New Rocket STARTS UP!!!

[M Fowler]

You have come under the spel my friend.

You were just excited to get your amp fired up and made a mistake that is all, no problem.

Glad you got it going.

[marcoloco961]

Well with my head hanging low... I'd better come clean.
I went to bed last night with wires pulled and schematics and layouts lying all over the place. Woke up early this morning and said "s--t, I put the tubes in the WRONG sockets". The 12AX7s where the EL84s should be, and vice versa. Got up early, went to the shop, soldered everything back together, put the tubes WHERE THEY BELONG and I now have the best sounding amp I've ever owned (even before putting good tubes in or trying out different speakers). The tone is thick and meaty, and chimey and clear. The reverb is subtle (I typically like lots of reverb) but sounds great. So far I've only played at low volume but I'm very impressed. I don't think I need to tweak anything. I'll let it cook for a while before turning it up.
THANK YOU TO EVERYBODY WHO HELPED ME MAKE THIS HAPPEN!!!!!!!!!!!!!!!! YOUR COLLECTIVE GENEROSITY IN HELPING LEARNERS LIKE ME IS MUCH APPRECIATED. I'm already planning my next build.

Your probably not the first to do that. LOL

Maybe the first to admit it............... Glad to hear she is up and running. Sorry you had to get in all the soldering practice.

[marcoloco961]

You have come under the spel my friend.

You were just excited to get your amp fired up and made a mistake that is all, no problem.

Glad you got it going.

Sorry to get off track here, but I do remember how nervous I was on my first start-up. Hands shook like a leaf. Made it almost impossible to take the HT readings. When I took the plate readings on the pre tubes and the speaker "crackled", I bout crapped myself. After a couple of times back in the amp and working on a few new ones, it's like second nature. No nerves at all.

Bet it would only take one good "ZAP" to put me on the nervous side again. Anyone else remember being overly nervous their first start up?

[Cliff Schecht]

You have come under the spel my friend.

You were just excited to get your amp fired up and made a mistake that is all, no problem.

Glad you got it going.

Sorry to get off track here, but I do remember how nervous I was on my first start-up. Hands shook like a leaf. Made it almost impossible to take the HT readings. When I took the plate readings on the pre tubes and the speaker "crackled", I bout crapped myself. After a couple of times back in the amp and working on a few new ones, it's like second nature. No nerves at all.

Bet it would only take one good "ZAP" to put me on the nervous side again. Anyone else remember being overly nervous their first start up?

Yeah, you'll get over that.

I was never really nervous about working on tube amps, at least in the beginning. I was so thirsty for knowledge that I pretty much ignored all of the safety rules (soldering while the amp is on, shorting caps to ground, generally disgusting lead dress, etc..) in an attempt to work quicker. Definitely got this building style out of my head not only once I was ridiculed by my dad for such sloppy work but because I kept shocking myself and it was getting annoying.

You learn to be methodical about checking over amps pretty quickly, especially once you get a feel for how everything should measure out under properly biased conditions. It pays to figure out a method for safely testing your creations (and any HV piece of equipment) and it's not like it's hard to do so, you just need to follow a few simple rules.

[mcrracer]

Still not working.
I got my start-up tubes which I installed (JJs, not the Saratovs).
I plugged into the bulb limiter with a 60 watt bulb and turned on the amp.
There was a little surge of bright then the bulb settled into a low glow.
I threw the standby switch and the bulb went BRIGHT. I waited as long as I dared, then shut down the amp. I tried one of my other amps to see if I needed to wait longer for the bulb to die down to a low glow after throwing the standby switch, but the cap charging flash was pretty short.
So... back into the wiring.

One curious thing that I found, while testing with my continuity tester, was that the B+2, 47uf cap read as a closed circuit to GROUND on the POSITIVE as well as the NEGATIVE side of the cap.
I pulled all the wires and the cap (at first I thought I must have a shorted out cap but the cap tested fine) and traced the positive side to ground via the wire that connects to the 100 ohm screen resistors that are connected to pin 9 of all the EL84 tubes (does that make sense?). I pulled all the tubes. Still have a closed circuit to ground via the 4 100ohm screen resisters.
Is there possibly a short in a tube socket? or is this right? It doesn't seem like it could be right. Any ideas?

The problem you describe here is not tubes in wrong. You said you checked with the tubes out!

[Cliff Schecht]

I recently put in all of the tubes backwards in my 5C3 clone and fired it up. Tends to make the amps not work and I'm glad/lucky that I didn't ruin anything.

[telentubes]

Hi mcrracer,
I meant to say that I pulled all the EL84s because that's where I was finding the problem. When I flipped over the amp to pull the EL84s, it never occurred to me that they should have been on the opposite side of the chassis than where they were when I was working on the inside (pretty stupid)! "Haste makes waist" comes to mind amongst other sayings that go along with a screw up. I'm lucky I didn't do any permanent damage and I learned something along the way. Thanks again for the help. When your new at things, a lot of the obvious isn't yet.

[M Fowler]

You guys need to start using the proper tube sockets with the right tubes.

Wire holders for the EL84s and tube shield base for the 12Ax7 types

[mcrracer]

You guys need to start using the proper tube sockets with the right tubes.

Wire holders for the EL84s and tube shield base for the 12Ax7 types

+1

[statorvane]

I'm already planning my next build.

Went for it, hook line, and sinker! Don't ask me how I know this....

[telentubes]

I do have shielded basses for the 12AX7s. That didn't stop me from loading them with the EL84s.
Anyhow, that's water under the bridge. I've got the chassis in a roughed out cab, pre tolex and face plate (haven't decided what to do yet). I'll post a pic later, but for now, I'll just be playing guitar (there goes the weekend). I'm amazed at the tone of this circuit, even with the old cheap tubes I had lying around. And yes, time to start planning the next project. I'm hooked.

[M Fowler]

Play the amp or let it cook in for awhile and any problems will come out after that, hopefull none. The more the amp is used such as jamming or gigging the better it will sound.

Glad the amp is working and your enjoying it that's why we are all here.

Mark

[angelodp]

Glad it worked out so well, I am a few days from putting in my reverb circuit into an existing rocket build. I take it the amp has little or no hum, as you did not mention any issues with hum. Did you happen to check the wires you used for the heaters, is that pvc 18 ga stranded and tinned?

Ange

[Structo]

I'm still concerned about the way you have those 100K bleeders wired.

The big 80uf cap should not have it's negative end going through the 100K to ground.

The negative end should go directly to ground and the two 100K resistors should be in series and go from the + to ground.
This is to bleed the current down when powered down.

On that power tranny, does it really have the 5v on the green wires and the 6.3v on the brown?

[M Fowler]

I see what you mean Tom but not sure if that would be a problem since technically both are going to ground.

But I always wire my caps directly to ground and the bleeder resistors to a solder tap on chassis directly off the front of the board.