Mission 5E3 Kit into 2x12 cab

well, i finally got started on my mission kit today. my buddy and i took turns doing the little stuff (he already builds great cabs, and we're doing this kit together to learn... its my amp though), and we're ready to start soldering. Its ridiculously hot, so we're going to hold off till tomorrow for the meat of things. Here are a few pics:

http://i101.photobucket.com/albums/m69/TheOne1932/P1000415.jpg
http://i101.photobucket.com/albums/m69/TheOne1932/P1000419.jpg

here you can see we got the switches and such put in:

http://i101.photobucket.com/albums/m69/TheOne1932/P1000422.jpg


we know we have ot rotate some stuff a little, but it moved along swimmingly. Can't wait to get into the meat of things tomorrow.

Oh, and here's a pick of me concentrating my attention to pics of the plug wiring (95 inside my house, you can see the beads of sweat on my head) while screwing in the fuse i believe:

http://i101.photobucket.com/albums/m69/TheOne1932/P1000416.jpg

I turn 26 on the 8th and i'm hoping to have it done as a big birthday present to myself.

Happy birthday!

Man, I hope it cools down. I'm in SoCal, but it's been hot here too.

as old tele man says "yeah, but it's a dry hot".

Its 6:55pm, 97 inside my house and we're soldering. oh yeah, you gotta love amp GAS.

Someone mentioned in your post on that last thread already...

Your cathode bypass caps are in backwards. Positive goes towards the tube sockets.

Yeah, i think that was the first thing we corrected today, but i appreciate the headsup.

as old tele man says "yeah, but it's a dry hot".

they say that in az as well but when it's 112 dry or not your getting the hot end of the hole...

they say that in az as well but when it's 112 dry or not your getting the hot end of the hole...

I hear ya, OTM is from AZ IIRC, and his quote was meant with a bit of dry humor. :mrgreen:

there's no "dry" humor when you're sweating your arse off like me. Its 10pm and my house is down to 90 degrees. Lovely, eh?

crap, broke pin 2 on v4, can i substitute pin 1 and go on? I'm supposed to be soldering green wires from the PT there

crap, broke pin 2 on v4, can i substitute pin 1 and go on? I'm supposed to be soldering green wires from the PT there

Yes, carefully remove the broke pin and replace it with one that isn't being used (I would take one from the rectifier tube socket pins 1,3,5 & 7 are unused on it).

what do u mean "replace it?" How does one go about that?

crap, broke pin 2 on v4, can i substitute pin 1 and go on? I'm supposed to be soldering green wires from the PT there



Check your PM.

Pins 2 and 7 are the 6V6's heaters. Pin 1 doesn't do anything.

I'll look for a spare Octal socket in my parts bin... if I find one I'll mail it to you.

Keep us all posted...

yeah, broke pin 1 in v5 now trying to pull it out... damn

what do u mean "replace it?" How does one go about that?


They are installed from the tube side of the socket, if you slightly twist the solder lug side to line up with the slot, you can push it out from the back of the socket through the front, just reverse the procedure to install the replacement. Be careful not to bend it too much, they break easily :mrgreen: (don't ask me how I know this).

yeah, broke pin 1 in v5 now trying to pull it out... damn

The rectifier socket only need 4, you got spares. You'll make it.

How's the weather today?

the high was 109! inside my house its currently 92. Oh well, its starting to cool down, but i just started breakng pin 7, sooo... my girlfriend got me a bottle of jack daniels single barrel for my bday yesterday, it might be time to make an ice and bourbon soon. we'll see

Well, i twisted it to line up with the slot, but i still can't get that little F-er out. needle nose and regular pliers won't get it to budge... ideas?

EDIT: GOT THAT LITTLE SUMBICH, time to soldier on.

Cool.

Bourbon on ice sounds great about now...

ok, for tomorrow i have a little bit to do and then it'll be finished hopefuly. I am confused on the shield cable for the pots and hoow to wire the jacks to completion. some of the pics on bruce's site aren't the best. I'm also confused on wiring the speaker jacks. but i feel confident it'll be good to go tomorrow.

suggestions anyone?

Is this what you need?
13048

ok, for tomorrow i have a little bit to do and then it'll be finished hopefuly. I am confused on the shield cable for the pots and hoow to wire the jacks to completion. some of the pics on bruce's site aren't the best. I'm also confused on wiring the speaker jacks. but i feel confident it'll be good to go tomorrow.


The input jacks have tip (+), shunt and ground (-) lugs.

