Asher Guitars WD Music Products Amplified Parts Mod Kits DIY Nordstarnd Pickups Warmoth.com
Asher Guitars WD Music Products Amplified Parts Mod Kits DIY Nordstarnd Pickups Warmoth.com
Asher Guitars WD Music Products Amplified Parts Mod Kits DIY Nordstarnd Pickups Warmoth.com

weber 5e3 build

Discussion in 'Shock Brother's DIY Amps' started by Finastbeans, Feb 26, 2011.

  1. Finastbeans

    Finastbeans TDPRI Member

    98
    Jan 12, 2011
    Maryland (DC area)
    I didn't really do that...is it necessary?

    Progress from last night...
    Tack soldered board, and shot of the underside which has been flipped so it lines up.
     

    Attached Files:


  2. mgwhit

    mgwhit Tele-Holic

    816
    Aug 1, 2008
    Louisville, KY
    Nope.
     

  3. Platefire

    Platefire Friend of Leo's

    Age:
    70
    Nov 3, 2003
    North Louisiana around Many
    OK, Sorry about the heater wiring continuity. I guess I've been doing an un-nessesary step! I learned something! Your board looks good. The only thing I would do different--which is my own hang-up and not neccessary is on cloth wiring where it fuzzes up on the end where you cut the cloth, I burn the fuzz off usually before I install the wire. Also I usually take my needle nose pliers and straighten the components leads up where I ruffeled them up from fitting--but you have to be very carefull if you do this because I have cut them in two doing this. This has nothing to do with operation and for appearance only. Platefire
     

  4. Finastbeans

    Finastbeans TDPRI Member

    98
    Jan 12, 2011
    Maryland (DC area)
    I hate that fuzz up thing, I was wondering how to clean it up. How do you burn them?
     

  5. Platefire

    Platefire Friend of Leo's

    Age:
    70
    Nov 3, 2003
    North Louisiana around Many
    Well--a match, lighter or stove burner. Just let it burn until the fuzz is off and then blow it out. The cloth insulation will keep burning in some cases so you may want to wear a glove so you can choke it off between your thumb and finger. You can practice on a scrap piece of cloth wire. If you look at my heater wiring closely in the attched picture you can see a little bit of black singe marks from the the burn.

    I find that is a good way to trim the insulation off cloth insulated wires in general is to burn off the amount I want to trim off instead of using wire insulation trimming tools because to me the cloth is hard to trim off and as you see it fuzzes up on the end. So I just burn off 1/4" or however long a lead I need, then wait for it to cool off and then just pull off the burnt residue with my finger. If there is a better way to do, I'm all ears!! ;)Platefire
     

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  6. Finastbeans

    Finastbeans TDPRI Member

    98
    Jan 12, 2011
    Maryland (DC area)
    lots of good information about grounding schemes here, I also found one more:
    http://music-electronics-forum.com/t2641/

    next up: going to wire up the flying leads, brass plate, jacks and pots. anticipating making brass plate ground connections outside of the chassis, by scratching up the location with a dental tool and using some additional flux before soldering...
     

  7. Platefire

    Platefire Friend of Leo's

    Age:
    70
    Nov 3, 2003
    North Louisiana around Many
    Yeah I followed your link to the discussion on grounding and agree with everything said. Good grounding makes a huge difference. Also I go to great effort to maintain as much space as possible between wiring. It's not always possible but if you have room get all the seperation you can.

    I hang out on the Hoffman Amp forum quite a bit and started a thread about
    the heater wiring because of my Mis-conception of how it should be done and MAN! did I ever get something started. Turned out to be a huge discussion, Har! Here is the link, check it out if you like!
    http://www.el34world.com/Forum/index.php?topic=11215.0

    I know you'll be looking forward to completing your amp but take your time and do everything right like you have been doing and you'll have great results. I double and triple check everything and still miss stuff. :oops:Platefire
     

  8. Finastbeans

    Finastbeans TDPRI Member

    98
    Jan 12, 2011
    Maryland (DC area)
    Thanks Mr Platefire... I probably won't get back to it until this weekend and I'm having a hard time concentrating on anything else :) All this time is making me come up with more questions:

    - do you think I need more space between the Resistor and the Cap which are cathode biasing the power tubes? That 5W resistor probably puts out some heat and I noticed yours are well spaced apart.

    - My layout/schematic for the kit does not call for referencing the heater current to ground through a pair of resistors, sounds like that is the "artificial tap" folks are discussing - did your PT come with a center tap for the heaters or are you enhancing the design for less hum?

    -Mike
     

  9. Platefire

    Platefire Friend of Leo's

    Age:
    70
    Nov 3, 2003
    North Louisiana around Many
    Well there is nothing like building your own amp. If you love guitar and great tone it's easy to get hooked on amp building. You'll have a little different feeling about an amp you build than a factory amp. The first one I did was a 5F1 Champ in 2001. I've been building ever since.

    I think your OK on you power tube cathod resistor and bypass cap. It looks like they are not toutching each other. If they are I would prise the apard just a little to get a little air between them.

