Trinity TC 15 Rookie Build

Discussion in 'Shock Brother's DIY Amps' started by alathIN, Nov 12, 2018.

  1. alathIN

    alathIN Tele-Holic

    Age:
    54
    Posts:
    773
    Joined:
    Oct 25, 2017
    Location:
    Indiana
    First off, I have to reference this thread showing Cigarman's TC-15 build. He did a beautiful job. As I'm working through this build, I keep flipping back and forth between the Trinity TC-15 Builder Manual, the TC-15 schematic, the TC-15 layout, and the Cigarman build thread on TDPRI.

    I also want to say how awesome Trinity is. One of the reasons I ordered from Trinity was their reputation for excellent documentation and support - which I have found to be well-deserved, and essential for a first time builder like me. Mr Cohrs at Trinity answers emails promptly and is often available to take phone calls. Their builders' manual and layout are full color and clearly illustrated with lots of "IMPORTANT" warnings that would not be obvious to a rookie.

    I also like how interesting Trinity's amps are. Yes, I get wanting to build a Tweed or a Plexi - they're awesome amps. But Trinity offers some amps/amp kits you don't see anywhere else. The TC-15 has two channels, one is the classic Vox AC30 top boost, and one is based on an older AC-15 with an EF86 preamp. The power section is two EL84s - basically an AC15. There's also a switch that changes the way the output transformer works and comes closer to Matchless tones.

    Trinity also has kits based on HiWatt and Dumble that will get a close look should I feel the need to build another amp.

    The story begins, in Edgar Allan Poe fashion, with the delivery of an oblong, surprisingly heavy box.
    [​IMG]
    Installing hardware
    [​IMG]
    Check the BOM and organize the semiconductors. I think it was on the trinity forum I saw someone putting all the caps and resistors into a chunk of styrofoam. Makes it easy to find them later.
    [​IMG]
    An option with most Trinity kits is the Voltage Regulation Module, an voltage-based attenuator that controls loudness by adjusting B+ up and down. Basically what you get is a Power Knob instead of a Power Switch.
    Being able to get nice tones without breaking the windows is probably the most important feature of an amp for me, so I knew I wanted to try this. If I don't like the kind of attenuation it provides, I can leave it on "max" and it's just like the amp would be with a straight up power switch.
    I found the VRM to be a bit of a tight fit over the power transformer.

    [​IMG]

    I could have installed the VRM upside down or sideways and had plenty of room, but just being stubborn, I got some nylon spacers to raise the power transformer just a touch higher and create some breathing room for the VRM. You can just see the off-white spacers under the PT in this picture. Also soldered leads on the VRM's mosfet, to make placement of the mosfet more flexible.
    [​IMG]
     
    Last edited: Nov 12, 2018
  2. alathIN

    alathIN Tele-Holic

    Age:
    54
    Posts:
    773
    Joined:
    Oct 25, 2017
    Location:
    Indiana
    Heater wiring
    [​IMG]

    Power side done, ready to test
    [​IMG]

    I had convinced myself there was something wrong with the VRM, so I called Mr Cohrs and he suggested this test. Hook up a 9V battery positive to the VRMs B+ in, and test voltage at B+ out. I was able to dial it up to about 6V and down to 0V, so apparently it's working. The problem was obviously in my head, not in the VRM.

    [​IMG]
     
    bftfender likes this.
  3. alathIN

    alathIN Tele-Holic

    Age:
    54
    Posts:
    773
    Joined:
    Oct 25, 2017
    Location:
    Indiana
    Power testing.
    [​IMG]

    By the numbers:
    120 volts
    1 indicator lamp glowing
    10 test spots with correct voltage
    zero ambulance rides
     
  4. alathIN

    alathIN Tele-Holic

    Age:
    54
    Posts:
    773
    Joined:
    Oct 25, 2017
    Location:
    Indiana
    Yesterday night and this morning were Turret Board Time.

    [​IMG]
    Installed an extra turret (albeit the wrong size) here between the .01 cap and the 220k resistor. This is where Trinity recommends putting the effects loop send and return, and I want to be able to come back and do that without leaving any components hanging in the air. If I take out the jumper between the cap and the resistor, I'll have the send/return points ready to go.

    [​IMG]

    There won't be any updates for a few days, because I've got a string of work days coming up.

