trinityamps.com

I just finished my Trinity Plexi build and I can truly say it is everything I expected it would be. Incredible! I had been researching amp kits for about six months and I thought that Trinity amps sounded the best and I was right. Talk about plug and play. Wow! Hats off to Stephen for providing such amazing amps.

I do have some mods planned such as switchable ss/tube rectifier and switchable fixed/self biasing but for right now I will be enjoying playing this incredible amp.


Pictures:
http://www.unimind.us/images/DSCN7290.JPG
http://www.unimind.us/images/DSCN7291.JPG
http://www.unimind.us/images/DSCN7292.JPG

Audio:
http://www.unimind.us/TrinityPlexi1.mp3

P.S. This was my first ever amp build. I have experience with building electronics but never an amplifier. It was a whole lot of fun.

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Les

http://www.soundclick.com/unimind

What are all those extra switches on the preamp end?

Wow! Nice build. And the sound clip was just...

The one between V1 and V2 is the boost switch, the one between V2 and V3 will be a NFB switch and the one between the impedance and output jack will be the bias switch.

-Les

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Les

http://www.soundclick.com/unimind

Thanks. It does sound amazing but now I notice that my voltages seem quite low. Maybe that is why it sounds the way it does.

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Les

http://www.soundclick.com/unimind

Yikes!

Is that just the amp cranked? Amazing.

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Go Buckeyes!

Man...if the low voltages turn out to be due to a mistake, PLEASE document the mistake! That is a SERIOUSLY brown-sounding amp!

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** b0b0 **
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- This Space For Rent -

Yes. That is just the guitar into the dimed TMB channel except bass on 0.



I don't think there are any mistakes. I was very meticulous and checked and rechecked everything. Most of the resistors are testing a little high i.e. 100k = 101.2k, 820 = 872, 56k = 57.4k etc. I swapped V1 and V2 and the voltages are a little more normal now. V1 plates were 75vdc now they are back at 134vdc which is what I measured when I was finished building. Still a little low but seems ok to me and with the way this amp sounds... I am not sure I want to fix the voltages.

-Les

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Les

http://www.soundclick.com/unimind

What type of cab/speakers are you using in that clip??

Mine does not sound remotely close to this plexi. My TMB channel is having issues with flabby muddy bass and less volume output compared to the normal channel. Any ideas? Cabinet is a 4x12 Marshall greenback loaded.

B+ is 340
V4 is 328
V5 is 328
V6 is 340

I will post my pre amp voltages later.

It's an old Peavey cab with 200 watt Scorpions at 4 ohms.

http://www.unimind.us/images/DSCN7297.JPG
http://www.unimind.us/images/DSCN7298.JPG

I have always loved this cab and speakers. I have had many cabs over the years but this one always sounded the best to me.

-Les

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Les

http://www.soundclick.com/unimind

Mine also has some muddy bass that I want to try to get rid of. I have my bass knob at 0. My current voltages are:

B+: 332
V1: 77 (I don't know why this keeps dropping so low)
V2: 232/155
V3:175
V4:307
V5:307

Overall my voltages seem a little low but I thought they were acceptable but I really need to figure out what is wrong at V1.

-Les

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Les

http://www.soundclick.com/unimind

I figured out what was wrong at V1. I had an old Boss delay pedal plugged into the amp when measuring voltages. Apparently if you do not have anything plugged into the input of the pedal it puts some kind of load on the input of the amp. When I unplugged everything from the amp or just had the guitar plugged in I get 134 vdc on V1a and 138 vdc on V1b.

Note to self: unplug the input before measuring voltages.

-Les

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Les

http://www.soundclick.com/unimind

That sounds crazy! Clean looking build!

If the low voltages turn out to be due to a mistake, PLEASE document the mistake! That is a SERIOUSLY brown-sounding amp!

