LeroyPatrol (29-07-20),OSIRUS (05-07-20)
I get a lot of 70's audio gear in on my workbench for repair, so I thought I'd just share some images for those who appreciate how this stuff was made back then.
Anyone else feel free to add to this thread with any pics of old stuff they get to fix ~ I'm sure more than myself will enjoy the view.
Unit: Sanyo DCX-6000K. AM/FM Stereo Receiver (1973-75)
Customer complaint: buzzing/humming on phono inputs
Diagnosis: 50year old Sanwa electrolytic caps have had enough
Repair: full re-cap of unit
RIAA pre-amp board being reworked
They don't make JP->AU mains adapters like this anymore =)
LeroyPatrol (29-07-20),OSIRUS (05-07-20)
Look Here -> |
I've still got a couple of these relics around the place, one in my men's den and one in my work shed. The one in the work shed, needs a bit of work to get it going again, but the other ones is working fine. Can't recall exactly what they are at the moment, one, IIRC is a Pioneer (model number can't remember) and the other, I think, is a Kenwood.
I'm out of my mind, but feel free to leave a message...
OK but only because you told me to
So I started digging and found my old Braun CSV500 covered in a metre of dust.
It is from 1967/68 but I 'bought' it late 70's or early 80's. When I say 'bought' I usually bartered things or more often for my tech services, like I build you a couple of cool speaker cabinets and you give me that old broken Braun amp
I never acquired this kind of stuff in a working condition as that would not excite me very much nor would I have had the glowing experience of a bargain.
Many years ago but in this Millenium I saw it on Ebay for almost 2 grand but in an immaculate condition.
This was my main HiFi amp for the entire 80's until I got my grubby hands on a Yamaha but I also had a HiFi valve amp running parallel with it. I always has some kind of emulated surround system.
The valve amp was lent to me for many years but the owner eventually did want it back. The Braun had a lot of grunt and was very bass heavy as well as it's physical weight of 13kg,
which felt more like 20kg every time I had to move or lift it in the tight spot on the shelves as the fiddly DIN input sockets were UNDER the amp !
I haven't dared to switch it on yet, will only do so with a variac, many caps would be obviously toast but I got to make some space and SWMBO already gave it "The Look of Disapproval".
Enjoy the guts, I am not resizing this, it is too beautiful :
Braun was very advanced back then and already implemented Module technology using Valve sockets :
The module I pulled out is a microphone pre-amp.
You can see a module I built myself, it is the phono pre-amp.
Last edited by Uncle Fester; 03-07-20 at 08:18 PM.
Update: A deletion of features that work well and ain't broke but are deemed outdated in order to add things that are up to date and broken.
Compatibility: A word soon to be deleted from our dictionaries as it is outdated.
Humans: Entities that are not only outdated but broken... AI-self-learning-update-error...terminate...terminate...
gulliver (04-07-20),Johnno (04-07-20),mitaux8030 (05-07-20),OSIRUS (05-07-20),wotnot (03-07-20)
Nice... right on the cusp of the thermionic valve being deprecated by the transistor age, gorgeous printed wire lines, real artwork.Braun was very advanced back then and already implemented Module technology using Valve sockets :
I've got one of these that I need to get stuck into and refurbish. Pioneer SM-Q300 valve receiver/amplifier. I don't have any decent pics of it, but here's a link to my post about it on another forum.
here's a couple of examples from the WWW
Johnno (04-07-20),Uncle Fester (04-07-20),wotnot (04-07-20)
That's very cool, gotta love the rear panel marking & open chassis =) Can you still get valves & HV caps for it? Last time I looked they were getting very thin on the ground (but I'll bet there's chinese knockoff these days B^)
This unit is also in need of a refurbish, but I won't get to it and probably sell it this year or such as 'last seen working good 25years ago, will require servicing before use' or similar. I've said that before, and what puts me off selling it, is primarily the weight of the thing.
Twenty two & a half kilos of 4track reel-to-reel tape deck....sans any reels or tape, and the AC power cord is MIA...dust cover is still with it. Last time I saw it working, and this was early/mid 90's, was at a mate's place (guitarist) who had it setup with another deck (a Sanyo iirc) to create a long delay tape loop a_la Robert Fripp/Frippertronics ..owner moved onto digital, and somehow lost the reels in a house move.
bob_m_54 (05-07-20),Johnno (04-07-20),mtv (04-07-20),OSIRUS (05-07-20),RFI-EMI-GUY (28-07-20),Uncle Fester (04-07-20)
Wow... Very nice gear guys... I don't have anything that old now-a-days. Sold my old reel-to-reel to a collector many years ago.
My first wife gave me that look also, sell them or there going in the bin kinda look.. I sold them and a few years later I pissed her off to.. LOL
I really like that 4 track tape wotnot.. Wish I kept mine now. Good stuff guys.
wotnot (05-07-20)
Yep, carried that machine around quite few times. The band bought the 3340 second hand around 1980 but it was in my practice room where I also lived back then in a really old large warehouse next to a train station, actually between the tracks.
