Route to happiness: a 5f2a, a Surfyverb and a Makita

Discussion in 'Shock Brother's DIY Amps' started by Paul-T, Aug 22, 2019.

  1. Paul-T

    Paul-T Tele-Meister

    Posts:
    217
    Joined:
    Nov 23, 2018
    Location:
    London
    Like many brothers and sisters here, I am going through a period of simplifying and editing in my life… which involves more acquisition!

    I've cut down my guitars to 4, soon to be 3 I think, and a few years back sold my bigger amps, including a Bandmaster reverb. Now I've sold tons more stuff to get my 63 Jazzmaster sorted, and it sounds great. But I want something a little bigger than my 54 Champ for the living room, and followed the sage advice of the classic gateway drug, a 5F2a.

    I've built fuzz boxes and other stuff before, but a key challenge for me is, without a dedicated workshop, to build a cabinet, for the Princeton - and also for a Surfy trem and reverb, which I will add to this thread. I hope to do so with the most basic of gear, namely a black and decker workbench, circular saw - and a Makita 1/2 router, picked up for a pittance, but which crucially fits with the cheapest and most foolproof box router jig I could find, the Leigh.

    References:
    I've followed through The Professor's build thread, in which he seems to ask every one of the important questions (and get good answers).
    As this is one of Hackworth's kit's I found this thread handy too.

    I've read through many threads on valves, er tubes, and acquired most of what I need, some NOS from a magnificent crazy shop in Lincoln which sells old aircraft bits, though I still need my rectifier. The downside of this shop is that somehow I picked up lots of resistors, vavle bases and other stuff for a Micro Deluxe. Oh dear.

    I've taken Rob's grounding scheme as my bible. I've looked at all the various PT and OT options. In particular, I've subscribed to jsnwhite's comments on using a 275-0-275 PT. I'm not looking for clarity and headroom. Hence I'll be using the Hammond 290CAX, with tapes at those voltages.

    I've followed a reasonably similar approach re OT, and jsnwhite has been very helpful there too. I'm using Classictone. Most people here will know they offer a basic small 4W Champ, the same with an 8 ohn tap, the upgraded 10-15W version, and an old-skool version which is perhaps even more gnarly and low powered. I went for the basic on the basis that, that's what boothill had in stock!

    I used the kit from Hackworth and I'm glad I did, it saved me lots of time and got me going mroe quickly. his kits are pitched exactly where I want to be, a couple of notches up from Weber etc, with decent but not boutique caps, mostly carbon film resistors but etc.

    Chassis
    Choice for chassis in Europe seems limited. We have Modulus
    https://modulusamplification.com/Tweed-Princeton-5F2a-Style-Chassis-P5692694.aspx
    Tube-town only seems to do a 5f1
    https://www.tube-town.net/ttstore/C.../TT-Chassis-Fender-Style-5F1-Champ::4851.html
    and Tube AMp Doctor
    https://www.tubeampdoctor.com/en/shop_Amp_Parts_AMP_Chassis/Amp_Chassis_Tweed_Princeton_5F2_2167

    Totterer helped turn me on to Amp Mart
    http://www.ampmart.com/en/productview.asp?sid=1069
    (they also list on line as Mable Audio, but are the same company)>
    They were responsivle and helpful. If you simply buy online, they charge $35 postage, but if you enquire first, it's only $18. They are also helpful with customs declarations to avoid the dreaded courier broker fees.

    Progress so far
    I've acquired various router bits, s/h drill holder, and have populated the board. I used a croc clip as a heat sink and soldered my capactiros quickly using the low power iron. The main problem for me was what to solder in what order, to avoid softening previous joints, and to leave space on the turrets for remaining wires. I think i'm ok. I used Hackworth's idea of a cardboard template to locate wires and make sure everything fits.

    Questions?
    There will be plenty more to come, but if you veteran 5F2a builders can cast an eye on the board for obvious errors, it would be appreciated. I've measured the resistance of every resistor before soldering, and this afternoon re-checked and every joint and value seems good.I followed Rob's colour scheme where I could to make it easier to check. Only the main caps aren't soldered in yet as I wanted to make sure I had access to the chassis mount screws etc.

    also, I wasnt certain where the board would mount, as this is essentially Hackworth's 5F1 and my chassis holes are not quite identical. This position, nestled right under the volume, looks similar to what I've seen. Correct?

