SIII build from scratch

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JMPGuitars
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Re: SIII build from scratch

Post by JMPGuitars »

Bieworm wrote:
Tue 01/10/23 11:54 am
- the most tricky part is the baffle itself, IE the tension and outlining the grill cloth. I have developped a very effective and easy way to do this. Believe me, everyone’s first attempt on this is plain awful.
That's funny, I find the grille cloth the easiest part. I used to stretch canvases for painting when I was young, so that part is similar enough.
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Re: SIII build from scratch

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JMPGuitars wrote:
Tue 01/10/23 12:28 pm
Bieworm wrote:
Tue 01/10/23 11:54 am
- the most tricky part is the baffle itself, IE the tension and outlining the grill cloth. I have developped a very effective and easy way to do this. Believe me, everyone’s first attempt on this is plain awful.
That's funny, I find the grille cloth the easiest part. I used to stretch canvases for painting when I was young, so that part is similar enough.
No no… grill cloth is very stubborn fabric… unless you use the f€nder type of cloth. But the ones marshall uses are very nasty on the corners. Especially the blues breaker type of grill cloth. Canvas has a tighter weave and bends more consistently than the thick grill cloth material
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Re: SIII build from scratch

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I first staple the cloth on the top side of the baffle … perfectly aligned. Then I turn the baffle upside down so the cloth faces the work bench. At the backside of the top side I screw a wooden beam the sticks put 10cm at each side. I flip the baflle back around with the clotch facing upwards and screw the beam to the work bench’s sufrace, with the bottom side of the baffle hanging an inch over the edge of the bench. Then I staple another beam to the very en of the grill cloth, perfectly alligned and parallel with the top beam. Now roll up the grill cloth with the bottom beam. Then I shove the old laptop bag shoulder handle over the ends of the bottom beam, and stretch the grill cloth over the bottom edge of the baffle with my hands. When I’m sure its nicely aligned I put my foot in the shoulder handle and press down very hard. That’s when I start stapling the cloth on the bottom edge.. not loosening the tension until it’s completely stapeled. That’s as tight as a drum head… the sides are easier…
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Re: SIII build from scratch

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Re: SIII build from scratch

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I am imagining how to do this with a baffle that has a valance
I am thinking that I need to start at the top edge under where the valance sits then pull tight onto the bottom then the sides
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Re: SIII build from scratch

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I am using Salt and Pepper Cloth that I got from solsound in England
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Re: SIII build from scratch

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AussieTim wrote:
Tue 01/10/23 11:23 pm
I am imagining how to do this with a baffle that has a valance
I am thinking that I need to start at the top edge under where the valance sits then pull tight onto the bottom then the sides
I’m not completely sure what you mean. Do you have examples?
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Re: SIII build from scratch

Post by AussieTim »

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Finally got around to finishing off the cabinet for my 18 watt build I have also completed a deluxe reverb which prompted me to polish off the 18 watter I made a big mistake with using vinyl from the fabric chain store here in Australia and found it was way too soft to really work with and tears too easily at some stage I will recover with proper tolex
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Re: SIII build from scratch

Post by dalebeachwood »

zaphod_phil wrote:
Wed 09/07/22 12:55 pm
AussieTim wrote:
Tue 09/06/22 5:58 am
Ok have had this thing running for a couple of months now and so far have found
1 switching valves doesn't seem to give a vastly different sound, probably not enough to worry about, I think I will remove the 6v6 valves and switch and just run with the el84s
2 Phil was right, it is pretty clean I will change some resistors and caps to make it into the Trinity Plexi 2 version
It is indeed very clean sounding in the online demo clip. but it's a very sweet silverFace--like clean 8)
I built a Trinity SIII-V6 head kit in 2016 that I use with a 2x12 Bluesbreaker cabinet, loaded with a Celestion G12 EVH and a Celestion G12-65. It was my first amp build, but I took my time, learned a lot and the amp came out great.

My SIII-V6, as in the comments by AussieTime and zaphod_phils, is indeed very clean sounding. I also, do not notice much if any difference between switching from the EL84s to the 6V6s. However, in all honesty I am never able to really crank the volume up. I did buy the Trinity VRM -Voltage Regulation Module but never got around to installing it.

I recently retired, and now with more time on my hands, decided to get back into tube electronics and started thinking about what I might do to re-voice the Trinity to be a bit less clean since I already have a couple of other very clean sounding amps; a 1983 Fender Deluxe Reverb II (6V6s) and a 2004 Magnatone Panaramic Stereo 2x10 (EL84s).

