Calling Rockstah - 1959 HW to 12xxx series spec

[rockstah]

excellent.
also a note the caps u replaced in the output section are .022u - u replaced them with .1u. just so u know this.
also the + of the 330u cap goes towards the tube.
that 472 cap u snipped was a 4700pf cap - wow!

interested to what u think this far.

Mark

The cap he snipped was a 4700pf, was that the bright cap?

yeah his bright channel volume pot had a cap that was marked 472 = 4700pf i do believe.

edited , left out the 2 in 472

[bluze81]

Wow 4700p bright cap, that amp should sound better with just that of there,let alone the other changes rockstah has recomended, I would like to see him change out the output transf, to a Metro Dagnall clone ,would make a big difference I would think?

[rockstah]

Wow 4700p bright cap, that amp should sound better with just that of there,let alone the other changes rockstah has recomended, I would like to see him change out the output transf, to a Metro Dagnall clone ,would make a big difference I would think?

i think everything should be tried before the tranny swap. my guess is them trannys dont sound all THAT bad. time will tell.

[vkaxeman]

Rockstah Thanks for the clarification on parts removed!

Something else to try at some point:
I just purchased 7 NOS mustards from Mickey:
http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... B:AAQ:US:1

I can see this swapping parts thing is going to become addicting.

[rockstah]

no problem. now put those new caps in asap.

you now need a .0022u for the bright channel and three .1u mustard caps.

[vkaxeman]

Working 2 jobs again and no time yet to fix the capacitor direction and fire the amp up yet. Hopefully in the next couple of days.

no problem. now put those new caps in asap.
you now need a .0022u for the bright channel and three .1u mustard caps.

Rockstah please mark up a pic again showing me exactly which ones to replace next and links to purchase the additional ones needed.

Thanks!

[rockstah]

Working 2 jobs again and no time yet to fix the capacitor direction and fire the amp up yet. Hopefully in the next couple of days.

no problem. now put those new caps in asap.
you now need a .0022u for the bright channel and three .1u mustard caps.

Rockstah please mark up a pic again showing me exactly which ones to replace next and links to purchase the additional ones needed.

Thanks!

u purchased 7 .022u

the spec you are going to run here calls for:
one - .0022u
four - .022u
three - .1u
one - .68u

so u are covered with your .022u purchase but u need to score the above values and quantities to fill your amp with mustards.

where to find them?
ebay and ask around. u might start with post in the classified section on what u in search of.

next: do all the can caps on top of the chassis read 50+50?

[rockstah]

[bluze81]

Wow 4700p bright cap, that amp should sound better with just that of there,let alone the other changes rockstah has recomended, I would like to see him change out the output transf, to a Metro Dagnall clone ,would make a big difference I would think?

everything should be tried before the tranny swap. my guess is them trannys dont sound all THAT bad. time will tell.

try everything else 1st absolutly, and if the trannys sound good its alot simpler mod and costs a whole bunch less, hope to hear it when the work is done, bluze

[wdelaney72]

I can't speak for the HW, but I know MANY here have agreed that
1) Marshall's re-issue trannys suck
2) Changing the OT is one of the most noticeable areas to altar the tone.

That would have been the 1st thing I changed.

[rockstah]

I can't speak for the HW, but I know MANY here have agreed that
1) Marshall's re-issue trannys suck
2) Changing the OT is one of the most noticeable areas to altar the tone.

That would have been the 1st thing I changed.

well,.. we are going to get a chance here to see how bad they actually suck. now i do see where u are coming from after reaidng about how bad they sound. yada yada.. i want to hear it.

after we are done with it it will produce some good clips.

i'll will say that im betting this amp will sound good.

Mark

[vkaxeman]

I finally found time / made time to fix the 330 cap in wrong direction. Turned on the amp and no smoke and I've got sound!
See the last pic at http://www.putfile.com/vkaxeman/images/161357
Too late to crank it and record though. Will have to do that tomorrow night and then post some mp3s/

rockstah:
u purchased 7 .022u the spec you are going to run here calls for:
one - .0022u
four - .022u
three - .1u
one - .68u
so u are covered with your .022u purchase but u need to score the above values and quantities to fill your amp with mustards.
where to find them? ebay and ask around. u might start with post in the classified section on what u in search of.
next: do all the can caps on top of the chassis read 50+50?

I ordered 7 .022u caps from Mickey based on George's 12 series 100 watt kit list. Is using 7 instead of 4 just another variation of a 12 series?

Just to clarify: The picture you posted just shows/highlights which parts I should be changing. You are not implying I replace the parts I just installed with the values in the picture?
I made some notes on your picture to make sure I understand the spec and the location of the parts. It looks like with the changes I have made already, I have the spec with the exception of possibly v1b coupler. The v1b coupler factory ERD cap has 2200pf on it. Is this the same as .0022u? And what you are suggesting is that I replace all the caps with NOS Mullards?

I will check tomorrow night and get back to you on what the can caps have printed on them.

THANKS!

[vkaxeman]

Forgot to note in the picture:
Is V1a supposed to have a 330u cap

[rockstah]

sorry to be confusing here. and yes 12 series has some variations. marshall went throughs ome changes during this period and there is variations on the spec.

i just identified all the caps on the board for you. the three .1u's needed are two in the output (phase inverter ) and one on the presence pot.

yes v1a cathode cap is a 330u like on your board right now. ( this doesn't really matter sense its the normal channel. it could be a 250u as well )

as well the v1b's coupling cap is to be a .0022u cap. ( same as 2200pf ) again on your board right now u have a .0022u there right now.

and yes sense u have the .022u mustards im implying to change all of your caps to mustards. again i just labeled all of them so in the future u know what im talking about and can acquire the right parts.

hope this makes sense now.

[vkaxeman]

Makes perfect sense!

Thanks Rockstah!