    And finally, I assume the "power amp ground" on Rob's ground screen, is a bolt/tag strip fastened to the chassis, correct?
    ground pa.jpg


    Main board pic .jpg board, top.jpg
     

    Attached Files:

    Last edited: Aug 22, 2019
    FRANKENJAG likes this.
  2. Paul-T

    Paul-T Tele-Meister

    Posts:
    217
    Joined:
    Nov 23, 2018
    Location:
    London



    and, for some local colour, this is the amazing shop, 150 miles from me, where I sourced lots of switches, resistors, valve bases and 12AX7. The proprietor is 93, nearly blind, and has been looking for the two 6V6 he had knocking around for around three months now! He believes the idea of building a valve amp, which distorts, is toally crazy. Nor does he suffer fools gladly. A bit like my old man. One of the world's last, great shops I reckon. He still has bits of Vulcan bombers, and other old instruments.
    Birkett1.jpg Image 25.jpg Image 26.jpg
     
  3. VintageSG

    VintageSG Friend of Leo's Ad Free Member

    Posts:
    3,234
    Joined:
    Mar 31, 2016
    Location:
    Yorkshire
    If you want to skip the cabinet building, Juke Tone offer a ( small ) range of tweed covered lovelies that may save your sanity. Tube Town do some cabinets ( uncovered ) that may be worthy of your attention, plus there's also the standby of the beehive kit ( I kid you not, a beehive )
     
  4. Paul-T

    Paul-T Tele-Meister

    Posts:
    217
    Joined:
    Nov 23, 2018
    Location:
    London
    I have the router now and I'm committed! I did consider Juketone early on but as I'm planning eventually to replace my old Champ I wanted something with similar, pine construction. Plus you know how it is, this might not be the last one I build, and I fancied a challenge.
     
  5. King Fan

    King Fan Friend of Leo's Ad Free Member

    Posts:
    3,886
    Joined:
    Jan 1, 2013
    Location:
    Salt Lake City
    Hey Paul. Good for you!

    I'm not sure I understand all your questions perfectly, and I’m not the guy who knows the 5f2a layout well enough to eyeball yours and say it’s right.

    Re Q2 are you asking where to locate your board relative to the actual chassis? Even if you use a cardboard template (good), it has to be marked and cut to match the actual chassis you’ll use.

    Re wiring and solder sequence, softening previous solder isn’t an issue. You can in theory do it over and over and over. The idea is 1) you want each wire or lead to be mechanically solid so re-melted solder won’t let it fall apart and 2) you want to wrap (180* to 270*) all the wires on the turrets except those that may need replacement (e-caps) or modding (? coupling caps, etc). These you try to mount in the top holes for easy replacement.

    You may have done this, but any underboard leads should be stripped long enough to poke up through the turret, stick out, and be bent over for a) mechanical surety b) visual inspection later.


    Sent from my iPad using Tapatalk
     
    Paul-T, Robear and robrob like this.
  6. Paul-T

    Paul-T Tele-Meister

    Posts:
    217
    Joined:
    Nov 23, 2018
    Location:
    London
    @King Fan thank you. I thought this board was better than average and now I realise it's distinctly worse!

    Thanks so much for letting me know about the underboard leads, that's completely new to me. I will redo those. I'll redo some of the other connections that wouldn't hold without solder.

    My template matches the chassis exactly, but the holes in the Chinese chassis are different from some I've seen. But I think I will be fine, I will update with more photos once I've redone the leads.

    I'm assuiming the "Power Amp Ground" on Rob's schematic has to be the one bolted to the chassis, would be great if someone could confirm. :)
     
  7. King Fan

    King Fan Friend of Leo's Ad Free Member

    Posts:
    3,886
    Joined:
    Jan 1, 2013
    Location:
    Salt Lake City
    Heh, Paul, I definitely wasn't critiquing your board. I'm happy if my generalized thoughts can be helpful, but I'm not going ooh, look at that mistake there... :)

    Re the power amp ground, yes. Rob's layout is my go-to here. But you're smart to check how any drawing, no matter how good, is to be implemented with wire and solder. Ground anchors are an excellent example.