Keep in mind that when you have two 68K resistors wired parallel it is like having one 34K resistor. When plugged into #1 input the signal is going from the tip lug to one 68K resistor AND from the tip of the #1 jack to the shunt of the #2 jack and out of the tip to the other 68K resistor. When plugged into the #2 input the signal is just going to one 68K resistor.

So, you can run leads from the 68K resistors to the tip and shunt lugs of the #2 jack and a short jumper from the shunt of #2 to the tip of #1.

for the output jacks, this is what bruce's site shows:

http://home.earthlink.net/~tweedmaster/images/MM-OT-secondary-jack.JPG9

i have no idea what i am supposed to infer from that in terms of where to solder

Your link is broken.

Which OT do you have?

missionamps

missionamps

Blue, brown and red primaries, green and black secondaries? If so, Red to B+, brown and blue to pin 3 of the power tubes, green to the tip (if you have 1 sorting and 1 non shorting, black to the shunt and ground lug...this will be the speaker out) then just wire tip to tip and ground to ground on the extension (non-shorting) jack.

yellow, green and black go to the jacks. what is tip to tip and ground to ground? this is what bruce told me, but i'm not quite following him:

"The OT jacks are grounded to the chassis by being mounted... the threaded bushing
is connected to the ground lug on the jack.
Either jack can have the black wire soldered to it's ground lug.

Yellow is 8 ohms and green is 4 ohms.
Black is common and or chassis ground."

yellow, green and black go to the jacks. what is tip to tip and ground to ground? this is what bruce told me, but i'm not quite following him:

"The OT jacks are grounded to the chassis by being mounted... the threaded bushing
is connected to the ground lug on the jack.
Either jack can have the black wire soldered to it's ground lug.

Yellow is 8 ohms and green is 4 ohms.
Black is common and or chassis ground."

My bad, different OT's

OK, just use two non-shorting jacks (no shunt), one will be the 8 ohm jack, so attach the yellow wire to the tip lug, the other jack will be for a 4 ohm speaker load so, attach the green wire to the tip lug of that jack. Attach the black to the ground lug of either one.


What I had described in my previous reply would be for an OT with only one ohmage out and would put the OT load to ground in the event the amp was used without a speaker plugged in (Fender did this in most of the Black and Silverface Amps)

haha, see... on hte output jacks there are two placess to solder ( as opposed to the input, which have three), i don't know which is the ground lug and which is the tip lug

haha, see... on hte output jacks there are two placess to solder ( as opposed to the input, which have three), i don't know which is the ground lug and which is the tip lug

Looking from the inside of the jack the ground log is connected to the "ring" part of the jack, the "tip" lug looks like it is not connected to anything.

On a shorting jack, the center lug is the the "shorting tip".

i'll have to investigate this and with pics provided in the morning. Its been another longer ridiculously hot day.

i'll have to investigate this and with pics provided in the morning. Its been another longer ridiculously hot day.

The "sleeve" is the ground lug.

http://i70.photobucket.com/albums/i115/teleamp/jack.gif

The "tip" lug is on the left in the pic below.

http://i70.photobucket.com/albums/i115/teleamp/images.jpg

ok, i think i get this. I'll take pics tomorrow and post them up. On a related note... if i have one 8 ohm outjack and one 4 ohm out, does that mean i can run an 8ohm cab outta one jack and a 4 ohm cab outta the other (at the same time)?

ok, i think i get this. I'll take pics tomorrow and post them up. On a related note... if i have one 8 ohm outjack and one 4 ohm out, does that mean i can run an 8ohm cab outta one jack and a 4 ohm cab outta the other (at the same time)?



No, you can run one or the other, not both

Cool thread. I hope it goes well and gets cooler. I have been wanting to build a kit but am worried bc I have never worked with installing tubes.

Cool thread. I hope it goes well and gets cooler. I have been wanting to build a kit but am worried bc I have never worked with installing tubes.


Its really not been that hard, the difficulties are when you encounter something you don't know all that much about (like my issues with what tip, ground and sleeve are). other than that its all like following a road map and soldering in each stop on your journey, don't be worried.

so, does this look correct before i get to soldering?

http://i101.photobucket.com/albums/m69/TheOne1932/P1000431.jpg

They look correct to me.

sweet, the end is in sight!

ok now, because bruces layout is color coded, i, like a moron, used teh shielding cable when it called for a black wire. any suggestions on what i should use in place of the shielding wire??

Oooh, that is a bummer. Black wires are generally for ground. Rewire with black wire, then if you don't have any shielded for the preamp section, it is OK.

The original '50s tweeds never used shielded wire at all anyway.

thats the thing, i used it to ground the EC board to the brass plate, that was the only place his layout really called for it [black wire]. then i get to this point and realize," shielded wire... wtf??"

