Marshall Studio 15 (Model 4001) 1989. Service, Circuit, Sounds.

Marshall Studio 15 (Model 4001) made 1989.
Service, including circuit description.
Bias adjustment.
Power measurement.
Sound tests.

[@philippberry4900]

I put mine in an 18 watt cab with a greenback. Big improvement. Plus it saves wear and tear on the original cab.

[@jeremytravis360]

The joy of valves Nick. I was watching this and it took me back to 1969 when I came to London and wanted to study electronics so I could make my own equipment. I went to evening classes with a lecturer called William Boyce who had worked to one of the Uk Television makers and I built a valve TRF receiver with a Jackson tuning capacitor and I think they were called Repanco coils that gave you the wavebands of the radio. In those days you could stay up into the early hours listening to radio chatter on SW. And the woodpecker. Valves circuits seem simple to modern electronics with a billion transistors in a phone or tablet.

[@danielvanhorn911]

Still love it, after all these years

[@albertarguelles3262]

Great Video I happen to own one and this is just Awesome. Thanks

[@cdk2968]

Great little combo! I've had mine since about '94 and it has been my go-anywhere amp ever since. Super versatile. I play mostly jazz and there are few Marshalls to be seen in that scene - but all those JC-120 blokes hate my amp for showing off how tacky that "chorus" sound actually is ... and mine is much less heavy... and it's all-tube ... I have been running a JBL K120 in it for about the past 15 years or so, great match!

[@minusstage3]

I'd imagine the master, bass, treble and volume were glued in place leaving only the mids to be adjusted. Probably a stage rig at one point, and the artist didn't want to lose positions. Either that, and /or the pots would crackle and pop when moved so they "fixed" it. I've seen it before. Not the smartest option of course since components change with age and so did the sound. Anyhow, great upload of a massive amplifier in a tiny package.

[@mikerobo2112]

I doubt it was a stage amp.

[@TheTinymart]

Hi Nick ! Could you confirm to me, if the output transformer is a 15w with a 7K primary ? And the power transformer 300-0-300v and 6,3v 2A And do you have some replacement transformers to suggest to me ? Thank’s

[@SDPickups]

Thanks, interesting video. I used mine in a pickup demo, but plugged it into an external pine cab with a 20 watt Greenback. Now THAT speaker is what makes the amp shine. Am going to install same Greenback into the Studio cab and see how it sounds in the small box kzbin.info/www/bejne/oIOpXmemgtqXabc

[@kevinbeckenham3872]

Marshall sounds tiny

[@Dan-mi7hn]

Not this one

[@kevinbeckenham3872]

Nick Marshall cheap end of there range are shit; they are made by contractors out in far east.

[@nickadams5411]

Hi Kevin. Good to know. And they fit Chinese valves (tubes) which are just terrible.

[@mikerobo2112]

Isnt it Jim.