Good to hear progress. Although there is a view, especially in the UK, that one should try and retain as many original caps as possible, I think that often just delays repairs. I once had a Heathkit power amp that only worked when I finally replaced the last remaining cap, which was a silver mica one.
 
Good to hear progress. Although there is a view, especially in the UK, that one should try and retain as many original caps as possible, I think that often just delays repairs. I once had a Heathkit power amp that only worked when I finally replaced the last remaining cap, which was a silver mica one.
Well i did have the option to keep the look of the caps but i realised that the amplifier would be sitting in the cabinet anyway. No real need for it too keep its look. TBH i think the amplifier needed modernising but in a good way. At least i will feel confident in it once its all complete and may play about with tonearms and cartridges/turntables etc. I may also add some small old goodmans/altec HF compression horns if i can figure where to get the horns! so much to do...
 
Your horn drivers can come from scrapped American Console radiograms. There are several members with excess stock here.
 
Your horn drivers can come from scrapped American Console radiograms. There are several members with excess stock here.
Thanks Pio1980, but remember I am in UK. The drivers are also not the norm. These i have are the pre trebax driver.
 

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Are the innards replaceable by spares, as in JBL, Altec, and others?
Not sure, I have not opened them up as I did not manage to find any info on them. Also I thought they may have parts with springs etc...they look like early trebax but slightly different in the outer housing though it maybe cosmetic. I had one Goodman's in a box and weirdly just found another although different in paint and label is an alternative ling altec version which is exactly the same and in the same box which is very rare...not sure how to attach a horn at the moment even if I knew what horn to use...
 
Horn drivers tend to be pretty simplistic inside. Basically a magnet and a diaphragm, maybe a piece of foam. Loosen the screws and you'll feel if there is a spring or anything likely to launch out of there. Just be careful with it. I have repaired horn drivers in the past, sometimes the fine magnet wire breaks somewhere that you can very carefully re-attach it. Its not easy, basically like soldering human hair back together, but it can be done.

My thinking was this: the part doesn't work now, whats the worst that can happen?
 
Horn drivers tend to be pretty simplistic inside. Basically a magnet and a diaphragm, maybe a piece of foam. Loosen the screws and you'll feel if there is a spring or anything likely to launch out of there. Just be careful with it. I have repaired horn drivers in the past, sometimes the fine magnet wire breaks somewhere that you can very carefully re-attach it. Its not easy, basically like soldering human hair back together, but it can be done.

My thinking was this: the part doesn't work now, whats the worst that can happen?
 
No I think it works but as I have no horn mouth that would fit. I am receiving the other altec driver in the next few days so may do a side by side examination.

I still have to wire tonearm, get armboard made, get cartridge etc.

Would like to tackle it soon though as like to know what I have in terms of audio etc.

Many thanks for the motivation
 
ah, ok. Misunderstood the issue. If it works, leave it be. If you end up with a horn that isn't a direct fit you can probably have an adapter made to marry the driver up.
 
So glad you have a good tech., he seems very knowledgeable about circuits, which is what you need for this type project. Best of luck to you and him, and keep us updated.
 
So glad you have a good tech., he seems very knowledgeable about circuits, which is what you need for this type project. Best of luck to you and him, and keep us updated.
Thanks a lot . Yes Andy the Tech has been brought up building and constructing valve gear since he was a kid. We have made lots of progress and we are nearing the final checking of the AM Amplifier. As I hear from Andy very soon it will be put back into the cabinet then hope we will reset the radio wiring and a bit of soldering. For vinyl playback I decided to put a DGI 78rpm turntable with ortofon S212 Tonearm and Ortofon Type A meister for true mono playback. I am still working on the little baby cabinet for modern music (mono/stereo) as I need a new Tonearm so that will have to wait a little longer.

I must admit I am very appreciative of posting a thread on the audiokarma site and having such great advice and knowledge by all here and will do a video and take some final pics in the coming weeks.
 

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Yeh, I carried my Dad's tube caddies around when I was just a little guy, but he was 95% TV repair. He worked for Magnavox so we did get a console to fix every now and then, but people didn't even buy matched output tubes. If one was bad, that's what they bought, and if he tried to tell them different they'd think he was trying to get in their pockets, ha. Those cabinets are beautiful man! So good to see this is getting the love it deserves and not getting snowed on in a landfill like so many.:(
 
Yeh, I carried my Dad's tube caddies around when I was just a little guy, but he was 95% TV repair. He worked for Magnavox so we did get a console to fix every now and then, but people didn't even buy matched output tubes. If one was bad, that's what they bought, and if he tried to tell them different they'd think he was trying to get in their pockets, ha. Those cabinets are beautiful man! So good to see this is getting the love it deserves and not getting snowed on in a landfill like so many.:(
Ahh, good old days and many good stories...maybe we should start a post here called "when I was little" lol.
 
I did a lot of caddy searching, and may have had some sections of a few of the tube substitution manuals memorized. Instead of going fishing together, my Dad and I ran service calls and picked up sets that had to come into the shop. We did antenna towers together too, and I always got the crummy jobs like running lead in wire through crawl spaces, and putting the 10 foot masts in the top of the towers. It was really fun though, I guess because I was doing it with my Dad. I just wish I'd paid more attention, but when he'd start looking at a schematic, I'd get bored pretty fast. One thing that still haunts me is when he got out of the business he offered me his stock, scopes, jigs, everything, and I turned it all down. Man, to have just his junk set parts pile would be crazy today, arghhhh. Oh, I do have a couple of his old Simpson 260s, one of which has the roll top case, mirrored scale, and little white reset button. I still use that one to read "run through" Ma in conjunction with a variac on new power supplies. Something about watching that needle is easier when you have 4 or 5 things you are trying to monitor at the same time.
 