    Would appreciate any tips/help/suggestions.
     
    hrstrat57 and KellyWalrus like this.
  5. KellyWalrus

    KellyWalrus TDPRI Member

    Age:
    30
    Posts:
    68
    Joined:
    Nov 2, 2018
    Location:
    Metro-Detroit
    Looks great! VERY clean solder job and layout. I'm jealous.
     
    alathIN likes this.
  6. clintj

    clintj Friend of Leo's

    Posts:
    4,945
    Joined:
    Apr 4, 2015
    Location:
    Idaho


    For your consideration for future builds. Nothing at all wrong with how you did yours (they look great), but this method leaves the upper turret positions open for other components which can help when you get into more advanced builds.
     
    King Fan, KellyWalrus and alathIN like this.
  7. alathIN

    alathIN Tele-Holic

    Age:
    54
    Posts:
    773
    Joined:
    Oct 25, 2017
    Location:
    Indiana
    That is slick.

    The builders guide for this amp tells you to do that wraparound thing when you connect to things off the turret board (or make your connections to bottom of the turret board).
    But I agree this way makes more sense - the stuff that's permanent goes on lower, leaves the tops open.

    Another thing I like: I find it takes some extra time or watts to get a turret heated up to where it will bond with solder - and I'm always afraid I'm going to cook something that doesn't want to get cooked. Doing it like in the video, you could do a lot of your "hot" work before you even put the components on the board.

    Man, where were you three days ago?!!??!!
    ;-)
     
  8. clintj

    clintj Friend of Leo's

    Posts:
    4,945
    Joined:
    Apr 4, 2015
    Location:
    Idaho
    To go even further, you can consider resistors and coupling caps as semi-permanent and electrolytic caps as temporary when planning ahead. Resistors, especially modern types, seldom fail unless a downstream component fails (failed tube, etc). E-caps are consumable items and replacement later is expected.

    Three days ago? I think I was taking a break before the site issues got me ticked off then. :) Like I said, just food for thought for later builds.
     
    Mr Ridesglide likes this.
  9. alathIN

    alathIN Tele-Holic

    Age:
    54
    Posts:
    773
    Joined:
    Oct 25, 2017
    Location:
    Indiana
    Had some busy work days and no time to work on my amp. Today got back to it, so it's a good day.
    Tube circuitry is addictive. I'm already planning my next project. (Gear Building Syndrome?)

    Spent the most time attaching leads to the turret board. I know there are different ways to do this. With the idea it would help me keep things neat, I decided to solder my connecting leads to the bottoms of the turrets. I'm not sure I'd do it again this way, but no major problems. It was an opportunity to double-check the turret board wiring (found two errors - misplaced jumpers). Then installed the turret board. With all those leads connected to the turret board, the satisfying neatness feeling is long gone. Should get better as I start connecting things.
    [​IMG]

    Then had some time for a few odd tasks.

    One of the oddest is the Tone Contour Switch. It's a six-position rotary switch for tone control on the EF-86 channel, which is supposedly modeled after an older era AC-15. I have never heard of an old Vox with this tone control, but I don't know much about old Voxes. I did see a YouTube demo of the tones from this channel when I was deciding what to build, and it sounded really good clean, crunchy, and in-between. That - plus the outright bizarreness of how this switch is wired - helped convince me to try building a TC-15. I've seen pictures of them that came out more neatly than this, but I think it will be functional (cross fingers)

    [​IMG]

    Last was making the Hi - Lo input jacks - one set for each channel.
    I imagine probably everyone knows about this already - I'm new, and happened to see it on a video from Boot Hills amplifiers - but I really like this idea of making a chassis face template for wiring things that would be a hassle to wire inside the chassis. My kids had left a piece of poster board on the laundry room floor, despite numerous requests to pick it up, so I decided it was fair game to borrow a chunk off the corner.
    [​IMG]
     
    King Fan likes this.
  10. Meteorman

    Meteorman Tele-Holic

    Posts:
    907
    Joined:
    Dec 23, 2012
    Location:
    State College PA
    and, if you're all thumbs like I am, you can template the whole chassis:

    [​IMG]Untitled
     
    King Fan and alathIN like this.
  11. gusfinley

    gusfinley Tele-Holic

    Posts:
    982
    Joined:
    Jun 11, 2014
    Location:
    SLC, UT
    It can be done simpler than this. Just temporarily install the parts on the outside of the chassis to wire them up. Your spacing will be perfect and then you just need to flip them around and install them in their proper place.
     
    alathIN likes this.
  12. alathIN

    alathIN Tele-Holic

    Age:
    54
    Posts:
    773
    Joined:
    Oct 25, 2017
    Location:
    Indiana
    UPDATE

    I don't remember what site I saw this, but dude had a different way of doing his shielded jumpers. I thought I'd give it a try and I like how it turned out. Start out the usual way, then solder a short lead on to the shielding.
    [​IMG]
    Bend the lead around and throw some heat shrink on it.
    [​IMG]

    So I installed the jumpers and, in theory, the amp is done.