So it was considered mine, nobody else knew what to do with it and I did our old demo tapes using simul synch in stereo ping pong with it and some other projects. The built in 'mixer' was super practical for this.
The 3340 was sold and I got my own Tascam:
A few decades later, it took me ages to find a pinch roller for it and works now fine. Image made today currently playing a demo tape done with the 3340:
That golden thing on the right, Echolette M40 is probably more interesting.
I have no clue if it still works, so that could a be later project, there is other stuff more 'urgent'.
It has 4x EL84 valves and heaps of ECC83 for the input stages. Could be as old as 1959 with the DIN inputs. Allegedly the Beatles used these at some stage.
It is a 4 channel PA for voice but you can get a clean Fender like guitar sound out of it too.
Fully 'clipping' it in the power stage with the right speaker cabinet gives you a bit of VOX AC30 sound which is what Brain May does with his 3 or 4 AC30s. This makes a hell of a noise and I don't live in a warehouse anymore. Would need to make a power soak or something.
I might try to rewire the preamp stages in series one day but the ECC83 overdrive is not the same as the pentode overdrive in the power stage and for some reason I didn't like triode overdrive using pedal boosters. You can't get a good sounding preamp overdrive with the classic Fenders either, so I assume a similar circuit being used.
Last edited by Uncle Fester; 04-07-20 at 10:35 PM.
Update: A deletion of features that work well and ain't broke but are deemed outdated in order to add things that are up to date and broken.
Compatibility: A word soon to be deleted from our dictionaries as it is outdated.
Humans: Entities that are not only outdated but broken... AI-self-learning-update-error...terminate...terminate...
I still have a Tascam 34 and a Teac Tascam Series 32-2B.
Good to see others keeping these alive.
wotnot (05-07-20)
@Wotnot, yeah I have about 3/4 of a set of spare valves for it, and there are still a lot of guys trading valves on websites like Stereonet Australia. Caps.. I'll cross that bridge when I come to it.
Love the R2R recorders you guys have. I had a TEAC unknown model number now, gave it to my little brother in 1974. It got stolen a couple of years later though. I have a Akai GX-210D here, also needs a refurbish and fault repair (someone let the smoke out). And yes, pinch rollers would be really hard to find these days too.
Every so often a Reel 2 Reel pops up on Gumtree, but people are asking insane prices for them.
wotnot (05-07-20)
Talking of 'Relic' things,
I have just decided to get the old C64 and its monitor and some cartridge games to sell on Gumtree or eBay.
What has amazed me, is that after 25yrs in storage it all worked first time i plugged it all up!!
So how come something close to 40yrs old can still work fine after all this time..?
"Don't build 'em like they used to...!!"
I watch this guy on Youtube - Mr Carlson's Lab - pretty much a genius and explains things really simple, for people like me, lol!
All good fun guys. Stay safe
GT250.
bob_m_54 (12-07-20)
A bit of reference from the good old days when Electronics and production still mattered in Australia, now sadly just a relic:
All fully readable.
Way back before my time but the early Radio Shack catalogues are also fun to browse through:
I never liked Tandy very much. I only got this around 1983 as payment for fixing a couple of TVs in a second hand shop but when you compare to what they had in their 1939 catalogue, it is a bit of a joke but an odd kind of thing the way it works and I suppose now a relic:
Edit: Wonder when somebody comes around here with their TRS-80
Last edited by Uncle Fester; 13-07-20 at 04:40 PM.
Update: A deletion of features that work well and ain't broke but are deemed outdated in order to add things that are up to date and broken.
Compatibility: A word soon to be deleted from our dictionaries as it is outdated.
Humans: Entities that are not only outdated but broken... AI-self-learning-update-error...terminate...terminate...
Johnno (14-07-20),mtv (13-07-20),VroomVroom (14-07-20),wotnot (13-07-20)
I did "inherit" a few boxes of old electronics magazines from the 70s and 80s from a friend who recently passed away. I gave them to my brother in law for his birthday!
I'm out of my mind, but feel free to leave a message...
This should make for an interesting rework ;
Bulk-caps were shot, this was as close as I could get for replacement, and of course the new caps aren't going to physically fit (snap-in pin pitch is correct)
Going to need move a bunch of things to the bottomside of PCB, to create some room.... fun fun fun...
edit: nope, not enough room for both caps side by side.... rethink...
Last edited by wotnot; 28-07-20 at 04:13 PM.
Odd, generally caps today are much smaller and less fat than back then.
On the Braun amp shown above, I replaced the main supply filter cap 5000µF 70V with a cap from Jaycar 8000µF 80V and it is quite smaller in diameter, but longer but that is rarely a problem. Only issue is the original had a thick mounting bolt on the top while Jaycar's has a strapped around mount, so a bit messy, not hard to do just doesn't look as nice as original so I will sustain from posting an image .
Changed a lot of other caps as well of course.
In general the issues with older caps are not always loss of capacity or ESR (which was often piss weak in those days anyhow) but high voltage (DC) leakage.
