Not so obvious problem RESOLVED

[ditdah]

Crack with speedball install.  I could use some advise...direction...guidance.

I've gone through the entire install 3 times now and can't figure out my problem.  I've done the following:
-reheated every solder joint
-verified connections as per the install instructions
---I connected terminal 4 on the transformer to 14U...as stated on page 19
-verified capacitor orientation
-verified LED orientation
-verified transistor orientation

Resistance checks (without power and tubes) were seemingly OK...except for the following:
Terminal 7 -      7.5K ohms
B3 -                 7.9K ohms and rising...should be 2.9K ohms
B6 -                 2.2K ohms and rising...should be 2.9K ohms
RCA center -     2.5K ohms...should be 90-100K ohms
...I assumed this to be possibly OK because of the speedball...so, I powered up.

Voltage checks (power and tubes installed)
Initial findings:
-output tube glows strongly...no glow at all from the 12AU7
-in every instance where there are LED's...1 of the 2 aren't lit up.  The exception being the ones on the center pin of the 12AU7 socket...they both glow.
Terminal 1 -      65VDC and dropping...should be 75 VDC
Terminal 2 -      177VDC, rapid drop to 70VDC and dropping...should be 170VDC
Terminal 4 -      69.4VDC...should be 170VDC
Terminal 5 -      62VDC and dropping...should be 75VDC
Terminal 7 -      53.1VDC...should be 100VDC
Terminal 9 -      52.5VDC...should be 100VDC
Terminal 13 -    65.2VDC...should be 170VDC
Terminal 15 -    found the resistor there sitting in melted solder!  I had to stop and unplug at that point...something is obviously wrong.

Now, I've been through the instructions 3 times...rechecked everything...re-soldered...etc etc...  I don't see where my problem is.  Any suggestions?  I guess my next step is to remove the speedball, install the 4 resistors and give that a shot...but I wanted to check in here first.  
I just don't see how I could have gone that wrong on the install.

 

[ditdah]

ok...did a little looking around and there's another person here who has a problem with similar symptoms as I have.  His post:  http://www.bottlehead.com/smf/index.php/topic,2976.0.html

I see his LED issue is nearly identical to mine...and voltage readings are similar...  I then found out...the metal transistors...I've installed them exactly in the wrong locations.  I have the ones that should be on the small pcb installed on the big one...and VS.  Question is...can that cause the melting solder I've experienced?

 

[Doc B]

You definitely need to fix the mixed up transistors. That may well solve the hot resistor.

 

[ditdah]

I've taken the speedball out of the circuit completely...installed the 4 resistors...and all resistance and voltage checks are perfect.  Amp works great.  So...that exercise was just to make sure I didn't destroy anything.  I'm impressed it held up after melting like that.  I'm guessing I may have shortened it's life a bit...but hey, all readings are just about bang on with the instructions.

I don't know what I was thinking when I installed those metal can transistors.  Even though it's clearly marked in the instructions...I "assumed" they were all the same and just installed.  I'll never assume like that again.

Now...how about some tips on removing those metal can transistors?  I tried a bulb solder sucker...and that's just too damn hard to do.  I tried some wick as well...worked to a point but I can't get those damn things out of there.  Any suggestions? 

Other than the time and money lost (mostly the time)...I'm not really heartbroken that the speedball isn't installed.  The base kit sounds really good.  It's dead quiet...not a hum, crack or anything.   

I'm really enjoying floyd via an iBasso DX100 into some Beyerdynamics T1's.

 

[Doc B]

Now...how about some tips on removing those metal can transistors?  I tried a bulb solder sucker...and that's just too damn hard to do.  I tried some wick as well...worked to a point but I can't get those damn things out of there.  Any suggestions? 

Get a helper. Give your helper pliers to pull out each leg, one at a time as you heat and solder suck the pad.

 

[ditdah]

Well, lesson learnt...next time, leave enough room to put pliers under the transistors...so your helper can get a grip on each leg. 

I'll give it another shot tomorrow when my patience has returned.  Thanks Doc

 

[Laudanum]

If they are flush to the board, personally, I'd probably just cut them out and desolder and remove one leg segment at a time then replace them with new ones.    But, it can probably be done with some persistance, and some help as Doc mentioned. 

 

[Grainger49]

Well, lesson learnt...next time, leave enough room to put pliers under the transistors...so your helper can get a grip on each leg. 

I'll give it another shot tomorrow when my patience has returned.  Thanks Doc

It is also a good practice, for the future, to leave the leads on transistors long so that the heat doesn't get into the junction.  Too much heat permanently damages the junction.  A hot iron or a slow one can make the transistor useless.

 

[ditdah]

Appreciate the input about leaving more lead space...will do so next time around.

