New Amp! Hardwood Simul-Class Purple Stripe Mark III Combo

[s-fresh]

Well I can't seem to hang on to any gear lately, once I get something figured out I decide to move on to something else. Hopefully this amp ends up sticking around. I haven't even got to play it yet, my little guys are sleeping now. Will give it a go tomorrow afternoon when I get home.

It's a DRG with EVM-12. Overall it seems to be in great shape for an '86. I'm stoked to join the Mark III club. I've had a II, IV, V and V:25 so far and haven't found exactly what I was looking for. Hopefully this is it! Considering making a consolidated pedal with crunch/lead/eq/reverb switches but need to decide if this one is a keeper first.

One question I did have, this came with four 6L6/STR420 power tubes. Being it is simul-class should I switch that outer pair to EL34s? I've read on some posts that certain 6L6s are okay in simul-class outers but others are not. Are Mesa STR-420s a safe one or should I not even try? I am mostly interested in the low-watt settings for now. That's why the purple stripe was particularly interesting to me. The manual does clearly say EL34 but I thought for some reason that was old information.

Here it is after a quick cleanup:

 

[s-fresh]

So far so good. I was able to get a lot of sounds I liked out of it, now for the slow process of setting it up so all three modes sound good together with shared settings.

The reverb is really weak. I will remove and see if it is damaged or just dirty soon.

 

[Promethean]

That's a beauty!

I have a purple stripe too and love it. Been gigging it for 30 years now.

Has it had the R2 level mod? That lets you dial in the mix of R1 $ R2. There is also a very simple mod to add more to the reverb depth to the MK3.

A clean boost (I use an MXR microamp) adds loads more options to goose R1 & R2. Boosted R2 is particularly nice. Very Marshall like.

I use mine currently with Mesa matched Svetlana =C= 6L6s which are great but I have used the mix of Mesa EL34 in outer pair and 6L6 in middle for lots of years. Slightly tighter bottom end with EL34s in 15w mode.

 

[Elpelotero]

I have used my Simul with 420's at times. Nothing bad happens, it works and sounds good. However, it is not a rugged tube, and wears out quickly. Since there are not that many of them out there, I'd switch it to something else for the outer sockets, another 6l6 or el34.

 

[kdorsey]

If nothing else, you should at least try the EL34s. You've got a Simul-Class amp and need to understand what makes it so unique. Especially, explore class A mode with EL34s. I'd also recommend using different cabs with different speakers because, IMO, the EV limits the potential of this amp.

 

[igfraso]

Marks III and IV were designed for STR 420 tubes so you are absolutely safe with them. Of course, try the EL34 as well.

One piece of advice: do the R2 Volume mod and the Reverb mod (I think the latter came from factory from Blue stripes on).

 

[s-fresh]

Thanks for all the replies!

I'm pretty sure this thing is 100% stock. Are all these mods at the level of a competent solderer or are these something only Mesa can do? I am in Northern California and my sister lives near Petaluma so I could probably drop it there at some point. Would rather do it myself if it isn't anything crazy.

Looks like I need to order some EL34s and try them out!

 

[BoogieHog]

Man that is a beauty! I got a Black Dot with a Red Stripe upgrade a few weeks ago that looks just like that. I'd keep that beauty for good!

 

[igfraso]

s-fresh:
if you are living relatively close to Petaluma, bring it to Mike Bendinelli. He will go through it (it is a 30-year old amp) and will do an in-depth cleaning and check capacitors, etc. The mods are cheap and he will do them as well for you. You won't regret it.

 

[Promethean]

I live in the UK and Mike B sent me the notes for the mods so I could do them myself. If you are close to them on California I am +1 dropping it in to them. Just not an option for me. None are hard to do and the main thing, if you are competent and soldering and using a meter, is to be secure with the safety rules around amps and charged caps, etc.

I've done:

'R2 Level Mod'. This adds a control (mine is dual gang pot in the direct level spot) that sets the R1/2 mix. It's pretty much set and forget. It's just a pot replacing one readily accessible resistor on the PCB. Documented well here. Transforms a MK3's versatility.

'Reverb Depth Mod' - this is a super easy mod that just puts a resistor in line with a lead from the PCB that terminates on the fx loop earth tab. I put a larger value than recommended in to get to Dick Dale levels if I want. It's got it all now from subtle to fender like.

'Reverb Glitch Mod' - this might be needed on your Purple Stripe. The symptom is a very low level of background noise/distortion when the reverb is used. An extra earth connection from a reverb transformer cable to earth (used the nearby reverb phono sockets earth tab) solves it perfectly. Mine is now completely noiseless.

There are suggestions in their notes for other value changes for a couple of components that I did not do.

I also put an in-line switch on the fan cables to silence it for recording. I might just try a new super silent fan soon.

With its age I will be ordering a new set of main Filter Caps to swap in the next few weeks. Probably worth getting done if recommended. I am just starting to hear a strange compression and garbled attack on clean notes hit hard.

I think the Mark 3 has some magic that I've not found with Mk5s or other mesa models. More 'alive'.

 

[BoogieHog]

I live in the UK and Mike B sent me the notes for the mods so I could do them myself. If you are close to them on California I am +1 dropping it in to them. Just not an option for me. None are hard to do and the main thing, if you are competent and soldering and using a meter, is to be secure with the safety rules around amps and charged caps, etc.

