Mesa Mini Rectifier fixed - with pics

randella

Had my amp running last night at rehearsal, into a 16-ohm 1x12" from the 8-ohm speaker jack - not ideal, but I figured won't do it any harm.  Running in full-fat 25W mode because, perversely, I think it sounds better than cranking it in triode 10W mode which can get a bit too saggy.

Masters on both channels cooking but not silly, probably about 10 o'clock, maybe a smidgen more.  My usual boxes, SD-1 into the front, effects out into reverb and then (standard Boss) EQ set flat but with a gain boost for leads, back into the effects return.

On the red (drive) channel - reverb sounded peculiar, like its repeats wanted to feed back; a full-on horrible squealing when I stepped on the EQ.  Not present on the clean(er) green channel.

I'm going to have a wild stab in the dark and say that the ECC83 at V5 (effects loop buffer) is shot.

Do we think I'm on the right track before I go home tonight and start messing around with valves?  As ever, wisdom appreciated.

http://www.mesaboogie.com/media/User%20Manuals/MiniRecto25_140424.pdf

randella

Recipe for unwinding after a stressful day at work.

1) Boot the cat off:

https://www.dropbox.com/s/el8lv2m4klgo5wg/IMG_26Jan2018at185349.jpg?raw=1

randella

2) Have a poke around inside for the sake of it:

https://www.dropbox.com/s/od68nquozn8g7qh/IMG_26Jan2018at185433.jpg?raw=1

randella

3) Make sure the neighbours are out and spend a happy half hour bashing out Metallica’s ...of Wolf and Man just because it always makes you grin:

https://www.dropbox.com/s/aaflws0dwigs6zz/IMG_26Jan2018at185532.jpg?raw=1

randella

Anyway - for the purposes of providing an archive of information for anyone else joining or searching the forum - it was a knackered ECC83 at V5.

rico

You are LWAG and I claim my £5. 

randella

@rico - the Lawrence Wilson Art Gallery at the University of Western Australia?

Wish I was, the sun might come out from time to time.

RandallFlagg

randella said:

2) Have a poke around inside for the sake of it:

https://www.dropbox.com/s/od68nquozn8g7qh/IMG_26Jan2018at185433.jpg?raw=1

That looks complicated! What are those round brown things?

I'm glad you got it sorted, I have a Mesa Express 5:25+ and daren't look inside.

grungebob

RandallFlagg said:

randella said:

2) Have a poke around inside for the sake of it:

https://www.dropbox.com/s/od68nquozn8g7qh/IMG_26Jan2018at185433.jpg?raw=1

That looks complicated! What are those round brown things?

I'm glad you got it sorted, I have a Mesa Express 5:25+ and daren't look inside.

I’m guessing the round brown things are the bottom of the tube/valve holders. 

Collings

RandallFlagg said:

randella said:

2) Have a poke around inside for the sake of it:

https://www.dropbox.com/s/od68nquozn8g7qh/IMG_26Jan2018at185433.jpg?raw=1

That looks complicated! What are those round brown things?

I'm glad you got it sorted, I have a Mesa Express 5:25+ and daren't look inside.

Those are the valve sockets

ICBM

They're a triumph of design and layout to get all that lot into a chassis that size, but I have to say I'm not looking forward to having to work on one for any fault that can't be fixed from the accessible side of the board...

DJH83004

+1 for that IC, imagine trying to change a relay 

earwighoney

ICBM said:

They're a triumph of design and layout to get all that lot into a chassis that size, but I have to say I'm not looking forward to having to work on one for any fault that can't be fixed from the accessible side of the board...

ICBM

DJH83004 said:

+1 for that IC, imagine trying to change a relay 

If you really have to you can carefully destroy the old relay leaving its pins sticking up from the board, then solder the new one to them - provided you can get at the sides! I've done one like that - can't remember which model but it was about a quarter of the work compared to taking the board, out even though it was awkward. A bit of a bodge, I know - but there's just so much difference in the amount of effort to give essentially the same result that I've learned to compromise sometimes...

