Real dumb newbie question

bluesbreaker59 · Post by **bluesbreaker59** » Thu Feb 17, 2005 5:39 pm

Okay so I got the stuff for my 50 watt PTP kit today. And now I have an incredibly DUMB question.

Do I solder the components to the side that "sticks out" or the side that is "flush".

Sorry for the dumb newbie question. This is obviously my first build and I couldn't tell from the pics which way is right.

Post by **VelvetGeorge** » Thu Feb 17, 2005 5:44 pm

No dumb questions on this board.

The components go on the side that sticks up. They float over the board and buss wire,

george

tooloud · Post by **tooloud** » Thu Feb 17, 2005 5:47 pm

The side that sticks up goes up...wires go around the bottom, electronic parts bend leads stick in hole.....The flat side is the bottom....

bluesbreaker59 · Post by **bluesbreaker59** » Thu Feb 17, 2005 8:26 pm

Thanks,

I figured that and I did it that way. I've got almost the whole board done and now ran into a problem.

The picture that I followed, on the tech reference CD, shows two .022uf caps at the right end of the board. I only had one left. Then it also shows two 10k resistors by the bias adjustment and I only had one.

Another picture on there shows using two .1uf caps where the .022 caps are on the tech reference CD, and it doesn't show using another 10k resistor at the bias adjustment. It just shows what looks like using a regular wire to jumper down there.

As you can all tell I'm not "techie" at all, but after the project today my soldering skills have gotten MUCH better.

Thanks for the help

Billy Batz · Post by **Billy Batz** » Thu Feb 17, 2005 9:53 pm

The picture that I followed, on the tech reference CD, shows two .022uf caps at the right end of the board. I only had one left. Then it also shows two 10k resistors by the bias adjustment and I only had one.

With the 2 10k resistors you can use just one 10k in that spot instead of 2. That will increase the voltage to the preamp which makes it a bit cleaner with a bit more headroom as opposed to a bit more saturated and gainier or what some people call browner. Just a bit though. Personally I think its a good idea in a 50W amp since there a bit on the saturated compressed side as it is. The 50W board layout on the CD has one 10k there and a jumper accross the top 10k spot.

I dont know if you are refering to the 2 .022uF caps that make an M shape along with the 2 100k resistors on the preamp side attached to V1? If so then you should have 2. Your not talking about the 2 .22uF caps on the 100W boards are you?

Another picture on there shows using two .1uf caps where the .022 caps are on the tech reference CD, and it doesn't show using another 10k resistor at the bias adjustment. It just shows what looks like using a regular wire to jumper down there.

OK I see you saw the pic I was refering to. Marshalls had a decent amount of variation. The spot with 1 10k and a jumper you could use 2 10ks like the later amps or 1 10k which is closer to the early value of 8.2k that was used in the same spot. As far as the 2 .1uF where the .022uFs are in another pic those are the 2 common values used for those parts called output coupling caps. The .1 will be bassier and the .022 will be clearer and thinner. Choice is your though you may have a certain set of caps to use anyway so you wont have a choice. Its just as well because if your unsure which you would want just use what you got and change it later if you feel the need to. Personally I prefer .1 there but I think the slight majority of people here actually prefer .022.

Flames1950 · Post by **Flames1950** » Thu Feb 17, 2005 10:25 pm

Hey Jason, did you end up getting the Bass board or the Lead?
The Bass would use the .1uF's, the Lead the .022's.
I didn't measure the plate voltage on that amp (I won't make that mistake again -- hehehehehe) but that may also determine whether you want the extra 10K or not by the bias adjustment pot. Like Billy said, it will be cleaner with only one 10K there. I've got some sitting here if you decide you need the extra 10K for a little more overdrive and brown goodness.
A quick word on the 10K's in there. It's real easy on those bluish grey resistors to mistake the third color band's color -- I often accidentally swap orange and yellow there, the difference between 10K or 100K. Double check them (and the smaller 100K plate resistors!!) if you can measure them. It's a big difference if they get switched by accident, and one that you won't like the sound of!!

bluesbreaker59 · Post by **bluesbreaker59** » Thu Feb 17, 2005 11:11 pm

I ended up getting the Lead board and asked George to give me all the parts to be able to swap it to a bass board.

You see, I can't read a schematic anymore, used to have to design them in AP Physics in High School but that's been a LONG TIME ago. So now I have to look at picture diagrams or chassis layouts.

Andy I was thinking about having you check my work if you wouldn't mind. Especially considering I'm color blind, and did this with no assistance from the wife or anyone else on colors.

Thank you again for chiming in, I REALLY appreciate the help. I also loved doing the project myself, however, as soon as I got done, I was thinking about doing an 18 watt kit.

bluesbreaker59 · Post by **bluesbreaker59** » Thu Feb 17, 2005 11:18 pm

Also one of the .1uf caps that I got was 400 volts, and the other two that I got were 630 volts, so which should I use where?

Also, I used the .1uf/630v that make the "M" shape near the bias pot, and I used the other one earlier, by the big clumping of resistors. Nothing scientific, just figured the two should be the same voltage?

Flames1950 · Post by **Flames1950** » Fri Feb 18, 2005 8:35 am

I also loved doing the project myself, however, as soon as I got done, I was thinking about doing an 18 watt kit.

Keep an eye on Weber VST's website. He's been showing 18watt and JTM45 kits as "coming soon" for a while now for $500, I think last time I lurked at his forum they should be coming in the next month or so maybe? The 18 watt comes cabinet and all, with either a Silver Bell speaker or one other choice. I almost got excited about his JTM45 but Ted admits that some components (trannies included I think) are of Asian origin. I can't think Ted would peddle anything that didn't sound great but I like the components (and origins of said components) of George's kits better so I kept hanging on for the Metropoulos JTM45. Besides, Ted's kits come with no instructions at all.......eeeek.

I can check it over for you if you want. I know what you mean about the color codes, about the time I'd try to skip double checking the resistor value with a meter I put the wrong one in. The 10K I put on the Normal channel's first 12AX7's plate was a real treat, dead clean and tinny.
If you have one 400V and two 630V caps, I'd go with the 400V at the clumping of resistors (I'm assuming you mean the phase inverter, kinda looks like a slightly crooked crow's foot with the .1uF to one side?) and leave the 630V caps for the output couplers right next to the "crow's foot." I don't know if you could tell tonewise, I would do it just to keep things neat and matched appearance-wise.