driver tubes dont light up after hookup wire replacement in mk3[PHOTOS]

hey all,
i upgraded hookup wire in both my VTA dynaco mark 3, one works just fine while the others both driver tubes dont light up and i get no sound. power tubes and 5ar4 rectifier lights up. no smoke or sparks, fuse is fine. what should i look at to try to figure it out. i have resoldered all the connections and still problem persists. any advise would be welcome. I understand this is is not ideal way to diagnose an amp, i welcome your input.








val

likely a cold solder joint or bad connection for the filament wiring

I resoldered filament wires, but will completely remove and solder in new wires now.
tx

so i resoldered filament wires completely, also went over all the other solder joints with hot iron and added solder, made sure good connection etc. still no go. here is a photo of powered up amp with completely different tube set that i know is good from my other mk3 amp. as you see no power to  driver tubes. speakers connected when test power on and i didnt bother with bias during brief test. i dont see anything fried and jumper wires on pcb are good. i dunno.

looks to me like your filament connection is incorrect. That twisted pair of wires going to your driver pcb, I assume are filament wires?
If yes, one of them seems to be going to pin 1&8 on the driver tube...it should be going to pin 7!, as the filament pins on the driver tube are 2 & 7

also, did you connect ground to the driver pcb? I see a wire in the B+ pad, but not in the GND pad next to it

MONTANA you are right. I cant beleive i made this mistake yesterday, maybe because it was 3am and NEEDED to install my new LAT International 20ga hookup wire. I will fix it now. I feel like a moron but i am glad nothing fried...that i could see. ok ok let me fix...

this is my ground. i think one GRND connection is ok right? just now soldered to correct pin. lets power it on.....

Montana thanks for that catch. All is well now and playing music beutifully. I do notice an improvement with new hookup wire, should be better with break in. not as much upgrade as the claritycapMR and the mundorf 100uf on top of PCB, but seems better to me. Thanks again and HAPPY FATHERS DAY!

Yes I've been curious as to the break-in period for that special kind of hookup wire. Not sure what the manufacturer recommends.

gruvlad wrote:Montana thanks for that catch. All is well now and playing music beutifully. I do notice an improvement with new hookup wire, should be better with break in.  not as much upgrade as the claritycapMR and the mundorf 100uf on top of PCB, but seems better to me. Thanks again and HAPPY FATHERS DAY!

no probs! Main thing is you can now enjoy the amps once again!

gruvlad wrote:this is my ground. i think one GRND connection is ok right? just now soldered to correct pin. lets power it on.....

yeah thats good....could not really see that ground wire from the photo's

wildiowa wrote:Yes I've been curious as to the break-in period for that special kind of hookup wire. Not sure what the manufacturer recommends.

I have heard people say some wire settles in about 40hrs or so, others say wire needs more...but I definatelly hear a positive difference from what was in there before,  some 22GA stranded copper that had some kind of tinned coating on it.

Holger,
Good on you for helping Gruvlad out. That were above and beyond the call of duty. Gruvlad, would sure appreciate an update on how that new silver wire burns in. Just remember that ~90 percent of the wire in your amps will still be copper, in the transformers. Don't think I wanna hand-wind one of those, whether toroid or EI. Bedinis used to wire their own EIs, took the both of them 3 days to wind a single one!

HOLY COW What a difference in sound quality this simple mod made! It was noticeble from the get go that it was better, a bit thick sounding at first but cleared up within first 5hrs. its been about 20hrs and I have been listening to some albums that i know pretty well and used to and i can tell you that it is a very positive result. Seems like this was the bottle-neck in my dynaco mk3's. I wont go into audiophile speek but a significant improvement in sound stage, and micro details.
Remember this was not solid core silver wire, it is 20ga hookup wire from LAT International. I am in no way afiliated with them, I just happen to have their IC200 MKII interconnect cables that i got a good deal on Agon. Sounded better than Kimber heros(more musical and smoother than Kimber hero) so i decided to use their hookup wire. very inexpensive modification. some instruments in background are more pronounced.

my system consists of
Musical Fidelity m1clic>Audio Research sp16>dynaco mk3>Magnepan SMGA Gunned just for reference.

Thank you again for taking the time and catching my mistake, much appreciated!

gruvlad wrote:HOLY COW What a difference in sound quality this simple mod made! It was noticeble from the get go that it was better, a bit thick sounding at first but cleared up within first 5hrs. its been about 20hrs and I have been listening to some albums that i know pretty well and used to and i can tell you that it is a very positive result. Seems like this was the bottle-neck in my dynaco mk3's. I wont go into audiophile speek but a significant improvement in sound stage, and micro details.
Remember this was not solid core silver wire, it is 20ga hookup wire from LAT International. I am in no way afiliated with them, I just happen to have their IC200 MKII interconnect cables that i got a good deal on Agon. Sounded better than Kimber heros(more musical and smoother than Kimber hero) so i decided to use their hookup wire. very inexpensive modification. some instruments in background are more pronounced.

my system consists of
Musical Fidelity m1clic>Audio Research sp16>dynaco mk3>Magnepan SMGA Gunned just for reference.

Thank you again for taking the time and catching my mistake, much appreciated!

gruvlad, how much wire did you use in the MK III. I'm seeing $30 for 15 feet on their website; was that enough to do the trick?

15feet is more than enough to do two mkiii's with about more than half left over, I think I used about 6ft or so, I havent measured how much I had left though. I replaced all the internal wiring possible except the bias probe wires.

gruvlad wrote:15feet is more than enough to do two mkiii's with about more than half left over, I think  I used about 6ft or so, I havent measured how much I had left though. I replaced all the internal wiring possible except the bias probe wires.

Well, I'm contemplating such a move myself. But you've two variables at work; the caps and the wire. It could perhaps be that the caps are settling in and that's what you're hearing. It took my silver-oil Mundorfs a few dozen hours to fully form up, but well worth the wait.

That is also possible, as I replaced the caps maybe 60hrs before the wire upgrade, but I heard a different sound right away with wire I remember.