go for it, most of these old sets didn't earth the chassis through the house mains wiring, grounding was done via the antenna setup, there is far too much noise in hundreds of feet of mains wiring to give any sort of performance for any set, there should be push-down leads on the back or top of the chassis where you connect ground to the green crimp-style terminal.

These 'cheap' sets are poor performers when it comes to sensitivity and range...but if you've got a good MW antenna setup it should be plenty for a set like this to get at least 5 stations.

You can't expect transistor performance from units made 60 years ago! =)

In a thunderstorm, turn off then unplug the set from the wall, then unplug the antenna from the terminal and then the earth from the other terminal, I generally setup a set of eye-hooks and screw them into the back of the cabinet then wrap the antenna and earth wires through them when not in use.

Every amplifier is different upon how they wire for 240v. In my set, you wire up one lead through a switch and then to common of the primary side and then the 240v tap directly to the other lead of the 240v incoming wiring.

---- Word about restoration ----

You have got a rather easy set to restore, I've got a 1940's set here without a magnetic-speaker. Mine is a fully electrostatic speaker, they have one coil for imitating a magnet and one for pushing/pulling against that 'magnet' which requires quite the expertiese to figure out /AND/ this one is completely covered in rust.

Chassis, transformer, dial plate, knobs, one pot is even destroyed.

Luckily, I have the speaker necessary as an exact replacement for my set, be very careful with yours, I noticed in the images you undone the output transformer from the back of the speaker, leave it alone, just brush all the dirt and stuff out of the speaker and set it up high.

My unit is very much like yours, mine has the exact same wooden cabinet as yours but a smaller dial hole and only three knobs, and a deeper chassis.

But I still intend on restoring it.

One last word, take your time and good luck !! I'd love to see your set restored and glowing like it did the day it was built =)

It's great to see other Aussie sets around and about getting restored.
 
One last word...

If you intend on pulling the shields off the coke-bottle tubes, and can't get the shields off the tubes without "taking that lead off", Then make sure you desolder the lead of the terminal which wraps around the top-cap, DO NOT just pull off the terminal from the top-cap as I GUARANTEE you that the entire top-cap will come off the actual tube!!

Cheers!
 
the old speaker

I already messed with the speaker ;-)
:bawling:
Oh well.
I think i may have already give up on this excercise. Yes my speaker also has no magnet, uses electromagnets instead, total waste of time, lol.
All the components on mine should "theoritcally" work. Everything was intact, until i messed with it :eek: . As far as the earthing goes, this unit was intact, the cords are still there, the wall plug has been cut off, but other than that it is all there, what worried me is that it doesnt have an earth, if i put an earth on it would it damage anything? But i think your saying it may only affect the sound quality. On the back it has phono inputs, this interested me a bit, they are very old style, would anyone know how to hook an external sound source up, if it was possible, ie cd player or an fm radio (boy they are high tech!)
The front glass plate has no numbers on it at all, it has pensil marks where the radio stations are!
Should all the capacitors be replaced before i plug it in? Should I replace all the wiring? Basically it looks "ok" but i wouldnt like the thought of it warming up with all that old wiring holding it together.
Actually the first thing i did was snip the cable from the speaker to the amp. Then i took the speaker out, and saw there was a plug to unplug the speaker from the amp :smash:
Thanks for your help, Any more suggestions greatly appreciated
 
Even if you did replace every capacitor in that amplifier, I wouldn't power it up without a speaker PROPERLY connected..

In reply to your latest comment, those 'capacitors' are actually vacuum tubes protected by a metal shield which wraps around it...

If you can't discern even this, DO NOT TURN THIS ON!!!!!!
 
phono input

on oldamp4.JPG
You can see the phono input, is it possible to use this as a fm radio input or alike.
Also i don't know if i phrased my statements well enough, basically i need to know what old components should i replace, for safety or for the fact they will fail. I know like in the yam 2200 the supply caps were dangerous if they leaked,,.. cause a major problem.
Daniel
 
The big square metal things are tuning coils..

They are technically capacitors, but you don't need to replace them..

Don't even touch em =)

But if they're aligned incorrectly you will need to know how to use an oscilloscope and many other things.

The *cough* "only" things you need to replace are /underneath/ the amplifier..and /maybe/ a vacuum tube.

Take a look underneath there and see how many wonderous things there are which need replacing, they should be covered in brown paper and very large, they have these values written on this paper called "MF" or "uF" or "V" or "VA"..

These are very old and very tired electrolyctic paper-wax capacitors.

