Developing the DIY "Champ" for first time builders

[M Fowler]

I don't pay much attention to posters saying things like tone sucking, tube choice, pot types, resistor brands/types or cap types because all of those things are purely subjective to the individual player.

Rock on

Mark

[surfsup]

Nice, guys! I look forward to the supre!

[xtian]

Hey, telentubes, looks like you have the two 2w resistors in the power section, 10K and 22K, reversed. 10K should go first, nearest the diodes, then 22K.

[xtian]

RJ: Your TAG SE100 v1.2c layout shows the two resistors going from coupling caps to ground as brown-black-green, when they should be brown-black-yellow (100Kohm).

[RJ Guitars]

RJ: Your TAG SE100 v1.2c layout shows the two resistors going from coupling caps to ground as brown-black-green, when they should be brown-black-yellow (100Kohm).

Yes I am looking at the CAD drawing and I'll agree mostly and disagree a little as well - The color code is definitely wrong unless you really like deep shades of green in your yellow, but hopefully they are not going to ground...

Drawing has been updated and will be posted ASAP. I am always appreciative when someone sees a boo boo and lets me know.

Page 16 for those that want the new drawing...

thanks,

rj

[xtian]

RJ: As this is a beginner's project, you might want to add polarity markings to the electrolytics.

Thanks! Just finished soldering my board. I added one new turret to help make the first stage cathode bypass switchable.

[telentubes]

Good eye xtian!
I'll switch those resistors.
Thanks

[telentubes]

Speaking of polarity, jvc may want to check the V2 cathode cap. Some one with better eyes may want to have a look at the pic on page 19. It looks like it may be in backwards. Apologies if this is a false alarm.

[surfsup]

xtian, could you clear something up for me in your first pic? The lead from the cathode resistor is nearly touching the turret with the cap on it. So what's the point of 3/8" turret distance when leads are many times much closer? ( aside from integrity of the circuit board material not having too many holes in one spot and breaking )

[xtian]

xtian, could you clear something up for me in your first pic? The lead from the cathode resistor is nearly touching the turret with the cap on it. So what's the point of 3/8" turret distance when leads are many times much closer? ( aside from integrity of the circuit board material not having too many holes in one spot and breaking )

I have about 3mm clearance there, so I'm not worried about any accidental short. The resistor is already grounded, and the bypass cap is going to run to a switch, and then to ground. There's no AC current there, only DC, so there should be no RF problems...is that what has you worried?

Let me know if I misinterpreted your question!

[RJ Guitars]

xtian, could you clear something up for me in your first pic? The lead from the cathode resistor is nearly touching the turret with the cap on it. So what's the point of 3/8" turret distance when leads are many times much closer? ( aside from integrity of the circuit board material not having too many holes in one spot and breaking )

I don't think the 3/8" distance is essential for electrical isolation in most cases concerning this amp. The turret spacing just gives you some room for the body on some of the bigger components like the filter caps and such. Things can get real close and friendly inside the tube itself so it kinda depends not only on distance but strategy in how you lay things out. It can be important not just keeping certain parts or wires away from each other but also paying attention to how they cross each other etc..

rj

[telentubes]

I used the schematic and layout which were posted earlier in this thread, which have the 22K and 10K resistors reversed. Other builders might want to make note of this so they don't make the same mistake. The later drawings are corrected.

[surfsup]

Okay thanks guys, as a noob I was thinking 3/8" is the minimum otherwise "arcing" would happen. Laugh it up, go ahead...

The lead seemed very close, way closer than 3/8th so I figured I'd ask...so its AC that might be a problem, so what levels of V are we to be concerned about then? All guitar amps should be fine, or just 15W or less lower powered?

[xtian]

You need a lot more voltage to arc. Van Der Graaff generators, for example, produce tens of thousands to millions of volts in order to get arcs of electricity.

[RJ Guitars]

I used the schematic and layout which were posted earlier in this thread, which have the 22K and 10K resistors reversed. Other builders might want to make note of this so they don't make the same mistake. The later drawings are corrected.

I went through and attempted to find any of the old stuff and remove it and give the reference to page 16 for the latest greatest.

If it makes you feel any better, I actually put those resistors in wrong on #1 before somebody pointed out the flaw to me. I'll be curious if you report back any sonic change when you make the swap. It shouldn't change your V1 voltage but might make an audible difference on V2.

When we are finally convinced that we've identified and eliminated all the flaws then maybe we can give it some sort of stamp of approval?

rj