Just got my OLD Marshall back

[OlinMusic]

I have had my 73 for a while and never had a tech check under the hood.

I just took my amp to Don Butler, also known as The Tone Man. Very cool guy , and VERY HELPFUL - I recommend him in the Greater Los Angeles area.

After checking my amp he said almost everything in it was original down to the filter cans (33 years old). He said the only thing altered were some resistors on the controls that were in the 200k range (am I saying this right?)

He said most Plexis of the era had 100 value resistors and suggested changing those back from 200s to 100s and swapping in new filter cans. He put in SOZO's and some sort of short, stubby BLACK colored filter cans (as opposed to the blue Daly's in there)

Results? AMAZING. The amps sounds sweeter and tighter than ever. Gets a good crunch without diming it, AND it TAKES FX MUCH BETTER ON THE FRONT END INCL DIGITAL UNITS! I am VERY VERYY IMPRESSED.

I am truly amazed! Can't stop playing it!

Does anyone know anything about these black filter cans or these resistor changes? What are they? What are Sozo's?

 

[firebirdVII]

Re: Just got my OLD Marshall back

Sozo makes replica mustard caps (originally used in many marshalls). A rectifier makes AC more similar to DC, but there are still ripples in the current. A filter cap flattens out the ripples to make a cleaner DC supply of current.

 

[mrid]

Re: Just got my OLD Marshall back

I'd guess the filter caps were JJ's. As for the 100k resistor, I'm guessing it has to do with the negative feedback circuit.

 

[OlinMusic]

Re: Just got my OLD Marshall back

Here I thought I'd get a bunch of responses on caps and filter cans and different types and the many tones you can get...

 

[ErikH]

Re: Just got my OLD Marshall back

Sorry, mang. Been too busy looking for a new amp. The cost of getting mine fixed is about the same as getting another one. Glad to hear that yours is still chugging along well.

Not sure what the resistor change did. Did he say where exactly they were in the circuit? The filter caps were probably starting to get a little dry, even though the amp has been used a lot. If that thing sat for half it's life without use those caps would have dried up years ago. Putting new ones in is like changing an oil filter, the power is just so much cleaner going through the amp. The Sozo caps are just a tighter tolerance cap than what was in there.

Back when that thing was built, most of those parts had a much wider tolerance so the value could be off +/- 15-20%. These days there's parts with much tighter tolerances, like +/- 1-5%, and that makes a huge difference in how the amp will sound.

Some think the tighter tolerances sound better, some think they take away from the magic making it too stiff. It's different for everyone.

EDIT: Another thing about the older parts is that as they age, they'll either get closer to or drift further away from their measured value making the amp sound better or worse, like aged wine.

 

[JacksonMIA]

Re: Just got my OLD Marshall back

Sweet! Sounds like the overhaul did its job. Enjoy!

 

[Gearjoneser]

Re: Just got my OLD Marshall back

There's very few techs that know Marshalls and Vox's better than Don Butler. Did you drive to his house in Santa Clarita?

I've always wondered why I see vintage Marshalls re-capped with those smaller black caps, rather than the long blue ones?? I'd like to know, myself.

 

[OlinMusic]

Re: Just got my OLD Marshall back

Don is a great guy. yes, I drove to his place in SC. He said those smaller caps are German made and that they are really high quality and effecient. A guy on HC recommended him, and on the phone he was the first guy in LA who didnt lecture me or give me BS. He answered my questions and offered me solutions to my needs.

He was confident BAR NONE that these black caps and the sozos were the way to go. He was right! I don't know parts, I jusdt know it soudns and feels, and takes FX better than EVER before. I get more of the grind without using my Variac.

when he tested the amp for me, it was thru a Vox cab with Celestion Blues in it, and it seriously had a beautiful vintage Vox-y quality, and cleaned up gorgeous. Thru my G12H30's it sounds like rock n roll, and it takes distortion pedals and makes em raw!