Platefire Update

[Platefire]

I am now the proud new owner of a Pacemaker. I have been avoiding working on tube amps ever since I found out I had A-fib and a slowed heart rate. I have a bad past record of being bit by DCV in mypast amp projects. So I'm now going to revert to just playing over them. I have a good amp tech friend about 30 miles away i can get to do any repairs I need. I'm still following the forum and have to throw my 2 cents in every now and then. Just thought I would let ya'll know

[scstill]

A few years ago my doc recommended a pacemaker with a defibrillator, Haha my insurance wouldn't cover the defib. Since I was close to retirement they suggested waiting for Medicare. Good thing I did 'cause now I don't need it.  Hope your life is better now....

The other day I got my first bite of DCV. Seemed to go thru chest and gave me some mild angina for a day or so. Need to be careful with that stuff.

I'm happy that you will continue to provide your tech wisdom here
and please continue to post your sound bites too....

[Platefire]

They told me not to lift over 5 pounds for a month or lift my hand above my shoulders on my left arm. This is to be sure you don't pull the two leads out that are attached to my heart. That is hard to do! You just unconsciously use your arm without thinking. So I picked up a arm sling to restrain my arm so I hopefully won't do myself any damage. No guitar for now but I've been  jamming on my harp one handed:>)

I've looked at your Cordovox build a couple of times lately trying to think of a solution, but everything I can think of has already been tried. There is got to be a solution if you can just fine it.

[bmccowan]

Hey Plate, I hope the pacemaker works out great. I know some folks who have had them for years without problems - except the batteries wearing down. I too have Afib and have had two Electric Cardioversions. i still work on amps but am extremely careful. I try to figure out everything with either no power to the amp, or very low power through a variac. But I just kept myself from buying another project amp (this was a bit of a milestone) and I'm going to start thinning out the completed projects (60 or so.)
Best wishes

[Platefire]

I reckon they got my Afib under control with a combination of Eliquis, Propafanone(meds), using a CPAP and a lot of Prayer. The pacemaker is set a 60 BPM where pre-pacemaker it got down in the 30's a couple of times while I was on a heart monitor while sleeping. I feel better and stronger now with the pacemaker. When I'm feeling good, it makes me want to pick up a guitar. So laying off for a month isn't easy!

I have considered being extremely careful working on a non-powered up amp the caps drained down. Trouble is, I thought I was being extremely careful the times I got bit:>) For some reason I get kind of hyped up and nervous when I work on a amp circuit. That may be the reason for my bad record of getting bit. Also in my early amping days, there were sometimes when I was finishing up a build, I would do an all niter to get r dun. That's not wise because mistakes happen when your really tired. But as you alluded to, amping is hard to give up, once you got it in you blood!
 

[bmccowan]

It sounds like you are making smart decisions. I would not encourage you to do otherwise. These thoughts are just general safety ideas that bounce around in my head.
I plug into a GFCI circuit, but I think that does little or nothing on the DC side.
I always keep one hand in my pocket if working on a live circuit.
I try to be patient and use meter clip leads which I attach with the power off and turn the power on to get a reading - this is slow, but keeps fingers out of a live chassis.
I add filter draining resistors as needed.
Other thoughts:
I used to be a pilot. Pilots use checklists. A checklist could serve as a reminder and boost awareness before going in.
I have thought about putting the project amp on its own switched outlet. A large pilot light mounted in front of you could let you know when power is going to the amp.

[rake]

Pacemaker?
Is that an EV or a gas engine??? 
May you now outlive at least three set of batteries! 
Take care of yourself!

[Platefire]

Well it seems to be the trend going EV so..............except getting a recharge is a little more involved for a PM. BTW they did a device check the other day and it showed I have 7 years charge remaining 

That is some very good points on ways to safely work on a tube amp. I'm very familiar with using a list for plotting a plan of what I want to do before going into a amp along with safety steps along the way. I'd say the two most important steps is avoid working on a live amp and even a power down amp you would need to find the safest way to bleed caps that you wouldn't get bit that way. I do have a bleeder jumper cable with insulated alligator clips on each end, insulated hook up wire and a in line 10K/2W resistor that's covered with shrink wrap.
 
So the challenge will be when one of my favorite amps develops a problem! I know in my rural area, very few people know how to work on tube amps. I know 2 in about a 50 mile radius. May be more but I'm not aware of them. I guess I'll cross that bridge when I
get there:>)

[bmccowan]

I hear you - not many techs in my area either. It's hard to charge enough to make it worthwhile.
BTW - +1 on the bleeder tool, but I was actually referring to permanently installing one or more. I usually use a 220K 2w resistor from the positive side of the first filter cap to ground. It bleeds the voltage pretty fast when the power is switched off.
 

[Platefire]

I was in the Amp repair for about 7 years after I retired. I had the same problem finding it hard to charge enough to make it worth my while. If I charged a reasonable Hourly rate for the research, trouble shooting, finding/ordering parts, actual labor time on repairs and testing, tweaking final results----I couldn't really charge what I felt I had into it. Truthfully I continued it as long as I did, because I enjoyed it. I finally got to where I just couldn't justify it anymore.