Oooh, that is a bummer. Black wires are generally for ground. Rewire with black wire, then if you don't have any shielded for the preamp section, it is OK.

The original '50s tweeds never used shielded wire at all anyway.

+1, I don't use shielded cable in my 5E3 scratch builds.

he runs the shield wre from pin 2 of the ax7 and runs it to the back of the volume put, should i just screw it?

It should run to the outer lug of the Volume pot with the internal shield grounded.

Shielded wire saps noise from the shielding to ground, the internal wire should still be wired to where it needs to go. The shielding is meant to reduce noise from getting to the internal wire.

In the case of a 5E3 the input jacks to grid resistors are such a short distance you don't even need any there, but in the volume to next gain stage's grid you're going a farther distance under the board (and possibly noisey components). In this case, that is where I would use shielded wiring on this build - IF you have any left. Otherwise, normal wire is fine.

Remember, the internal wire goes from the grid (pin 2) of V2 to the right outer lug of the Volume pot, the shielding under the jacket goes to ground. The best place to ground the shielding is on the pots grounded left outer lug (which should then be grounded as well).

i am about an inch short. I COULD link two pieces and put heat shrink around the joint to insulate... if you think thats worth trying

i am about an inch short. I COULD link two pieces and put heat shrink around the joint to insulate... if you think thats worth trying



Nah, not on shielded wire.

Just go ahead and use ordinary wire. If you start getting noise, try rerouting that wire first.

should i still solder some of it to the back of the volume pot?

i am about an inch short. I COULD link two pieces and put heat shrink around the joint to insulate... if you think thats worth trying
I would get some shielded wire at your local electronics store and use that.

they're closed for the weekend...

should i still solder some of it to the back of the volume pot?



NO! That would simply ground out V2's 1st grid.

Ok, shielded wiring is a bit unusual. Let me explain it:

There is a normal wire inside a internal jacket. On the outside of that jacket is a shield (either mesh or foil), then the external jacket.

The internal wire is your signal wire. The wire or foil mesh (the shielding) on the outside of the "real" signal wire's jacket should be grounded to create the shield around the internal wire.

({(o)})

The 1st "(" is the outer jacket.
The "{" is the shielding (mesh or foil) which is to be grounded.
The 2nd "(" is the internal wires jacket (usually a coaxial style waxy white jacket).
The "o" is the internal wire which is to be wired to the signal portions of the circuit.

Strip the outer jacket (usually black), seperate the foil/mesh from the internal jacket and solder that to ground (back of the pot or leftside outer lug), then strip the internal jacket and solder the wire in there to the pot's rightside outer lug.

On the tube socket end, strip down to the internal wire and solder that to pin #2 - no grounding needed on the tube socket end. As long as the shielding is grounded on one end, your internal signal wire (feeds volume pot signal to pin #2 grid) will be shielded from external noise.

Just use normal wire for now... if you encounter noise, then worry about finding shielded wire.

I believe I used ZERO shielded wire on my 5E3 build. I don't use shielded wire as a common practice unless:
1. It's a high gain preamp.
2. I always use it in reverb circuits of the amp (whether a high gain build or not).

Normal wire works fine. If noise is a problem reroute this wire until the noise is gone. If that doesn't help THEN wait to buy shielded wire.

so lets just say i continue with the build until monday when i can get some more... if i use normal cloth wire i just solder it at pin 2 of v2, run it under the board like i would the shield cable and then solder it to the right lug of the vol pot?

sorry, posted that after you postd yours

so lets just say i continue with the build until monday when i can get some more... if i use normal cloth wire i just solder it at pin 2 of v2, run it under the board like i would the shield cable and then solder it to the right lug of the vol pot?



Yes. Wire from pin #2 to the outer lug. That's all.



Essentially both plates from V1 (one is Normal the other Bright) send the channels' signals to the Volume pots from their 0.1uF coupling caps. The one volume pot is jumpered to the other (thus the interactivity of volume controls), the volume pots then sends the channels' signals to V2 by feeding it to V2's first grid (pin #2).

This signal is then fed from V2's first plate (pin #1) to it's second triode's grid (pin #7 at the 1meg resistor). Basically this is a form of cascading. So yes, a tweed 5E3 is cascaded :)

V2's 2nd triode's cathode feeds one 6V6's grid (usually by means of a 1500 ohm/1.5k resistor to pin 5, often using the unused pin #6 as a solder lug), and the 2nd triode's plate sends it to the other 6V6 (again, pin #5 through a 1.5k grid resistor). This 2nd triode of V2 is the Phase Inverter and sends opposite phases of the preamp signal to each power tube. This is how the 5E3 is a push-pull or Class AB amp.

my question now lies with the 100k resisitors that run from the 22u4 on the EC board to pins 7 & 2 on V4, any suggestions?

my question now lies with the 100k resisitors that run from the 22u4 on the EC board to pins 7 & 2 on V4, any suggestions?



