Steve luckey 18W TMB

[adamG]

Hi Guys,

I've started building of this circuit. It seems very interesting too.
Previously, I accomplish a couple other amps of 50W. I feel it's time to make 18W construction.
I have question ,what choke shall I apply and can I use EZ81 instead of 5Y3? If so, then what pri.sec. AC voltage of PT shall be?
Another silly question is that Am I reading right the solution of bias voltage taken directly from 275V tap?

Thanks in advance.

Regards,

adam

[sluckey]

I have question ,what choke shall I apply and can I use EZ81 instead of 5Y3? If so, then what pri.sec. AC voltage of PT shall be?

You can use the small Fender choke that Hoffman sells. EZ81 works fine and needs 6.3v for filaments. You can just connect the filaments on the same string as all the other tubes. I used a Hammond 270FX for my amp. Hoffman also sells the perfect PT and OT for this amp. His PT has a separate 5v/6.3v filament winding dedicated for rectifier use. Look at the Fender small choke and Heyboer 18 watt Power transformer and Output transformer on this page...

Another silly question is that Am I reading right the solution of bias voltage taken directly from 275V tap?

That's correct.

The November amp is really an 18W Plexi rather than an 18W TMB. It is still one of my favorites. Please share your project with us.

[adamG]

EZ81 works fine and needs 6.3v for filaments. You can just connect the filaments on the same string as all the other tubes. I used a Hammond 270FX for my amp. Hoffman also sells the perfect PT and OT for this amp. His PT has a separate 5v/6.3v filament winding dedicated for rectifier use.

Thank you for reply.
Fortunatelly ,I can wind the PT by myself. Therefore, I got my favourite one...independence. When I can see something interesting ,I just start doing it.
Yes, I know the filament is 6,3V.Shall I stay with 275V for EZ81 or reduce is? Actually ,I do not know the voltage drop of EZ81.That's why I asked.
I'll follow this small Fender Choke.
May I ask for advise how to wire 4-inputs in November Project? The reason of them is the chassis was manufactured for classic JTM45, 1,5 years ago. Also, I like those inputs;)
Shall I apply standard JTM/Plexi resistors?


Please share your project with us.

Of course, I will.

Thank you.

Regards,

adam

[adamG]

Hi Guys,

Till now ,I've manufactured and painted chassis.
Main board is almoust done.PT and OT are also ready.
During next weeks, I'll be making assembling of the whole amp...
Sorry for blurry photos.When the build is going stepped, I'll provide better ones.

Regards,

adam 

[adamG]

Hi Guys,

Recently, I assembled my amp.
Here's few photos.
Withing next sunny days ,I'll take ones of M.style shell.
The Amp sounds pretty well. Steve projected a very good one.
Thank you!

Regards,

Adam

[sluckey]

That looks great! I assume you got the four input jacks worked out? It's just like the Plexi 1987.

[adamG]

Thank you Steve.Yes, the faceplates were made to accomodate JTM45. Therefore, I used four jacks
Yesterday, I compared previously accomplished 36W with your design. Both of them sound pretty well.I am really happy.
To tell you the truth, I am looking forward to your other projects, as well. Have you made Plexi-JCM800 project?
I've already manufactured chassis, gathered electronics, wired trannies for it...
Thank you Steve.

Regards,

Adam

[sluckey]

That looks great on the inside too. I'm impressed! I never built the Dual Marshall but have not forgotten it. I don't really want any more big amps so I'll probably just build the Dual preamp and stick it in my "Stuffed Vox" project. Winter time's a'coming! 

[adamG]

Thank you Steve once again.
You know, I'd also like to implement your project November into 36W amp with OD stage made on first tube. That's another experiment of my own I wish to compare D-style OD stage with this one.
Could you suggest me what components need to be on 2nd triode-1st tube?
Other component shall be acc.to November Project.

Thanks in advance.

Adam

[Fresh_Start]

THAT is a beautiful build!  Your lead dress, soldering, etc. all look really good.

Is your ground bus attached to the board somehow or to the chassis?  It took me a minute to see it because it's so close to the edge of the board.

Did you change the circuit from the November schematic?  Just wondering about the small PCB behind the two Level pots.

Cheers,

Chip

[adamG]

Hi,

Sorry for deleyed reply.
Thank you for a kind word of adjudgement.
Ground bar is soldered to main board by two or three eyelets,then connected to star ground point close to PT.
Yes, November Project is extended with D_mble style OD stage ,similar to Greezer's TBM.
What small PCB do you mean?! The only small one is relay PCB.

Regards,

Adam. 

[adamG]

Few photos of head..

Regards,

Adam

[sluckey]

That certainly outshines mine by a long shot! Very nice work.

[Ritchie200]

I'm still trying to get past the part about you winding your own tranny's!!!!!
VERY nice work!

Jim

[adamG]

Hi guys,

Good looking amp is the first issue. Another one is how it souds.
I believ it's ok. Anyway, It's not my judgement ,after all.

Riche,

Winding OTs by myself is not as much complicated as I know how to manufacture it. I've got such skills.
Very fortunatelly , a generous gentleman gave me their data to retrofit M_rshall and F_nder OTs.
I hear, they works very well, acc.to my ears, of course;)

Regards,

Adam

[tubenit]

Remarkable build!  Bravo!

[adamG]

Thank you Boss ;)

I just like those babies. That's the best hobby I've ever had.
When my copy of TOS is done, I promise to publish sound clips, if it is ok.



Regards,

Adam