You know it's strange, but I don't remember hearing about the permanent bleeder tool before?? First thing I thought of was WOW! seems like that would be dangerous having the main power rail going through a 220K R to chassis! Almost like a direct short. So I guess the current will flow in the direction of least resistance to the rest of the amp until the power is turned of, then It will find the path of the bleeder circuit??? Is that how it works?

[SEL49]

You know it's strange, but I don't remember hearing about the permanent bleeder tool before?? First thing I thought of was WOW! seems like that would be dangerous having the main power rail going through a 220K R to chassis! Almost like a direct short. So I guess the current will flow in the direction of least resistance to the rest of the amp until the power is turned of, then It will find the path of the bleeder circuit??? Is that how it works?

Lot's of people do this. 220K is not a direct short! Far from it. Say your B+ is 440V. Putting a 220K resistor across 440V will draw 2mA. That's a whopping .88 watts.   

[Platefire]

Well thanks! I've done a very good job of overlooking that up to now

[rafe]

Pacemaker?
Is that an EV or a gas engine??? 
May you now outlive at least three set of batteries! 
Take care of yourself!

It's the Epiphone version of the Gibson GA5T

[Platefire]

It's really hard to just quit using your left arm for 6 weeks or not lift anything over 5 pounds. Of course your not so restricted with your right hand, still awkward!I wore a sling on my left arm up until yesterday marking it a month since. Played guitar yesterday. The Dr. kind of leaves it open ended one month or 6 weeks to restrict yourself. I sure don't wand to damage the healing incision or pull the leads lose from over exertion. So I'm may hold myself back a little longer

BTW--That's a cool looking Epi Amp! Don't remember seeing that one before. If I had to guess, I would say that is a Champ like circuit with a tremolo?

[bmccowan]

After my Cardioversion the instructions were to lift no more than 10lbs for the first week. When I got home, a 40lbs bag of dog food from Chewy was on the door stoop.
Epi amp - that is a cool one. I think that model is 1961 or 62 EA-50T and is likely electrically identical to the most unusual version of the Gibson GA-5T which has a 5Y3, a 12Ax7, and a 6bm8. Half the 6bm8 wiggles the trem. I've wanted to build one for some time now. I populated a board just before medical stuff stalled the project. Gibson apparently did not have much of an imagination regarding the alphabet or numerals as within the GA-5 Skylark EA-50 Pacemaker family there are at least:
6SJ7 > 6V6
12ax7 > 6V6
12ax7 > 6BM8
6eu7 > 2x6AQ5
6eu7 > 2xEL84
12au7 > 2xEL84

[Platefire]

I just started back driving. Thank the Lord, I had my wife Connie drive for me while I was out of commission:>). Just hauled off a months worth of trash bags that I had only half filled to keep the weight down. Finally working my way back to kind of a new normal

I haven't had much experience with Epi or Gibson amps. I did have a 1960 GA-40 LP amp until my Son adopted it and also a Gibson Atlas Bass amp. On amps I started out as a Fender user and later had several Peaveys and returned back to Fender tubes about the time I got into amp building/mods. Last few years I been a pretty good fan of Epi Guitars. Considering the cost of Gibson Guitars these days, Epiphone carries enough resemblance of quality, appearance, sound and play-ability of the Gibson's to not warrant the difference in price---for my purposes   

[bmccowan]

Its great to get back to doing for yourself, even if your wife is happy to help. I soon will be driving my wife around for about a month due to some eye work. That'll not be fun: "slow down, slow down, you are scaring the Hell out of me, there are deer and other animals around!"

I've rebuilt many Gibson amps. The good - they have their own interesting voice, and most of them look cool. The bad - some have weird T-filters that tend to muffle the tone (but those are easy to mod/eliminate) - many have crappy quality capacitors - many have crowded rats-nest wiring that makes re-wiring a challenge. Unlike Fender, there is no consistency of layout, some have component boards, some are point-point, some have terminal strips. They stayed cheap when vintage Fender and Marshall values started their rise 20-30 years ago. But now bargains are hard to find.
I'm with you on Epi and also Squire guitars. I do have a couple of vintage Gibson guitars and love them, but I would not pay today's prices as they should be in the hands of better players. I also have a couple of Japanese Fenders that are super nice, but those have now climbed the $ ladder.

[Platefire]

On my two Gibson amps, they worked good and I didn't need to do any repairs. I did look at the board and wiring. Like you said, was a rats nest and if I remember correctly seems like the board was populated on both sides?? I decided to leave well enough alone on the electronics and not mess with them. On the GA-40 LP amp I did do some cab work as when I got it, the tolex was stripped down to bare wood and it had no back plate. So I did my first tweed covering job and did build a back plate for it. Installed new oxblood grill cloth
and the Gibson logo was broken and half was missing, so I made another one out vinyl base material. It still had the original foot switch
that was made out of wood.