    Face plate, channel 2, master, and power. Channel 2 is modeled after the classic Vox Top Boost.

    [​IMG]

    Channel 1 - EF86 preamp and 6 position tone switch. Apparently this is typical of an earlier generation Vox AC15.

    [​IMG]


    The whole shebang

    [​IMG]

    Power section

    [​IMG]

    [​IMG]

    Output section: phase inverter tube socket, power tube sockets, impedance selector, output jacks.

    [​IMG]

    Channel 1 volume and tone

    [​IMG]


    Channel 2 volume, bass, treble

    [​IMG]

    So, I said it's done in theory.

    Next time I get back to this, it will be time to double-check the circuit paths, power up, and test voltages.
     
    islander likes this.
  13. alathIN

    alathIN Tele-Holic

    Age:
    54
    Posts:
    773
    Joined:
    Oct 25, 2017
    Location:
    Indiana
    Oops - double post
     
    Last edited: Nov 22, 2018
  14. ahiddentableau

    ahiddentableau Tele-Meister

    Posts:
    216
    Joined:
    Jul 8, 2018
    Location:
    Middle of Nowhere
    Nicely done.

    How's the VVR working for you in this amp? I built one a while back but I haven't done the VVR.
     
    alathIN likes this.
  15. islander

    islander Tele-Meister

    Posts:
    300
    Joined:
    Oct 8, 2012
    Location:
    the Island, BC, Canada
    Looks great! Nice and clean build! I recently built the Triwatt. Their info packet, manuals(i printed the full triwatt build out) forum, and people here, made for a fun relaxing build. Stephen and the team are great to deal with, prompt with emails and it is my favourite amp. Just saving up to do a tc-15 build now.
     
    alathIN likes this.
  16. gusfinley

    gusfinley Tele-Holic

    Posts:
    982
    Joined:
    Jun 11, 2014
    Location:
    SLC, UT
    This looks great! I want to hear your impressions of the EF86 vs Top Boost.

    By the way the aerospace industry uses "solder sleeves" for grounding shields. Its solder and heatshrink in one. Slide it over your shield, hit it with a heat gun and you get 100% shield termination with a nice little wire that you can crimp a pin onto to carry the shield through your connector.

    This may be what you saw being used.

    Skip to 1:15 for a demonstration.

     
    King Fan likes this.
  17. alathIN

    alathIN Tele-Holic

    Age:
    54
    Posts:
    773
    Joined:
    Oct 25, 2017
    Location:
    Indiana
    It passed the AC power up test, and I hooked it up to a 9v battery and it will dial voltage up and down to the grid.
    As for how it sounds, will have to wait until I am playing it.
    For a while I had an Egnater with a 1-20W power dial which I believe was also voltage attenuation. I felt like it helped get good tones at lower volumes, but I felt like the more attenuation you used, the tone started to suffer.
    I also have a Weber Minimass so I am hoping with the VRM plus the Minimass I can use both kinds of attenuation in their "sweet spot." Because, being basically an AC15 output stage, this amp has ridiculously more power than I need.

    I'd like to hear more about your Triwatt. That and the OSD both look very interesting, and one or the other is on my "next build" list.
    I agree with you about Trinity's support and documentation - makes it a much more fun project knowing someone has your back. The forum seems a little quiet these days.
    My favorite thing about Trinty, though, is their very interesting off-the-beaten-track amps. You don't see a lot of Hiwatt and Dumble kits out there.

    Not long ago they had a vintage Hiwatt on That Pedal Show and it sounded freaking amazing. Three or four shows later they're still raving about it. I immediately thought "Triwatt, you're next." On that episode they used the Hiwatt to demonstrate attenuation. It sounded like that amp had 30,000 feet of headroom. With the attenuator, they were able to get it to a place where the output tubes were saturated but still not distorted. I think it's the best clean tone I have ever heard in my life. Does your Triwatt do that?

    That is very slick.
    It was somewhere on an amp building forum that I saw the technique I tried, and his was improvised like mine was.
    If you had to do more than a handful of shielded cable terminations, that solder sleeve thing would save some significant time.

    I will post a review here after playing for a while.

