While my SET amp sleeps, the ST70 comes to life!

[wiredbecker]

My daughter and design consultant are making noises about hitting Ikea for furniture for the new house--assuming it ever gets started. I might hitch a ride. What about Foothill's flea market?

I haven't been to Foothill's flea market yet..

The Laney College flea market is only open on Sundays these days. It takes a good hour to get through the whole thing. About the only Saturday flea market that I go to with any frequency is the Ashby Flea Market that is conveniently located at the Ashby BART stop on the Richmond line. It makes sense to drive because you never know what you'll find... Fortunately Ashby is quite small. You can get through it all in a half hour.

Definitely go early. The good stuff goes quickly.

Also in Oakland is the Oakland Coliseum Flea which is located close to various storage facilities which sellers use to populate their stalls. The Coliseum flea is primarily new goods and knock offs which sorta sucks.

In SF there's the Alemany flea market. Might only be open Sundays and prices tend to be quite high..

[wiredbecker]

So I took a couple of my st70 projects in to my 300b amp class at the Randall Museum last Saturday and got one running later that day. The one that was unsafe to power was my flea market find that I referenced in this thread.

The previous owner had bypassed the fuse and kluged in another transformer under the hood! Stock st70 transformer is a PA 060. This particular unit is running a "512-21358A" which fits nicely within the stock cutout along with the kluged transformer which I mistook for a choke that they had jammed in there with double stick tape!

I might just end up building up a 70 with updated caps, board and new PA 060..

Anyone heard of a "512-21358A"?

[wiredbecker]

Can anyone suggest a similar replacement power switch for a st70? I'm trying to complete orders at both digikey and mouser. Thanks!

[wiredbecker]

Has anyone used Triode's replacement PA060? Does it orient and mount on the chassis identically?

http://store.triodestore.com/mq060.html

[Dynacophil]

Can anyone suggest a similar replacement power switch for a st70? I'm trying to complete orders at both digikey and mouser. Thanks!

I bought a bunch looking exactly like the originals here in europe :)
If you're interested i do a pic...
otherwise I can send you all the old originals I replace...

The triode should fit exactly like the original... but - I only have a st35 stuffed with triode trannies. Those fit not perfectly but still ok. But... the chassis is dynakitparts, so i don't know who to blame :)

[wiredbecker]

Thanks for the offer and information Phil. I'd like to put a new switch in this old 70. I guess I'll just keep looking at SPST On Off switches...

[dcriner]

Even if an electrolytic cap reforms, I would replace it. I would even replace an old electrolytic that seemed good and didn't require reforming. They go bad.

[wiredbecker]

Thanks Doug.

[Ty_Bower]

Can anyone suggest a similar replacement power switch for a st70? I'm trying to complete orders at both digikey and mouser. Thanks!

The CW Industries slide switch GF-1623 was a fantastic replacement for the stock switches in my Dynaco Mark III. The fit is perfect, and the contacts are rated for a minimum 6,000 cycles at the maximum load of 16 amps, 125 VAC. I wish Mouser still sold them; I'd bet they fit the Stereo 70 too.

http://www.mouser.com/Search/ProductDet ... GF16230001

[wiredbecker]

What about this one Ty?

http://www.mouser.com/ProductDetail/CW- ... k1IbS74%3d

Looks good to me, same size.. 11amp.. 125V.

[Ty_Bower]

What about this one Ty?

Dunno, I haven't tried that one. If it's anything like the other CW switch, I'd imagine it would be a quality part. I used the GF-1623 because it was recommended in a thread around here somewhere.

edit: Here's the recommendation. I figure if Bob advocates it, that was enough for me.
http://www.diytube.com/phpBB2/viewtopic ... 84&start=7

[wiredbecker]

Ha! This is what Bob had to say over on AK. Good to know I can still pick up what I need from the Shack.

"Hi Chris,

You can get a suitable replacement Dynaco ST-70 power slide switch at any Radio Shack. It is Radio Shack part number 275-401. This switch will work and fit the opening perfectly. The only minor glitch is that the Radio Shack switch is not threaded like the original Dynaco slide switch. It's not really a problem though. All you have to do is place two 4-40 nuts on the other end of the two screws that hold the switch on. Link is below ...

http://www.radioshack.com/product/in...ductId=2062488

Bob Latino"

[Dynacophil]

Thanks for the offer and information Phil. I'd like to put a new switch in this old 70. I guess I'll just keep looking at SPST On Off switches...

difference: no threads (needs bold & nut, 250V)

Those I believe, 78€cents
http://www.conrad.de/ce/de/product/7011 ... 05/0216300

Technische Daten
Typ: R13-602A-05
Schaltstrom: 6 A
Ausführung: 1 x Ein/Aus
Schaltspannung: 250 V/AC
Isolations-Widerstand: Min. 100 MΩ/500 V/DC
Kontakt-Widerstand: Max. 50 mΩ
Spannungs-Festigkeit: 1000 V/AC/60 s
Size: (L x B x H) 35 x 13.5 x 15 mm
Typ: R13-602A-05
Einbaumaße: 6,5 x 13 mm · Lochabstand: 28,5 mm


looks as the radioshack stuff...
but no info on radioshack - except "supported language = english" rofl

[wiredbecker]

Had a great night tonight as I tore this amp down to the chassis! Tomorrow I'll hopefully get the output transformers sanded down and painted up for the rebuild. :)