10 years after the unit was manufactured these capacitors would have become useless, their dielectric would have dried out and this capacitor is not a capacitor anymore, it is now a little piece of dynamite.

If it says 10uF 400 VA then you need to replace this capacitor with a 10uF 400VA capacitor.. not with a 10uF 63v capacitor, a 63v capacitor will be 337 volts below it's necessary rating and will explode!!!

You can't get this stuff from Jaycar or DSE, there is a supplier in queensland whom will happily supply you with most low-value capacitors, other than that you need to import them.

If you do it incorrectly then you just may get an electric shock of 400 volts or more...Then I won't have to worry =)

I urge you not to work on this unit, this is my personal opinion and I leave it to you..
 
are fair enough

yeah thats what i originally thought they were, until u mentioned capacitors, yes underneath the caps n everything is still very good, has been protected (underneath of course) I think i may put this one aside, put a nice chip amp in, hmm maybe even a tft display .... could be crazy...
For parts n stuff i must recommend a site for you
www.rockby.com.au cheap as sh*t. Thanks for your help, i still may look further into this amp. getting to late tonight...
Daniel
ps, what inspired u into old amps like this.. i was just really bored at the time and saw it sitting in the shed..
msn messenger priscared at hotmail .com
 
If there is no faceplate then the unit is already lost, go ahead and put in a chip amp, replace the faceplate with an LCD display, rip out the lovely speaker and inject some "kick-***" 12" woofers...

I'm sure the wooden cabinet will make a lovely reverb baffle for the sound you wish to reproduce.

I'm not being abusive to you personally, if I reacted to every person who would so viciously attack a piece of Australian history I wouldn't have anywhere to sit my cup of tea...

There are times when you come to the point of no return for these old sets and you just have to gut it and scrap what you don't need, If you believe that this is so, go right ahead, I'd love to hear from you after you've modernised a nice cabinet such as this, see what your opinions are about doing this to another set and such..

---- Second question ----

My inspiration for fiddling with the old-man's sets comes from the fact that I loved american radio shows as a young teenager, Repairing Australian vacuum tube radios only came naturally as I picked up the fascination with Science in general, from Physics to Theory and Radio Communications and my time spent with my father and his brother, as they re-constructed 1930's battery sets with original components.

The thing that wooed me further was when they setup a spark-gap transmitter.

Today, I service and operate fully-operational vacuum tube televisions and radios/radiograms, I watch Dr-Who every Moday at 6PM directly from Your ABC.

I should mention that Hollywood played a part in it, I love vintage Sci-Fi.

Cheers!
 
I'm not being abusive to you personally, if I reacted to every person who would so viciously attack a piece of Australian history I wouldn't have anywhere to sit my cup of tea...

There are times when you come to the point of no return for these old sets and you just have to gut it and scrap what you don't need, If you believe that this is so, go right ahead, I'd love to hear from you after you've modernised a nice cabinet such as this, see what your opinions are about doing this to another set and such..

---- Second question ----

My inspiration for fiddling with the old-man's sets comes from the fact that I loved american radio shows as a young teenager, Repairing Australian vacuum tube radios only came naturally as I picked up the fascination with Science in general, from Physics to Theory and Radio Communications and my time spent with my father and his brother, as they re-constructed 1930's battery sets with original components.

The thing that wooed me further was when they setup a spark-gap transmitter.

Today, I service and operate fully-operational vacuum tube televisions and radios/radiograms, I watch Dr-Who every Moday at 6PM directly from Your ABC.

I should mention that Hollywood played a part in it, I love vintage Sci-Fi.

Cheers!
 
yeah ill look into it tommorow

there may still be hope in this valve amp yet.... i will restore the cabinent first though..
dam those who invented thy digital amp... devalue my amplifers! So basically i will start with checking all the valves, seeing if i can get replacement capacitors, and rewiring it..... painfully and slowly.... better put the speaker back together...
Daniel
 
There are also options for the cabinet, you can use a belt sander and sand all of the original stain back and then stain and "shellac" it with new products..

It looks fantastic with a brand-new stain, but some will say that it also ruins any originality of the unit, You can beg to differ because you have to replace 100% of the capacitors in a radio anyway, but you're still using old vacuum tubes, so it's a personal preference thing..

You can also clean up the cuts and dints in the woodwork with imitation-wood filler, then gloss it, you get most of the original stain and woodwork from 60 years ago, but you also repair the woodwork.

My father prefers to sand old cabinets back fully then restain, I prefer to leave them as is and just clean them with a damp cloth...

Up to you bud! =D
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.