    I have ambitions (delusions) of making a YouTube demo. If that ever happens I'll link it here.
     
    ahiddentableau likes this.
  18. alathIN

    alathIN Tele-Holic

    Age:
    54
    Posts:
    773
    Joined:
    Oct 25, 2017
    Location:
    Indiana
    Went through the Trinity start-up procedure. Overall no real problems, just a enough oddball occurrences to keep me on my toes. At one point I was measuring voltages and my phone rang, vibrating a box of parts on my desk, and I almost needed to change my pants ;-)

    I used the light-bulb-in-series power limiter trick, which I hadn't done before, and the bulb started glowing a creepy dim reddish-brown, just like in a basement in a Stephen King movie. And then (duh) I couldn't figure out why all my voltages were off when I was plugged into a voltage-limiting power cord (duh).

    Once I replaced the light bulb thing with a normal power cord, everything fell pretty closely in line with what Trinity says is correct.

    measured number (Trinity's spec)
    V1
    p1 72 (85)
    p3 2.0 (1.9)
    p6 109 (131)
    p8 2.0 (1.9)

    V2
    p1 145 (137)
    p3 1.36 (1.46)
    p6 145 (137)
    p8 1.36 (1.46)

    V3
    p1 174 (169)
    p3 1.2 (1.3)
    p6 275 (279)
    p8 173 (160)

    V4 (PI)
    p1 260 (256)
    p2 46 (47)
    p3 69.6 (69)
    p6 256 (254)
    p7 47 (47)
    p8 69 (69.7)

    V5 EL 84 1
    p3 8.4 (8.3)
    p7 381 (384)
    p9 219 (242)

    V6 EL 84 2
    p3 84 (8.2)
    p7 381 (384)
    p9 218 (242)

    V7 5AR4
    P8 391 (380)

    Next step in the procedure was plug in and play.
    First impressions:
    the EF86 channel is LOUD and has a really nice crunch
    the Top Boost channel isn't shrill at all - I actually had to turn up the treble to 6ish and the master cut to zero to get in the right range
    Both channels: the low end is punchy as all get out. Reminiscent of a Fender Twin (one of the speakers in my 2x12 cabinet is a Weber reproduction of a vintage Fender speaker; that might be part of it).
    I play fingerstyle and this amp is very touch sensitive. I felt like I could hear my fingerprints.

    Too late to play much or really get into it, lest I wake all the kids instead of just one ;-)

    More detailed report to come.
    But initial impression is extremely pleased.

    [​IMG]
     
  19. islander

    islander Tele-Meister

    Posts:
    300
    Joined:
    Oct 8, 2012
    Location:
    the Island, BC, Canada
    [QUOTE="alathIN, post: 8744433]


    I'd like to hear more about your Triwatt.... The forum seems a little quiet these days.
    My favorite thing about Trinty, though, is their very interesting off-the-beaten-track amps. You don't see a lot of Hiwatt and Dumble kits out there.

    Not long ago they had a vintage Hiwatt on That Pedal Show and it sounded freaking amazing. Three or four shows later they're still raving about it. I immediately thought "Triwatt, you're next." On that episode they used the Hiwatt to demonstrate attenuation. It sounded like that amp had 30,000 feet of headroom. With the attenuator, they were able to get it to a place where the output tubes were saturated but still not distorted. I think it's the best clean tone I have ever heard in my life. Does your Triwatt do that?
    [/QUOTE]

    So first off, my favourite clean has to go to my first love, my 62 bandmaster...but this one ranks up there. Now I haven't played a cranked hiwatt to compare, so I'll have to watch that video, but tonight, I pinned the master and turned the normal to 10 oclock quickly with single coils, pure clean punch, my kids were getting ready for bed, so that's all I have for you there
    But as you mentioned, they don't straight copy.It's not only a dr103 ,it has a linked input, and it's also got a later overdrive circuit added. That is magic. So touch sensitive when set low. I have just been cranking the gain to experiment. Didn't have any idea it has that much gain on tap.
    The forum has been quiet for me too, but the amount of info that is there for all your build needs is great. My build is a few down here on tdpri
     
    Last edited: Nov 25, 2018
    alathIN likes this.
  20. ahiddentableau

    ahiddentableau Tele-Meister

    Posts:
    216
    Joined:
    Jul 8, 2018
    Location:
    Middle of Nowhere
    The idea of combining attenuation methods is exactly what I want to try, but I don't have an attenuator (yet--it's near the top of my build list). If you get around to trying that combination please make a report--i'd love to know how it works for you. Maybe you can save me some money!
     
IMPORTANT: Treat everyone here with respect, no matter how difficult!
No sex, drug, political, religion or hate discussion permitted here.


  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.