So the only way to test them is solder out one side and connect them to a lab supply with sensitive amp meter at the max DC rating - 5%. After a minute the leakage from a 500µF should be less than 100µA. It usually improves after a long time out of service.
Why this effort?
With this (non Asian) vintage stuff, it is desirable the keep the original state and many of the larger and very visible old German caps still performed well under these test conditions, below 10µA leakage, so I could avoid humiliating it with too many Chinese parts. Mostly only the tiny ones where faulty and the large filter cap is nested so well away you would have to remove it out of it's mount to see that it has Suntan written on it.
So all up I am happy with the result and it performs outstanding, background hiss almost non existent on phono with both pre gain and volume at max.
The loudness control is insane, the volume pot has 6 taps for that(3 for each channel), meaning my records sound fantastic at any volume. With my Yamaha amp from 2005 they only sound good at window shattering volume.
I don't get it, what's the deal that modern amps don't have adjustable loudness control anymore?
Last edited by Uncle Fester; 28-07-20 at 06:06 PM.
Update: A deletion of features that work well and ain't broke but are deemed outdated in order to add things that are up to date and broken.
Compatibility: A word soon to be deleted from our dictionaries as it is outdated.
Humans: Entities that are not only outdated but broken... AI-self-learning-update-error...terminate...terminate...
I have a bucket load of Caps, all sorts... New/Old Stock, Probably another 20 containers like these below.. Maybe I have something that will fit.. Let me know
Last edited by Johnno; 28-07-20 at 10:35 PM.
Uncle Fester (29-07-20),wotnot (29-07-20)
Thanks Jonno for the offer but I have bucket loads of those types too and the ones I used look just like them.
The main power filter cap I swapped would be 2-3 decades older, very different style and without the bolt the mount looks like an eye sore, this is not on a PCB.
The main reason I swapped it was that we have here in OZ wonky mains voltages up to 265V. This amp was designed back then for 220V, so even if I could source the original German Frako cap, it would be questionable to use in Australia, and a higher voltage rating of that original type would have certainly physically not fit.
As I don't intend to sell it it is not that critical to preserve originality.
Last edited by Uncle Fester; 29-07-20 at 12:49 PM.
Update: A deletion of features that work well and ain't broke but are deemed outdated in order to add things that are up to date and broken.
Compatibility: A word soon to be deleted from our dictionaries as it is outdated.
Humans: Entities that are not only outdated but broken... AI-self-learning-update-error...terminate...terminate...
Johnno (29-07-20)
Ditto, appreciate the offer, but that board I'm working isn't really 'relic' age (although nearly 20yo), and because it's out of CN, the cap sizing is non-standard-dimensions measured in whitworth or something ..haha, and 'closest match' pitches you at $14 Elna's, and 'cost effectiveness' results in me buying the caps pictured...which are genuine KEMET out of EU...still a very decent cap, but short&obese, not tall&slender.
I can actually get them, out of CN ... 8200uF/50VDC in the required matched sizing...and I can get 2 of them for the cost of one Kemet, so you can guess how good they're NOT going to be (just as good as the swelled ones you're replacing), -and- the thing has to be fixed & gone in time for someone's birthday, so the pressure's on! Current global situation being what it is, time from CN to AU is out to lunch, twice (once leaving/once again arriving), and I don't have the time to wait..stuck between rock & a tight place, you buy what's available, and adapt, to achieve cost effective repair - it is what it is these days.
The 'thing' that it is, is here --> ...m'kay? This is one of those oh so often cases, where you're putting in quality components, that the unit doesn't 'deserve', because it's of so low quality throughout it's entire construction.
With equipment of engineering quality that reflects in pictures here-above, IMHO you're drawn and held to the constraint of (at least) replacing the worn components, with that of equal quality ... and -that- means, if the capacitor you're replacing has lasted 'x' decades in service before failure, you replace them with types that can return the same time in duty...so with 70's era stuff, you're looking at 40+ years endurance, with the typical usage the unit has been subject to over that time.
That means the Sanyo unit at the beginning of this thread, only gets some of the best - Nichicon, Panasonic, Rubycon will be all part of that refurb .... you go to Jaycar (when you can) for 'junk' equipment repairs =)
I think if I put the greencaps and perhaps 2 of the rectifier diodes bottomside of board, I can redrill the thru-holes of one/both caps to fit them into the increased area
Last edited by wotnot; 29-07-20 at 02:51 PM.
Johnno (29-07-20)
My vintage Altec Lansing speakers. Not something you see everyday.
Johnno (01-08-20),lsemmens (01-08-20),Uncle Fester (01-08-20),wotnot (01-08-20)
Update: A deletion of features that work well and ain't broke but are deemed outdated in order to add things that are up to date and broken.
Compatibility: A word soon to be deleted from our dictionaries as it is outdated.
Humans: Entities that are not only outdated but broken... AI-self-learning-update-error...terminate...terminate...
Johnno (01-08-20)
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