@Aussie Tim, did you ever change caps and resistors to make it into a Trinity Plexi 2 version? If so, I would be interested in your results and any advice you might have.

I would also be interested in any suggestions from others as to where I might want to start to make my SIII a little less clean, and possibly a bit more "Marahall like".

Thanks, Dale
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Re: SIII build from scratch

Post by Bieworm »

Study the SL TMB schematic and layout. This amp has plenty of drive at lower volume. Maybe it’s a pretty easy surgery of your current amp…

viewtopic.php?t=24430
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Re: SIII build from scratch

Post by AussieTim »

PXL_20231006_120153066.MP.jpg
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dalebeachwood My computer died a couple of months back and I did not see your post so I apologise for that.
I replied to your message but when I checked it looks like it didn't send.
I haven't got around to doing surgery on my amp yet but still intend to do so.
Since then I built a 65 deluxe reverb, I know, from the evil side but I love it
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Re: SIII build from scratch

Post by AussieTim »

OK time to build another 18 watter after my foray into the other side
I am intending to build a 36 watter with an ef 86 on channel 1
I will be using one of Craigs reference boards as a the platform to build it on, This will be a departure from building "old fashioned" amps so I want to incorporate a couple of modern features.
I want to play around with channel switching, an effects loop and maybe a FET input, I have been looking at Grainger Amplifications stuff which seems to have all of these goodies, has anyone had any experience with this stuff.
I am also on the hunt for a suitable speaker to use,
I know Celestion Greenbacks are meant to be the ducks guts as are their alnicos, but I need convincing, the last couple of amps I had with Celestions were not good and I used other speakers instead that sounded better
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Re: SIII build from scratch

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AussieTim wrote:
Thu 04/25/24 10:15 am
but I need convincing, the last couple of amps I had with Celestions were not good and I used other speakers instead that sounded better
What type did you try? There are only a handful of good current production celestions IMHO. I don’t look beyond and do recommend: all alnico types, the G12M, G12H30 Heritage (NOT anniversary, they suck!), some V30’s in few situations,..

certainly avoid the cheap series with the small stickers, the classic80, G12T, V type,…

Anyway, a well broken in greenback is a really nice match for the 18W in any form. Not spectacular, but really decent nevertheless
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Re: SIII build from scratch

Post by JMPGuitars »

I like all the WGS options I've tried, and some from Eminence better than anything I've had from Celestion.
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Re: SIII build from scratch

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Im with Josh so far, Eminence and WGS have been the speakers that seem to outshine the stock offerings, It was probably the Celestions that Bjorn was mentioning all I know was I didnt like the noise they made
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Re: SIII build from scratch

Post by AussieTim »

Hi Guys
Any suggestions on the best way to achieve footswitch channel switching I was thinking it would be something simple like a remote controlled AB box mounted in the amp, but as I have looked into this I have found all sorts of weird and wonderful ways of doing it that I would never have dreamed of. My previous builds have been all been separate channel "traditional" and I have heard the arguments against switching but I want to build this one as a single input amp so I can annoy the cork sniffers in the audience with sucked tone and loud pops, and all the other reasons why switching sucks
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Re: SIII build from scratch

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I do relays switching with twin channel amps. It looks difficult when in virgin mode, but it’s not THAT hard😉
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Re: SIII build from scratch

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Hey Tim

Here's a schematic + layout about the 'how to' in case you decide to choose this option. The relay will ground one or the other channel, leading the signal of the unused channel to ground.
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Re: SIII build from scratch

Post by JMPGuitars »

Bieworm wrote:
Fri 05/17/24 5:52 am
Hey Tim

Here's a schematic + layout about the 'how to' in case you decide to choose this option. The relay will ground one or the other channel, leading the signal of the unused channel to ground.

The board you're using has 2 relays on it, but your schematic is showing only 1. Are you only using 1 relay in reality, or is something else going on with that board? Do you have a schematic for the relay board?
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Re: SIII build from scratch

Post by Bieworm »

JMPGuitars wrote:
Fri 05/17/24 10:40 am
The board you're using has 2 relays on it, but your schematic is showing only 1. Are you only using 1 relay in reality, or is something else going on with that board?
I know. I use one relay for tremolo switching and the other relay for channel switching. But the channel switching relay also switches the reverb to a lower wet signal when overdrive channel is engaged.
JMPGuitars wrote:
Fri 05/17/24 10:40 am
Do you have a schematic for the relay board?
here it is:
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