Turtlerock Forum

Hi Folks,

So I was lucky enough to score a pair of these a while back, looks like they haven't been used for quite a while so I think it's about time to change that

Just wanting to draw on the very helpful knowledge on here about these units, basically I want to know what I may need to do to get them up and running. In a perfect world I'd send them off to Rob, but living in Tassie and looking at my bank balance I'd say that's off the cards for a while lol.

The units were pretty dusty, so I've given them a thorough cleaning inside and out. They have the Cannon type power connectors on them which I'm going to make up cables for - but apart from that are they ok to fire up? (I mean I guess a power supply recap and calibration would be good but just to start off with).

Is there a service manual I can look over? I haven't been able to find any info regarding schematics etc, also does anyone have the info for wiring the In/Out audio cables for it as it has a screwstrip on the back, with some rather unhelpful numbers.

I can take pictures if needed, just wanted to get the ball rolling.

Cheers guys.

Hi Richard

I have an owners manual left over from when I owned a couple of Big1A's.
I'm happy to send to you for the price of postage.

I would suggest getting rid of the canon power supply cable system and replacing it with IEC, the earth pin is miniscule and AFAIK they are not legal in Australia due to safety concerns though I could be wrong there.

Awesome Ben that would be very much appreciated, thanks

You might be right Steve, not only that they are now no longer being made and selling for a bloody fortune on the used market. Which is a little annoying because I think *everything* that ABC owned was fitted with these.

Kinda wonder if they were discontinued because of safety regulations? I'll look into fitting an IEC.

Ah, AWA broadcast gear,always fun. Yes replace the big electro in the power supply and most of the other ones too.It will be at least 40 years old ( if original) and well & truly fornicated. Be careful with the mfe-3001 fet.These are made from unobtainium & the legs corrode and break. They went out of production by motorola in 1981. There is no replacement.I do have a small stash but they a not cheap.
Ascertain if it is a BIG-1 or a BIG-1A. They are the same but different.
Unless it has been recalibrated to symmetrical it will most likely be set up for +125% /- 99% modulation. These things are AM transmission limiters & that's how we make it loud without pinching the carrier. It won't sound right unless that's the sound you're after. You can modify them for variable attack and release quite easily. There are jumpers for 0.5,1 and 2 seconds release . you replace the fixed resistors with a pot there is also a setting for 2 stage limiting to stop it pumping. More for broadcast though. These things were set up then left for 20 years in hot dusty buildings. So a little TLC and it will turn out great. I have soft copies of both versions manuals.pm me and I'll email them

Cheers man PM sent

A refurbished, aligned and A/R modified Big 1 is an awesome thing. A pair can be stereo linked. In a perfect world you'd send them to me. In the real world, if you get stuck let me know.

hmm you know Rob I think I may just have to do that - it's a little more involved than I expected.

Can you PM me a rough idea on how much it would cost? Times not an issue just more cost at this point.

Finally took some pics