I left space between the pcb and transistor...just not enough for pliers to get into.  I think I'm going to have to just cut them off as commented.  I was already thinking about that honestly.

 

[Noskipallwd]

Did the same thing with my transistors, taught me a good lesson. Read and follow the instructions step by step. Doesn't mean you won't make a mistake, but makes it less probable.

Cheers,
Shawn

 

[jrebman]

regarding getting those transistors out -- do you have a heat gun for heatshrink tubing? If so, you can make a heat shield out of a piece of aluminum foil with a hole cut in it just a bit bigger than the area of the 3 leads.  Clamp the pc board in a vise, affix the heat shield you just made, grab the transistor with some pliers, and heat the 3 solder pads concurrently with the heat gun.

Also, one of those little 2-piece scribes can be used to get under the transistor.

Yes, the bulb solder suckers are almost useless, but the good spring-loaded ones with the aluminum body (weller makes a very nice one) can do a great job with a bit of practice.

As for mixing up the transistors on the speedball -- you're certainly not the first to do it, and you won't be the last either .

Good luck,

Jim

 

[ditdah]

All,
Appreciate the advise.  All of which I'll look into...including the heat gun.  I have a nice milwaukee heatgun...but as I found out last night...maybe too powerful.  I destroyed the mesh stuff and it melted...and the heatshrink split on the power cord I was making!  It's not pretty.  I tell ya...had to wrap it all up in electrical tape...but it works just fine  

you know...just like with the speedball and the base crack kit.  I was so happy I was doing such a good job...only for something to go wrong.  Well, I'm over it...I'll have to find some way of correcting that some day.

mistake after mistake...man...makes me feel young again.  hahaha...it's incredible what you forget over the years if you aren't doing this stuff all the time.

 

[jrebman]

Aluminum foil is your friend in that situation too .  Just make a cone out of foil (like a dog would wear) and cover all the nylon mesh and just leave the heat shrink exposed.  Works like a champ -- never melted any mesh since using this technique.

HTH,

Jim

 

[ditdah]

Much appreciated Jim.  I'll try just that when I get my S.E.X. 2.1 in...I ordered a power cord kit for that as well.  Hopefully I don't slaughter that one too!  I'm confident and appreciate the tip!

Cheers,
Ken

 

[Grainger49]

All,

Appreciate the advise.  All of which I'll look into...including the head gun.  I have a nice milwaukee heatgun...but as I found out last night...maybe too powerful.  I destroyed the mesh stuff and it melted...and the heatshrink split on the power cord I was making!  It's not pretty.  I tell ya...had to wrap it all up in electrical tape...but it works just fine      .  .  .   

I have a heat gun I bought 15 years ago, refurbished.  I don't remember the manufacturer but it has two settings:  Extremely Hot and Way Too Hot For Anything!

The Tech-Flex on my Bottlehead power cords have the same problem.  I feel your pain.

 

[Doc B]

Some heat guns have extra tips you can put on to redirect the hot air. We have one that is wide and narrow. It lets us get pretty close to the top of the heat shrink without blowing too much heat on the Tech Flex

 

[ditdah]

I've got one of those wide, flat tips on my gun as well.  I think it comes down to being much more careful where I'm directing the hot air.  I wasn't initially aware that that mesh stuff would melt like that.  I'm still curious about why the heatshrink split...I guess just too much heat.  it split on the clear plug.

Well, on my next kit, I'll use some aluminum shielding as well as much more care about how I use the heat gun.  I'm hoping for better results.

 

[Doc B]

I have not seen the heat shrink split. It will curl over right at the end if you don't heat it somewhat evenly.

 

[ditdah]

I noticed the curling as well.  I was able to get that to smooth out, but that's when I ended up melting the mesh material.  I'll use some aluminum foil or shield of some sort next time around.  

On the hospital quality plug (clear plug) it split twice (clarification:  the heat shrink split...not the plug).  The first time, I was able to trim off the effected area and scoot up the unshrunk tube over the plug and start over.  However, it split again.  I also notice that the tubing crept down further away from the edge that it started...leaving behind about a half inch of that sealing goop.  That happened on both plugs.  I figured in all cases it was me...applying too much heat or something.  Give me a day or so. I'll unwrap the electrical tape and take a shot and send it to you.

 

[Laudanum]

Ive seen heatshrink split when it has a partial, lengthwise slit in it.   Doesnt even have to be full length or all the way through.   Makes sense because thats the best way to remove it.    Honestly, Ive never had a problem with shrinking the stuff, including not melting techflex, using a Milwaukee heat gun on low (without a nozzle).   But then again, I used boat loads of heatshrink in my work (used to shrink it with a wide nozzle torch).  This was the bigger, thick, adhesive lined stuff for .500" - 1.00" cable and associated fittings.    Anyway, just takes some doing to get the hang of it like anything else.