The group of four large relays on this one looks impossible to do that way though - they're too close together. I wonder if that's why Mesa have fitted what looks like a covered access point through the chassis there! I've looked inside one of these but I forgot to check.

randella

@RandallFlagg - ta!  It hardly puts me within stealing distance of @ICBM 's crown, but an educated guess and a five-minute fix, so I'm happy again (and it'll get our bassist/sound wizard in a better mood).

I had to Google the 5:25+ as, outside of the Recs and Marks, I'm a bit of a Mesa dunce.  One thing's for sure, it'll be well made.  In mine it was nice to see the pots connected with fly leads instead of being board mounted, and the numerous daughter boards seem to use good-quality connectors.  I wouldn't like to diagnose a more complicated issue, there's not a square millimetre of the PCB that isn't populated but that's the price I pay I guess for wanting a compact, lightweight amplifier with two modern-sounding channels.

In an ideal world, if my spine was up to it and we sacked the keyboard player to make room I'd use a JCM800 and a Deluxe Reverb.  Then I wake up.

And yeah, they're valve sockets

riffpowers

Can I ask what you think of the amp ?! You’ve got a similar guitar to me and I was look8mg for a compact but good head with rhythm / lead channel capability that sounds good for overdriven stuff . I don’t need loads of gain , I use a jcm800 with a ts9 in front at the moment ,

randella

riffpowers said:

Can I ask what you think of the amp ?! You’ve got a similar guitar to me and I was look8mg for a compact but good head with rhythm / lead channel capability that sounds good for overdriven stuff . I don’t need loads of gain , I use a jcm800 with a ts9 in front at the moment ,

@riffpowers - sorry bud, completely missed this. 

I think very highly indeed of the amp.  If you’re after that Marshall sound then it’s not the box for you - only a Marshall can do that.

The Mesa does, however, do a version and a very good one.  The drive channel has two modes, ‘vintage’ and ‘modern’ - you can probably guess.  Vintage gets you that Van Halen-y ‘brown’ souped-up JCM800 thing, but it’s not a copy.  Anyone who knows their onions would immediately spot it’s from California and not Milton Keynes.

Think loose, raucous, high-quality valve amp on the edge with a bit more in the low mids, Cali-style, as opposed to the upper-mid bark of a good Marshall.  It has levels of drive that you couldn’t imagine but, importantly, it still sounds the business when you’re only using half or less on the preamp gain dial.

It sounds good at spare-room levels but Lordy me, get it cranked and it’s night and day.  Anyone reading this who wants Recto chunk while the missus is trying to watch telly - a Code or Katana is probably a safer bet.

The clean channel I have set permanently to ‘pushed’ mode.  Again it ain’t no Deluxe Reverb, but it’s my favourite sound in the amp.  The nearly-driven thing that modellers have yet to properly nail, or at least the ones I’ve used.  Get it loud with a good Strat, neck pickup, lovely.

There’s a Marshall TSL2000 in our rehearsal room and, whilst it’s possible to get a reasonable sound out of it despite the lowly opinions of them, the Mesa is genuinely a class above.  There’s no comparison.

It seems well made too, it’s very solidly built.  It’d be a pig to fix if something serious went wrong, but then it does a lot more than a plexi Superlead and in a box a quarter of the size.  It’s also extremely portable as a result.

I use it on 25w mode in rehearsal and with a 1x12” it holds its own against an enthusiastic drummer.  It’s mic’d (now Red-Boxed) at gigs.

TL;DR - yeah, it’s tops.  Go and try one, that’s the only way you’ll know for sure if it’s for you as we might have very different expectations.

riffpowers

Thanks !! I think I need to try one .

Jalapeno

they're awesome - it's my go to amp.

nick79

Another vote for the Mini Rec here. Love mine, very versatile. As randella say's, pushed mode is fantastic. 
I think a lot people see the tread plate grill on the front and just assume its only a metal amp for the brutalzz (cant blame them) but it does so much more. 
Its a loud 25w (i use mine through a 4x12 sometimes and it's laughably loud). I've never had a problem with it not being loud enough but bear in mind it's using 2 el84's so won't have the huge bottom end of a bigger amp using el34's/6l6's. 

Again, not a problem for me but something to bear in mind if you are used to running a jcm800 at full bore.