2nd Gen Build Started (that didn’t take long…)

[martin manning]

My PI tube plates are about 10v apart; does this indicate a grossly mismatched tube?

Not necessarily, and in any case you have the PI trimmer to iron that out.

[Raoul Duke]

Did the initial PI calibration and the trim pot only needed to move about 1 millimeter CW. Of course - I’ll verify once everything is hooked up and running.

Tomorrow I’ll finish up the preamp connections, heaters, and B+4 and 5.

Really looking forward to hearing this amp! I hope it’s close to what I’m expecting based on what I think I’m building here. I’ve listened to the first 3 generations’ demos plenty and will be thrilled with something somewhere in that (fairly wide) range. Fingers crossed

[Raoul Duke]

Here’s a random new guy question:

Given the space and alignment issues I’m experiencing with this build, is it a bad idea to put the V1 and 2 terminal strips up on washers - allowing the plate leads to pass underneath - thus providing more separation and shortening them by 33-66%?

Anybody ever done this and regretted it or know of why it might not work?

Thanks in advance!

[martin manning]

I don't see a problem doing that. You are not using the ground lug for anything, so making that connection a little less direct electrically doesn't matter.

[Raoul Duke]

Thanks Martin!
I’ve looked at the gut shots and don’t have the space for the lazy curves without encroaching on the following tube’s territory and really crowding things. I saw the layout shows direct lines but figured that was for simplicity in understanding and didn’t want to be too literal given my position on the learning curve; so I wanted to throw it out there and see.

I appreciate the input

Almost ready to make noise.

[martin manning]

Its seems that HAD didn't develop that big loop style until a bit later. You're right, layout drawings are somewhat idealized, but hopefully they convey the essentials.

Turns out there's a font for your logo, "Steadmanesque."

[Matt J]

Here’s a random new guy question:

Given the space and alignment issues I’m experiencing with this build, is it a bad idea to put the V1 and 2 terminal strips up on washers - allowing the plate leads to pass underneath - thus providing more separation and shortening them by 33-66%?

Anybody ever done this and regretted it or know of why it might not work?

Thanks in advance!

I've gotten where I've started doing that with ODS builds and haven't had an issue with it. I just use a longer #4 bolt to hold the tube socket in place and have the standoff attached between two nuts. I use some heavy wire cutters to clip off the unused center ground lug so I doesn't get in the way later. I have a 2nd Gen I'm working on now (Seems to be the trend around here!) I'll put more pictures up later, but you can see a bit of how I attach the standoffs in this image. I have had issues in past having to do longer runs or crimping lead wires around standoffs so I prefer to do this now.
Matt J.

[Matt J]

Its seems that HAD didn't develop that big loop style until a bit later. You're right, layout drawings are somewhat idealized, but hopefully they convey the essentials.

Turns out there's a font for your logo, "Steadmanesque."

As a big Hunter S. Thompson fan I LOVE this!

[Raoul Duke]

Thank you both for the input!

Martin - I really like the logo idea Love RS’ artwork. He’s the only artist that could do HST justice.

Matt - saw your avatar a long time ago and knew our paths would cross eventually, lol.

Having a bit of a panic moment right now because I thought I had the references for the pins mixed up (the bA, K, RGs) but I think I’m ok. Just traced out what I did with the PI and I think I’m on track. Learning new stuff is “mind-bottling”, lol.

Thanks again guys!

[Raoul Duke]

All right, just one more piece of co-ax for the OD CW and I think I’m there. Not the prettiest, but I’m learning.

IMG_0202.jpeg

It’ll have to wait til tomorrow - I’m going upstairs and having a beer; it’s been a busy week, lol.

[Raoul Duke]

Quick semi-off topic question:

If an unknown set of 6L6GC tubes is checked for shorts and only shows continuity on pins 2 and 7, how comfortable would you all feel trying them out?

Just found a set of tubes I was given because the previous owner put them in an amp and one tube was off by one pin (worn key in tube socket) and the amp blew its fuse immediately when switched on. I was going to tear them apart and make bias probes - but I checked out Frenchie’s video on testing with a DMM and the only continuity on both tubes was pins 2 and 7.

Thinking of trying them in this build… Would you?

[Colossal]

That came out great, Raoul. Well done.

[ijedouglas]

All right, just one more piece of co-ax for the OD CW and I think I’m there. Not the prettiest, but I’m learning.
IMG_0202.jpeg
It’ll have to wait til tomorrow - I’m going upstairs and having a beer; it’s been a busy week, lol.

Nice work. Something to take note of, you may have done this already and the cap markings are incorrect, but 2nd/3rd Gen amps had all the caps outerfoil to the pots except for the bass cap

[Raoul Duke]

That came out great, Raoul. Well done.

Thank you Sir! I appreciate your kind words!
I see the flaws - but it’s only my second scratch build and third overall - so if it sounds good, I’ll be real happy!

And of course, I couldn’t have done it without all the help I get from the good folks here! I appreciate everyone’s input immensely!

Thanks again

[Raoul Duke]

All right, just one more piece of co-ax for the OD CW and I think I’m there. Not the prettiest, but I’m learning.
IMG_0202.jpeg
It’ll have to wait til tomorrow - I’m going upstairs and having a beer; it’s been a busy week, lol.

Nice work. Something to take note of, you may have done this already and the cap markings are incorrect, but 2nd/3rd Gen amps had all the caps outerfoil to the pots except for the bass cap

Thanks Ian!
I did not know that and have followed the foil position of the 4th gens. I will definitely make note though; if this amp sounds like I think it should - I’ll probably build a more period correct one in the future.

The more I read about HAD, the more likely it is that I may try a total authentic version of something just for posterity. I have to improve my understanding and construction techniques first though, lol.