    Though many folks just use a PT bolt (usually the upper right corner) for the power amp ground, best practice (PT bolts can loosen over time) is to drill a separate hole and use a separate bolt. While we're at it, best practice also (solidly) swages a ring terminal on each ground wire and layers the terminals between a star washer and a keps nut, with some thread locker just to cement the deal. There's usually plenty of room in a 5e3.

    upload_2019-8-27_9-45-54.png

    On the same topic, as you likely know, you want a completely, mechanically and electrically, separate bolt for your household safety earth / ground.
     
    Paul-T and tubedood like this.
  8. D'tar

    D'tar Friend of Leo's

    Posts:
    2,133
    Joined:
    Jan 11, 2013
    Location:
    WNY
    You are short a Filter Cap.. B+1

    [​IMG]

    upload_2019-8-27_15-20-12.png
     
    King Fan and Paul-T like this.
  9. Luthier Vandros

    Luthier Vandros Tele-Holic Silver Supporter

    Posts:
    632
    Joined:
    Aug 19, 2015
    Location:
    Down by ya mom an them's
    Lovely post!

    I live near Fullerton, CA and have been on a mission to find an old TV repair shop that still stocks parts, but as you might have imagined, they are all but extinct. You're blessed to be where you are! Someone needs to take over that store for that gem of a man. We need a business continuity plan stat!

    Best of luck on your journey!
     
    King Fan and Paul-T like this.
  10. Paul-T

    Paul-T Tele-Meister

    Posts:
    217
    Joined:
    Nov 23, 2018
    Location:
    London
    thanks. He is lovely - but very grumpy. I always tell him I'm off too see a proper old person, my auntie who's 94, and they're warming to me. Pulled out some 12AU7 this weekend, when I went up to see the folks. Which is bad news of course... means I'm scheduling a Deluxe Micro before I've finished this one. Still no sign of the 6V6 though.

    It is 39 degrees in London and too hot in my work shed to get the soldering gun out. But I will update.
     
  11. King Fan

    King Fan Friend of Leo's Ad Free Member

    Posts:
    3,886
    Joined:
    Jan 1, 2013
    Location:
    Salt Lake City
    LOL and OMG. I told you I wasn't good at visually checking circuits. Of course D'tar always sees the small stuff that I miss -- like a big huge filter cap -- and here I am out in the weeds about soldering. :D

    Paul, are those both 22uF caps? What plan / layout are you following? You'll note the 5f2a was designed at 32 (as 16x2) / 8 / 8, as opposed to the 5F1 at 16 / 8 / 8. If you go F&T, a nice 30uF first filter (reservoir) will fit nicely on your board. I'm no expert, but too much filtering after that, especially at B+3, can make your amp too 'stiff' and less vintage.

    I bet you just neglected to populate those turrets with the right bits...
     
    Paul-T likes this.
  12. Paul-T

    Paul-T Tele-Meister

    Posts:
    217
    Joined:
    Nov 23, 2018
    Location:
    London
    My bad, I should have said I was leaving the main caps until last, I wanted to solder the main earth cable and make sure the board fits in the chassis before adding the three electrolytics so they're not subjected to any heat etc. The two there aren't soldered in place yet.

    @hackworth1 recommended this cap layout, three x 22uF. IIRC He suggested that's what Fender would have used had electrolytics been cheaper at the time.
     
    King Fan likes this.
  13. King Fan

    King Fan Friend of Leo's Ad Free Member

    Posts:
    3,886
    Joined:
    Jan 1, 2013
    Location:
    Salt Lake City
    Ah. Good for you. Dave/Hackworth knows his stuff, and I’m sure 22 x 3 will work well.


    Sent from my iPad using Tapatalk
     
    Paul-T likes this.
  14. Paul-T

    Paul-T Tele-Meister

    Posts:
    217
    Joined:
    Nov 23, 2018
    Location:
    London
    thanks so much everyone for tips so far.

