[morzh]

Tim,

sorry, I am not getting it. Is there someone to help you?

[tim1]

I forgot to ask what cartridge fits the TPA-1. I asked Gib at Westtech and he did not know because I want to get a extra good needle cartridge thanks.

[morzh]

It was "Philco Mono Astatic" 66-1 with Astatic "K" saphire or diamond needle, Philco Part ## for the cartridge and needle 325-8001 and 325-8002 respectively.

[morzh]

OK, I eventually took over that thing as even when Tim and I called each other on Skype it proved to be too much to do remotely.
It came in the mail today and in two hrs after that (well, about 1hr work) it sang just fine.

Then there were additional problem the last of which I just fixed.
Most problems initially occured due to the PCB being phenolic paper (FR2) and the traces on those do not adhere to the board well. So when a heavy part is soldered and then subjected to vibration the solder joint will unglue and then the trace will eventually snap and the solder joint will be separate from the trace.

So, in the order of having been discovered:

1. A black wire (-3V) came off. But that could be a result of troubleshooting.
2. A trasnsformer pin's solder joint got separated from the trace.
3. A large resistor 's pin did the same.
4. -3V pin (the one with the wire broken) did the same.
5. The electrolytic cap's minus pin did the same (could be the result of troubleshooting).

All was fixed by ceaning the soldermask off the traces and then flooding it with solder to join with the pin.
I also soldered over a couple of suspicious places.

6. Most wires coming to the board were on the verge of breaking off, so I cut them off, stripped and re-soldered.
7. So was one of the battery holder contacts, same thing done.

Others:

8. The speed pot did not regulate speed, it would be either maximum or none. Upon closer look the pot was exactly that - either close (in the max speed position) or fully open. Surprisingly, the opposite pin (unused to that point) behaved fine and smoothly regulated the resistance fro 0 to 100 Ohm as it should. This made me suspect the other pin separate from the resistive element.
I simply resoldered the wire to the unused pin, and now it regulates speed fine, only in the opposite direction from what"s written, "slow" is not fast and "fast" is slow.

9. The volume pot was scratchy, opened it, cleaned the element, put some deoxit in and a dab of deoxit plus lithium grease. Works fine now.

10. After I thought I was done a couple of times the motor barely moved and the amp buzzed unhappily. I suspected the power switch. I took off the disk, and it was very dirty and when pressed in a bit the symptom disappeared. Cleaned it with alcohol, then applied Deoxit; works fine now.

11. The last one, once in a while the volume disapeared, the amp only playing a little at the maximum volume. Looked at it, saw the quick connect tht goes to the adapter move a lot. First thought the whole pin moves but then realized that luckily it was just a quick connect - when touched, the symptom appeared or disapeared; so I took it off, compressed it a bit, pushed it on again. Plays fine now.

So if no other surprises show up, it is ready to ship back.

PS. I think the motor, from the way it looks (there are some thin wires separating together with someone'os hair.....) is on its last leg.

Tim,

I need you to get me a shipping label and for the box twice the size you used - I cannot risk sending it back in it. We got lucky once...the second time it might not work so well.

Whew!

   

[morzh]

Today saw something under the tonearm.....a bare wire from the crystal.

Someone added the push-ons in the past by soldering wires with pushon with the wires going to the amp and put some black tape over.
Well, I put an extra piece of black tape to keep teh bare piece from touching the tonearm (no damage but will cut the signal), plus compressed push-ons a it more.

Those should be different connectors, those made from very thin flexible berillium bronze plated with something, like the ones I have on my turntable...this is a makeshift.

But I got a bit scared to involve myself deeper with it, as it is so flimsy, and the old Russian adage says "do not disturb crap, it won't smell" and this is where I decided to limit myself. Schematics are one thing, fine wires and mechanics is another.
If handled properly this thing will work for years more.....


PS. Anyone has experience in shipping these? I mean, should I put some cushoning material between the lid and the turntable and so on? Thios got just fine to me without ANY cushoning whatsoever, but I want to thread on the side of caution.
And the PCB itself might develop new cracks so this is incentive enough for me to cushion it well afer all the wprk put in remedying the cracks in copper.

[morzh]

The last last thing....