I did a lot of caddy searching, and may have had some sections of a few of the tube substitution manuals memorized. Instead of going fishing together, my Dad and I ran service calls and picked up sets that had to come into the shop. We did antenna towers together too, and I always got the crummy jobs like running lead in wire through crawl spaces, and putting the 10 foot masts in the top of the towers. It was really fun though, I guess because I was doing it with my Dad. I just wish I'd paid more attention, but when he'd start looking at a schematic, I'd get bored pretty fast. One thing that still haunts me is when he got out of the business he offered me his stock, scopes, jigs, everything, and I turned it all down. Man, to have just his junk set parts pile would be crazy today, arghhhh. Oh, I do have a couple of his old Simpson 260s, one of which has the roll top case, mirrored scale, and little white reset button. I still use that one to read "run through" Ma in conjunction with a variac on new power supplies. Something about watching that needle is easier when you have 4 or 5 things you are trying to monitor at the same time.

I can imagine what stories we all have to tell or remember for that...

For me the golden age of music was from 1955 to 1965. I prefer listening to unusual and early recordings plus my two little toddlers love to boogie to the beat! with 45s so its nice to keep alive someones life passion that creates from the heart. Its important to keep these amazing designs before they are no more. Its been a really great learning experience understanding and studying vintage gear and music of the era! and obviously always learning and its enjoyable too.

Also the good thing regarding hi fi is that there is so much to learn with different opinions on nearly everything audio! I recently spoke to a friend and mentioned i did not think tonearms should have antiskating / balancing as they did not help and he started to mention centripetal force etc, even looking at the audio karma thread had so so many different opinions it was an excellent read. I still have my opinion though but like i say it all depends on the type of records or music you play and how you like to listen to it. For me its true mono.
 
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As you all are aware its been over 4 months now so when the tech guy arrived i was very excited to have it back. I made a cup of tea for my guest and myself and we set about installing the amplifier into the radiogram which in truth is extremely easy. Plugged the inputs then set about trying to setup the radio winding strings which were not at all very easy to do i may say. Many many tries and probably an hour or so later I finally figured it out and the volume and radio was now set. Stage two was to finally see if we could hear anything or hope the amplifier did not blow up!. Luckily it turned on and the valves began to glow giving a warm humming. It felt good to see it all with correct valves in order even though there were still two missing on the pre-am amplifier which i would still like to get to the bottom of (maybe another thread). I was told they weren't important or not in use and as the amplifier worked there was no reason to worry about.

So, the amplifier started and we set the dial to radio and heard lots of hissing, crackling and humming - good and bad! good that it was working but bad as we could not get great reception and there was evident distortion and disturbance coming from the both the 12" Goodmans and 6" Whitley Stentorian. Quite a lot of hiss from the smaller and i was starting to worry. We added a temp radio antenna and plugged in the FM aerial - things improved but still not great - still at least it was sort of working. Stage 3, checking the radiogram. Well we tried! The thing with this radiogram was the creator of the amplifier and cabinet created most of the inputs into the cabinet than the amplifier. So we have lots of wiring, and i mean lots. Wiring to and from everything and everywhere so things were quite confusing. The turntable was connected but no sound or power, also the tonearm had no audio. By this time it was 3 hours in and the tech guy had to leave.

The next day i switched on and tried to listen and observe the amplifier. This was very interesting...firstly the humming was excessive so i listened very carefully and touched the first power valve and the humming reduced quite a lot. I then began to systematically remove each valve then turn on to see if the noises or hums vanished - well to say i was annoyed, well i was. I removed the first valve and could hear rattling from the valve, and rattling also from a number of the valves plus loose bases. After removing the smaller output valves (which run the smaller speaker) also made a big difference. Luckily i had a spare pair of KT66 which could be used as a test and so i installed them and turned on again - better and less hum. A sigh of relief and time for a cup of tea later i was starting to get a clearer picture.

Also i had another tech guy come over and we noticed an output that wasn't earthed and so when that was done it seemed to help greatly. There are still some issues but i am getting there. Changing some valves, switch cleaning the rotary control that got jammed, adding the turntable and getting it to work and rewiring some power cables and speaker wiring that is a little too brittle. I would love to re-wire the whole cabinet but for now i would prefer to take everything slowly as most tech guys work very slowly and i do not want to send it out for more months.

i was hoping to have a conclusion for you all (and myself) but it seems that there is always something more to do! lol! The good the bad and the ugly!@@@@@

Here are some pics of the amplifier in use....


To be continued...
 

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Interesting that it has open sockets. Are they wired up underneath? Just wondering if maybe they were used to supply power to some other component that is either no longer present, or that the original builder planned to add but never did. Thats a lot of the trouble with custom homebrew gear, if you don't have the builder's documentation or the builder to ask questions of, you sort of have to reverse engineer it and figure out what you have. Some people enjoy the technical challenge of that (I do anyway) but its very time consuming.


If the amplifier works, it sounds like there are issues remaining on the tuner.
 
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