Unimind,
I was wondering if you have gone any further with your dual rectifier plan, or your cathode/fixed bias switch. I would really like to have one or both of these mods in my next build. I have been going back and forth over the past few months on whether to build an 18 watt, or a 20 watt 2016. The 20 watters have the tighter sound, the 18's have the warmth. I have noticed a few companies selling amps that are supposed to capture the best of both amps. Im pretty sure the main difference between the two is the rectifiers, and the biasing. So with those 2 switches, one has both sounds at his disposal.
I recently completed a Trinity 18 watt Plexi kit for a friend of mine. I am now sold on the quality of the Trinity kits, and I would like to build the V6 Plexi for myself next. If I could implement the dual rectifier, and the dual biasing, along with a VRM and the dual output tubes, boy, that would really be something !

Both the Marshall 20W and 18W amps are cathode biased. So that's not something which differentiates them. The 20W is SS rectified and runs higher voltages, which gives the couple of extra watts of power. However, EL84s sound more sterile at 400V. It's not only about the warmth, but the rich complex harmonics you get from the 18W. If you want to tighten up the feel of an 18W you can use a huge cathode cap on the EL84s, in the 1000uF to 2200uF range to make the bias voltage stiffer. You can also use SS rectification, provided you keep the B+ voltage to around 330V.

Now there's no need for a rectifier switch, if you use SS rectifiers (preferably UF4007s) and a sag resistor. A value of around 100 to 120 ohms 7W will perfectly emulate the sag of an EZ81 tube. So you only need to switch the resistor in or out of circuit for when you want or don't want sag. The problem is with the rise in B+ voltage when you short out the sag resistor. The way to get around that problem is to use some zeners to reduce the B+ when in non-sag mode. It's all pretty simple to do.

And here are some previous comments from people who have played both the 2061 and the 18W.





HTH

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Great tones come in small glass jars!

I do appreciate the response and the information Zaphod. I will definetly investigate this further.. As far as the 18 watt vs 20 watt, I know there are lots of people who prefer the 18, probably the majority, but I have seen many who also sway the other way, who say the 20 more closely replicates the "plexi" sound. I have been investigating this for a good while. Now I know what the 18 watt sounds like, theres one sitting 2 feet from me, its the 20 watter I havent heard much of. I do like the way the 18 watt sounds, and its growing on me more each day.

That's nuts. The 18W's harmonic complexity is way more Plexi like. The 20W is bold and brash, but it just doesn't have that juicy vibe that real classic Plexi has. An 18W totally *nails* the cranked Plexi tones of AC/DC or early ZZ Top. Even more so, if you build one of the "TMB" 18W variants that also has a Plexi preamp channel, such as the Trinity TMB or Trinity Plexi. AT one time Bill Gibbons was gigging Trinity TMB 18W amps.

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Great tones come in small glass jars!

Koss59 says
10-24-2009, 11:14 AM
Both great amps! I have both, the 1974x is great for rehearsals and small jazz/blues gigs the 2061x through a 4-12 is amazing and holds its own easily with a loud rock band, all those classic tones are there. I can see people using the 1974x a bit in home but never the 2061x as it's just too loud.
Here's some clips of both amps if your interested.
http://www.youtube.com/user/koss59
His 20 watt sounds pretty nice.....

Loopmaster says
I have both and the 2061 can be balls to the wall AC/DC whereas the 1974X is more like a Bluesbreaker. Just my opinion

Tuna says (he has both too, but looong post)
The 2061 w/2061CX cabinet is classic Plexi to my ears. What a killer looking head and cabinet. All of your favorite old rock band tones, ABB, Led Zep, ACDC amd more. It is a loud amp in your house and has to be pretty much cranked to get that cool overdriven sound unless you use an OD pedal. This amp has a tighter sound than the 1974, my guess would be the diode rectifier in this amp versus the tube rectifier in the 1974X, as well as the non aged Celestions. (I think the new ones are coming with the new preaged G-12H.)

Dont get me wrong I am in NO way bashing the 18 watt. The Trinity Plexi TMB 18 watt i have here is awesome. However, I think the 2061 is a pretty viable amp in its own right.