YAOB (yet another one-zero-two build)

[aflynt]

Since my plans are set and most of the parts have either arrived or are on the way for my 102 build, I figured I'd start a thread documenting my progress.

I'm going to use the CE Pedals black chassis and Agbamplifiers boards. I figured I just use the precision PS and newer-era bias board layout since that's what the Agbamplifiers boards are set up for. I'm also ditching the courtesy outlet, ground switch and 1/2 power switch since the chassis doesn't really have holes for them and I don't really think I'll need them anyway. I also figure I'll put a LNFB bypass switch in the impedance selector switch hole since my OT only has a 4 ohm tap.

For iron I've got a '68 Showman PT, and a '73 Quad Reverb OT and choke. I also snatched 1 CTS 1M audio, 2 2-35 250Ks, and a 1 100K Linear pot from the Quad. I'm using PEC pots for the rest. I'm not sure which controls I'll use the CTS 1M and 100K for since volume, master, drive and ratio all seem to be pretty critical. Hopefully the PECs sound decent. I have a buch of Piher carbon films on the way for most of the signal resistors, and Electra MF7Cs for the plates and cathodes and a few other places. I'm going to use mostly NOC carbon comp for the rest of the signal resistors since I already have a whole bunch of them.

Here's a picture of what I've amassed so far for the build.
[img764]http://www.aaronflynt.com/wp-content/up ... 24x764.jpg[/img]

I'm really looking forward to putting this together since it's a pretty interesting challenge complexity-wise. Hopefully I can get it sounding decent enough to be part of my main live rig.

-Aaron

[Dr d]

I'd say you've got everything in place to make a great sounding amp. Looking forward to watching your progress. You will get all the help you will ever need from this wonderful forum. Good luck!

[dcribbs1412]

Nice looking box-o-parts aflynt
you are gonna have fun.
Also might want to consider(start planning)building a dlator to go with this circuit and a decent outboard reverb/delay...
Chances are you're gonna get hooked...

Darin

[aflynt]

Nice looking box-o-parts aflynt
you are gonna have fun.
Also might want to consider(start planning)building a dlator to go with this circuit and a decent outboard reverb/delay...
Chances are you're gonna get hooked...

Darin

That's definitely in the works. I might just get the Ceriatone kit for the D'lator. I did a board layout and build for a double Hermida/GGG reverb a few months back that I was planning on integrating into the D'lator.

-Aaron

[amplifiednation]

Looks great man! The 102 is a really cool circuit. Very smooth with lots of bloom! Its great you got the parts out of the Twin, I think the old OT will add some nice mojo. I used a 4ohm Twin OT for mine too. I'm looking forward to seeing your progress.

[aflynt]

I spent the day yesterday just procuring hardware, fitting stuff to the chassis and creating the attached rainbow spaghetti vomit layout. Doing the layout really helped me suss things out since the build is incorporating little things from various sources with the twin pt, rs relay transformer, ce chassis and agbamps boards. Hopefully it's correct.

-Aaron

EDIT: v2 - Updated the layout to use the Kobicon / Calrad FET input jack.
EDIT: v3 - Updated the layout to fix missing preamp cathode ground and incorrectly wired presence pot.
EDIT: v4 - Updated the layout to fix eyelets / pads overlapping components and added polarity indicator to presence cap.
EDIT: v5 - Updated the layout to more accurately show how the wires should be routed.
EDIT: v6 - Updated the layout to fix issue of backwards preamp tubes. Also updated wire colors to reflect what I have on hand.
EDIT: v7 - Added a treble reduction network to the switching jacks on the loop send/return. Added an LNFB switch. Brought the wiring closer to actual accepted routing practices. Updated dropping string values. Added info on voltages and trimmer settings.
EDIT: v8 - Changed some instructions text to make more sense. Made pot jumper wiring more consistent. Switched PS grid resistors back to 5k1 as per #102.

[guitardude57]

Nice job on the drawing.

Looks like this is giving me an excuse to use a precision PS board I've been sitting on, for a couple of years.

I have a Windsor head that has huge chassis real estate, (I got in a trade) and will build this or a 124. I can easily knock a hole or 3 more, for the tube FX loop, and maybe a Reverb, etc. It is a 4X EL34 as is.

Let us know how things progress with your amp.

Mike

[aflynt]

Nice job on the drawing.

Looks like this is giving me an excuse to use a precision PS board I've been sitting on, for a couple of years.

I have a Windsor head that has huge chassis real estate, (I got in a trade) and will build this or a 124. I can easily knock a hole or 3 more, for the tube FX loop, and maybe a Reverb, etc. It is a 4X EL34 as is.

Let us know how things progress with your amp.

Mike

Thanks! Sounds like a cool project! I uploaded a new version of the layout. Looking over the one I posted before, I realized that I'd forgotten to update the FET input jack part of the diagram.

-Aaron

[ToneMerc]

Per the layout the pres needs to be connected to terminals 2 & 3 or you could jumper terminals 1 & 2.

TM

[Structo]

Nice layout. Visio?

The only thing that jumped out at me was the lack of ground on the preamp cathodes.

[aflynt]

Per the layout the pres needs to be connected to terminals 2 & 3 or you could jumper terminals 1 & 2.

TM

Thanks for pointing that out!

Nice layout. Visio?

Thanks! I use a program called Omnigraffle on my Mac for things like this.

The only thing that jumped out at me was the lack of ground on the preamp cathodes.

Thanks again!

I suppose the only consolation for having made such boneheaded mistakes in my layout is that I didn't actually go through the effort of soldering them in place yet. Hopefully I'll get it right for the actual build.

I'll upload the fixed layout in a minute...

-Aaron

[guitardude57]

Yes, now that I've had some time and some coffee...

V1 and 2 caths have no ground.

Presence pot wiring and missing cap

Both terminals on precision PS radial caps, marked +


Mike

[aflynt]

Yes, now that I've had some time and some coffee...

V1 and 2 caths have no ground.

Presence pot wiring and missing cap

Both terminals on precision PS radial caps, marked +


Mike

Thanks for the help! I just fixed the V1 & 2 cathodes and presence pot per Tonemerc and Structo. What you're seeing on the PS radials is actually the eyelets showing through on top of them (which is also a mistake). I can't seem to find the missing cap, though. Where is it?

-Aaron

[ToneMerc]

Aaron, you did such a great job here. This is trivial, but you could mark the polarity of the tant pres cap.

TM

[guitardude57]

)K, I see the cap on the board (2.2)
I'm just used to seeing a .1uF hung on the presence pot...