True all valve distortion

[Mats A]

Wonder since the MA only has three preamp valves is it only valve distortion or is it some little diode lurking around there? If you can get all this overdrive with only three preamp valves the fourth or even more like on most newer Marshalls seems almost unnessesary. Is the master pre or post phase inverter valve? I really dig the tone of this amp :shredder

[SteveD]

The MA distortion is all valve, there are no diodes or transistors lurking around. The tone stack is driven by a common cathode stage rather than using a stage up as the traditional cathode follower which has no voltage gain. The amp has no master volume, only individual Clean and OD channel volumes.

The MA is a very good amp given the price point that had to be met.

Glad you like it Mats.

[Papus]

Nothin' wrong with being built to a price.... how else are beginners supposed to enter the world of valves?
Even the Space Shuttle was built to a price.

[ArtyPaul]

I've just picked up a stock clearance (but new) pre-revoicing MA50H for £298. What a bargain. I'm tight on space at home, so it's being played through a 1912 1x12 cab. Initially I was using the stock speaker, and with this the top end was a little fizzy and the reverb a touch indistinct. I've since swapped the speaker to an Eminence Red Coat Governor, and now the fizziness has gone and generally clarity has been improved. The last piece of the puzzle is an MXR 10-band EQ running in the effects loop.

I'm really very happy with the sound I'm getting. I can go from ZZ Top to Black Label Society to Bay Area thrash, and it all cleans up well with the guitar's volume control. I guess we all have a different tone in our heads that we're aiming for, but given how great this amp sounds to me I'm really surprised by some of the negative feedback it's been getting. Sure, you need to sit with it for a few days to find the sweet spots, but isn't that the same with any amp? In fact, I normally find the sounds that I think are great almost immediately are the ones that I grow tired of most quickly. I have a few other bits and pieces (an original Guv'nor and an MXR GT-OD to give different flavours of overdrive, and a Line M9 as a noise gate and for delay/mod effects) that add to the versatility, but really if I had to run with just the amp and the EQ I'd be happy.

I still haven't had a chance to get this into a rehearsal room and crank it up properly, so this is based off running the volume at a maximum of 9 or 10 o'clock. That's still plenty loud though and enough, I hope, to give a good idea of how the amp will sound at full tilt.

Time to arrange a session with a drummer friend who pulls off a pretty mean Dave Lombardo impression, I think....

Paul.

[jagermike66]

@ artypaul

....just you wait til it reaches volume 5-6, there is a noticable growth in balls. Then when you hit volume 8 and it happens again! *dribbles*, only problem is at that volume i'm leaving my hard hitting drummer behind (poor sod doesnt have a volume nob). And iv only got the 50watt version! immense power.

Enjoy!

[SteveD]

Welcome to the forum ArtyPaul.

[ArtyPaul]

@jagermike66: I can't wait to crank it! The drummer I play with from time to time is damn loud, so I'm looking forward to the expression on his face when he hears the MA. To be honest, I think he'll love it. He's very positive about guitars.

@SteveD: wow - it's pretty great to be welcomed by the guy who actually designed the amp I'm enjoying playing so much! Cheers.

Paul.

[jagermike66]

yeah steve loves it. Very patient considering he probably answers the same set of questions hundreds of times! Let us know how you get on when you crank it!

[txslowhand]

@ artypaul

Hi Paul,
Welcome to the forum (I've only been around here for a month or so). Glad to here you like the MA as well. Wow, you got a bargain at £298 (can't figure out how where the "£" key is on my yank keyboard ). That's about $475 in my some what worthless currency. I also have a pre revoiced MA50H that I just purchased back in May. Not sure what the revoiced models sound like so I can't compare the two. "Ignorance is bliss" I guess. Anyway, great minds think alike. I also run my MA50H to a Eminence Red Coat Governor. I really cheaped out and re-purposed my old Crate combo cabinet for the Governor speaker. I would have bought a 4x12 to go along with the HA50H but hey, I have kids in college....need I say more?

And yes, like most if not all Marshall amps, the MA50H needs to be cranked as well to get "that tone" everybody is seeking. A trick a lot of us MA owners are doing is to use an OD pedal or similar as an attenuator (or master volume) in the effects loop. This allows you to crank the volume up and drive the tubes at a level that doesn't shatter the windows. Give this a try, it really works for me. As a matter of fact, I just got a really cheap passive attenuator on eBay that works better than an OD pedal (for me anyway).

My main battle right now is hum which I suspect is from a ground loop situation. The hum starts when I go from standby to on. The hum is a true hum and not just white noise/static. I have a hum eliminator on order and will see if that does the trick.

Again, welcome to the forum. SteveD is a good guy. He takes time out of his schedule to answer questions out on the forum.

[ArtyPaul]

@txslowhand

I'm right there with you as far as repurposing old gear - the 1x12 cab was an eBay purchase from a few years back, which I had originally hoped to use with a Digitech modeller and a cheap power amp. I ended up with feedback problems I just couldn't solve, so it got tucked away for a rainy day. I can't justify spending a lot of money on gear either - the stuff I use has been gathered over many years, with the original Guv'nor actually being bought from Jim Marshall at a shop called Allbang & Strummit (long gone) when they first launched. Other bits and pieces have generally also come from eBay, sales or have been gifts. The MA is actually a good example of that - I would probably have carried on with my old amp if it hadn't been at such a ridiculously good price.