V4? The far left 6V6 tube socket?

I'm not sure I know what you mean.

Are these the 100 OHM "artificial" center taps for the heaters? If so, they are not 100 "K" (100,000 ohms as opposed to 100 ohms). This elevates them over a negative DC voltage to help eliminate more hum from the 6.3v AC heater supply - IF - this is what you're talking about.

Please clarify.

i guess they're the 2 1/2w 100 ohm filament supply balancers, my bad

Are the Mission instructions that bad?

check your PM box, shepherd.

whats really annoying are the various discrepancies between the layout sent with the kit and the "directional" pics on the mission site.

i guess they're the 2 1/2w 100 ohm filament supply balancers, my bad

now, these aren't on teh weber layout or another 5e3 layout i have at my house in a book, anyone got any ideas?

now, these aren't on teh weber layout or another 5e3 layout i have at my house in a book, anyone got any ideas?



Other layouts use PT's with real heater center taps.

If the PT used doesn't have a CT for heaters, you can artificially make one with two 100 ohm resistors.

It's not crucial to the amp working, but definitely help with added hum.

the problem is that his layout and his pics are radicaly different and i have no idea where to place them. his layout has them running from the EC board, his pics have two of them in V4. what am i supposed to do with that, you know?

well, i decided to power it up and see what happened. the light came on, but apparently only V4 is getting power, cuz its the only tube that lit up. nothing burned, nothing smoked, nothing hissed or popped. I know i need to go thru now and measure voltages, but i have no idea how to do that. here's a pic of my buddies multimeter, anyone familiar with these:
http://i101.photobucket.com/albums/m69/TheOne1932/P1000441.jpg

V5: http://i101.photobucket.com/albums/m69/TheOne1932/P1000432.jpg

V4: http://i101.photobucket.com/albums/m69/TheOne1932/P1000433.jpg

V3: http://i101.photobucket.com/albums/m69/TheOne1932/P1000434.jpg

output jax: http://i101.photobucket.com/albums/m69/TheOne1932/P1000435.jpg

V2: http://i101.photobucket.com/albums/m69/TheOne1932/P1000436.jpg

V1:http://i101.photobucket.com/albums/m69/TheOne1932/P1000437.jpg

input jax: http://i101.photobucket.com/albums/m69/TheOne1932/P1000438.jpg

Pots: http://i101.photobucket.com/albums/m69/TheOne1932/P1000439.jpg

on/off, fuse, standby: http://i101.photobucket.com/albums/m69/TheOne1932/P1000440.jpg

EC board: http://i101.photobucket.com/albums/m69/TheOne1932/P1000443.jpg

lamp: http://i101.photobucket.com/albums/m69/TheOne1932/P1000444.jpg

sorry bout the pics, my camera is not so great.

anyone? many thanks :)

Check your pm's

i'll check that connection, but i'm more concerned about only v4 heating up and nothing else (v5, v3, v2 and v1)getting power... all my connections in there look sound, i don't know how to use my multimeter. to drain the caps i just hook one aligator clip to the positive ends of the filter caps (the big black ones) and the other end to the chasis and wait a few seconds, right?

Check your heater center tap wiring. Make sure you used 100 OHM, and then make sure you used 100K for your plate resistors (swapping these will make for no sound).

Take some farther back shots too, for perspective.

Can you understand how everything is shaping up in the circuit or does it still feel "paint by numbers" to you? If so, you need to slow down. Slow down and try to visualize what is happening at each part of the circuit.

A 5E3 is very basic as far as amp designs go. As you begin to understand each part of the circuit, you'll begin to understand how things should go, and THEN how to troubleshoot. You can't troubleshoot a paint-by-numbers.

i am definetely understanding how it all works, the farther into the kit i got, the more i understood the whole thng.

as for the problem: there's not going to be any sound if only one of the tubes lights up, but i don't know how to use my multimeter to see where the problem(s) are. i don't have the manual for it. As for draining my caps, was my description above accurrate ?

Here's the manual.
http://www.jewellinstruments.com/pdffolder/triplettpdfs/84-852.pdf

You got the right idea for draining the caps but you forgot that you need to put a resistor in between the two clips. Not just any resistor either. If you go too big you will have to wait too long.

so i put one clip to the positive end and one to the chasis, but i touch a resistor to the leads coming off the positive and negative ends of the cap to make the draining start?

http://studentweb.eku.edu/justin_holton/caps.html

Measure them caps - chances are they're pretty close to empty already.