I've done:

'R2 Level Mod'. This adds a control (mine is dual gang pot in the direct level spot) that sets the R1/2 mix. It's pretty much set and forget. It's just a pot replacing one readily accessible resistor on the PCB. Documented well here. Transforms a MK3's versatility.

'Reverb Depth Mod' - this is a super easy mod that just puts a resistor in line with a lead from the PCB that terminates on the fx loop earth tab. I put a larger value than recommended in to get to Dick Dale levels if I want. It's got it all now from subtle to fender like.

'Reverb Glitch Mod' - this might be needed on your Purple Stripe. The symptom is a very low level of background noise/distortion when the reverb is used. An extra earth connection from a reverb transformer cable to earth (used the nearby reverb phono sockets earth tab) solves it perfectly. Mine is now completely noiseless.

There are suggestions in their notes for other value changes for a couple of components that I did not do.

I also put an in-line switch on the fan cables to silence it for recording. I might just try a new super silent fan soon.

With its age I will be ordering a new set of main Filter Caps to swap in the next few weeks. Probably worth getting done if recommended. I am just starting to hear a strange compression and garbled attack on clean notes hit hard.

I think the Mark 3 has some magic that I've not found with Mk5s or other mesa models. More 'alive'.

I agree with every bit of that especially that last quote!

 

[Wyzard]

My favourite MkIII blue stripe runs a close-ish second behind my IIC+s. "Alive" would be a good description, but the MkIIIs are several degrees harder to drag kicking and screaming to tonal dead-centre on any given night than the C+s.

So they are what they are; but I confess - I love the fight.

 

[s-fresh]

Well instead of doing on these mods I went out and found another amp that has all these changes already made. Its a Simul-class Mark III red stripe head with GEQ and reverb. "III+" upgrade, reverb fix, R2 volume mod, and a pentode/triode switch. It also came with fresh Winged "C" EL34s and 6L6s power tubes. I just got it all unpacked and am looking forward to tomorrow morning when everyone wakes up so I can take it for a spin. I've been buying/selling a lot of Mesa stuff and this is probably my best find so far. It looks like someone wanted to do pretty much everything to their Mark III. Stoked!

Thanks for all the responses, everyone!

 

[MkIII Renegade]

Well instead of doing on these mods I went out and found another amp that has all these changes already made. Its a Simul-class Mark III red stripe head with GEQ and reverb. "III+" upgrade, reverb fix, R2 volume mod, and a pentode/triode switch. It also came with fresh Winged "C" EL34s and 6L6s power tubes. I just got it all unpacked and am looking forward to tomorrow morning when everyone wakes up so I can take it for a spin. I've been buying/selling a lot of Mesa stuff and this is probably my best find so far. It looks like someone wanted to do pretty much everything to their Mark III. Stoked!

Thanks for all the responses, everyone!

I hope the new one (replacement?) still has the hardwood/wicker cab. That is a true beauty!

I had my III upgraded with R1, R2Vol and Reverb mods, and it my favorite amp of all! The Lead channel especially is to die for.

 

[MkIII Renegade]

I think the Mark 3 has some magic that I've not found with Mk5s or other mesa models. More 'alive'.

I agree! I have not played the fabled Mk IIC+, but I have played several other Mesas and have a MkIV. The MkIII has my favorite Lead channel, hands down. 8)

 

[s-fresh]

I hope the new one (replacement?) still has the hardwood/wicker cab. That is a true beauty!

It does! One of the big reasons I've been fawning over this amp and waiting for the right time and for them to drop the price a little.

I've had a really hard time finding original Mesa hardwood/wicker heads. I guess the hardwood speaker cabs are even harder to find, but I do have a line on one now.

 

[MkIII Renegade]

If you are going to keep both, then you could have an especially awesome MkIII live rig with two hardwood amps! One amp tweaked to perfection for Lead (no compromise) and one for clean/rhythm, and true stereo delay and other effects.

I was casually searching for years for a deal on a hardwood/wicker MkIV combo, but had to jump on my black tolex Wide Body when I got a smokin' deal with someone who either didn't know what he had, or was desperate for cash. In some ways, I wished I had waited a bit longer to find a hardwood, though. Those are truly special amps, and should only increase in value over time.

I definitely recommend the mighty EVM12L for your future hardwood cab. A high percentage of them probably already have it. My Thiele 1x12 is a BRUTE with the EV!

 

[s-fresh]

Thanks, MkIII Renegade!

I sold this one, but also just sent the payment for a package deal of blue stripe combo with EVM-12L and Thiele with EVM-12L, both in hardwood/wicker. I'm on the fence about keeping the blue stripe (at least it already has the R2 mod), but stoked to have found another hardwood Thiele, I haven't seen many for sale. I should pick that pair up in a few weeks. I'm not sure about the dual amp/stereo thing at this point, but I would like to find a standard sealed back cab to stick a V30 in. The search continues!

 

[s-fresh]

Woot! Picked up my new Thiele cab today. The match is pretty good. I does show just how bad/weird the wicker on the Mark III head is though, not a close match at all and it doesn't look like any of the other wicker grills I've had around. I guess I will be redoing that as well as the the logos.

 

[MkIII Renegade]

The wood is definitely a perfect match! Looks factory. 8)