NOS John Mayer Sig / Wonderland 100W

[dbharris]

Thanks Taylor! Pretty hard for a newbie to get it to look as clean as your builds!

-Dan

[dbharris]

Wired up the output tubes. If anyone sees something wrong or lead dress that could be improved please let me know.

I went to mount the PT and OT and realized I ordered a modern mount OT, not a vintage style. Ugh. I am not positive, but I think when I ordered from Triode they did not have the OT part number I originally searched for, but I saw they had a Classic Tone Fender Twin iron set so I just went with that. Did not realize or double check the mounting pattern. Anyone using my BOM please be aware if you are referencing the Classic Tone data sheets.

I guess I have no choice but to drill a couple extra holes in the chassis. Hate to do that at this stage in the game and with the other mounting holes so close...time to fire up the drill press later tonight.

If anyone has recommendations for a better way to address the OT mounting issue, please let me know. Thanks!

-Dan

[dbharris]

Drilled a couple holes, mounted the OT and PT, and wired up the rectifier and bias supply. I had to drill out the relief holes on the bias board I guess because my wire is pvc not teflon insulation. I also couldn't fit the backer board on because the threads on my standoffs were not long enough.

A bit of a rats nest right now with so many loose leads.
Next up are the main board and power supply board.

-Dan

[norburybrook]

Looking good Don't worry about drilling extra holes ~:) think of it as extra ventilation. I've had to resort to all kinds of brackets, drilling ,filing etc to mount transformers in chassis

No one ever sees inside the chassis really anyway once it's built and in a cabinet.


Seeing your build makes me want to fine up mine. I shall do that this week. I don't think I have any sound clips or video of mine so it may be pertinent to do so, so you can hear the difference between the voltage divider values as mine is now on a pot.


M

[dbharris]

That would be great Marcus! All of your builds and recordings sound fantastic. Can't wait to hear your amp.

-Dan

[dbharris]

Got the power board populated and wired up. Also connected a few ground wires. On to the main board next.

-Dan

[dbharris]

Populated the board and ran a bunch of flying leads. Will start hooking up the under board connections and then leads to pots/tube sockets. I'll be out of town next weekend visiting my parents (who both got the covid vaccine recently woohoo!). Not sure if I'll be able to run a smoke test before then or not.

If anyone sees anything amiss, I appreciate the second set of eyes.

Thanks!

-Dan

[bryankloos]

Looks great!

What schematic and layout are you working off?
I hope it sounds as good as it looks!

Bryan

[dbharris]

Tonight, I was also able to hook up the B+ runs and other under the board connections as well as the leads to all the pots. Next up is tube side connections and then heaters.

IMAG2161.jpg

I mistakenly thought the red film caps in the two rock were panasonics, but they are much bigger. If I start swapping components to tweak sound, I may try to track down the same caps they used first. For lead dress, I am trying to mirror the two rock amp as much as possible, but the tube sockets are rotated, and there are other slight differences between the layouts.

I also see Taylor is using CTS pots for the Gain and Master in his amps, I am assuming the J taper variety. I am starting with the Alphas like the two rock but may swap out if the taper feels off.

Thanks Bryan! I am using the layout that Taylor posted and some pictures he posted for reference in this thread:
https://ampgarage.com/forum/viewtopic.php?f=4&t=29774

Note that there are 2 small errors in the layout...there should be a jumper to put the 2x 220 uf caps in series and the wiper from the Gain pot connects to V1b. There are also a few connections not shown on the layout, like some of the reverb transformer wiring.

The layout and Taylor's boards do not match exactly, but are very close and not hard to figure out. The pics he has posted of his early JM builds match the boards that he sells and the wiring usually matches the color coding on his layout.

RColgan also posted a modified layout recently that had some different values and component types for some resistors and ceramic caps. I haven't heard back from him yet on where that info came from. Taylor's layout seems more similar to the photo of the prototype amp floating around, but I think was made from one of the 25 limited run.

I am using this schematic:

Two Rock John Mayer Production Schematic.jpg

This thread is also a helpful build with lots of pics:
https://ampgarage.com/forum/viewtopic.php?f=4&t=32888

-Dan

[Colossal]

Well done on the forensics. Yes, I've caught the same discrepancies preparing for my build (transformers just arrived). Your amp is looking sharp!

[dbharris]

Thanks Colossal! I'm looking forward to following your build.

[rccolgan]

Great looking build!!!! The crudely overlaid modifications I did were based on my research physically having access to a real JM sig as well as a few post-25 run amps . I was able to look under the board using mechanic's endoscope and dentist mirrors. The largest difference seemed to be the use of carbon film E48/E96 numbering sequence series resistors, 120pf treble cap, and the reverb mixing resistor. I'll be building a new one soon with the info I gathered to join the fun with you guys! Looking forward to it

[dbharris]

Great looking build!!!! The crudely overlaid modifications I did were based on my research physically having access to a real JM sig as well as a few post-25 run amps . I was able to look under the board using mechanic's endoscope and dentist mirrors. The largest difference seemed to be the use of carbon film E48/E96 numbering sequence series resistors, 120pf treble cap, and the reverb mixing resistor. I'll be building a new one soon with the info I gathered to join the fun with you guys! Looking forward to it

Ryan, thanks for the info! I have some extra ceramic caps to try for the bright cap and treble cap. I'll be interested to hear how you like the different reverb mixer ratio. That should be a pretty significantly wetter signal right?

-Dan

[dbharris]

Nearly finished but I didn't have enough time this weekend to complete the wiring. Finished all of the tube side board connections. I guess that I mixed up my color coding for plates and cathodes on V3 when I initially wired the tube socket. But left it as is.

Then moved on to the heaters. I used 18 ga teflon insulated solid core for the power tubes. I am going to use 20 ga pvc insulated stranded for the preamp heaters. The rest of the amp uses 22 ga pvc insulated pre-bond stranded. It keeps its shape OK, but I wish I had ordered solid core teflon 22 ga. Now I have a bunch of this pvc stuff, but it isn't too bad.

Taylor shipped out my cabs, they should be here on Wednesday. Can't wait to see them! Hoping I can sneak in some time during the week to finish the heaters, run a smoke test, and form the caps.

-Dan

[talbany]

Here is I believe a few JM Custom''s If anyone cares

JMCustomInnen.jpg

JohnMayerCustomInnen.jpg

Tony