Don't freak out - just be safe.

Photos from a distance may help us with perspective - but no heater voltage to the rest of the tubes should be easy to figure out...

i'll get some new pics up tomorrow.

i need to pick up a resistor to drain the caps, but i don't know whcih kind, the page i was linked to suggests a Xicon 25k 10W cement power resistor, but my local shop doesn't know if they have one. is there a general part i am looking for more likely to be carried?

Don't be afraid too much about the caps, just use common sense :!:

I usually use my multimeter to drain/check the caps. If you turn off the amp, but leave the standby switch on, the charge on the caps should leave rather quickly. Then check the voltage over them with your multimeter - you can see it drop.

But do remember to unplug the amp everytime you're going inside. I already got zapped twice when my finger accidentally touched the on/off switch :razz:

I'm pretty busy till tomorrow afternoon, but i think i've isolated the problem(s) so i'm confident i can get it up and running soon. Its time though, that i gave my review of mission amps.

all parts: top notch, boutique level from what i've gathered

layout: the layout is mostly perfect save for the various discrepancies between the layout and the pics included online. different colored resistors, different placement of parts when comparing pics can lead to confusion. One would assume there would be a level of uniformity in this regard, but, apparently not.

Directions/pics: severely lacking. The pics online often do not match the layout and do not offer the best angles for a beginner or for anyone who isn't well versed in this particular amp. the lack of organization among the pics is annoying as well. There are no directions is general though.

Email help: apparently i paid for this when i bought the kit, but i don't think i got much. from the start when my girlfriend was buying this for me (mind you, she knows nothing about amps other than blackface is good and handwired is good) she emailed mission amps to recieve no reply. Discouraging, but she knew i wanted to do a build so she bought it regardless. I have emailed them a few times only to see long delays between sent and response times and the current one (no response since sunday when i sent a bunch of pics for them to look at, which they encourage!) which has only frustrated me more.

Having done this whole kit now, i would buy the mission kit again. I would not recommend it for a 1st timer though. From what i now know, i would highly recommend Marsh Amplification ktis. they both offer much more help and direction than mission amps and were prompt in responding to my emailed questions. They have an indepth instruction guide as well.

As far as draining the caps, use your MMeter to see if they even need to be drained. Generally low watt old tweeds don't hold charges very long. You'll likely not need to drain them at all.

If you do need to, there are about a million websites with basic instructions and even photos, for the timid.

When it comes to the layout and resistor colors, it is important to be able to read schematics when it comes to this kind of thing. Look at BOTH where possible.

In any case, the color of the resistor is generally meaningless. Larger blue resistors are usually Metal Oxide power resistors, which means 1, 2, or 3 watt (generally dropping resistors in the filter and B+ circuit). White, boxy, ceramic resistors are generally 5 or 10 watt resistors (often the cathode resistors). Tan, or small blue are general purpose resistors (usually 1/8 - 1/2 watt)... with the small blues usually being Metal Film, tan being Carbon Film, and darker brown being Carbon Composite... usually.

The wattage means using the appropriate power handling in the right spots. A lot of wattage goes through the power tube cathodes (even if not a lot of negative voltage does). For the B+ and filtering it's safest to go with 1, 2, or 3 watt Metal Oxide resistors. For high gain areas where noise is a concern (generally only in preamp tube plate resistors) Metal Film is better.

Learning what voltage, watts, and impedance actually means helps too.

What is important in the layout is the color bands (if the layout shows that). Getting to know the color codes is important too. This way you'll know a resistor's value just from looking at it.

jc-
I got yer PM and checked some stuff out, you were right. I have learned tons from this, i just am disappointed with the complete lack of direction and shabby tech support.

i just am disappointed with the complete lack of direction and shabby tech support.

I have to disagree with you. I built a 5E3 a few weeks ago, and in 95% of the times, I received an email back from Bruce within a day. I do agree with you regarding the minimal documentation. In that case both Bruce and this forum were a great help. But to be honest, it's an advanced project, which requires some knowledge and experience.

I've been waiting since sunday for a response, and i even sent a 2nd email asking if he'd had a chance to look at the pics yesterday. Still no response, leaving me annoyed. The whole project really isn't that hard, i just think bruce could do more to make the project more cohesive. It is completely lame that he hasn't emailed me back though.

Just wanted to update everyone and let them know that I'm completely in love with the 5E3 thru a 2x12 cab. everyone should have that type of rig. perfect for gigs, no need for stomp boxes. just a guitar, a cable and an amp. perfect. Of course, the amp building bug has taken ahold...