Mesa boogie dual rectifier rust

richylee

Hey guys I'm looking to buy a Mesa boogie dual rectifier multi watt so I'm looking on eBay etc I found one that has what looks like rust on the inside of the amp. Is this normal ? 

richylee

Here is the amp in question https://www.ebay.co.uk/itm/162508058539 

webrthomson

That listing is now gone - but in a work no - it would indicate the amp has been stored somewhere humid or moist.

richylee

It's still on eBay but won't let me copy the link 

ICBM

http://www.ebay.co.uk/itm/162508058539

It's been stored somewhere damp. It's probably fine, but I would want to have it thoroughly checked by a tech, and I definitely wouldn't pay the normal price for it, just in case.

Especially if it came from Guitar Guitar...

richylee

Ok thanks lads 

NelsonP

Not really what you are looking for at all, but a cracking deal ?
http://www.ebay.co.uk/itm/Mesa-Boogie-Studio-Preamp-/192187946714?hash=item2cbf4b56da:g:Xe0AAOSwKytZGf89

richardhomer

I'm sure some WD40 would soon Rectifier....

richylee

Haha nice 

revsorg

This nightmare repair video really put me off Boogies - they just seem so complex...

BintyTwanger77

ICBM said:

http://www.ebay.co.uk/itm/162508058539

It's been stored somewhere damp. It's probably fine, but I would want to have it thoroughly checked by a tech, and I definitely wouldn't pay the normal price for it, just in case.

Especially if it came from Guitar Guitar...

Well now I'm worried... that's where I got my RoV and it's with them for a warranty check-up now, though I did buy it at the price it was pre-hike.

ICBM

revsorg said:

This nightmare repair video really put me off Boogies - they just seem so complex...

They are quite complex, but not actually that bad to work on usually, and fairly reliable in the first place so they tend not to need it very often.

The JFET switching is a well-known problem on them though, that is true - as are those jumper cables.

professorben

NelsonP said:

Not really what you are looking for at all, but a cracking deal ?
http://www.ebay.co.uk/itm/Mesa-Boogie-Studio-Preamp-/192187946714?hash=item2cbf4b56da:g:Xe0AAOSwKytZGf89

Whilst that is a GREAT price currently, it sounds nothing like a Recto, trust me I own one.

Its more Mkii or iii in character, that mid heavy sound. 
It doesn't do the loose boomy low end wallop that a recto does, it's much tighter and thicker. 

olafgarten

professorben said:

NelsonP said:

Not really what you are looking for at all, but a cracking deal ?
http://www.ebay.co.uk/itm/Mesa-Boogie-Studio-Preamp-/192187946714?hash=item2cbf4b56da:g:Xe0AAOSwKytZGf89

Whilst that is a GREAT price currently, it sounds nothing like a Recto, trust me I own one.

Its more Mkii or iii in character, that mid heavy sound. 
It doesn't do the loose boomy low end wallop that a recto does, it's much tighter and thicker. 

I think the low end wallop is more about the power amp than the pre amp. 

ICBM

olafgarten said:

I think the low end wallop is more about the power amp than the pre amp. 

It is, but the Studio/Mark series preamp is completely different from the Rectifier preamp too, so they sound nothing alike and still wouldn't even if you put a Studio preamp through a Rectifier power section.

Essentially the Mark Series sound is a hot-rodded Fender Blackface circuit with the EQ pre-distortion, and a Rectifier is a hot-rodded Bassman/Marshall circuit with the EQ post-distortion. Even with the graphic EQ being post-distortion, a Mark can't sound like a Rectifier or vice versa.

DJH83004

From the photos it look very much like The iron laminations on the transformer have picked up some surface rust, you do see it quite often depending where they have been stored. Regarding reliability the main issues I have come across have been channel switching faults, particularly with the switching relays, as they are a pig to get out. At least with the through plated boards you can get most components out from the component side, but alas not the relays.

ecc83

"The JFET switching is a well-known problem on them though, that is true - as are those jumper cables."

What sort of problems with the FETs IC? Do the devices themselves fail or the control systems?

As I am sure you are aware(!) I am familiar with a range of products that use them extensively. Mind you, the mixer industry is pretty much based on FET audio switching and you don't hear of problems. IIRC the J112 is the most commonly used device, do Mesa use same?

Dave.

DJH83004

Looking in my own Mesa 'bits' bin Dave, they seem to be J175 that I have as spares, and quite a few miniature relays ! 

ICBM

Yes, usually J175. The transistors themselves fail - presumably they don't like being in a high-voltage valve environment. Even though they should be decoupled, some aren't entirely if other things go wrong, eg preamp valve failure with a leak to grid.

I'm not a great fan of the switching on modern Mesa amps, I much preferred the Vactrols they used to use - although those aren't immune from failure either - but we know why they don't use them any more!

To be perfectly honest I am beginning to not be a fan of complicated valve amps with automated switching in the valve sections at all, they often cause more problems than they solve...