    Newbie question 1: I used the carboard template to get wire lengths correct - but do folks use it to wire eg valve bases up and then transfer the lot to the chassis?

    Newbie question 2: I've noticed people comment on how, for example, turrets can interfere with the input jacks. That implies there's an approved orientation with, I guess, the tip connector in a particular place. Is there an approved way round to mount them, and why?
     
  15. Robear

    Robear TDPRI Member Ad Free Member

    Posts:
    59
    Joined:
    May 11, 2016
    Location:
    The West Desert of Utah
    Paul-T, how did the build go so far? I contemplated using a template for my first build, but ended up just wiring in place because I’m impatient like that. If I had used a template I thought I would wire in place and transfer to the chassis. It seemed like the right way to do it. Which way did you end up going and how did it go, if you don’t mind my asking.
     
    Paul-T likes this.
  16. Paul-T

    Paul-T Tele-Meister

    Posts:
    217
    Joined:
    Nov 23, 2018
    Location:
    London
    I am trying to wire in place. Although, this being my first build, I have to look at loads of photos before I commit to anything.

    I soldered the connections to the 12AX7 base using the approach (wires from outside, underneath) from photos on Rob's site. Does that look ok? I've followed his colour scheme exactly, except where he has orange on his layout (from the volume middle wiper) I've used blue and white. Does that look ok? I'm certain the connections are tight enough so there won't be any shorts. I know it looks like the plastic sheathing is distorted/melted, but the flat points are where I gripped them with my needle-nose pliers while stripping, the PVC is still intact. 12AX7 base.jpg Board with one base.jpg
     
    Last edited: Sep 8, 2019
    Robear likes this.
  17. Paul-T

    Paul-T Tele-Meister

    Posts:
    217
    Joined:
    Nov 23, 2018
    Location:
    London
    If anyone want to post photos of valve-base (ok, tube-base) soldering they approve of... please fire away!
     
  18. Paul-T

    Paul-T Tele-Meister

    Posts:
    217
    Joined:
    Nov 23, 2018
    Location:
    London
    while folks are wondering whether to send me back to the remedial class... this is the last couple of hauls from that tiny shop.

    NOS Mullard and Brimar 12AX7. THen the sharp-eyed among you will spot two Raytheon 5814, the military 12AU7, and you will deduce that before getting my 5F2a working I already seem to be accumulating stuff for a Micro Deluxe. Bad PT. What I shall do with the Siemens germanium 107 equivalent, who knows. But buying switches isn't naughty. There are three different double throw, all for £1 each. The middle one is very funky, it's a double double throw.

    I have no idea what make the carbon film resistors are, nor how old they are, but I think it was £1 for all of them. Bits from Jack 1.jpg switches.jpg resistors.jpg
     
  19. Paul-T

    Paul-T Tele-Meister

    Posts:
    217
    Joined:
    Nov 23, 2018
    Location:
    London
    OK, I think I'll wire up the rectifier base in the chassis, likewise add the heaters later. I'll spend the rest of this afternoon re-checking all the connections and resistances before I instal. Need to test-fit transformers, too, I've checked the Hammond PT but not the Classictone 40-18115 OT.

    Diodes fitted as per The Professor's thread.

    diodes.jpg two bases.jpg

    I realise I don't knwo how the jacks wire. I am guessing the switched tip is to earth it when not plugged in and have to work that out.

    OT doesn't fit the Chinese chassis. Couldn't see where it fits on @totterer 's build, but as usual the answer lies on the Prof's thread.
     
    Last edited: Sep 8, 2019
  20. Paul-T

    Paul-T Tele-Meister

    Posts:
    217
    Joined:
    Nov 23, 2018
    Location:
    London
    i found input jack wiring illogical because I thought S stood for sleeve. Now I realise S stands for Switch or Shunt (I've never used mono switched jack sockets before although of course they're standard). And that fits with the jacks I have - so I finally understand, years after everyone else.

    As usual, enlightenment, and the last word on input jacks was on Rob's site.
     
    King Fan likes this.
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.