SSS #2 Started

[ATL Strat]

Hi Eric,

Please remember that the tech who did the schematic actually had the amp on his bench - no one else had this "primary material" to work from. I would go 100% with the original schematic unless I had a good reason to deviate.

Good luck!

[bcook]

The 470k resistors are the ground reference for the power tube grids. Definitely try those first.

I noticed that the 470k resistors from power section grid resistors to ground were ommitted on Aaron's layout (they show up in the schematics). Can someone tell me what the purpose of these resistors is? Is it something unique to a Cathode Follower setup?

Thanks for pointing this out and I'm embarrassed that I missed this detail. Especially since I have put some thought into this section.

Originally, I used the 1.5K resistors which are on the schematic I didn't catch the 470Ks. Then, at the advise of a few, I switched the grid resistors to the more conventional 5.1K, but it always bothered me.

It's bothered me because either the tech who drew the schematic was either consistently dyslexic, substituting 1K5 for 5K1, four times on the schematic or I was missing something. So I think I'll try going back to the 1K5 and adding the 470K and see what happens........... mojo?

Just to check in on progress:

1. Kind of figured out how to use my oscilloscope and signal generator and I've traced the signal through the amp.

2. In the process, I found one eyelet which I didn't solder and two erroneous connections.

3. With those fixed I get signal through the amp but the signal is very weak, whisper level.

So I got signal but no power.

I'm thinking that the next step is to swap the 5K1 for the 1K5 and add the 470K to ground maybe that has to be for the cathode follower to work....... and I'm thinking that I should get my voltages in line with the data from the schematic.

Thanks for looking.

Eric

[Reeltarded]

Hi Eric,

Please remember that the tech who did the schematic actually had the amp on his bench - no one else had this "primary material" to work from. I would go 100% with the original schematic unless I had a good reason to deviate.

Good luck!

For instance; the amp doesn't work.

[CHIP]

Hi Eric,
Any progress on your build?
I wondered if the error Sergio told you about on V1b helped the problem
.
http://ampgarage.com/forum/download/file.php?id=28420

[dorrisant]

Eric, since you have heard this circuit with 6650s and 6L6s... Which do you prefer and why? Do you recall what it was that was causing this issue?

I just read this post through. I can't believe I missed this one. I was probably stuck on the Wreck side at the time. I was sure there was gonna be some clips at the end...

I'm gonna scour the whole thing once more and take a few notes. I have the exact same chassis and it is calling to me to fish or cut bait. I designed some PCBs for the preamp boards and the cap board... The only one that I think I need to design is the bias board for the cathode follower driver coolness.

I know I'm bumping this old thread, but I have reason to believe it will get some closure...

[martin manning]

The recent one with 2x 6550 is UL. I think that, and many other differences, would muddy the water...

[M Fowler]

What is the real Dumble #002 boards layout?

Anyone have a #002 board design to share?

Mark

[Aaron]

http://ampgarage.com/forum/viewtopic.ph ... t&start=30

Aaron