Sony TC500a Teardown questions!

Discussion in 'Tube Audio' started by nick parkin, Jan 8, 2019.

  1. FlaCharlie

    FlaCharlie AK Subscriber Subscriber

    Messages:
    847
    Location:
    Gainesville, FL
    Well, if you want to buy a ready made chassis, Hammond now sells them with walnut options.

    https://www.hammfg.com/electronics/small-case/chassis

    https://www.digikey.com/products/en?keywords=HWCHAS1310AL

    Not exactly cheap at $78 but looks quite nice. Here's the bottom plate, which is sold separately: https://www.digikey.com/products/en?keywords=HW1310ALPL

    Here's a thread I posted a while back explaining how to get free shipping from Digi-Key:
    http://www.audiokarma.org/forums/in...hipping-on-parts-orders.739513/#post-10018562
     

     

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  2. nick parkin

    nick parkin AK Subscriber Subscriber

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    I appreciate the links and advice. I just ordered a step down transformer to reduce my 124 volts mains to 110-115 ish volts and shipping was $6, and I forgot to order a few small parts as well. As for the chassis, I made a cad mode layout and eyeball edits and inches, and a length of 12 inches. I can buy a 1/8” thick 7”x12” aluminum plate for $6.99 each! All I have to do is go the local woodshopvsnf buy a plank of my favorite woof and I’ll be all set. I’d like to do ,y own finger joints and everything.
     
  3. gadget73

    gadget73 junk junkie Subscriber

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    lay the parts out on a cardboard sheet with your chassis size marked on it to see if it makes sense first. Something I can tell you from experience is that working inside an overly cramped chassis is a PITA.

    If you're doing the finger jointed box and top plate method, maybe consider making the top plate captive. Basically you'd need to cut a groove into all four pieces wide enough for the plate to sit in. Assemble the box 3 sided, slide the plate in, then install the last piece of wood to secure it. JMO but I think it would look nicer than a box with a plate screwed to the top of it.
     
  4. nick parkin

    nick parkin AK Subscriber Subscriber

    Messages:
    436
    I will definitely do a three sided box for making the amp. Ive already tried building the amp in my other single ended chassis that is 4" wide and 10" long, and it is just enough size for the circuit, however with the new output transformers and power trannys, it needs a little more width so I think 7" should be plenty, plus the extra length. My goal is to make a neat, organized looking circuit. Do you have any insights as to the placement of the chokes and output transformers? Do I need to mount them off axis to each other so the magnetic fields do not interfere?
     
  5. 6DZ7

    6DZ7 Super Member

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    Think outside the amp box. You'll have more fun with more room. Good luck with your project.
     
    Last edited: Jan 12, 2019
  6. gadget73

    gadget73 junk junkie Subscriber

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    Location:
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    I meant do it as a 4 sided box, but put the metal plate in before the last side goes on so it won't come out. You'd have to use a table saw and cut a slot in the four pieces to give the top plate somewhere to go, and it can't be so close to the top that the upper "lip" won't support itself.

    Power supply should generally be as far from the signal stuff as possible. Choke and PT should be at 90 degrees to one another, and if possible also 90 to the output transformers. The OPT can be in the same plane though.

    I have an amp that is basically 6x14 and its honestly a pretty miserable thing to work inside of. I've got other amps that are just barely big enough to fit all their parts, and they all suck to work on in their own way. Don't crowd yourself if you don't have to. The bottom starts closing in pretty fast once parts go in.
     

     

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  7. nick parkin

    nick parkin AK Subscriber Subscriber

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    yes they do I already started building the RH84 on my chassis from my other amp and it was 1.5" deep and 10" x 4" footprint and it is just wayy too small. Maybe with the original power transformers and output trannys it would work, but it definitely won't work with the new trannys as they are all much bigger. The nice thing about starting from scratch is I don't have to be a salve to the original layout and the layout im planning on doing is designed in a way to minimize the distance between all the parts on the circuit. ie, the rectifier is next to the power tranny, the output terminals are next to the output transformers etc....

    As for the groove and sliding in the metal plate, id rather not do that as I don't have anything to cut the groove with. I was going to do the finger joints by hand with a chisel and use a drill bit as wide as each grove to drill a hole and remove some material first.
     
  8. 6DZ7

    6DZ7 Super Member

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    I love the smell of burning insulation, in the morning.... It's easier to pass a camel through spaghetti than a hot soldering tip...
     
    Last edited: Jan 12, 2019
  9. nick parkin

    nick parkin AK Subscriber Subscriber

    Messages:
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    AFE31A8B-3201-4E41-8B37-53C0F114C7FF.jpeg I cut up the rear I/O plastic panel and made some nifty little labels for my speaker outputs and aux inputs. I need to find another TC500a I/O panel to get a second “speaker out” label.
     
  10. FlaCharlie

    FlaCharlie AK Subscriber Subscriber

    Messages:
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    Location:
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    Perhaps you can find someone who is parting out a TC500a but it may take you a while to find one. But, usually, when I see stuff on eBay being parted out the parts are extremely overpriced.