    On heater grounding, as I understand it, if your power transformer has a heater center tap, you just ground that. Every power transformer I've ever bought didn't have a center tap, so I had to make an artificial center tap by grounding each side with a 100 Ohm resistor. If you got the center tap, just ground that, if not build the artificial center tap. Platefire
     

  10. Finastbeans

    Finastbeans TDPRI Member

    98
    Jan 12, 2011
    Maryland (DC area)
    Quick note, got the amp fired up today, and it sounds great. Thanks everyone who posted, it really helped. I will follow up with some details in a bit.
     

  11. Finastbeans

    Finastbeans TDPRI Member

    98
    Jan 12, 2011
    Maryland (DC area)
    ok - I am trying to figure out if this is a "normal" interactivity issue with the amp (which otherwise sounds great)... here is the scenario:

    plugged into normal channel
    tone = ~5
    normal vol = ~3
    ...turn up the bright vol and it seems to "add granularity" --> so far so good but when i take it up past 10, 3 things start to happen (between 10-12 on bright channel)
    1. the volume starts to gradually drop back down pretty noticeably
    2. i start hearing a "sshhhhhhhhh" almost like very audible tape hiss
    3. the sound that is leftover gets thinner and thinner

    plug into the bright channel and the same thing happens with
    tone = ~5
    bright = ~3
    ...turn up the normal channel volume past 10 and same symptoms.

    Otherwise the amp is sounding great. I have not taken voltage readings. I've got a Zenith NOS 5Y3 with 2 Groove Tube 6V6, V1=Electro Harmonix 12AY7, V2=Electro Harmonix 12AXZ

    So far I have not zapped myself, I have drained the filter caps 3 times shunting V1 PIN 1 to the chassis with an insulated alligator clip wire. Have not attempted to take any voltage readings yet.
     

  12. Finastbeans

    Finastbeans TDPRI Member

    98
    Jan 12, 2011
    Maryland (DC area)

  13. Platefire

    Platefire Friend of Leo's

    Age:
    70
    Nov 3, 2003
    North Louisiana around Many
    I haven't got my 5E3 with me to check but as I recall the decreasing volume interactivity by adjusting the other channel is pretty much normal. I assume you have double checked to make sure you've got your tone stack is hooked up like schematic? If you have, then it should be OK. The interactivity between channels is useful to some degree only-to extreams a little out of whack. Platefire
     

  14. Finastbeans

    Finastbeans TDPRI Member

    98
    Jan 12, 2011
    Maryland (DC area)
    ok - update - I played 3 gigs with the amp and it sounded great. than I demo'd the amp for my buddy a short drive away and the bright channel stopped working - no sound. brought the amp home, took it apart tested connections and everything seems fine, put back together bright channel works.

    ....time passes... bright channel stops working again, this time apparently for good. so I play with the normal channel for awhile. pack the amp in my car to demo for a different friend... fire the amp up, no normal channel. amp is just quiet.

    so i took voltage readings tonight...

    376V @ 20uF filter cap + connected to OT center tap
    344V @ 16uF filter cap + connected to PIN 4 of 6V6s
    267V @ 16uF filter cap + connected to B+ for preamp tubes
    367V @ PIN3 6V6 (left one)
    342V @ PIN4 6V6 (left one)
    365V @ PIN3 6V6 (right one)
    343V @ PIN4 6V6 (right one)
    265V @ PIN1 12AX7
    4.85V @ PIN3 12AX7
    216V @ PIN6 12AX7
    51.6V @ PIN8 12AX7
    140.3V @ PIN1 12AY7
    2.15V @ PIN3/8 12AY7
    134.8V @ PIN6 12AY7

    Those seem to look within range? Any suggestions on where to look next?
    Is it possible to damage amp components by flipping the bias switch when the amp is not in standby mode? That is the only lead I have right now - continuity tests seem to be checking out.
     

  15. bsnow17

    bsnow17 Tele-Meister

    Age:
    31
    288
    Feb 16, 2010
    delaware
    Try swapping in a new preamp tube since one channel went then the other it sounds like maybe you lost one triode first then the other went
     

  16. Cruisin Home

    Cruisin Home Tele-Meister

    290
    Jan 28, 2011
    NH
    good advice on change preamp tube. Also make sure tube socket is tight and making good connection.
     

  17. cousinpaul

    cousinpaul Friend of Leo's

    Jun 19, 2009
    Nashville TN

    It might also be a good idea to move the resistor a little further away from the bypass cap. It gets hot.

    I put my impedence switch next to the speaker jack. You could eliminate the standby switch (note that the original 5E3 had a ground switch there and no standby) and put the voicing switch up on the control panel.
     

  18. TxTeleMan

    TxTeleMan Tele-Afflicted

    Jul 1, 2008
    Austin, Texas
    Perhaps there is a bad solder joint or a loose ground bolt, something that opens when hot.
     

  19. Finastbeans

    Finastbeans TDPRI Member

    98
    Jan 12, 2011
    Maryland (DC area)
    Found it, the ground connection from v2 cathode became disconnected from brass plate. Those solder joints are really sketchy, I think I need a new strategy or they will keep popping off.
     

  20. t-luxe

    t-luxe Tele-Afflicted

    Nov 23, 2009
    so. cal

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