As far as the effects loop goes, having read this forum even before I bought my MA, the first thing I did when I got the head was to stick my GT-OD in the effects loop in the manner which Nebulozny and others have discussed. For me, it muffled the tone too much. I've found that the new speaker in combination with the 10-band EQ does the trick in terms of giving me the sound in my head, and the EQ also has a volume slider on it, so although it doesn't attenuate massively, it takes the edge off a little. I'm happy enough to run with two different settings - one for home use and one for louder volume use - and tweak as required.

I've played for so long through various modelling solutions, that what I'm really dying for now is just one amp to absolutely push as far as I can, and to learn inside out. And I really like the idea of doing that through a relatively simple but great sounding amp like the MA. If I have too many options, I end up tweaking the amp all day long and not doing any playing. With the MA I just keep finding inspiring tones that make me want to play. I don't think you can ask for more than that.

Paul.

[jagermike66]

+1 for the EQ. I have tried it with the OD in the fx loop trick and it did muffle a bit too much for my sound. I found a 10 band EQ is also the way to go at lower volumes. For gigging and rehearsals I just run it as it is without the EQ. Mine is running through a 4x12" V30s cab and the power tubes are KT77s instead of the stock EL34s. For me these additions are immense. The KT77s in particular are fantastic, they give you all that upper mid bark that EL34s are famed for, but you get a much larger range similar to a 6L6. Anywho I degress.....I'm also a fan of the keep it simple rule. I was very close to buying a JVM at one point but then I thought, well its great but theres too much stuff I probably wont end up using on it. Sure it sounds better on it's own than the MA does IMO, but with my pedals and guitars, I get a far more unique sound from the MA, which is more important isnt it!

[Phano36]

Welcome to the forum Mats A

Glad that you like your new MA50H. I own a MA100C for more then one year now and I still love it !
I also own a Fender tube amp and a very old (1965 YB1) Traynor vintage tube amp and none of them sound like
my MA. For me, buying the MA was not a matter of budget. it was a matter of getting the Marshall sound that my 2 other amps were not able to provide. Also like Jagermike66 for me the simple it is, the better ! I hate having 200 knobs to manage and the MA was able to provide me a simple aproach of, BASS, MID, TREBLE, GAIN nothing complicate !

[ArtyPaul]

@jagermike66

Excuse my ignorance - this might be a totally obvious issue - but when you replaced the EL34s with KT77s did you need to get the amp re-biased? After 25 years of playing this is my first valve amp - I always believed those people who said I wouldn't get a good sound out of a valve amp at bedroom volumes. I now realise this is mainly the case if you're relying solely on power amp distortion, but as my style is based just as much on pre-amp break up I now realise I've been missing out for absolutely no reason all these years. It also means that I'm still pretty ignorant about what you can and can't get away with on an all-valve amp. Forums like this help massively. And I have to say - with the sound I'm getting out of the MA I don't feel like I've compromised or economised at all. So any advice is much appreciated!

Paul.

[txslowhand]

@jagermike66

Excuse my ignorance - this might be a totally obvious issue - but when you replaced the EL34s with KT77s did you need to get the amp re-biased? After 25 years of playing this is my first valve amp - I always believed those people who said I wouldn't get a good sound out of a valve amp at bedroom volumes. I now realise this is mainly the case if you're relying solely on power amp distortion, but as my style is based just as much on pre-amp break up I now realise I've been missing out for absolutely no reason all these years. It also means that I'm still pretty ignorant about what you can and can't get away with on an all-valve amp. Forums like this help massively. And I have to say - with the sound I'm getting out of the MA I don't feel like I've compromised or economised at all. So any advice is much appreciated!

Paul.

Unless you stay with the exact same tubes, it's always a good idea to rebias after changing out your power tubes. Specs will tend to vary between the different tube makes which require a bias adjustment. With that being said, a bias adjustment would be required if changing from el34s to kt77s. Now is it the end of the world if you don't rebias? Probably not. The only consequence might be poor tone or shorter tube life due to the tubes being over biased. Bottom line,when in doubt...rebias. Have to give steveD credit for his design of the MA with respect to how easy he has made it to adjust the bias on the MA.

[Phano36]

ArtyPaul

I would like to add from txslowhand comment . Be carefui before changing tubes since not all tubes have the same pin out.
i.e you never want to swap EL34 to 6L6GC. This swap could damage your amp. So be careful !
The differences between EL34 (penthod tube) & KT77( Beam Tetrods tubes) operate on slightly different principal.
but the pin out is the same and can be swap with a minor re-biasing. (look in the forum for pics instructions on re-biasing)

I never tried it but the believe is that KT77 have more bottom and less presence (bright) but I'm thinking about it
for next time my tubes have to be changed.

Have fun and be careful :shredder !