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Hi All,

My sIII is finally making sweet noise. It sure took a while. I sourced the parts myself. I tried to save a little in some areas to spend more where it counts. The parts include a Trinity OT (Thanks, Stephen!), Hammond 270EX PT, Turretboards chassis, Sozo caps, CF resistors, Alpha pots, Mullard tubes, and an RCA recto.

My voltages were right in the ballpark:

V1
Pin 1 - 149V
Pin 6 - 145V

V2
Pin 1 - 176V
Pin 6 - 265V
Pin 7 - 176V
Pin 8 - 176V

V3
Pin 1 - 209V
Pin 2 - 52V
Pin 3 - 76V
Pin 6 - 210V
Pin 7 - 53V
Pin 8 - 76V

V4
Pin 3 - 12.2V
Pin 7 - 353V
Pin 9 - 330V

V5
Pin 3 - 12.2V
Pin 7 - 350V
Pin 9 - 330V


I only made a couple small changes:
I used a shared 1K screen resistor instead of 100R.
I made a virtual CT for the heaters using two 100R resistors and tied them to the power tube cathodes to elevate them. (The Hammond doesn't have a CT for the heaters.) The heater voltage is a little high - 6.75VAC.

Here's some pics:

Congratulations on your new addition!! How does she sound? (It is a she, isn't it?)

I'm just sitting down to start my sIII combo today (my first build). Those pictures just gave me the inspiration to warm up the soldering iron! Looking at your head chassis, I'm a little jealous. My combo chassis doesn't look quite so roomy to me and my fat fingers.

Enjoy your new sIII.

Thanks, Jimmy. 'She' sounds quite good. I was surprised at how much I like the normal channel. Nice and fat. (Oops, I'm not talking about 'her' weight now.) I haven't learned how to do sound clips yet, otherwise I'd post some.

This is my third amp, but I haven't tried a combo yet. I must admit I do like the soldering bit. Now, I just have to get to work on my cab...

Nice job Sonny! Looks clean in there! Boy you hit the voltages very close with that PT.
Now, some more playing and some more thoughts on the tone!

Where did you get the panel done?

_________________
Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

Thanks, Stephen. The PT worked out pretty well. The stand-up style tranny gives you more 'play' room inside the chassis. If I were to build another, though, I'd buy your set. It would be nice to have the rectifier on a separate winding, heater CT, classic look, etc. You don't end up saving much with separate shipping anyway. The Hammond does seem to get a bit warm after being on a while.

I'll definitely be playing it some more today. Only 99 more hours to go on those Sozo's I think they sound good already. This amp does seem to prefer humbuckers. My 335-style guitar gets some really nice tones. I'll have to experiment with the Strat a little more.

I drew up the faceplates in Corel Draw and had a local trophy shop engrave them. I had them reverse-engraved on the back (plexi-style?). The shop forgot to do the backfill, so I shot them with a little flat black spray paint (Krylon) to get the black lettering. I think they use ink, traditionally. This is the first time I had the faceplates done before I drilled the chassis. Much easier.

They look pretty good. Does the gold have a metallic flake to it?

I thinnk that by the time you pay for all the shipping from various suppliers, it's less hassle and sometime cost, in the long run to buy a kit. Unless you have a good parts inventory!

Now you need a boost switch!!

_________________
Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

I'm pretty sure this is the material the shop used to make the plates:

http://www.rowmark.com/laser/Reverse_La ... ermark.asp

Those look exactly like the samples they showed me. I chose the Gloss/Smooth Gold material. The gloss made the gold color look deeper than the matte sample for some reason. Probably like a clear coat on a car finish. Looking closely at the plates, you can see a very fine metal flake.

I found some info on the reverse engraved plates at BNP Lasers website after the fact:

http://www.bnplasers.com/AMPBUILDERSMATERIALS.htm

They mention backfilling with paint. Luckily the Krylon paint I used was an acrylic lacquer. However, I did put some 3M spray adhesive on the back of the plates to help them stay put. Hopefully it won't cause any issues. Maybe the layer of paint will protect them.

Still thinking about that boost switch...