SA212 For Sale in Melbourne

[synthi]

Apologies for the crappy camera-phone photos in poor light... and for the missing shots of the pre-amp tube sockets.
This is all that turned out reasonably from the ones I took.
Will hopefully get better shots on saturday.
Any idea what's going on with the additional metal-film resistors and ugly ground-wire on V1? (photo 10, first of my 2nd post)

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[synthi]

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[Dr.HI-TONE]

I failed to notice that this is a Vibrato and Reverb amp.
You did very well!
some of the pics are too narrow in spectrum for me to get an idea of what is going on, but Mark may be able to figure it out.

[synthi]

Thanks Doc! I must admit that the front pic I first posted is the most flattering one though. What you can't see are a couple of scrapes through the tolex on the top and on one bottom corner, as well as a bit of piping missing top. It's also lost the caps on the ends of the handles somewhere along the line. All in all pretty solid for a combo that's clearly seen some road miles though.
As mentioned, the plan will be to put it back as close to stock as possible, cleaning up the few little things inside that don't quite meet my standards of amp-OCD and then maybe fit some Tonkerlites, as suggested in the thread linked to by Dave above.

The old Celestion G12Ms will come out and end up in a 2x12, which will be a nice bonus. I'm guessing they were fitted knowingly along with the 2.2k screen grid resistors. Surely no-one would be insane enough to knowingly fit 2 x 25w speakers in a 100W amp.

No need for the Prof to end up with eyestrain - detailed Hires photos will be coming in the next week or so.

[Dr.HI-TONE]

That is an SA212R

it is very rare and cool!
You will want 100w drivers in it, to be safe. I think Tonker lites are 100w.?? I'll have to doubel check.
It is a beast, but a damn cool beast!

[synthi]

The tonkerlites are rated 125W each. Just called the local distributor and the local RRP =
Even the local trade price (which they will not sell to me for, as I don't have a registered business) is significantly higher than US prices.

I will message you soon off-forum about shipping options to .AU from VHR.

[Dr.HI-TONE]

OK,
That green wire to V1 is a ground..........?????
I don't know why.

[synthi]

OK,
That green wire to V1 is a ground..........?????
I don't know why.

I won't know for sure until I get to have a proper look, but the metal film resistors are connected between the V1 heater connections and that new ground point I am guessing in some attempt to hum-balance the heater circuit. Will post more details (and photos) when I have them.

[mhuss]

Congrats!

I am guessing in some attempt to hum-balance the heater circuit.

That seems likely.

I have a 212R 100 watter, they are rare and wonderful (and HEAVY) beasts. Mine still has the original (odd) Fanes in it.

--mark

[synthi]

Some better photos now available here: http://gallery.me.com/mattkg#100024

We (forum member snarfusmaximums and I) ended up replacing the screen-grid resistors with 100ohm ones and replacing V1 with a good Telefunken smooth plate and V4 with a NOS Mullard CV4024 (the rest are brand-new Tungsol 12AX7). Definitely sounds like a Hiwatt (and better/louder than before), but still nowhere near 100W output (B+ @ 465V, biased around 20W idle). We were running it with the internal speakers disconnected and a Marshall quad connected to the 16 ohm jack.
Didn't get a chance to measure the output into the dummy load, but that'll be happening soon. A bit noisy (hum), maybe the caps are due to be changed after all, though only the blue RS 32/32uF looks like it has much of a bulge.

Am busy at the office now, but will be back later on with some questions. I wonder why the output is down when the voltages look good... I guess the B+ could be sagging under load. Will investigate further this weekend coming.

p.s. forgot to mention it was supplied fitted with a pair of JJ EL34 and a pair of JJ KT77. They biased quite differently (almost 10mA difference), so were removed and replaced with a good set of modern Tungsols for testing.

-Matt.