# 18 watt amp build



## J S Moore (Feb 18, 2006)

This is the first time I have built an amp. This is the 18 watt sIII head kit from Trinity. I have about 20 hours into it so far and the amp itself is finished. Just need tubes and the head box ( which is coming). Here's a shot of the completed amp:









It's a little blurry but not too bad. Here's a shot of the power tranny which turned out better.









A blurry shot of the whole board:









I was impressed with how easily the kit went together. Mostly because of the great instructions.


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## zdogma (Mar 21, 2006)

That's a real beauty, John, nice job. I had a chance to play one of Steve Cohrs 18 watters recently, and it was exceptional. I really like his new transformers. 

The one I played was built by Steve, and it was his standard amp, not the sIII. It was much gainier than I had expected (JCM 800 or maybe a bit more), but in a good way, not buzzy or fizzy. I think the sIII has a bit lower gain.


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## Mr. David Severson (Feb 3, 2006)

I can't wait for mine!!!


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## Stratin2traynor (Sep 27, 2006)

Great job on the amp. That is what I am ultimately working towards getting. I'm going to sell my other amps (except my newly acquired 65 DRRI) and use the coin to buy the Trinity 18 kit - and an Xbox 360 but that another story. 

As for the cab, are you going with the 1x12 or 2x12 and what speakers will you be using??

Scratch the previous cab question. Just re-read the post.


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## J S Moore (Feb 18, 2006)

It is a bit lower gain, but that's what I was looking for. A closer sound to the original Marshall. It came with the optional boost so I can choose a bit higher gain. 

I have a 2x12 extension cab coming and I just picked up a pair of Eminence GB12 speakers which are their greenback clones. Recommended by Wild Bill so I thought I would give them a try.


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## greco (Jul 15, 2007)

Fantastic looking build !! Congratulations.
Thanks for the chassis pics.

I have a simple technical question. Is there a specific reason for connecting the various wires to the underside of the components board (apart from cosmetics)?

I'm asking this as I'm building a Champ clone (no kit....please don't ask) and I'm almost sure that I read that the wires *could* be attached on the top of the board for easier repairs/mods later, and possibly also for an easier build. However, almost everyone seems to use the approach you have used. 

Thanks for your comments.

Dave


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## Stratin2traynor (Sep 27, 2006)

I'm not sure if I want a 1x12 or 2x12 combo or a head and 2x12 cab. Decisions, decisions. Once I decide I'm going to sell the necessary gear to make the buy. Any suggestions? Bearing in mind that I am a basement player.


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## J S Moore (Feb 18, 2006)

As far as the wires on the bottom I think it looks cleaner. Every turret has a wire connection so the majority of the mods would be replacing resistors and caps with different values. The wires would just get in the way then.

I choose the head and cab just to have something different. I've already got a combo and it's damn heavy to move around. I figured this configuration might be a bit easier. I may be wrong though. 

A closed back cabinet will project forward more than an open back, but the open back will produce a fuller sound with projection front and back. I personally just like the sound of two 12" speakers.


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## Kapo_Polenton (Jun 20, 2007)

Yeah the GB12's get great reviews... another alternative are the sammi 50's. I like mine soo far.. tight low end.. balance the celestions RI greenies well.


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## Guest (Sep 27, 2007)

What's the difference between the SIII, TMB and V6 kits from Trinity? Are they all Marshall variants?


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## J S Moore (Feb 18, 2006)

The TMB is a little higher gain than the sIII, both two channel, and the V6 is swtichable between EL84 and 6V6 output tubes. They are all based on the original Marshall.


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## Robert1950 (Jan 21, 2006)

I believe you can also jumper the sIII.


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## J S Moore (Feb 18, 2006)

Yeah, I'm having a lot of fun with that! :rockon2:


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## J S Moore (Feb 18, 2006)

Here's some shots of the head and cab that Steve sent me.



















I'll have them by the weekend and I'll take some shots fully assembled.


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## a Pack of Wolves (Sep 5, 2007)

i have a 15 watt filmosound amp made from a bell and howell film projector's amp.the old school film projectors you would talk along to movies with.

the amp pops right out of the projector and mades a killer head for the projector's matching speaker.

actually there's is room enough in the speaker box to drop the amp right in there and you've got a wonderful little combo amp.

the speaker is a 12 inch that can take 25 watts,so the 15 watts coming out of the amp is handled well and there is some nice sonic depth.

the amp only really breaks up when it's pushed near (7 or 8 out of 10) volume wise.you can get a warm clean workable tone for any style other than metal.
i don't really use the amp at it's limits ever.

the first tube is a 5 series tube (not a 12ax7) but not sure off hand,not really sure what that does to the whole thing,i know it's a tube that was meant to be really low noise back in the day. 
i've actually got a couple of tubes in it that are from the 50's (r.c.a and g.e.)

having gotten this amp (say 3 months ago) i have become 'returned on' to smaller tube amps.it started 5 months ago when i got a little national amp (6 watts?) which i traded for the filmosound.

---just want to add the amp is from the 60's (63?) and the speaker/speaker box is from the 50's (55-57?),and everything works great.


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