Rgv40 nvasion halp!!!

[Kich]

Its here.
My own picture i weel put later. I haw not foto now.

[J M Fahey]

Hi kich. Thanks for posting, but I don't get it.
Can't you just post the original schematic, and just place an "X" where tracks were cut and draw a different-color line showing what you jumpered?
Thanks.

[Kich]

Hi kich. Thanks for posting, but I don't get it.
Can't you just post the original schematic, and just place an "X" where tracks were cut and draw a different-color line showing what you jumpered?
Thanks.

Little later il do it. I very busy now. Sorry!

[J M Fahey]

Ok, when you have some free time. Thanks.

[Kich]

Wery sorry for my silence guys!!! I was busy!

I'm back!

Its here.

See atached files.

[J M Fahey]

Hi Kich, now I like it.
Earlier you spoke about bypassing the DSP, I had told you it was not necessary because you got that just by setting the Effects pot on 0, but now you bypass the whole SS blok.
Good, now it becomes more Marshalesque.
Two suggestions:
1) jumper the 470K resistor (designator unreadable) which goes from the treble control wiper towards where you solder your red cable
2) Replace the A50K master volume pot with an A500K or A1M one.
You will fully restore your amp to classic tube specs.

[Kich]

Hi Kich, now I like it.
Earlier you spoke about bypassing the DSP, I had told you it was not necessary because you got that just by setting the Effects pot on 0, but now you bypass the whole SS blok.
Good, now it becomes more Marshalesque.
Two suggestions:
1) jumper the 470K resistor (designator unreadable) which goes from the treble control wiper towards where you solder your red cable
2) Replace the A50K master volume pot with an A500K or A1M one.
You will fully restore your amp to classic tube specs.

thanks J M Fahey!
I will try this. But I did not understand, what must be done with jumper the 470K resistor?..

[J M Fahey]

Short answer: that 470K is too much now (after the mod) so replace it with a short wire link/jumper, or simply tack solder a small piece of wire from one of its pads to the other (effectively shorting it).
Now your tone stack will "see" that 50K volume control, which is too low for it, so replace that pot with a 500K or 1M audio pot.
Remember:
1) You are restoring it to its tube amp roots
2) You have removed a few SS buffers in there, so you must be more careful than before with (passive) impedance matching.
If you ask me, well worth the effort.
Good luck and post some MP3.
And start saving for that Black Vodka bottle and some Beluga Caviar for my next visit to Moscow.

[Kich]

Thank you J M Fahey! I'll try it! Bypass R17 (470K) and replace the volume controller on the 500K.
Thank you
If you go to Moscow - tell me! Vodka will be! :-)
MP3'll post when the mod will be made.

[Kich]

Hello J M Fahey!
I opened the amplifier back to resolder VR volume control. and replace it on A500K but ... There on my motherboard already has A1M ... There is no resistor 50K!
Should I change it on A500K or not? Should I make a jumper for R17 (470K) in this case? What should I do?

I also want to ask: how can I make a headphone line output from the preamp?

Thank you!

[J M Fahey]

Good !! You already have a correct value pot (A 500K or A 1M). Now solder a 470 pF ceramic capacitor across that 470K resistor. You will get closer to a Marshall sound, which I guess is good.
You will get your earphone and line out from the speaker out.
If you want to play silent, yiu must replace the speaker with a 10 ohm (for an 8 ohm speaker) or 5 ohm (for a 4 ohm speaker) 10 or 15 W power resistor.
Under no circumstances can that output transformer be left with no load.
I will draw a schematic and post it tonight (Buenos Aires night, that is )

[Kich]

Thank you! I'll wait!
:-)

[Kich]

J M Fahey Where are you? :-)

Should I remove R17 or not?

[J M Fahey]

J M Fahey Where are you? :-)

Should I remove R17 or not?

Hi kich, leave it there.
You need those 470pF in parallel with those 470K.

[Kich]

Hello! I did it. Sorry, but I am very busy ... This week, a lot of work. I will write the details next week. OK? And lay out samples.