New in the community and proud of it

[deeder]

Hi There!
very new here, I'd like introduce myself with you. So first of all I'm a musician, guitarist/lead singer in a three piece band located in Paris.
Since it was quite difficult to find some good amps repairman, I've been involved more and more in tube amps design in order to do the maintenance things on my gear. The beginings were difficult, but for now I'm ok with high voltage. Idem with my guitars, I do set up them by myself too, never dispointed by the result
At this time, I build a Marshall 1987 '68 species, my first one and it's not a piece of cake. But it seems that I have a positive attitude to do that. The next step will be to build a Trainwreck Express, my little hommage to Mister Fischer.
I hope you'll be tolerant with my english, because I'm going to spend many years with you guys...

PS: I'm proud to be a part of your community.

Edited 05/04: typo on Ken's name.

[martin manning]

Bienvenue! Are you still working on the 1987 Plexi, or have you completed it?

[deeder]

Merci!
Actualy I'm wiring the power supply. I have done the heaters, main caps, power transformer, fuses.
I spend a lot of time to decide how I'll do the grounding dress and I've decided to do that not like Ken Bran did, but using 6 different lugs for screen, plate, inputs, negative feedback, power transformer and IEC socket. Some amp builders call that Totem or something like that.
As far I know google is my best friend!
I have tried the lacing method to get a very clean chassis, ala Marshall, but it's too much for me.
Next step: the output transformer.

[martin manning]

Post some photos if you want some constructive criticism. There are some good layouts on the web for that amp, such as here: http://home.comcast.net/~mamp17/1987%20Layouts.html

[deeder]

Yes indeed Martin!
I'll begin soon a new thread in the Marshall section about it. And you're right I need some help, too many unanswered questions...
As you mention it, I'm using the Steve Miller layout for that build. Maybe I would add an internal jumpering since this amp will become my main pedal board platform.
Seeing your avatar, I can't resist to post my other passion: my little baby Malinois, she is one year old and her name is Isis...

[eniam rognab]

Hola mi amigo!

and welcome

puppy is very pretty

[martin manning]

Your Isis is a pretty girl! As you will see, there are a number of "dog people" here.

I sketched up an alternate to using the pot bus ground as Marshall did... food for thought.

Edit: Added alternate PI ground (from bottom of presence pot) to power stage cathode with OT secondary ground.

[deeder]

Hum... I gonna gnaw this bone

[martin manning]

Made a small update above...

[Littlewyan]

Lovely dog

deeder - Did you mange to get hold of the filter capacitor that sits on the Turret Board? I've been trying to find one as I'm building myself a 1987 soon but can't find one anywhere for the life of me! I think I'll have to use two 47uF Caps.

[deeder]

Thanks for her, lovely and smart too. We were together in the wood this afternoon, lot of fun
To answer your question, I found one Erie 32µF/32µF Dual Axial 350 V (fully reformed) at Valvestorm: http://valvestorm.com/NOS%20and%20Rare%20Stuff
This part is expensive, so maybe you can have a look at this cap F+T 33µF/33µF Dual Axial 450 V for less.
I think the 1987 design has been changed at the end of the sixties and this cap was located outside the turret board above the chassis. Refering to the SDM layout Martin has posted with the 32+32 for the preamp on the board, it's clear that it is a '68/'69 species. It seems that this kind of filtering is more touch sensitive and give more compression also. My readings tell me that 50+50 in the preamp kills a bit too much of that.

[deeder]

@ eniam, thanks mate for the compliment. Sometimes she's tough and rough like a kind of 'in your face' dog but always gentle. I have to spend a lot of time with her to do the right education.

[Littlewyan]

Sweet, think I'll go for the F and T, just found a website that sells them. I'll keep mine on the board as it'll save me having to make another hole in the chassis I'm getting. Or I'll mount it JTM45 style.

Thanks for your help

Forgot to say, welcome to the community! You've only been here 5minutes and you've already helped me out!

[deeder]

That is kewl, I'm just passionate. Don't we are all brothers in amps!? I think so
I going to open a thread about my build in the Marshall section, will be a pleasure to meet you here and get some help too.