If you want a direct replacement, do as the man said. If you want a substitute try Magnetic Components 40-18029.

Todd,

I have done two OTS style 50W amps (OTS 50 and OTS FM Mod) using the MC iron. The OTS 50 is up and running and the FM just passed the light bulb test last night.

I like to give credit where due but unfortunately, I forgot the forum member who suggested these components. Point being, others have used these trannies before me.

Appreciate your list.
Rick

Negative feedback in the clean channel is switchable on the Modern Eagle Mod.

+1 On the lamp method. Positive results (On or Off). No gray areas. Really inexpensive too.

Red/Grn-Red/Yel

I used this OT

http://www.classictone.net/40-18001.pdf

And this choke

http://www.classictone.net/40-18003.pdf

You won't need the extra 6V transformer if you use this:

http://www.classictone.net/40-18029.pdf

I built an OTS50 last month using it. The 5V winding works fine for the relay power supply. Delivers between 11.5V and 13.5V. The relay nominal pickup voltage is 12V but according to Nik it will work down to 8V. I wouldn't want to go that low but I think my range is good.

Funny thing is they don't have an equivalent for a 100W version.

Good Luck!!

Nice work. I like the cab. When I finished my first (OTS 183) I left a note of thanks here too but not in as much detail as yours. I'm almost done with my second OTS and I will say it's much easier. I did take the time to write up a build sequence and a make wiring diagram of the input lacks, which helped a lot.
By the way, the ground switch is a throwback to the old days before we had grounded (three wire) power cords. It would connect a capacitor to ground between either of the two power cord wires (the objective being to connect the cap to the grounded neutral wire) to reduce hum and reduce shock hazard. Now that we are using IEC type power sockets the switch isn't required. It's just there for show.

I wouldn't be too concerned. You're talking less than 3% (710/690=1.029). That's like your line voltage going from 118V to 121.5V. You wouldn't notice. By the way Ceriatone's PT's come can with a 50V or 60V bias winding (Check the web site pics). Mine is 50V and works fine.

Search E-Bay for "Tektronix Oscilloscope Probe". Tons available BIN. I have a Tek 466 and got a pair of 1X-10X probes for less that $20. Matter of fact, here you go:
http://cgi.ebay.com/Two-New-100MHz-Oscilloscope-Probes-Probe-Tektronix-HP-/160549907389?pt=LH_DefaultDomain_0&hash=item2561852bbd

Same happened with me. Just short of two weeks. Shipped 12/29/10; delivery attempt 1/10/11 but sig required. So I picked it up on 1/12. It takes a few days to show up in the tracking system.

Had to bump this thread. I also am considering the Hammond PT but had a concern that the mounting screw centers don't fit the chassis mounting holes. Any suggestions on a fix?

Thanks,
Rick

Nothing like building your own. I'm ready to build anotherbut I don't have room. Time to sell something I guess.
I was wondering when someone would notice the dummy. 200W @4 or 16 Ohm; 100W @8 Ohm. I built it for the JCM800. It's got KT88's.

Sure. Here ya go. I'm afraid the lead dress isn't up to snuff in some places but it fired up fine on the first try.
The tube shields are on now. I was still jockeying preamp tubes around in this shot.

Hello All,
Joined in November and haven't had much to contribute here. But, I purchased an OTS 183 (50W) from Nik completely unassembeld and just finished it. Maybe it's my geezer ears but this amp sounds great with only about three hours playing time on it. Thanks to all members who contributed build information and photos. They helped immenesly. And thanks to Nik for a great product.

Hope to be a regular here from now on.

BTW my avatar will be updated as soon as the 183 cab arrives.

Rick