    Another option is a trophy shop which routinely makes plaques and similar on a variety of materials. Places that make banners and signs might also be a good source. There is a couple near me that work out of a flea market who make signs and banners. I asked them once and they said they can print anything I'd like on thin material that I could then fasten to an amp.
     
  11. Lou F Quincy

    Lou F Quincy New Member

    Messages:
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    Location:
    Pacific Northwest
    Very interesting information. I have a working TC-500 that I am probably not going to modify with any deep changes but I am intrigued by the projects of others. I wouldn't have thunk that the speakers would be worth anything to anybody except a restorer, and though mine sound ok in nearfield play, my curiosity will wire in some other speaker options.

    Here's an idea for an amp box . . . thrift stores often have old lidded wooden silverware cases that are in great shape and can be easily modified and gutted.
     

     

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  12. nick parkin

    nick parkin AK Subscriber Subscriber

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    I caved in and bought myself a $89 Ryobi Miter saw and I made a nice little box out of maple. Now I have my top plate with all the holes drilled out and I will post a picture of it later.

    I also went and purchased another TC500a up in Wisconsin.

    This one has an even nicer set of output transformers. Cosmetically, the first pair looked mediocre. These newer ones look great. Unfortunately, for the coral holey baskets, one speaker had a replacement speaker, and the other had a coral, but someone took it out and covered the surround and half the cone in hot glue!

    I also got another IO board so I can make the second speaker out decal.
     
  13. FlaCharlie

    FlaCharlie AK Subscriber Subscriber

    Messages:
    847
    Location:
    Gainesville, FL
    Seems like you're making good progress. Since you're concerned about the cosmetics of the OTs I assume you're mounting them topside instead of under the chassis like the amp on the Glow in the Dark site. I've had good results from painting the metal frames on a couple.

    Yeah, I'm all about scrounging and repurposing.

    You can also put OTs under some kind of cover. Small metal cans from the grocery store can be used for this. Although I haven't gotten around to using them yet, I took some small rectangular (forget the brand) International Coffee containers and painted them satin black and they look really nice. Also the small metal cans that almonds are sold in can be used if the OTs will fit underneath.
     
  14. Lou F Quincy

    Lou F Quincy New Member

    Messages:
    17
    Location:
    Pacific Northwest
    Thanks for the heads up to Glow In The Dark. Fascinating info about the Coral Holey Basket speakers. I've had a pair of
    Dayton Audio PS95-8 3-1/2" Point Source Full Range Drivers - 8 Ohm gathering dust, and I was thinking of swapping them, but they are only about 85 in efficiency.
    Admittedly, my sole R2R tape "Foxy Lady" by Cher is not worthy of critical listening but the RCA LINE INPUTs do allow me to find better music source material.
    The LINE OUTPUTS going to a Carver MXR130 gives a bit more shimmer to some desktops (Solid) through the TC-500 but I'm afraid to run it without having the Holey Baskets hooked up for amp load, so all four speakers going . Is that a justifiable fear?
    I think my next project may be a set of open baffle speakers.

    Whatever happens, this is a fun new toy.

    Good on you Nick for making your own box. Most rewarding option.
     
  15. nick parkin

    nick parkin AK Subscriber Subscriber

    Messages:
    436

    It’s not an incredible box but it is MY box that I spent time making and there’s noithing more rewarding than that.

    As for cosmetics, the Output transformers will be mounted on the inside. Here are some photos

    B2E8BFA7-B71F-45A3-84E9-446EA3E3DF6E.jpeg 25805E38-5801-4272-B5B4-D439CA69C67F.jpeg
    I decided to mount the ugly looking transformers in this amp F8202018-AE2C-4AE9-BD09-F5C76500FE44.jpeg
     
  16. Lou F Quincy

    Lou F Quincy New Member

    Messages:
    17
    Location:
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    Not sure of the dimensions of your transformers but . . .

    Spam cans are 3.25" x 4" x 2.2".

    [​IMG]

    Classy !
     

     

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  17. FlaCharlie

    FlaCharlie AK Subscriber Subscriber

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    847
    Location:
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    Yeah, but you need to eat the spam first. The "nutrition" label is pretty scary. Maybe if you have a dog . . .
     
  18. gadget73

    gadget73 junk junkie Subscriber

    Messages:
    38,130
    Location:
    Southern NJ
    what, not a fan of salted fat in the form of pink "meat" ? :)
     
  19. HowardK

    HowardK AK Subscriber Subscriber

    Messages:
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    I had fried Spam and Mayo sandwich for lunch today and picked up a TC-500a today! I decided to hook it up to my main system (99db speakers) instead of the little dinky holey basket. And all I can say is WOW!!!
     
  20. Lou F Quincy

    Lou F Quincy New Member

    Messages:
    17
    Location:
    Pacific Northwest
    " ... all I can say is WOW!!! " HowardK

    The Glorious Spam sandwich or the satisfying sound?

    Congrats on the TC-500a find. They're fine units. What speakers did you use and how did you wire them?
     
    Last edited: Feb 22, 2019

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