The cartridge is NOT 66-1 or any ceramic 66xx (66-TY, looks the same as 66-1). Starting from the fact it is not aluminum but white plastic and the shape is totally different and the pins are arranged vertically one over another, not horizontally.
I guess this is also the reason they changed the wire clamps.
I have an itch to fix this but so far it's been a freeby and with this a cartridge is anywhere from 96 bucks at Turntableneedles.com to 35 bucks for two in this auction
http://www.ebay.com/itm/2-NOS-ASTATIC-66...5afabb96df

but ine is oxidized and the condithion, even if it is NOS, is unknown.



PS. Just thought of it....I have plenty of receptacle connectors contacts that crimp on the #28-30 wires and are in fact the same material and thickness (berillium copper and are even gold-plated) as the turntable head connectors that go onto the cartridge pins. Some might fit the pins of the adapter cartridge. If this works I will 1) try to fit the contacts 2) try to yank the wires, crimp the contacts on, 3) hopefully throw away that mess of push-ons that create problems, plus eliminate thet soldering mess and black tape. That would be a final touch on otherwise fully working TPA-1, short of buying a new needle or cartridge (which I leave to Tim to do as this might get a bit expensive).

[Ron Ramirez]

PS. Anyone has experience in shipping these? I mean, should I put some cushoning material between the lid and the turntable and so on?

Yes, definitely put some bubble wrap or foam between the lid and turntable. Try to arrange it so that the tone arm cannot move in shipment.

Place in a box large enough so that you can get at least two inches of your favorite packing material completely surrounding the TPA-1 (top, bottom, all sides).

Packing peanuts do work - if you use enough of them. The trick is to use so much that you have difficulty closing the box flaps.

Finally, do Tim a favor and send it back via FedEx Ground/Home Delivery. Don't use Parcel Select from the post office.

[morzh]

does Fedex come picking up packages from residences? - i do not have an account. And it goes on Tim's expence so how much more is it usually to Fedex vs mail?

PS. Unfortunately Fedex office is not local and the post office is. And I have no Fedex account so they need to weigh it etc ect. and it requires visit to the office. US Mail Will have to do this time.

[morzh]

Wow, talk about weather...I sent this thing last Wednesday morning, it just came recently today.
I guess this is where living in burbs has its disadvantages.

Tim says it plays OK, and I sent it by UPS.
So I guess it is about 90% packing and then 10% luck.(it was double-boxed).

[tim1]

I am trying to figure out how the on off switch stays in one position when it is on or off. I know a thin wire goes through a hole in the lever under the turntable which touches 2 contacks but since the wire was broken ofnder there but is it a small spring that should be on the piece of wire thankst connects to on the other end. I can't tell what i

[morzh]

Tim

As I explained it to you yesterday:

1. There is no spring on the wire. The wire IS the spring.
2. The wire is made from stainless steel and it is thin. It looks like a guitar string, the one used for the upper "E" string.
3. The wire always arches and thus pushes on the roller which IS the closing contact for the power switch, which in turn is formed by two spring leaf contacts and the roller.
4. The roller goes in between the two spring leaf contacts that are the middle point of the 4 batteries and are normally open (the roller is NOT pushed between them). The roller, when pushed between them, shorts them together applying the power to the whole player.
5. The steel wire and the roller create a bi-stable (flip-flop-like) structure: as the wire arches it is constantly pushing the roller and the roller thus remains in one of its two stable positions: one is "Switch Open" and another is "Switch Closed".
6. A lever coupled with the tone arm pushes the roller in between the two positions and the wire simply pushes to keep it in the positions once it reaches them.

This is it.

[tim1]

I had a machine shop person come over and he told me just what I thought. The wire can not flop the other way when there is a curve in the wire. He put the end of the wire through the hole in the pivoting piece that contacks the 2 contacks when it is moved one way and he wrapped the other end of the wire around the head of a rivot which sticks up slightly and that did not work. Does any one have a picture of the switch area so I can show him thanks.

[morzh]

Tim

I do not clearly remember if the wire actually changes the arch direction when it flip-flops but it does not have to as long as the roller is at the end positions. The arch provides pressure, with no arch there is no pressure.


Does someone have a phonograph with a similar power switch (controlled by the tone arm - when you move tonearm away from the disk it starts and when it reaches the center it stops).

[PhilcoFordTesla]

enjoying this thread, just learned my first childhood amp is in these things and waiting for my new ebay TPA-1 in the mail!  hope they packed it right, already got a tracking #  Thx for having the schematic!!!

-Bob

[morzh]

TPA appeared on eBay? Cool.
Good for you I didn't know

It has been over 5-1/2 years, wow...